MINI REVIEW article

Front. Immunol., 13 February 2025

Sec. Viral Immunology

Volume 16 - 2025 | https://doi.org/10.3389/fimmu.2025.1541532

HIV-1 Tat-induced disruption of epithelial junctions and epithelial-mesenchymal transition of oral and genital epithelial cells lead to increased invasiveness of neoplastic cells and the spread of herpes simplex virus and cytomegalovirus

  • Department of Medicine, School of Medicine, University of California, San Francisco, San Francisco, CA, United States

Abstract

Human immunodeficiency virus (HIV-1) transactivator Tat is a unique multi-functional viral protein secreted by infected cells. Although its primary function is to promote HIV-1 transcription, secreted Tat interacts with neighboring cells and induces numerous disease-associated pathological changes. Despite the substantial reduction of viral load and disease burden, Tat expression and secretion persist in people living with HIV who are undergoing treatment with highly effective combination antiretroviral therapy (cART). Tat interacts with both oral and genital epithelial cells and impairs their mucosal barrier functions, which facilitates the entry of other pathogenic viruses. Tat-mediated interactions with both human papillomavirus (HPV) -infected and HPV-negative neoplastic epithelial cells lead to epithelial-mesenchymal transition and increased invasiveness of malignant cells. Likewise, Tat-induced disruption of oral epithelial cell junctions leads to herpes simplex virus-1 (HSV-1) infection and spread via exposure of its receptor, nectin-1. HIV-1 Tat facilitates infection and spread of human cytomegalovirus (HCMV) by activating mitogen-activated protein kinases (MAPK) and promoting NF-κB signaling, both critical for the replication and production of progeny virions. HIV extracellular Tat also plays a critical role in human herpesvirus 8 (HHV8) -caused Kaposi sarcoma (KS) pathogenesis by synergizing with HHV-8 lytic proteins and promoting the proliferation, angiogenesis, and migration of endothelial cells. Collectively, these findings emphasize the critical impact of HIV-1 Tat on HIV/AIDS pathogenesis during the cART era and highlight the need for further research on the molecular mechanisms underlying Tat-mediated interactions with oral and genital mucosal epithelial cells.

1 Introduction

The HIV-1 trans-activator of transcription protein, Tat, regulates the viral promoter and is responsible for transcriptional elongation, which is critical for HIV replication. Tat is also involved in regulating the expression of cellular genes and key signaling pathways, which are critical for the production and spread of HIV. Moreover, HIV-1 Tat is continuously secreted into the blood circulation of HIV-1-suppressed individuals and may reach various tissues and organs leading to their dysfunction.

HIV coinfection is common with several pathogenic human viruses, including high-risk HPV (), HSV-1 and -2 (), HCMV (), Kaposi’s sarcoma-associated herpesvirus (KSHV) () and hepatitis C virus (HCV) ().

Accumulating evidence supports that interactions of Tat with oral and genital mucosal epithelial cells disrupt their intercellular junctions and facilitate the spread of pathogenic human viruses, including HPV, HSV, and HCMV. Moreover, Tat may induce epithelial-mesenchymal transition (EMT), which is critical for the invasion of HPV-infected neoplastic epithelial cells. Tat plays a critical role in the development of Kaposi’s sarcoma (KS) by promoting proliferation, angiogenesis, and/or migration of target endothelial cells. The focus of this mini-review is to discuss the interaction of Tat with oral and genital mucosal epithelial and endothelial cells and to elucidate its role in the impairment of the mucosa barrier and induction of EMT, factors that are critical for the spread of viruses and acceleration of neoplastic processes, respectively.

2 HIV-1 Tat: structure and function

HIV-1 Tat is a small (14-16 kDa) protein encoded by the viral genome that includes several important functional domains (). The two forms of Tat generated by alternative splicing include one generated from a two-exon transcript that varies in length from 86 to 101 amino acids (aa) depending on the specific viral isolate. The second form of Tat is translated from a singly spliced one-exon transcript and is 72 aa long. The Tat amino-terminal domain (aa 1-48) contains a cysteine-rich motif that is responsible for activating HIV-1 transcription via its binding to a transactivation of response (TAR) element of the newly transcribed viral genomic RNA (). The arginine-rich basic domain of Tat (aa 49-58) plays a critical role in its nuclear localization and binding to the TAR element (). The basic domain of Tat also contains a protein transduction domain (PTD) which is a specific motif, YGRKKRRQRRR that mediates Tat internalization by bystander cells via interactions with heparan sulfate proteoglycans (HSPGs) (). The Tat glutamine (Q)-rich domain (aa 60-72) also contributes to its interaction with the TAR element and mediates Tat-induced apoptosis (, ). HIV-1 Tat also contains a carboxy-terminal (aa 65-80) arginine, glycine, and aspartic acid (RGD) motif that facilitates its binding to various integrins, including αvβ1, αvβ3, and α5β1 ().

3 HIV-1 Tat: expression and secretion in HIV-1 suppressed individuals

One of the important features of HIV-1 Tat is its efficient secretion from virus-infected cells (, ) Tat crosses the plasma membrane via unconventional pathways that do not involve the endoplasmic reticulum and/or the Golgi/trans-Golgi network (). Although the molecular mechanisms underlying Tat secretion remain unclear, secretion involves Tat binding to phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) located in the inner leaflet of the plasma membrane, an interaction mediated by the basic domain of Tat (aa 48–57) and a conserved tryptophan (aa 11) (). This interaction initiates oligomerization-mediated pore formation in the membrane, followed by Tat translocation and incorporation into exosomes, which mediate Tat’s secretion (, , , ). Secretion may also require Tat interactions with three short, non-consecutive cytoplasmic loops at the carboxy-terminus of the cellular Na+, K+-ATPase pump alpha subunit ().

HIV-1-infected lymphocytes, macrophages, and dendritic cells/Langerhans cells (DC/LCs), as well as cell-free virus and viral RNA/DNA, have all been detected in oropharyngeal and genital mucosal epithelia and in salivary, and cervicovaginal secretions of people living with HIV (PLWH) who were undergoing combination antiretroviral therapy (cART) as well as those who were not (, ). HIV-1 Tat-positive CD4+ lymphocytes, macrophages, and DC/LCs were detected in the oropharyngeal and anogenital mucosal epithelia of PLWH, including those undergoing treatment with cART ().

Westendorp and colleagues () were the first to demonstrate HIV-1 Tat secretion into the bloodstream; this finding has since been confirmed by others (, ). In pre-cART era, serum Tat concentrations in PLWH typically ranged from 0.1-40 ng/mL, sometimes reaching levels as high as 250-550 ng/mL (). HIV-1 Tat was also detected in the serum of PLWH who achieved viral suppression with cART, where Tat concentration ranged from 0 to 14 ng/ml (). Tat was detected in 25% of cART-treated individuals (). The serum concentrations of Tat during early cART and late cART were 2-40 ng/ml and 0.2-9 ng/ml, respectively (, ).

HIV-1 Tat was also detected in the blood-cerebrospinal fluid of 37% of PLWH maintained on a long cART regimen (, ) at concentrations in the 0.2-6.5 ng/mL range. Functional Tat was detected in exosomes from 34.4% of these individuals (). Secretion of Tat was detected in the saliva of ART-treated and -untreated individuals ().

Tat was detected in brain and cerebrospinal fluid in the absence of virus replication (). Furthermore, in experiments performed in vitro, Tat was expressed and secreted from HIV-infected cells treated with protease inhibitors that inhibited viral replication, indicating that Tat production and secretion requires no cleavage events catalyzed by the viral protease (, ). Thus, Tat may continue to be expressed and released in the presence of a protease inhibitor, which is among the critical components of cART (, , ). Tat/TAR-containing exosomes can be endocytosed by HIV-1-infected cells that contain an inactive (latent) provirus (). Internalized Tat/TAR may then reactivate the latent provirus via induction of host signaling pathways such as those involving NF-κB and transactivation of the HIV-1 long terminal repeat (LTR), which may explain Tat expression detected in PLWH maintained on cART (). Tat expression in PLWH treated with cART may also result from ongoing abortive and/or spontaneous viral transcription that promotes expression of viral early genes, including Tat (, ). Collectively, these findings suggest that HIV-1 Tat is produced continuously by infected cells and released into circulation despite ongoing cART and that circulating Tat may be delivered directly to tissues and organs and internalized into epithelial and other host cells.

Furthermore, cART drugs have only a limited capacity to penetrate solid tissues, including lymph nodes and epithelial tissues (), Thus, HIV-1 replication may persist in these drug-inaccessible environments, leading to the expression and release of Tat and its spread within the surrounding tissues and organs. Cervicovaginal secretion of HIV-1 in ART-treated women with low to undetectable plasma viral loads suggested that there may be a cohort of local intramucosal HIV-1-infected cells that remained capable of producing virus due to lack of drug accessibility (, ). This hypothesis might also explain the persistent detection of HIV-1 in the semen of ART-treated infected men with undetectable viral loads in circulation (). Collectively, these findings suggest that ART-inaccessible tissues may serve as a reservoir for HIV-1 and that these cells may release Tat continuously into the surrounding environment (, ).

4 HIV-1 Tat disrupts tight junctions of epithelial cells

The oropharyngeal, ectocervical, vaginal, and foreskin epithelia consist of a multilayered, stratified squamous epithelium; the endocervical and intestinal mucosa is also covered with a monostratified simple epithelium. These epithelial cells form numerous intercellular junctions (, ). Among these, tight and adherens junctions are critical for maintaining the morphological and physiological features of mucosal epithelia (Figure 1). Tight junctions within the mucosal epithelium form an intramembranous “fence” that links neighboring cells and maintains a physical barrier that protects against external environment (). Tight junctions are established by the transmembrane proteins known as occludin and claudins in association with the cytoplasmic proteins zonula occludens-1 (ZO-1), ZO-2, and ZO-3 (Figure 1B, left panel), which linked to the actin cytoskeleton (). Junctional adhesion molecule 1 (JAM-1) is specifically localized at the tight junctions of epithelial cells and is involved in the regulation of junctional integrity and paracellular permeability (). Intercellular adherens junctions are formed by homotypic interactions of the transmembrane protein, E-cadherin, which is connected to intracellular proteins p120 and α- and β- catenins and the actin cytoskeleton ().

Figure 1

Tight junctions in oral, intestinal, and genital mucosal epithelia are disrupted in PLWH, leading to barrier impairment (Figure 1B, right panel, and C) (, ). Interactions of HIV-1 Tat with oral epithelial cells lead to activation of MAPK and substantial disruption of complexes containing ZO-1, occludin, and claudin-1 (). HIV-1 glycoprotein (gp)120 also disrupts epithelial junctions; combinations of Tat and gp120 amplify HIV-1-induced impairment of mucosal epithelial barrier functions (, , ). In oral epithelial cells, HIV-1 Tat activates MAPK and NF-κB signaling, leading to the upregulation of matrix metalloproteinase (MMP)-9 expression and activity (), and the degradation of epithelial junctions.

5 HIV-1 Tat induces epithelial-mesenchymal transition and amplifies the invasiveness of human papillomavirus-infected neoplastic cells

Human papillomavirus (HPV) is an oncogenic virus (, ). The incidence of HPV-associated oropharyngeal, cervical, and anal cancer is approximately 6-, 22-, and 80-times higher, respectively, in PLWH compared to those who remain uninfected (). Although a highly effective anti-HPV vaccine is available, its value is limited in PLWH because most of these individuals have already been infected with high-risk HPVs, including HPV-16 and HPV-18.

Although HIV-1 may increase the incidence of HPV-associated cancers by attenuating immune responses, accumulating evidence has indicated that the direct interaction of HIV proteins with HPV proteins and HPV-infected epithelial cells may also play a critical role in the progression of HPV-associated malignancy ().

Tat (and/or gp120) proteins disrupt tight junctions of oral and genital mucosal epithelium, thereby reducing the barrier function of mucosal epithelium and facilitating paracellular penetration of HPV-16 (). This facilitated HPV paracellular spread through strata spinosum and granulosum layers, leading to the infection of basal/parabasal cells, the site of initiation of the HPV life cycle ().

Tat-induced activation of MAPK and transforming growth factor (TGF)-β signaling in normal and neoplastic oral and genital epithelia led to epithelial-mesenchymal transition (EMT) (, ), which is a physiologic process that provides critical contributions to embryonic development (). However, EMT also promotes epithelial neoplasia, including the invasion and spread of cancer cells (). EMT results in the loss of polarity of epithelial cells, which is followed by loss of adherens (E-cadherin) and tight junctions as well as critical cell-adhesive properties (Figure 2). While in the intermediate stages of EMT, cells may express both mesenchymal (i.e., vimentin) and epithelial (i.e., E-cadherin) markers. Cells with this hybrid phenotype may be highly invasive and contribute to the formation of cancer metastases (Figure 2B) (). Cells displaying the hybrid phenotype will then develop a spindle cell-type shape and express additional mesenchymal markers, including vimentin, fibronectin and N-cadherin and lost E-cadherin; these cells are also highly invasive (Figure 2C) ().

Figure 2

). This will lead to the activation of MAPK and TGF-β signaling pathways followed by induction of the EMT phenotype in which epithelial cells lose intact tight and adherens junctions and (B) coexpress E-cadherin and vimentin. Cells displaying this hybrid EMT phenotype also express stem cell markers and become CSCs with the potential to migrate through the basement membrane and initiate invasive cancer. (C) Further progression of EMT may lead to the loss of E-cadherin expression and a parallel upregulation of N-cadherin and vimentin as cells acquire a mesenchymal spindle-like morphology. These cells may also be highly invasive and capable of migration.

Neoplastic cells with an EMT phenotype may also express stem cell markers and become cancer stem cells (CSCs) with undifferentiated stem cell properties with the capacity for self-renewal and uncontrolled proliferation (). CSCs detected in solid oropharyngeal and genital tumors express numerous stem cell markers, including CD44, CD24, CD133, aldehyde dehydrogenase 1A, CD10, CD147, CD117, CD24, podoplanin, laminin subunit beta 3, and laminin subunit gamma 2 (, ). Recent results suggest that the expression of one or more of these CSC markers may significantly increase resistance to drugs and apoptosis and promote survival, growth, and expansion of invasive cancers ().

Activation of the TGF-β signaling pathway is critical for the induction of EMT in neoplastic cells (, ). The binding of the mature form of TGF-β to its receptor TGFBR2 initiates activation of Smad family transcription factors and other specific transcriptional regulators, including Slug, Twist1, and Snail. These events lead to the upregulation of N-cadherin, fibronectin, and vimentin and the downregulation of E-cadherin (, ) following induction of EMT.

HIV-1 Tat binding to α5β1 and αvβ3 integrins via its RGD domain increases Ras-induced ERK phosphorylation and activation of MAPK signaling (), which is critical for upregulation of the TGF-β signaling pathway and induction of EMT (, ). HSPG activates TGF-β signaling by depositing latent TGF-β -binding protein-1 in the extracellular matrix, thereby enhancing the TGF-β binding to its primary receptors (), which is also critical for EMT induction. Tat binding to HSPG may modulate the HSPG-enhanced interaction of TGF-β with its receptors (). Although TGF-β signaling is critical for EMT induction, additional signaling pathways also contribute to this process depending on the cell type and cellular microenvironment. For example, introduction of HIV-1 Tat and gp120 to cells of the HPV-16-infected cervical cancer SiHa cell line led to the induction of EMT and cell migration and invasion secondary to the activation of the Wnt/β-catenin pathway (), indicating that the Tat/gp120-activated Wnt/β-catenin signaling pathway also contributes to EMT progression (). Transcriptome analysis revealed that Tat/gp120-treated cells responded by upregulating keratin 17 and downregulating glycogen synthase kinase 3β, which promote the increase in vimentin and decrease in E-cadherin expression, respectively (i.e., EMT induction) ().

Prolonged interactions (five days) of HIV-1 Tat and/or gp120 with HPV-16-immortalized oral (UM-SCC-47), cervical (CaSki), and anal (AKC-2) epithelial cells induce EMT and increased invasiveness of neoplastic cells (). Furthermore, cells with Tat and/or gp120-induced EMT cells that co-expressed vimentin and E-cadherin and presented an intermediate/hybrid stage of EMT became poorly-adherent and easily detached (). These cells also expressed CSC markers CD44 and CD133 and were more invasive, suggesting a specific role for hybrid EMT cells in cancer-associated metastasis.

HIV-1 Tat exposure also led to reductions in p53 expression, transcription of cell cycle inhibitors, and increased proliferation of HPV-18 infected cervical cancer HeLa cells (). HIV-1 Tat also transactivated the HPV long control region and increased HPV18 E7 expression in HeLa cells ().

Consistent with in vitro data, analysis of tissue samples from patients with cervical intraepithelial neoplasia (CIN) and cervical cancer who were infected with high-risk HPVs revealed significantly lower levels of E-cadherin and cytokeratin and higher levels of N-cadherin and vimentin expression in HIV-infected patients than those who were HIV-negative ().

HIV-1 Tat inhibited epithelial differentiation and apoptosis of HPV-negative colorectal cancer cells (LIM1215 and LIM2537), increasing their invasiveness and tumorigenicity (). HIV-1 Tat protein also induced EMT and increased invasiveness of HPV-negative lung epithelial (A549, H358) () and oral carcinoma (HSC-3) () cancer cell lines. These results suggest that HIV-1 Tat may promote the development of malignancy in both HPV-negative and HPV-infected neoplastic epithelial cells.

HIV-1 Tat-induced EMT may also promote epithelial neoplasia associated with other oncogenic viruses. For example, hepatitis C virus (HCV) coinfection with HIV-1 is detected quite frequently; approximately 30% of HIV-infected individuals may be coinfected with HCV (). Primary liver cancer is more aggressive in patients with HIV-HCV coinfection than in those with HCV infection alone (). HIV-1 Tat-induced EMT may develop in liver epithelial cells, thus accelerating HCV malignancy in coinfected individuals.

TGF-β expression remains persistently elevated in the blood of PLWH undergoing cART as well as those who are not (). HIV-1-associated elevations of TGF-β contribute to the activation of EMT-associated profibrotic processes in various epithelial organs, including kidney, liver, and lung () (, ). It is possible that the elevated levels of TGF-β expression may induce EMT and ultimately increase invasiveness in precancer or cancer cells found in PLWH.

HIV-1 Tat induces TGF-β expression in epithelial cells, macrophages, and other cells (, , , ), which may contribute to its persistent elevation observed in PLWH. Persistent elevation of circulating TGF-β in PLWH undergoing cART may result from the continuous expression and secretion of HIV-1 Tat. Circulating TGF-β may reach the neoplastic tissues where it induces EMT and increased invasiveness. This may be one of the mechanisms underlying the persistence of HPV malignancy in PLWH treated with cART.

Taken together, the results of these studies suggest that direct interactions of extracellular HIV-1 Tat with neoplastic mucosal and other epithelial cells may lead to induction of EMT and increased invasiveness, leading to the acceleration of HPV-associated and HPV-negative malignancies (Figure 2). HIV-1 Tat-induced EMT may have a more rapid effect on the acceleration of HPV-infected neoplasia, given that oncogenic HPVs also induce EMT. For example, several groups reported that HPV-16 E6 and E7 oncoproteins induced the increased expression of MMP-2 () which is an enzyme that cleaves E-cadherin () and leads to the loss of adherens junctions and the induction of EMT (). Both HIV- and HPV-induced EMT may have synergistic effects in the progression of HPV-associated neoplasia in PLWH.

6 HIV-1 Tat-mediated disruption of mucosal epithelium promotes herpes simplex virus and human cytomegalovirus spread

6.1 HIV-1-induced disruption of oral mucosal epithelium facilitates the spread of herpes simplex virus-1

HSV-1 and 2 may reactivate and replicate in the oral and genital epithelium of PLWH and can lead to ulcers and necrotic lesions (). HSV-1 reactivation may occur despite ongoing cART (, , ). Although the increased risk of developing an HSV infection may be mediated in part by HIV-1-induced immune dysfunction, it may also be associated with direct and/or indirect molecular interactions between the two viruses.

As discussed in Section 4., interactions of HIV-1 Tat with oral epithelial cells can lead to the disruption of both adherens and tight junctions via the activation of the MAPK and NF-κB signaling pathways and the upregulation of MMP-9 (, ). HIV-1 Tat-mediated disruption of oral epithelial junctions facilitates the paracellular spread of HSV-1 ().

The HSV-1 envelope gD binds to the cell adhesion protein nectin-1 (), which is sequestered within intercellular junctions (Figure 1B); this localization plays a critical role in limiting HSV access to epithelial cells (). HIV-1 Tat-mediated disruption of adherens junctions liberates nectin-1, thereby promoting HSV-1 gD binding to nectin-1. Thus, the extent of HSV-1 infection is substantially increased in disrupted compared to intact epithelial cells (). Disrupted adherens junctions expose sequestered nectin-1 and thus accelerate the cell-to-cell spread of HSV-1. The introduction of anti-nectin-1 and anti-HSV-1 gD antibodies substantially blocked HSV-1 infection and cell-to-cell spread of the virus, indicating a critical role played by HIV-1 Tat-induced disruption of epithelial junctions and the liberation of nectin-1 in HSV infection and spread ().

HSV-1 is latent in sensory neurons in healthy individuals with normal immune surveillance mechanisms (). However, HIV-1 infection/acquired immunodeficiency syndrome (AIDS)-induced immune dysfunction leads to HSV-1 reactivation in neurons and the development of mucosal disorders (). As noted above, HIV-1 Tat-mediated liberation of nectin-1 from cells with disrupted adherens junctions also promotes the spread of HSV-1 from neurons to epithelial cells. Thus, HIV-1 Tat-mediated disruption of intercellular junctions potentiates HSV-1 infection by facilitating paracellular and cell-to-cell spread of the virus within the mucosal epithelium and between epithelial cells and neurons. This mechanism may provide a mechanism to explain the rapid development of HSV-associated oral lesions in HIV-1-infected individuals.

6.2 HIV-1 Tat promotes human cytomegalovirus infection and spread in oral epithelium

HCMV can promote the development of oral mucosal lesions, retinitis, hepatitis, esophagitis, pneumonia, encephalopathy, and/or gastrointestinal inflammation (). Nearly all HIV-1-infected individuals are co-infected with HCMV (, ). HCMV activation has also been reported in HIV-1-associated/AIDS disease ().

HIV-1 Tat-induced disruption of tonsil epithelial junctions impaired their barrier function and promoted the paracellular spread of HCMV (). Moreover, HIV-1 Tat-induced activation of NF-κB and MAPK signaling in these cells increases the extent of HCMV infection. NF-κB activation is critical for transactivation of the major immediate early HCMV promoter and the initiation of viral replication (). MAPK activation also plays an important role in HCMV replication and the production of viral progeny ().

Thus, HIV-1 Tat-induced disruption of the integrity of the oral mucosal epithelia may promote HCMV paracellular spread, which is critical for the initial entry of the virus in HCMV-negative individuals and the development of a systemic viral infection. Tat-induced HCMV paracellular spread is also important for transmitting the virus within the mucosal epithelium and the infection of intraepithelial and submucosal monocytes and macrophages, which may play an important role in promoting HCMV persistence (). HIV-1 Tat-mediated induction of HCMV replication in epithelial cells through activation of NF-κB and MAPK signaling may contribute to viral amplification and dissemination, which lead to the development of mucosal lesions and other diseases.

HIV-1 Tat-induced disruption of epithelial junctions may promote infection and spread of other viruses that use tight junction proteins as receptors. For example, Hepatitis C Virus (HCV) uses occludin and claudins 1, 6, and 9 for entry (). Reovirus entry requires JAM-1, occludin, and ZO-1 (, ); occludin is critical for coxsackievirus infection (). HIV-1 Tat-induced disruption of epithelial tight junctions may expose these sequestered tight junction proteins to their cognate viruses, leading to their more rapid entry and spread.

7 HIV extracellular Tat plays a critical role in KS pathogenesis by promoting the proliferation, angiogenesis, and migration of endothelial cells

Kaposi’s sarcoma-associated herpesvirus (KSHV), known as human herpesvirus 8 (HHV8), is an etiological agent of Kaposi sarcoma (KS) (), which is an AIDS-defining tumor with uncontrolled growth of endothelial cells with abnormal angiogenesis (). KS may develop on the skin and/or oral/intestinal mucosa and can spread to lymph nodes and lungs ().

HIV extracellular Tat plays a critical role in KS pathogenesis by synergizing with KSHV lytic proteins and thus promoting the proliferation of endothelial cells, their angiogenesis, and migration (, , ). HIV Tat interaction with endothelial cells leads to increased expression of the KSHV G protein-coupled receptor (vGPCR) and its signaling, which promotes viral infection and tumorigenicity (). HIV Tat also promotes KSHV interleukin -6 (vIL-6)- and K1-induced angiogenesis (, ). HIV Tat-promoted increase of the oncogenic activity of KSHV proteins mostly occurs by Tat-associated regulation/modulation of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway (, , ). Tat may also be involved in the expression of miRNAs, which increase angiogenesis, and thus accelerate KSHV-associated tumorigenesis ().

In the pre-cART era, KS was approximately 20 – 50 fold more common in persons with HIV/AIDS than in the general population (, ). In PLWH, cART treatment markedly reduced the incidence of KS (, ). However, recent findings suggest that in PLWH the risk of KS is increasing despite the normalization of CD4 count and lack of HIV viremia (). Increasing KS in PLWH with cART has been suggested as a wake-up call for research on HHV-8 ().

The secretion of Tat in PLWH undergoing cART may contribute to the development of KS via Tat-induced proliferation, angiogenesis, and/or migration of HHV-8-infected endothelial cells. Moreover, results presented in other studies revealed that extracellular Tat promotes decreased expression of the tight junction proteins, claudin-1, claudin-5, and ZO-1 and/or ZO-2 in endothelial cells, leading to disruption of their intercellular junctions (, ). These changes may damage endothelial cells and increase the permeability of blood vessels, leading to endothelial barrier dysfunction, inflammation, and related disorders in the surrounding tissues (, 300). This has been well characterized in studies of HIV-1 Tat-induced disruption of brain microvascular endothelial cells, which leads to impairment of the blood-brain barrier (BBB) and ultimately HIV-associated neurocognitive disorders (300303). Tat-induced disruption of BBB may also result from Tat-mediated apoptosis of brain endothelial cells (304), as well as Tat-facilitated elevations in MMPs (), endoplasmic reticulum (ER) stress, and mitochondrial dysfunction (304, 305).

KSHV-infected microvascular endothelial cells lose the capacity to express vascular endothelial cell markers (e.g., VE-cadherin, CD31, CD34, CD36, vascular endothelial growth factor receptor-3, and vascular endothelial growth factor C) and acquire expression of mesenchymal markers (fibroblast-specific protein-1, alpha 2 smooth muscle actin, type I/III collagen, vimentin, and N-cadherin), displaying endothelial-mesenchymal transition (EndMT) and invasive and migratory properties along with increased survival (306313). KSHV-activated Notch-induced transcription factors Slug and ZEB1 were identified as critical for KSHV-induced EndMT (306, 307). TGFβ signaling pathway is also required for EndMT induction (314). However, KSHV did not activate the TGFβ signaling pathway in endothelial cells (306, 307). In persons diagnosed with HIV-KSHV coinfection, HIV-1 Tat-induced activation of the TGF-β signaling pathway might synergize with KHSV-induced Notch signaling, thereby accelerating migration and invasion of neoplastic endothelial cells.

8 Conclusions

HIV-1 Tat is expressed and secreted from HIV-infected cells of both ART-treated and untreated individuals. HIV-infected CD4+ lymphocytes, macrophages, and DC/LCs can migrate into the oral and cervical epithelium and secrete HIV-1 Tat protein in both neoplastic and non-neoplastic epithelial environments. HIV-1 Tat – epithelial cell interactions lead to activation of MAPK/NF-kB signaling followed by the disruption of tight and adherens junctions of epithelial cells and impaired barrier and immune/innate immune cell functions within the mucosal epithelium. HIV-1 Tat-activated MAPK and TGFβ-signaling in neoplastic epithelial cells induce EMT accompanied by the expression of the CSC markers CD133 and CD44, which amplifies the invasiveness of both HPV-infected and HPV-negative premalignant and malignant cells. HIV-1 Tat-induced disruption of epithelial junctions facilitates infection and spread of HSV-1 by liberating its otherwise sequestered gD receptor, nectin-1. HIV-1 Tat-activated NF-kB and MAPK signaling in epithelial cells promote the replication of HCMV and increase the production of viral progeny, respectively, leading to the spread of the virus within the oral mucosal epithelium. HIV Tat also plays a critical role in HHV-8-caused KS malignancy by promoting the proliferation, angiogenesis, and migration of neoplastic endothelial cells. Thus, HIV-1 Tat clearly contributes to the pathogenesis of HIV/AIDS despite the availability of cART. These findings emphasize the need for further investigation focused on the molecular mechanisms of Tat action in non-HIV-infected cells, including normal and neoplastic epithelial and endothelial cells. The development of a therapeutic vaccine targeting HIV-1 Tat may address some of these critical complications, including Tat-mediated disruption of epithelial junctions and induction of EMT.

Statements

Author contributions

ST: Writing – original draft, Writing – review & editing.

Funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This project was supported by the National Institute of Dental and Craniofacial Research (NIDCR) R01DE028129 and National Cancer Institute (NCI) R01CA232887 grants (to ST).

Conflict of interest

The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declare that no Generative AI was used in the creation of this manuscript.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

  • 1

    FerenczyACoutleeFFrancoEHankinsC. Human papillomavirus and HIV coinfection and the risk of neoplasias of the lower genital tract: a review of recent developments. CMAJ. (2003) 169:431–4.

  • 2

    FontaineJHankinsCMayrandMHLefevreJMoneyDGagnonSet al. High levels of HPV-16 DNA are associated with high-grade cervical lesions in women at risk or infected with HIV. AIDS. (2005) 19:785–94. doi: 10.1097/01.aids.0000168972.65304.6b

  • 3

    FontaineJHankinsCMoneyDRachlisAPourreauxKFerenczyAet al. Human papillomavirus type 16 (HPV-16) viral load and persistence of HPV-16 infection in women infected or at risk for HIV. J Clin Virol. (2008) 43:307–12. doi: 10.1016/j.jcv.2008.07.013

  • 4

    Perez-GonzalezACachayEOcampoAPovedaE. Update on the epidemiological features and clinical implications of human papillomavirus infection (HPV) and human immunodeficiency virus (HIV) coinfection. Microorganisms. (2022) 10. doi: 10.3390/microorganisms10051047

  • 5

    TanDHKaulRWalsmleyS. Left out but not forgotten: Should closer attention be paid to coinfection with herpes simplex virus type 1 and HIV? Can J Infect Dis Med Microbiol. (2009) 20:e1–7.

  • 6

    BohlDDKatzKABernsteinKWongERaymondHFKlausnerJDet al. Prevalence and correlates of herpes simplex virus type-2 infection among men who have sex with men, san francisco, 2008. Sex Transm Dis. (2011) 38:617–21. doi: 10.1097/OLQ.0b013e31820a8c10

  • 7

    TurnerKRMcFarlandWKelloggTAWongEPage-ShaferKLouieBet al. Incidence and prevalence of herpes simplex virus type 2 infection in persons seeking repeat HIV counseling and testing. Sex Transm Dis. (2003) 30:331–4. doi: 10.1097/00007435-200304000-00011

  • 8

    LamaJRLucchettiASuarezLLaguna-TorresVAGuaniraJVPunMet al. Association of herpes simplex virus type 2 infection and syphilis with human immunodeficiency virus infection among men who have sex with men in Peru. J Infect Dis. (2006) 194:1459–66. doi: 10.1086/jid.2006.194.issue-10

  • 9

    SuligoiBDorrucciMVolpiAAndreoniMZerboniRRezzaGet al. Prevalence and determinants of herpes simplex virus type 2 infection in a cohort of HIV-positive individuals in Italy. Sex Transm Dis. (2002) 29:665–7. doi: 10.1097/00007435-200211000-00008

  • 10

    GianellaSMassanellaMWertheimJOSmithDM. The sordid affair between human herpesvirus and HIV. J Infect Dis. (2015) 212:845–52. doi: 10.1093/infdis/jiv148

  • 11

    GianellaSLetendreS. Cytomegalovirus and HIV: A dangerous pas de deux. J Infect Dis. (2016) 214 Suppl 2:S67–74. doi: 10.1093/infdis/jiw217

  • 12

    AdlandEKlenermanPGoulderPMatthewsPC. Ongoing burden of disease and mortality from HIV/CMV coinfection in Africa in the antiretroviral therapy era. Front Microbiol. (2015) 6:1016. doi: 10.3389/fmicb.2015.01016

  • 13

    LaboNMileyWBensonCACampbellTBWhitbyD. Epidemiology of Kaposi’s sarcoma-associated herpesvirus in HIV-1-infected US persons in the era of combination antiretroviral therapy. AIDS. (2015) 29:1217–25. doi: 10.1097/QAD.0000000000000682

  • 14

    WoodberryTSuscovichTJHenryLMMartinJNDollardSO’ConnorPGet al. Impact of Kaposi sarcoma-associated herpesvirus (KSHV) burden and HIV coinfection on the detection of T cell responses to KSHV ORF73 and ORF65 proteins. J Infect Dis. (2005) 192:622–9. doi: 10.1086/jid.2005.192.issue-4

  • 15

    PyakurelPPakFMwakigonjaARKaayaEBiberfeldP. KSHV/HHV-8 and HIV infection in Kaposi’s sarcoma development. Infect Agent Cancer. (2007) 2:4. doi: 10.1186/1750-9378-2-4

  • 16

    BoshKACoyleJRHansenVKimEMSpeersSComerMet al. HIV and viral hepatitis coinfection analysis using surveillance data from 15 US states and two cities. Epidemiol Infect. (2018) 146:920–30. doi: 10.1017/S0950268818000766

  • 17

    BoshKACoyleJRMuriithiNWRamaswamyCZhouWBrantleyADet al. Linking HIV and viral hepatitis surveillance data: evaluating a standard, deterministic matching algorithm using data from 6 US health jurisdictions. Am J Epidemiol. (2018) 187:2415–22. doi: 10.1093/aje/kwy161

  • 18

    ShermanKERousterSDChungRTRajicicN. Hepatitis C Virus prevalence among patients infected with Human Immunodeficiency Virus: a cross-sectional analysis of the US adult AIDS Clinical Trials Group. Clin Infect Dis. (2002) 34:831–7. doi: 10.1086/339042

  • 19

    PlattLEasterbrookPGowerEMcDonaldBSabinKMcGowanCet al. Prevalence and burden of HCV co-infection in people living with HIV: a global systematic review and meta-analysis. Lancet Infect Dis. (2016) 16:797808. doi: 10.1016/S1473-3099(15)00485-5

  • 20

    DaytonAISodroskiJGRosenCAGohWCHaseltineWA. The trans-activator gene of the human T cell lymphotropic virus type III is required for replication. Cell. (1986) 44:941–7. doi: 10.1016/0092-8674(86)90017-6

  • 21

    BohanCAKashanchiFEnsoliBBuonaguroLBoris-LawrieKABradyJN. Analysis of Tat transactivation of human immunodeficiency virus transcription in vitro. Gene Expr. (1992) 2:391407.

  • 22

    DebaisieuxSRayneFYezidHBeaumelleB. The ins and outs of HIV-1 Tat. Traffic. (2012) 13:355–63. doi: 10.1111/j.1600-0854.2011.01286.x

  • 23

    ClarkENavaBCaputiM. Tat is a multifunctional viral protein that modulates cellular gene expression and functions. Oncotarget. (2017) 8:27569–81. doi: 10.18632/oncotarget.15174

  • 24

    ChiozziniCToschiE. HIV-1 TAT and IMMUNE DYSREGULATION in AIDS PATHOGENESIS: a THERAPEUTIC TARGET. Curr Drug Targets. (2016) 17:3345. doi: 10.2174/1389450116666150825110658

  • 25

    GotoraPTvan der SluisRWilliamsME. HIV-1 Tat amino acid residues that influence Tat-TAR binding affinity: a scoping review. BMC Infect Dis. (2023) 23:164. doi: 10.1186/s12879-023-08123-0

  • 26

    FrankelADPaboCO. Cellular uptake of the tat protein from human immunodeficiency virus. Cell. (1988) 55:1189–93. doi: 10.1016/0092-8674(88)90263-2

  • 27

    CashmanSMSadowskiSLMorrisDJFrederickJKumar-SinghR. Intercellular trafficking of adenovirus-delivered HSV VP22 from the retinal pigment epithelium to the photoreceptors–implications for gene therapy. Mol Ther. (2002) 6:813–23. doi: 10.1006/mthe.2002.0806

  • 28

    NagaharaHVocero-AkbaniAMSnyderELHoALathamDGLissyNAet al. Transduction of full-length TAT fusion proteins into mammalian cells: TAT-p27Kip1 induces cell migration. Nat Med. (1998) 4:1449–52. doi: 10.1038/4042

  • 29

    VivesEBrodinPLebleuB. A truncated HIV-1 Tat protein basic domain rapidly translocates through the plasma membrane and accumulates in the cell nucleus. J Biol Chem. (1997) 272:16010–7. doi: 10.1074/jbc.272.25.16010

  • 30

    EnsoliBBuonaguroLBarillariGFiorelliVGendelmanRMorganRAet al. Release, uptake, and effects of extracellular human immunodeficiency virus type 1 Tat protein on cell growth and viral transactivation. J Virol. (1993) 67:277–87. doi: 10.1128/jvi.67.1.277-287.1993

  • 31

    RuizAPAjasinDORamasamySDesMaraisVEugeninEAPrasadVR. A naturally occurring polymorphism in the HIV-1 tat basic domain inhibits uptake by bystander cells and leads to reduced neuroinflammation. Sci Rep. (2019) 9:3308. doi: 10.1038/s41598-019-39531-5

  • 32

    RuizAPPrasadVR. Measuring the uptake and transactivation function of HIV-1 tat protein in a trans-cellular cocultivation setup. Methods Mol Biol. (2016) 1354:353–66. doi: 10.1007/978-1-4939-3046-3_24

  • 33

    TyagiMRusnatiMPrestaMGiaccaM. Internalization of HIV-1 tat requires cell surface heparan sulfate proteoglycans. J Biol Chem. (2001) 276:3254–61. doi: 10.1074/jbc.M006701200

  • 34

    KingJEEugeninEABucknerCMBermanJW. and neurotoxicity. Microbes Infect. (2006) 8:1347–57. doi: 10.1016/j.micinf.2005.11.014

  • 35

    LoretE. HIV extracellular Tat: myth or reality? Curr HIV Res. (2015) 13:90–7. doi: 10.2174/1570162x12666141202125643

  • 36

    BarillariGSgadariCFiorelliVSamaniegoFColombiniSManzariVet al. The Tat protein of human immunodeficiency virus type-1 promotes vascular cell growth and locomotion by engaging the alpha5beta1 and alphavbeta3 integrins and by mobilizing sequestered basic fibroblast growth factor. Blood. (1999) 94:663–72.

  • 37

    BarillariGSgadariCPalladinoCGendelmanRCaputoAMorrisCBet al. Inflammatory cytokines synergize with the HIV-1 Tat protein to promote angiogenesis and Kaposi’s sarcoma via induction of basic fibroblast growth factor and the alpha v beta 3 integrin. J Immunol. (1999) 163:1929–35. doi: 10.4049/jimmunol.163.4.1929

  • 38

    UrbinatiCMitolaSTanghettiEKumarCWaltenbergerJRibattiDet al. Integrin alphavbeta3 as a target for blocking HIV-1 Tat-induced endothelial cell activation in vitro and angiogenesis in vivo. Arterioscler Thromb Vasc Biol. (2005) 25:2315–20. doi: 10.1161/01.ATV.0000186182.14908.7b

  • 39

    VogelBELeeSJHildebrandACraigWPierschbacherMDWong-StaalFet al. A novel integrin specificity exemplified by binding of the alpha v beta 5 integrin to the basic domain of the HIV Tat protein and vitronectin. J Cell Biol. (1993) 121:461–8. doi: 10.1083/jcb.121.2.461

  • 40

    BrakeDADebouckCBieseckerG. Identification of an Arg-Gly-Asp (RGD) cell adhesion site in human immunodeficiency virus type 1 transactivation protein, tat. J Cell Biol. (1990) 111:1275–81. doi: 10.1083/jcb.111.3.1275

  • 41

    DickensAMYooSWChinACXuJJohnsonTPTroutALet al. Chronic low-level expression of HIV-1 Tat promotes a neurodegenerative phenotype with aging. Sci Rep. (2017) 7:7748. doi: 10.1038/s41598-017-07570-5

  • 42

    TugizovSMHerreraRChin-HongPVeluppillaiPGreenspanDMichael BerryJet al. HIV-associated disruption of mucosal epithelium facilitates paracellular penetration by human papillomavirus. Virology. (2013) 446:378–88. doi: 10.1016/j.virol.2013.08.018

  • 43

    RayneFDebaisieuxSBonhoureABeaumelleB. HIV-1 Tat is unconventionally secreted through the plasma membrane. Cell Biol Int. (2010) 34:409–13. doi: 10.1042/CBI20090376

  • 44

    RayneFDebaisieuxSYezidHLinYLMettlingCKonateKet al. Phosphatidylinositol-(4,5)-bisphosphate enables efficient secretion of HIV-1 Tat by infected T-cells. EMBO J. (2010) 29:1348–62. doi: 10.1038/emboj.2010.32

  • 45

    Lorenzo-RedondoRFryerHRBedfordTKimEYArcherJPondSLKet al. Persistent HIV-1 replication maintains the tissue reservoir during therapy. Nature. (2016) 530:51–6. doi: 10.1038/nature16933

  • 46

    ShmakovaATsimailoIKozhevnikovaYGerardLBoutboulDOksenhendlerEet al. HIV-1 Tat is present in the serum of people living with HIV-1 despite viral suppression. Int J Infect Dis. (2024) 142:106994. doi: 10.1016/j.ijid.2024.106994

  • 47

    MeleARMarinoJChenKPirroneVJanetopoulosCWigdahlBet al. Defining the molecular mechanisms of HIV-1 Tat secretion: PtdIns(4,5)P(2) at the epicenter. Traffic. (2018). doi: 10.1111/tra.2018.19.issue-9

  • 48

    RayneFDebaisieuxSTuAChopardCTryoen-TothPBeaumelleB. Detecting HIV-1 tat in cell culture supernatants by ELISA or western blot. Methods Mol Biol. (2016) 1354:329–42. doi: 10.1007/978-1-4939-3046-3_22

  • 49

    RayneFVendevilleABonhoureABeaumelleB. The ability of chloroquine to prevent tat-induced cytokine secretion by monocytes is implicated in its in vivo anti-human immunodeficiency virus type 1 activity. J Virol. (2004) 78:12054–7. doi: 10.1128/JVI.78.21.12054-12057.2004

  • 50

    VendevilleARayneFBonhoureABettacheNMontcourrierPBeaumelleB. HIV-1 Tat enters T cells using coated pits before translocating from acidified endosomes and eliciting biological responses. Mol Biol Cell. (2004) 15:2347–60. doi: 10.1091/mbc.e03-12-0921

  • 51

    AgostiniSAliHVardabassoCFittipaldiATasciottiECeresetoAet al. Inhibition of non canonical HIV-1 tat secretion through the cellular na(+),K(+)-ATPase blocks HIV-1 infection. EBioMedicine. (2017) 21:170–81. doi: 10.1016/j.ebiom.2017.06.011

  • 52

    Rodriguez-InigoEJimenezEBartolomeJOrtiz-MovillaNBartolome VillarBJose ArrietaJet al. Detection of human immunodeficiency virus type 1 RNA by in situ hybridization in oral mucosa epithelial cells from anti-HIV-1 positive patients. J Med Virol. (2005) 77:1722. doi: 10.1002/jmv.20409

  • 53

    ChouLLEpsteinJCassolSAWestDMHeWFirthJD. Oral mucosal Langerhans’ cells as target, effector and vector in HIV infection. J Oral Pathol Med. (2000) 29:394402. doi: 10.1034/j.1600-0714.2000.290805.x

  • 54

    GotoYYehCKNotkinsALPrabhakarBS. Detection of proviral sequences in saliva of patients infected with human immunodeficiency virus type 1. AIDS Res Hum Retroviruses. (1991) 7:343–7. doi: 10.1089/aid.1991.7.343

  • 55

    KakizawaJUshijimaHOkaSIkedaYSchroderHCMullerWE. Detection of human immunodeficiency virus-1 DNA, RNA and antibody, and occult blood in inactivated saliva: availability of the filter paper disk method. Acta Paediatr Jpn. (1996) 38:218–23. doi: 10.1111/j.1442-200X.1996.tb03473.x

  • 56

    LiuzziGChirianniAClementiMBagnarelliPValenzaACataldoPTet al. Analysis of HIV-1 load in blood, semen and saliva: evidence for different viral compartments in a cross-sectional and longitudinal study. Aids. (1996) 10:F51–6. doi: 10.1097/00002030-199612000-00001

  • 57

    MaticicMPoljakMKramarBTomazicJVidmarLZakotnikBet al. Proviral HIV-1 DNA in gingival crevicular fluid of HIV-1-infected patients in various stages of HIV disease. J Dent Res. (2000) 79:1496–501. doi: 10.1177/00220345000790071101

  • 58

    QureshiMNBarrCEHewlittIBoorsteinRKongFBagasraOet al. Detection of HIV in oral mucosal cells. Oral Dis. (1997) 3 Suppl 1:S73–8. doi: 10.1111/j.1601-0825.1997.tb00380.x

  • 59

    QureshiMNBarrCESeshammaTReidyJPomerantzRJBagasraO. Infection of oral mucosal cells by human immunodeficiency virus type 1 in seropositive persons. J Infect Dis. (1995) 171:190–3. doi: 10.1093/infdis/171.1.190

  • 60

    ZuckermanRAWhittingtonWLCelumCLCollisTLucchettiASanchezJLet al. Factors associated with oropharyngeal human immunodeficiency virus shedding. J Infect Dis. (2003) 188:142–5. doi: 10.1086/jid.2003.188.issue-1

  • 61

    NuovoGJFordeAMacConnellPFahrenwaldR. In situ detection of PCR-amplified HIV-1 nucleic acids and tumor necrosis factor cDNA in cervical tissues. Am J Pathol. (1993) 143:40–8.

  • 62

    ClemetsonDBMossGBWillerfordDMHenselMEmonyiWHolmesKKet al. Detection of HIV DNA in cervical and vaginal secretions. Prevalence and correlates among women in Nairobi, Kenya. JAMA: J Am Med Assoc. (1993) 269:2860–4. doi: 10.1001/jama.1993.03500220046024

  • 63

    SonzaSMutimerHPOelrichsRJardineDHarveyKDunneAet al. Monocytes harbour replication-competent, non-latent HIV-1 in patients on highly active antiretroviral therapy. Aids. (2001) 15:1722. doi: 10.1097/00002030-200101050-00005

  • 64

    HenningTRKissingerPLacourNMeyaski-SchluterMClarkRAmedeeAM. Elevated cervical white blood cell infiltrate is associated with genital HIV detection in a longitudinal cohort of antiretroviral therapy-adherent women. J Infect dis. (2010) 202:1543–52. doi: 10.1086/656720

  • 65

    CroweSMSonzaS. HIV-1 can be recovered from a variety of cells including peripheral blood monocytes of patients receiving highly active antiretroviral therapy: a further obstacle to eradication. J leukocyte Biol. (2000) 68:345–50. doi: 10.1189/jlb.68.3.345

  • 66

    JayakumarPBergerIAutschbachFWeinsteinMFunkeBVerdinEet al. Tissue-resident macrophages are productively infected ex vivo by primary X4 isolates of human immunodeficiency virus type 1. J Virol. (2005) 79:5220–6. doi: 10.1128/JVI.79.8.5220-5226.2005

  • 67

    WestendorpMOFrankROchsenbauerCStrickerKDheinJWalczakHet al. Sensitization of T cells to CD95-mediated apoptosis by HIV-1 Tat and gp120. Nature. (1995) 375:497500. doi: 10.1038/375497a0

  • 68

    XiaoHNeuveutCTiffanyHLBenkiraneMRichEAMurphyPMet al. Selective CXCR4 antagonism by Tat: implications for in vivo expansion of coreceptor use by HIV-1. Proc Natl Acad Sci U S A. (2000) 97:11466–71. doi: 10.1073/pnas.97.21.11466

  • 69

    PoggiAZocchiMR. HIV-1 Tat triggers TGF-beta production and NK cell apoptosis that is prevented by pertussis toxin B. Clin Dev Immunol. (2006) 13:369–72. doi: 10.1080/17402520600645712

  • 70

    GerminiDTsfasmanTKlibiMEl-AmineRPichuginAIarovaiaOVet al. HIV Tat induces a prolonged MYC relocalization next to IGH in circulating B-cells. Leukemia. (2017) 31:2515–22. doi: 10.1038/leu.2017.106

  • 71

    PoggiACarosioRFenoglioDBrenciSMurdacaGSettiMet al. Migration of V delta 1 and V delta 2 T cells in response to CXCR3 and CXCR4 ligands in healthy donors and HIV-1-infected patients: competition by HIV-1 Tat. Blood. (2004) 103:2205–13. doi: 10.1182/blood-2003-08-2928

  • 72

    EnsoliBBarillariGSalahuddinSZGalloRCWong-StaalF. Tat protein of HIV-1 stimulates growth of cells derived from Kaposi’s sarcoma lesions of AIDS patients. Nature. (1990) 345:84–6. doi: 10.1038/345084a0

  • 73

    JohnsonTPPatelKJohnsonKRMaricDCalabresiPAHasbunRet al. Induction of IL-17 and nonclassical T-cell activation by HIV-Tat protein. Proc Natl Acad Sci U S A. (2013) 110:13588–93. doi: 10.1073/pnas.1308673110

  • 74

    MarchioSAlfanoMPrimoLGramagliaDButiniLGenneroLet al. Cell surface-associated Tat modulates HIV-1 infection and spreading through a specific interaction with gp120 viral envelope protein. Blood. (2005) 105:2802–11. doi: 10.1182/blood-2004-06-2212

  • 75

    HendersonLJJohnsonTPSmithBRReomaLBSantamariaUABachaniMet al. Presence of Tat and transactivation response element in spinal fluid despite antiretroviral therapy. AIDS. (2019) 33 Suppl 2:S145–S57. doi: 10.1097/QAD.0000000000002268

  • 76

    ChoiJYHightowerGKWongJKHeatonRWoodsSGrantIet al. Genetic features of cerebrospinal fluid-derived subtype B HIV-1 tat. J Neurovirol. (2012) 18:8190. doi: 10.1007/s13365-011-0059-9

  • 77

    ArtsEJHazudaDJ. HIV-1 antiretroviral drug therapy. Cold Spring Harb Perspect Med. (2012) 2:a007161. doi: 10.1101/cshperspect.a007161

  • 78

    BachaniMSacktorNMcArthurJCNathARumbaughJ. Detection of anti-tat antibodies in CSF of individuals with HIV-associated neurocognitive disorders. J Neurovirol. (2013) 19:82–8. doi: 10.1007/s13365-012-0144-8

  • 79

    DubeMTastetODufourCSannierGBrassardNDelgadoGGet al. Spontaneous HIV expression during suppressive ART is associated with the magnitude and function of HIV-specific CD4(+) and CD8(+) T cells. Cell Host Microbe. (2023) 31:150722 e5. doi: 10.1016/j.chom.2023.08.006

  • 80

    FletcherCVStaskusKWietgrefeSWRothenbergerMReillyCChipmanJGet al. Persistent HIV-1 replication is associated with lower antiretroviral drug concentrations in lymphatic tissues. Proc Natl Acad Sci U S A. (2014) 111:2307–12. doi: 10.1073/pnas.1318249111

  • 81

    HuangYHoqueMTJenabianMAVybohKWhyteSKSheehanNLet al. Antiretroviral drug transporters and metabolic enzymes in human testicular tissue: potential contribution to HIV-1 sanctuary site. J Antimicrob Chemother. (2016) 71:1954–65. doi: 10.1093/jac/dkw046

  • 82

    Lorenzo-RedondoRFryerHRBedfordTKimEYArcherJKosakovsky PondSLet al. Persistent HIV-1 replication maintains the tissue reservoir during therapy. Nature. (2016) 530:51–6. doi: 10.1038/nature16933

  • 83

    Di MascioMSrinivasulaSBhattacharjeeAChengLMartiniovaLHerscovitchPet al. Antiretroviral tissue kinetics: in vivo imaging using positron emission tomography. Antimicrob Agents Chemother. (2009) 53:4086–95. doi: 10.1128/AAC.00419-09

  • 84

    CumminsJEChristensenLLennoxJLBushTJWuZMalamudDet al. Mucosal innate immune factors in the female genital tract are associated with vaginal HIV-1 shedding independent of plasma viral load. AIDS Res Hum Retroviruses. (2006) 22:788–95. doi: 10.1089/aid.2006.22.788

  • 85

    DebiaggiMZaraFSpinilloADe SantoloAMaseratiRBrunoRet al. Viral excretion in cervicovaginal secretions of HIV-1-infected women receiving antiretroviral therapy. Eur J Clin Microbiol Infect Dis. (2001) 20:91–6. doi: 10.1007/s100960000442

  • 86

    GrahamSMHolteSEPeshuNMRichardsonBAPanteleeffDDJaokoWGet al. Initiation of antiretroviral therapy leads to a rapid decline in cervical and vaginal HIV-1 shedding. AIDS. (2007) 21:501–7. doi: 10.1097/QAD.0b013e32801424bd

  • 87

    NeelyMNBenningLXuJStricklerHDGreenblattRMMinkoffHet al. Cervical shedding of HIV-1 RNA among women with low levels of viremia while receiving highly active antiretroviral therapy. J Acquir Immune Defic Syndr. (2007) 44:3842. doi: 10.1097/01.qai.0000248352.18007.1f

  • 88

    VernazzaPL. Genital shedding of HIV-1 despite successful antiretroviral therapy. Lancet. (2001) 358:1564. doi: 10.1016/S0140-6736(01)06665-X

  • 89

    ShethPMKovacsCKemalKSJonesRBRaboudJMPilonRet al. Persistent HIV RNA shedding in semen despite effective antiretroviral therapy. AIDS. (2009) 23:2050–4. doi: 10.1097/QAD.0b013e3283303e04

  • 90

    SchluterHWepfRMollIFrankeWW. Sealing the live part of the skin: the integrated meshwork of desmosomes, tight junctions and curvilinear ridge structures in the cells of the uppermost granular layer of the human epidermis. Eur J Cell Biol. (2004) 83:655–65. doi: 10.1078/0171-9335-00434

  • 91

    LangbeinLPapeUFGrundCKuhnCPraetzelSMollIet al. Tight junction-related structures in the absence of a lumen: occludin, claudins and tight junction plaque proteins in densely packed cell formations of stratified epithelia and squamous cell carcinomas. Eur J Cell Biol. (2003) 82:385400. doi: 10.1078/0171-9335-00330

  • 92

    LangbeinLGrundCKuhnCPraetzelSKartenbeckJBrandnerJMet al. Tight junctions and compositionally related junctional structures in mammalian stratified epithelia and cell cultures derived therefrom. Eur J Cell Biol. (2002) 81:419–35. doi: 10.1078/0171-9335-00270

  • 93

    BrandnerJMKiefSGrundCRendlMHoudekPKuhnCet al. Organization and formation of the tight junction system in human epidermis and cultured keratinocytes. Eur J Cell Biol. (2002) 81:253–63. doi: 10.1078/0171-9335-00244

  • 94

    TakanoKKojimaTGoMMurataMIchimiyaSHimiTet al. HLA-DR- and CD11c-positive dendritic cells penetrate beyond well-developed epithelial tight junctions in human nasal mucosa of allergic rhinitis. J Histochem Cytochem. (2005) 53:611–9. doi: 10.1369/jhc.4A6539.2005

  • 95

    BlaskewiczCDPudneyJAndersonDJ. Structure and function of intercellular junctions in human cervical and vaginal mucosal epithelia. Biol reprod. (2011) 85:97104. doi: 10.1095/biolreprod.110.090423

  • 96

    TugizovSMHerreraRVeluppillaiPGreenspanDSorosVGreeneWCet al. HIV is inactivated after transepithelial migration via adult oral epithelial cells but not fetal epithelial cells. Virology. (2011) 409:211–22. doi: 10.1016/j.virol.2010.10.004

  • 97

    TugizovSMHerreraRVeluppillaiPGreenspanDSorosVGreeneWCet al. Differential transmission of HIV traversing fetal oral/intestinal epithelia and adult oral epithelia. J Virol. (2012) 86:2556–70. doi: 10.1128/JVI.06578-11

  • 98

    GoMKojimaTTakanoKMurataMIchimiyaSTsubotaHet al. Expression and function of tight junctions in the crypt epithelium of human palatine tonsils. J Histochem Cytochem. (2004) 52:1627–38. doi: 10.1369/jhc.4A6339.2004

  • 99

    TugizovS. Virus-associated disruption of mucosal epithelial tight junctions and its role in viral transmission and spread. Tissue Barriers. (2021) 9:1943274. doi: 10.1080/21688370.2021.1943274

  • 100

    TugizovS. Human immunodeficiency virus-associated disruption of mucosal barriers and its role in HIV transmission and pathogenesis of HIV/AIDS disease. Tissue Barriers. (2016) 4:e1159276. doi: 10.1080/21688370.2016.1159276

  • 101

    SawadaNMurataMKikuchiKOsanaiMTobiokaHKojimaTet al. Tight junctions and human diseases. Med Electron Microsc. (2003) 36:147–56. doi: 10.1007/s00795-003-0219-y

  • 102

    NiessenCM. Tight junctions/adherens junctions: basic structure and function. J Invest Dermatol. (2007) 127:2525–32. doi: 10.1038/sj.jid.5700865

  • 103

    NaikUPEckfeldK. Junctional adhesion molecule 1 (JAM-1). J Biol Regul Homeost Agents. (2003) 17:341–7.

  • 104

    HartsockANelsonWJ. Adherens and tight junctions: structure, function and connections to the actin cytoskeleton. Biochim Biophys Acta. (2008) 1778:660–9. doi: 10.1016/j.bbamem.2007.07.012

  • 105

    EppleHJAllersKTrogerHKuhlAErbenUFrommMet al. Acute HIV infection induces mucosal infiltration with CD4+ and CD8+ T cells, epithelial apoptosis, and a mucosal barrier defect. Gastroenterology. (2010) 139:1289–300. doi: 10.1053/j.gastro.2010.06.065

  • 106

    EppleHJSchneiderTTroegerHKunkelDAllersKMoosVet al. Impairment of the intestinal barrier is evident in untreated but absent in suppressively treated HIV-infected patients. Gut. (2009) 58:220–7. doi: 10.1136/gut.2008.150425

  • 107

    AssimakopoulosSFDimitropoulouDMarangosMGogosCA. Intestinal barrier dysfunction in HIV infection: pathophysiology, clinical implications and potential therapies. Infection. (2014) 42:951–9. doi: 10.1007/s15010-014-0666-5

  • 108

    SufiawatiITugizovSM. HIV-associated disruption of tight and adherens junctions of oral epithelial cells facilitates HSV-1 infection and spread. PloS One. (2014) 9:e88803. doi: 10.1371/journal.pone.0088803

  • 109

    SufiawatiITugizovSM. HIV-induced matrix metalloproteinase-9 activation through mitogen-activated protein kinase signalling promotes HSV-1 cell-to-cell spread in oral epithelial cells. J Gen Virol. (2018) 99:937–47. doi: 10.1099/jgv.0.001075

  • 110

    SchiffmanMDoorbarJWentzensenNde SanjoseSFakhryCMonkBJet al. Carcinogenic human papillomavirus infection. Nat Rev Dis Primers. (2016) 2:16086. doi: 10.1038/nrdp.2016.86

  • 111

    SathishNWangXYuanY. Human papillomavirus (HPV)-associated oral cancers and treatment strategies. J Dent Res. (2014) 93:29S36S. doi: 10.1177/0022034514527969

  • 112

    BusharaOKroghKWeinbergSEFinkelmanBSSunLLiaoJet al. Human immunodeficiency virus infection promotes human papillomavirus-mediated anal squamous carcinogenesis: an immunologic and pathobiologic review. Pathobiology. (2022) 89:112. doi: 10.1159/000518758

  • 113

    LiuGSharmaMTanNBarnabasRV. HIV-positive women have higher risk of human papilloma virus infection, precancerous lesions, and cervical cancer. AIDS. (2018) 32:795808. doi: 10.1097/QAD.0000000000001765

  • 114

    PalefskyJM. Human papillomavirus-associated anal and cervical cancers in HIV-infected individuals: incidence and prevention in the antiretroviral therapy era. Curr Opin HIV AIDS. (2017) 12:2630. doi: 10.1097/COH.0000000000000336

  • 115

    ZhuZZhangYWangHJiangTZhangMZhangYet al. Renal cell carcinoma associated with HIV/AIDS: A review of the epidemiology, risk factors, diagnosis, and treatment. Front Oncol. (2022) 12:872438. doi: 10.3389/fonc.2022.872438

  • 116

    McLemoreMSHaigentzMJr.SmithRVNuovoGJAlosLCardesaAet al. Head and neck squamous cell carcinomas in HIV-positive patients: a preliminary investigation of viral associations. Head Neck Pathol. (2010) 4:97105. doi: 10.1007/s12105-010-0171-9

  • 117

    LeeSOLeeJELeeSLeeSHKangJSSonHet al. Nationwide population-based incidence of cancer among patients with HIV/AIDS in South Korea. Sci Rep. (2022) 12:9974. doi: 10.1038/s41598-022-14170-5

  • 118

    NegriFMissaleGAntoniADPortaC. Hepatocellular cancer therapy in patients with HIV infection: Disparities in cancer care, trials enrolment, and cancer-related research. Transl Oncol. (2021) 14:101153. doi: 10.1016/j.tranon.2021.101153

  • 119

    IsaguliantsMBayurovaEAvdoshinaDKondrashovaAChiodiFPalefskyJM. Oncogenic effects of HIV-1 proteins, mechanisms behind. Cancers (Basel). (2021) 13. doi: 10.3390/cancers13020305

  • 120

    LienKMayerWHerreraRPadillaNTCaiXLinVet al. HIV-1 proteins gp120 and tat promote epithelial-mesenchymal transition and invasiveness of HPV-positive and HPV-negative neoplastic genital and oral epithelial cells. Microbiol Spectr. (2022) 10:e0362222. doi: 10.1128/spectrum.03622-22

  • 121

    LienKMayerWHerreraRRosbeKTugizovSM. HIV-1 proteins gp120 and tat induce the epithelial-mesenchymal transition in oral and genital mucosal epithelial cells. PloS One. (2019) 14:e0226343. doi: 10.1371/journal.pone.0226343

  • 122

    DoorbarJ. The papillomavirus life cycle. J Clin Virol. (2005) 32 Suppl 1:S715. doi: 10.1016/j.jcv.2004.12.006

  • 123

    OcanaOHNietoMA. Epithelial plasticity, stemness and pluripotency. Cell Res. (2010) 20:1086–8. doi: 10.1038/cr.2010.127

  • 124

    LamouilleSXuJDerynckR. Molecular mechanisms of epithelial-mesenchymal transition. Nat Rev Mol Cell Biol. (2014) 15:178–96. doi: 10.1038/nrm3758

  • 125

    LeeMYShenMR. Epithelial-mesenchymal transition in cervical carcinoma. Am J Transl Res. (2012) 4:113.

  • 126

    HsuYMChenYFChouCYTangMJChenJHWilkinsRJet al. KCl cotransporter-3 down-regulates E-cadherin/beta-catenin complex to promote epithelial-mesenchymal transition. Cancer Res. (2007) 67:11064–73. doi: 10.1158/0008-5472.CAN-07-2443

  • 127

    LeeMYChouCYTangMJShenMR. Epithelial-mesenchymal transition in cervical cancer: correlation with tumor progression, epidermal growth factor receptor overexpression, and snail up-regulation. Clin Cancer Res. (2008) 14:4743–50. doi: 10.1158/1078-0432.CCR-08-0234

  • 128

    GillesCPoletteMPietteJDelvigneACThompsonEWFoidartJMet al. Vimentin expression in cervical carcinomas: association with invasive and migratory potential. J pathol. (1996) 180:175–80. doi: 10.1002/(SICI)1096-9896(199610)180:2<175::AID-PATH630>3.0.CO;2-G

  • 129

    MaZZhangCLiuXFangFLiuSLiaoXet al. Characterisation of a subpopulation of CD133(+) cancer stem cells from Chinese patients with oral squamous cell carcinoma. Sci Rep. (2020) 10:8875. doi: 10.1038/s41598-020-64947-9

  • 130

    ChinnSBDarrOAOwenJHBellileEMcHughJBSpectorMEet al. Cancer stem cells: mediators of tumorigenesis and metastasis in head and neck squamous cell carcinoma. Head Neck. (2015) 37:317–26. doi: 10.1002/hed.23600

  • 131

    Caspa GokulanRDevarajH. Stem cell markers CXCR-4 and CD133 predict aggressive phenotype and their double positivity indicates poor prognosis of oral squamous cell carcinoma. Cancers (Basel). (2021) 13. doi: 10.3390/cancers13235895

  • 132

    WangPYangBHuangHLiangPLongBChenLet al. HIV gp120/Tat protein-induced epithelial-mesenchymal transition promotes the progression of cervical lesions. AIDS Res Ther. (2023) 20:82. doi: 10.1186/s12981-023-00577-1

  • 133

    BarillariGBeiRManzariVModestiA. Infection by high-risk human papillomaviruses, epithelial-to-mesenchymal transition and squamous pre-malignant or Malignant lesions of the uterine cervix: A series of chained events? Int J Mol Sci. (2021) 22. doi: 10.3390/ijms222413543

  • 134

    GuptaPBPastushenkoISkibinskiABlanpainCKuperwasserC. Phenotypic plasticity: driver of cancer initiation, progression, and therapy resistance. Cell Stem Cell. (2019) 24:6578. doi: 10.1016/j.stem.2018.11.011

  • 135

    JollyMKBoaretoMHuangBJiaDLuMBen-JacobEet al. Implications of the hybrid epithelial/mesenchymal phenotype in metastasis. Front Oncol. (2015) 5:155. doi: 10.3389/fonc.2015.00155

  • 136

    JollyMKMurphyRJBhatiaSWhitfieldHJRedfernADavisMJet al. Measuring and modelling the epithelial- mesenchymal hybrid state in cancer: clinical implications. Cells Tissues Organs. (2022) 211:110–33. doi: 10.1159/000515289

  • 137

    Grosse-WildeAFouquier d’HerouelAMcIntoshEErtaylanGSkupinAKuestnerREet al. Stemness of the hybrid epithelial/mesenchymal state in breast cancer and its association with poor survival. PloS One. (2015) 10:e0126522. doi: 10.1371/journal.pone.0126522

  • 138

    RuscettiMQuachBDadashianELMulhollandDJWuH. Tracking and functional characterization of epithelial-mesenchymal transition and mesenchymal tumor cells during prostate cancer metastasis. Cancer Res. (2015) 75:2749–59. doi: 10.1158/0008-5472.CAN-14-3476

  • 139

    StraussRLiZYLiuYBeyerIPerssonJSovaPet al. Analysis of epithelial and mesenchymal markers in ovarian cancer reveals phenotypic heterogeneity and plasticity. PloS One. (2011) 6:e16186. doi: 10.1371/journal.pone.0016186

  • 140

    JollyMKHuangBLuMManiSALevineHBen-JacobE. Towards elucidating the connection between epithelial-mesenchymal transitions and stemness. J R Soc Interf. (2014) 11:20140962. doi: 10.1098/rsif.2014.0962

  • 141

    Celia-TerrassaTJollyMK. Cancer stem cells and epithelial-to-mesenchymal transition in cancer metastasis. Cold Spring Harb Perspect Med. (2020) 10. doi: 10.1101/cshperspect.a036905

  • 142

    YanYZuoXWeiD. Concise review: emerging role of CD44 in cancer stem cells: A promising biomarker and therapeutic target. Stem Cells Transl Med. (2015) 4:1033–43. doi: 10.5966/sctm.2015-0048

  • 143

    JuFAtyahMMHorstmannNGulSVagoRBrunsCJet al. Characteristics of the cancer stem cell niche and therapeutic strategies. Stem Cell Res Ther. (2022) 13:233. doi: 10.1186/s13287-022-02904-1

  • 144

    GhaziNSaghravanianNTaghi ShakeriMJamaliM. Evaluation of CD44 and TGF-B expression in oral carcinogenesis. J Dent (Shiraz). (2021) 22:3340.

  • 145

    MirhashemiMGhaziNSaghravanianNTaghipourAMohajertehranF. Evaluation of CD24 and CD44 as cancer stem cell markers in squamous cell carcinoma and epithelial dysplasia of the oral cavity by q- RT-PCR. Dent Res J (Isfahan). (2020) 17:208–12. doi: 10.4103/1735-3327.284727

  • 146

    SaghravanianNAnvariKGhaziNMemarBShahsavariMAghaeeMA. Expression of p63 and CD44 in oral squamous cell carcinoma and correlation with clinicopathological parameters. Arch Oral Biol. (2017) 82:160–5. doi: 10.1016/j.archoralbio.2017.06.011

  • 147

    BoseBNihadMSudheerSP. Pluripotent stem cells: Basic biology or else differentiations aimed at translational research and the role of flow cytometry. Cytom A. (2023) 103:368–77. doi: 10.1002/cyto.a.v103.5

  • 148

    MarcatoPDeanCAGiacomantonioCALeePW. Aldehyde dehydrogenase: its role as a cancer stem cell marker comes down to the specific isoform. Cell Cycle. (2011) 10:1378–84. doi: 10.4161/cc.10.9.15486

  • 149

    MarcatoPDeanCAPanDAraslanovaRGillisMJoshiMet al. Aldehyde dehydrogenase activity of breast cancer stem cells is primarily due to isoform ALDH1A3 and its expression is predictive of metastasis. Stem Cells. (2011) 29:3245. doi: 10.1002/stem.563

  • 150

    EmichHChapireauDHutchisonIMackenzieI. The potential of CD44 as a diagnostic and prognostic tool in oral cancer. J Oral Pathol Med. (2015) 44:393400. doi: 10.1111/jop.2015.44.issue-6

  • 151

    TongDSunJHuangPLiMZhangF. p75 neurotrophin receptor: A potential surface marker of tongue squamous cell carcinoma stem cells. Mol Med Rep. (2017) 15:2521–9. doi: 10.3892/mmr.2017.6291

  • 152

    Barzegar BehroozASyahirAAhmadS. CD133: beyond a cancer stem cell biomarker. J Drug Targeting. (2019) 27:257–69. doi: 10.1080/1061186X.2018.1479756

  • 153

    MiyataYKumagaiKNagaokaTKitauraKKanedaGKanazawaHet al. Clinicopathological significance and prognostic value of Wilms’ tumor gene expression in colorectal cancer. Cancer biomark. (2015) 15:789–97. doi: 10.3233/CBM-150521

  • 154

    AminiSFathiFMobalegiJSofimajidpourHGhadimiT. The expressions of stem cell markers: Oct4, Nanog, Sox2, nucleostemin, Bmi, Zfx, Tcl1, Tbx3, Dppa4, and Esrrb in bladder, colon, and prostate cancer, and certain cancer cell lines. Anat Cell Biol. (2014) 47:111. doi: 10.5115/acb.2014.47.1.1

  • 155

    Herreros-PomaresA. Identification, culture and targeting of cancer stem cells. Life (Basel). (2022) 12. doi: 10.3390/life12020184

  • 156

    Herreros-PomaresAde-Maya-GironesJDCalabuig-FarinasSLucasRMartinezAPardo-SanchezJMet al. Lung tumorspheres reveal cancer stem cell-like properties and a score with prognostic impact in resected non-small-cell lung cancer. Cell Death Dis. (2019) 10:660. doi: 10.1038/s41419-019-1898-1

  • 157

    BaillieRItinteangTYuHHBraschHDDavisPFTanST. Cancer stem cells in moderately differentiated oral tongue squamous cell carcinoma. J Clin Pathol. (2016) 69:742–4. doi: 10.1136/jclinpath-2015-203599

  • 158

    BaillieRTanSTItinteangT. Cancer stem cells in oral cavity squamous cell carcinoma: A review. Front Oncol. (2017) 7:112. doi: 10.3389/fonc.2017.00112

  • 159

    AmorNGBuzoRFOrtizRCLopesNMSaitoLMMackenzieICet al. In vitro and in vivo characterization of cancer stem cell subpopulations in oral squamous cell carcinoma. J Oral Pathol Med. (2021) 50:52–9. doi: 10.1111/jop.13101

  • 160

    de AndradeNPRodriguesMFRodiniCONunesFD. Cancer stem cell, cytokeratins and epithelial to mesenchymal transition markers expression in oral squamous cell carcinoma derived from ortothopic xenoimplantation of CD44(high) cells. Pathol Res Pract. (2017) 213:235–44. doi: 10.1016/j.prp.2016.12.009

  • 161

    de CamargoMRFrazonTFInacioKKSmiderleFRAmorNGDionisioTJet al. Ganoderma lucidum polysaccharides inhibit in vitro tumorigenesis, cancer stem cell properties and epithelial-mesenchymal transition in oral squamous cell carcinoma. J Ethnopharmacol. (2022) 286:114891. doi: 10.1016/j.jep.2021.114891

  • 162

    OrtizRCLopesNMAmorNGPonceJBSchmerlingCKLaraVSet al. CD44 and ALDH1 immunoexpression as prognostic indicators of invasion and metastasis in oral squamous cell carcinoma. J Oral Pathol Med. (2018) 47:740–7. doi: 10.1111/jop.2018.47.issue-8

  • 163

    RodiniCOLopesNMLaraVSMackenzieIC. Oral cancer stem cells - properties and consequences. J Appl Oral Sci. (2017) 25:708–15. doi: 10.1590/1678-7757-2016-0665

  • 164

    RodriguesMMiguitaLDe AndradeNPHegueduschDRodiniCOMoysesRAet al. GLI3 knockdown decreases stemness, cell proliferation and invasion in oral squamous cell carcinoma. Int J Oncol. (2018) 53:2458–72. doi: 10.3892/ijo.2018.4572

  • 165

    ShigeishiHBiddleAGammonLEmichHRodiniCOGemenetzidisEet al. Maintenance of stem cell self-renewal in head and neck cancers requires actions of GSK3beta influenced by CD44 and RHAMM. Stem Cells. (2013) 31:2073–83. doi: 10.1002/stem.1418

  • 166

    ShigeishiHBiddleAGammonLRodiniCOYamasakiMSeinoSet al. Elevation in 5-FU-induced apoptosis in head and neck cancer stem cells by a combination of CDHP and GSK3beta inhibitors. J Oral Pathol Med. (2015) 44:201–7. doi: 10.1111/jop.2015.44.issue-3

  • 167

    SiqueiraJMHegueduschDRodiniCONunesFDRodriguesM. Mechanisms involved in cancer stem cell resistance in head and neck squamous cell carcinoma. Cancer Drug Resist. (2023) 6:116–37. doi: 10.20517/cdr.2022.107

  • 168

    XavierFCASilvaJCRodiniCORodriguesM. Mechanisms of immune evasion by head and neck cancer stem cells. Front Oral Health. (2022) 3:957310. doi: 10.3389/froh.2022.957310

  • 169

    PalABarrettTFPaoliniRParikhAPuramSV. Partial EMT in head and neck cancer biology: a spectrum instead of a switch. Oncogene. (2021) 40:5049–65. doi: 10.1038/s41388-021-01868-5

  • 170

    KrishnanHRayesJMiyashitaTIshiiGRetzbachEPSheehanSAet al. Podoplanin: An emerging cancer biomarker and therapeutic target. Cancer Sci. (2018) 109:1292–9. doi: 10.1111/cas.2018.109.issue-5

  • 171

    LiaoCWangQAnJLongQWangHXiangMet al. Partial EMT in squamous cell carcinoma: A snapshot. Int J Biol Sci. (2021) 17:3036–47. doi: 10.7150/ijbs.61566

  • 172

    KisodaSMouriYKitamuraNYamamotoTMiyoshiKKudoY. The role of partial-EMT in the progression of head and neck squamous cell carcinoma. J Oral Biosci. (2022) 64:176–82. doi: 10.1016/j.job.2022.02.004

  • 173

    GordonKJBlobeGC. Role of transforming growth factor-beta superfamily signaling pathways in human disease. Biochim Biophys Acta. (2008) 1782:197228. doi: 10.1016/j.bbadis.2008.01.006

  • 174

    BlobeGCSchiemannWPLodishHF. Role of transforming growth factor beta in human disease. New Engl J Med. (2000) 342:1350–8. doi: 10.1056/NEJM200005043421807

  • 175

    WendtMKTianMSchiemannWP. Deconstructing the mechanisms and consequences of TGF-beta-induced EMT during cancer progression. Cell Tissue Res. (2012) 347:85101. doi: 10.1007/s00441-011-1199-1

  • 176

    Barrallo-GimenoANietoMA. The Snail genes as inducers of cell movement and survival: implications in development and cancer. Development. (2005) 132:3151–61. doi: 10.1242/dev.01907

  • 177

    ToschiEBacigalupoIStrippoliRChiozziniCCeresetoAFalchiMet al. HIV-1 Tat regulates endothelial cell cycle progression via activation of the Ras/ERK MAPK signaling pathway. Mol Biol Cell. (2006) 17:1985–94. doi: 10.1091/mbc.e05-08-0717

  • 178

    ChenQSivakumarPBarleyCPetersDMGomesRRFarach-CarsonMCet al. Potential role for heparan sulfate proteoglycans in regulation of transforming growth factor-beta (TGF-beta) by modulating assembly of latent TGF-beta-binding protein-1. J Biol Chem. (2007) 282:26418–30. doi: 10.1074/jbc.M703341200

  • 179

    UrbinatiCMilanesiMLauroNBertelliCDavidGD’UrsiPet al. HIV-1 tat and heparan sulfate proteoglycans orchestrate the setup of in cis and in trans cell-surface interactions functional to lymphocyte trans-endothelial migration. Molecules. (2021) 26. doi: 10.3390/molecules26247488

  • 180

    NyagolJLeucciEOnnisADe FalcoGTigliCSanseverinoFet al. The effects of HIV-1 Tat protein on cell cycle during cervical carcinogenesis. Cancer Biol Ther. (2006) 5:684–90. doi: 10.4161/cbt.5.6.2907

  • 181

    TorneselloMLBuonaguroFMBeth-GiraldoEGiraldoG. Human immunodeficiency virus type 1 tat gene enhances human papillomavirus early gene expression. Intervirology. (1993) 36:5764. doi: 10.1159/000150322

  • 182

    HuynhDVincanEMantamadiotisTPurcellDChanCKRamsayR. Oncogenic properties of HIV-Tat in colorectal cancer cells. Curr HIV Res. (2007) 5:403–9. doi: 10.2174/157016207781023974

  • 183

    LiuYPChenCHYenCHTungCWChenCJChenYAet al. Human immunodeficiency virus Tat-TIP30 interaction promotes metastasis by enhancing the nuclear translocation of Snail in lung cancer cell lines. Cancer Sci. (2018) 109:3105–14. doi: 10.1111/cas.2018.109.issue-10

  • 184

    RubinoCStincoMIndolfiG. Hepatitis co-infection in paediatric HIV: progressing treatment and prevention. Curr Opin HIV AIDS. (2024) 19(6):338–47. doi: 10.1097/COH.0000000000000882

  • 185

    SultanaCFalangaCChicinGIonLGranceaCChiriacDet al. HIV, HCV and HIV-HCV coinfections in the general population versus inmates from Romania. Viruses. (2024) 16. doi: 10.3390/v16081279

  • 186

    GobranSTAncutaPShoukryNH. A tale of two viruses: immunological insights into HCV/HIV coinfection. Front Immunol. (2021) 12:726419. doi: 10.3389/fimmu.2021.726419

  • 187

    GobranSTPagliuzzaAKhedrOFertAChomontNBruneauJet al. DAA-mediated HCV cure reduces HIV DNA levels in HCV/HIV coinfected people. J Virol. (2023) 97:e0110523. doi: 10.1128/jvi.01105-23

  • 188

    BourcierVWinnockMAit AhmedMSogniPPambrunEPoizot-MartinIet al. Primary liver cancer is more aggressive in HIV-HCV coinfection than in HCV infection. A prospective study (ANRS CO13 Hepavih and CO12 Cirvir). Clin Res Hepatol Gastroenterol. (2012) 36:214–21. doi: 10.1016/j.clinre.2011.11.002

  • 189

    TheronAJAndersonRRossouwTMSteelHC. The role of transforming growth factor beta-1 in the progression of HIV/AIDS and development of non-AIDS-defining fibrotic disorders. Front Immunol. (2017) 8:1461. doi: 10.3389/fimmu.2017.01461

  • 190

    Wiercinska-DrapaloAFlisiakRJaroszewiczJProkopowiczD. Increased plasma transforming growth factor-beta1 is associated with disease progression in HIV-1-infected patients. Viral Immunol. (2004) 17:109–13. doi: 10.1089/088282404322875502

  • 191

    MainaEKAbanaCZBukusiEASedegahMLarteyMAmpofoWK. Plasma concentrations of transforming growth factor beta 1 in non-progressive HIV-1 infection correlates with markers of disease progression. Cytokine. (2016) 81:109–16. doi: 10.1016/j.cyto.2016.02.009

  • 192

    DickinsonMKliszczakAEGiannoulatouEPeppaDPellegrinoPWilliamsIet al. Dynamics of transforming growth factor (TGF)-beta superfamily cytokine induction during HIV-1 infection are distinct from other innate cytokines. Front Immunol. (2020) 11:596841. doi: 10.3389/fimmu.2020.596841

  • 193

    YimLYLamKSLukTYMoYLuXWangJet al. Transforming growth factor beta signaling promotes HIV-1 infection in activated and resting memory CD4(+) T cells. J Virol. (2023) 97:e0027023. doi: 10.1128/jvi.00270-23

  • 194

    ChinnapaiyanSDuttaRKNairMChandHSRahmanIUnwallaHJ. TGF-beta1 increases viral burden and promotes HIV-1 latency in primary differentiated human bronchial epithelial cells. Sci Rep. (2019) 9:12552. doi: 10.1038/s41598-019-49056-6

  • 195

    ReinholdDWrengerSKahneTAnsorgeS. HIV-1 Tat: immunosuppression via TGF-beta1 induction. Immunol Today. (1999) 20:384–5. doi: 10.1016/S0167-5699(99)01497-8

  • 196

    ZauliGDavisBRReMCVisaniGFurliniGLa PlacaM. tat protein stimulates production of transforming growth factor-beta 1 by marrow macrophages: a potential mechanism for human immunodeficiency virus-1-induced hematopoietic suppression. Blood. (1992) 80:3036–43. doi: 10.1182/blood.V80.12.3036.3036

  • 197

    AboushalaAKugelGHurleyE. Class II composite resin restorations using glass-ionomer liners: microleakage studies. J Clin Pediatr Dent. (1996) 21:6770. doi: 10.1128/jvi.00270-23

  • 198

    HuROyaizuNKalyanaramanVSPahwaS. HIV-1 gp160 as a modifier of Th1 and Th2 cytokine response: gp160 suppresses interferon-gamma and interleukin-2 production concomitantly with enhanced interleukin-4 production in vitro. Clin Immunol Immunopathol. (1994) 73:245–51. doi: 10.1006/clin.1994.1194

  • 199

    LijnenPJPetrovVVFagardRH. Induction of cardiac fibrosis by transforming growth factor-beta(1). Mol Genet Metab. (2000) 71:418–35. doi: 10.1006/mgme.2000.3032

  • 200

    MehtaTBuzkovaPKizerJRDjousseLChoncholMMukamalKJet al. Higher plasma transforming growth factor (TGF)-beta is associated with kidney disease in older community dwelling adults. BMC Nephrol. (2017) 18:98. doi: 10.1186/s12882-017-0509-6

  • 201

    Hernandez-GeaVFriedmanSL. Pathogenesis of liver fibrosis. Annu Rev Pathol. (2011) 6:425–56. doi: 10.1146/annurev-pathol-011110-130246

  • 202

    BarisoniLBruggemanLAMundelPD’AgatiVDKlotmanPE. HIV-1 induces renal epithelial dedifferentiation in a transgenic model of HIV-associated nephropathy. Kidney Int. (2000) 58:173–81. doi: 10.1046/j.1523-1755.2000.00152.x

  • 203

    SchwartzEJCaraASnoeckHRossMDSunamotoMReiserJet al. Human immunodeficiency virus-1 induces loss of contact inhibition in podocytes. J Am Soc Nephrol. (2001) 12:1677–84. doi: 10.1681/ASN.V1281677

  • 204

    MedapalliRKHeJCKlotmanPE. HIV-associated nephropathy: pathogenesis. Curr Opin Nephrol Hypertens. (2011) 20:306–11. doi: 10.1097/MNH.0b013e328345359a

  • 205

    BruggemanLARossMDTanjiNCaraADikmanSGordonREet al. Renal epithelium is a previously unrecognized site of HIV-1 infection. J Am Soc Nephrol. (2000) 11:2079–87. doi: 10.1681/ASN.V11112079

  • 206

    LuTCHeJCWangZHFengXFukumi-TominagaTChenNet al. HIV-1 Nef disrupts the podocyte actin cytoskeleton by interacting with diaphanous interacting protein. J Biol Chem. (2008) 283:8173–82. doi: 10.1074/jbc.M708920200

  • 207

    KoppJBKlotmanMEAdlerSHBruggemanLADickiePMarinosNJet al. Progressive glomerulosclerosis and enhanced renal accumulation of basement membrane components in mice transgenic for human immunodeficiency virus type 1 genes. Proc Natl Acad Sci United States America. (1992) 89:1577–81. doi: 10.1073/pnas.89.5.1577

  • 208

    ZhongJZuoYMaJFogoABJolicoeurPIchikawaIet al. Expression of HIV-1 genes in podocytes alone can lead to the full spectrum of HIV-1-associated nephropathy. Kidney Int. (2005) 68:1048–60. doi: 10.1111/j.1523-1755.2005.00497.x

  • 209

    LotzMClark-LewisIGanuV. HIV-1 transactivator protein Tat induces proliferation and TGF beta expression in human articular chondrocytes. J Cell Biol. (1994) 124:365–71. doi: 10.1083/jcb.124.3.365

  • 210

    StettnerMRNanceJAWrightCAKinoshitaYKimWKMorgelloSet al. SMAD proteins of oligodendroglial cells regulate transcription of JC virus early and late genes coordinately with the Tat protein of human immunodeficiency virus type 1. J Gen Virol. (2009) 90:2005–14. doi: 10.1099/vir.0.011072-0

  • 211

    RatnamKKHeCJKlotmanP. Nef as a proliferative factor for kidney epithelial cells in HIV-associated nephropathy. Clin Med Oncol. (2008) 2:539–45. doi: 10.4137/CMO.S661

  • 212

    HusainMD’AgatiVDHeJCKlotmanMEKlotmanPE. HIV-1 Nef induces dedifferentiation of podocytes in vivo: a characteristic feature of HIVAN. AIDS. (2005) 19:1975–80. doi: 10.1097/01.aids.0000191918.42110.27

  • 213

    FarrowNCmielewskiPDonnelleyMRout-PittNMoodleyYBertoncelloIet al. Epithelial disruption: a new paradigm enabling human airway stem cell transplantation. Stem Cell Res Ther. (2018) 9:153. doi: 10.1186/s13287-018-0911-4

  • 214

    Rout-PittNFarrowNParsonsDDonnelleyM. Epithelial mesenchymal transition (EMT): a universal process in lung diseases with implications for cystic fibrosis pathophysiology. Respir Res. (2018) 19:136. doi: 10.1186/s12931-018-0834-8

  • 215

    LotzMClark-LewisIGanuV. HIV-1 transactivator protein Tat induces proliferation and TGF beta expression in human articular chondrocytes. J Cell Biol. (1994) 124:365–71. doi: 10.1083/jcb.124.3.365

  • 216

    JiangYChaiLWangHShenXFasaeMBJiaoJet al. HIV tat protein induces myocardial fibrosis through TGF-beta1-CTGF signaling cascade: A potential mechanism of HIV infection-related cardiac manifestations. Cardiovasc Toxicol. (2021) 21:965–72. doi: 10.1007/s12012-021-09687-6

  • 217

    BettacciniAABajAAccollaRSBasoloFTonioloAQ. Proliferative activity of extracellular HIV-1 Tat protein in human epithelial cells: expression profile of pathogenetically relevant genes. BMC Microbiol. (2005) 5:20. doi: 10.1186/1471-2180-5-20

  • 218

    YamamotoTNobleNAMillerDEGoldLIHishidaANagaseMet al. Increased levels of transforming growth factor-beta in HIV-associated nephropathy. Kidney Int. (1999) 55:579–92. doi: 10.1046/j.1523-1755.1999.00296.x

  • 219

    PimDBanksL. Interaction of viral oncoproteins with cellular target molecules: infection with high-risk vs low-risk human papillomaviruses. APMIS. (2010) 118:471–93. doi: 10.1111/j.1600-0463.2010.02618.x

  • 220

    ShiauMYFanLCYangSCTsaoCHLeeHChengYWet al. Human papillomavirus up-regulates MMP-2 and MMP-9 expression and activity by inducing interleukin-8 in lung adenocarcinomas. PloS One. (2013) 8:e54423. doi: 10.1371/journal.pone.0054423

  • 221

    Smola-HessSPahneJMauchCZigrinoPSmolaHPfisterHJ. Expression of membrane type 1 matrix metalloproteinase in papillomavirus-positive cells: role of the human papillomavirus (HPV) 16 and HPV8 E7 gene products. J Gen virol. (2005) 86:1291–6. doi: 10.1099/vir.0.80551-0

  • 222

    CardealLBBoccardoETerminiLRabachiniTAndreoliMAdi LoretoCet al. HPV16 oncoproteins induce MMPs/RECK-TIMP-2 imbalance in primary keratinocytes: possible implications in cervical carcinogenesis. PloS One. (2012) 7:e33585. doi: 10.1371/journal.pone.0033585

  • 223

    NoeVFingletonBJacobsKCrawfordHCVermeulenSSteelantWet al. Release of an invasion promoter E-cadherin fragment by matrilysin and stromelysin-1. J Cell Sci. (2001) 114:111–8. doi: 10.1242/jcs.114.1.111

  • 224

    SymowiczJAdleyBPGleasonKJJohnsonJJGhoshSFishmanDAet al. Engagement of collagen-binding integrins promotes matrix metalloproteinase-9-dependent E-cadherin ectodomain shedding in ovarian carcinoma cells. Cancer Res. (2007) 67:2030–9. doi: 10.1158/0008-5472.CAN-06-2808

  • 225

    YouTKKimKMNohSJBaeJSJangKYChungMJet al. Expressions of E-cadherin, cortactin and MMP-9 in pseudoepitheliomatous hyperplasia and squamous cell carcinoma of the head and neck: their relationships with clinicopathologic factors and prognostic implication. Korean J Pathol. (2012) 46:331–40. doi: 10.4132/KoreanJPathol.2012.46.4.331

  • 226

    DavidJMRajasekaranAK. Dishonorable discharge: the oncogenic roles of cleaved E-cadherin fragments. Cancer Res. (2012) 72:2917–23. doi: 10.1158/0008-5472.CAN-11-3498

  • 227

    TobianAAGrabowskiMKSerwaddaDNewellKSsebbowaPFrancoVet al. Reactivation of herpes simplex virus type 2 after initiation of antiretroviral therapy. J Infect Dis. (2013) 208:839–46. doi: 10.1093/infdis/jit252

  • 228

    Lomeli-MartinezSMGonzalez-HernandezLARuiz-AnayaAJLomeli-MartinezMAMartinez-SalazarSYMercado GonzalezAEet al. Oral manifestations associated with HIV/AIDS patients. Medicina (Kaunas). (2022) 58. doi: 10.3390/medicina58091214

  • 229

    WaldAEricssonMKrantzESelkeSCoreyL. Oral shedding of herpes simplex virus type 2. Sex Transm Infect. (2004) 80:272–6. doi: 10.1136/sti.2003.007823

  • 230

    PosavadCMWaldAKuntzSHuangMLSelkeSKrantzEet al. Frequent reactivation of herpes simplex virus among HIV-1-infected patients treated with highly active antiretroviral therapy. J Infect Dis. (2004) 190:693–6. doi: 10.1086/jid.2004.190.issue-4

  • 231

    TanDHRaboudJMKaulRWalmsleySL. Antiretroviral therapy is not associated with reduced herpes simplex virus shedding in HIV coinfected adults: an observational cohort study. BMJ Open. (2014) 4:e004210. doi: 10.1136/bmjopen-2013-004210

  • 232

    KrummenacherCNicolaAVWhitbeckJCLouHHouWLambrisJDet al. Herpes simplex virus glycoprotein D can bind to poliovirus receptor-related protein 1 or herpesvirus entry mediator, two structurally unrelated mediators of virus entry. J Virol. (1998) 72:7064–74. doi: 10.1128/JVI.72.9.7064-7074.1998

  • 233

    YoonMSpearPG. Disruption of adherens junctions liberates nectin-1 to serve as receptor for herpes simplex virus and pseudorabies virus entry. J Virol. (2002) 76:7203–8. doi: 10.1128/JVI.76.14.7203-7208.2002

  • 234

    GrindeB. Herpesviruses: latency and reactivation - viral strategies and host response. J Oral Microbiol. (2013) 5. doi: 10.3402/jom.v5i0.22766

  • 235

    DrewWL. Cytomegalovirus infection in patients with AIDS. Clin Infect Dis. (1992) 14:608–15. doi: 10.1093/clinids/14.2.608-a

  • 236

    KovacsASchluchterMEasleyKDemmlerGShearerWLa RussaPet al. Cytomegalovirus infection and HIV-1 disease progression in infants born to HIV-1-infected women. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group. N Engl J Med. (1999) 341:7784. doi: 10.1056/NEJM199907083410203

  • 237

    NigroGKrzysztofiakAGattinaraGCMangoTMazzoccoMPorcaroMAet al. Rapid progression of HIV disease in children with cytomegalovirus DNAemia. AIDS. (1996) 10:1127–33.

  • 238

    ChandwaniSKaulABebenrothDKimMJohnDDFideliaAet al. Cytomegalovirus infection in human immunodeficiency virus type 1-infected children. Pediatr Infect Dis J. (1996) 15:310–4. doi: 10.1097/00006454-199604000-00006

  • 239

    GieRPGoussardP. CMV pneumonia in HIV-infected and HIV-uninfected infants: a neglected disease? Int J Tuberc Lung Dis. (2017) 21:1209–10. doi: 10.5588/ijtld.17.0714

  • 240

    GianellaSLetendreS. Cytomegalovirus and HIV: A dangerous pas de deux. J Infect Dis. (2016) 214 Suppl 2:S67–74. doi: 10.1093/infdis/jiw217

  • 241

    GriffithsPBaraniakIReevesM. The pathogenesis of human cytomegalovirus. J Pathol. (2015) 235:288–97. doi: 10.1002/path.2015.235.issue-2

  • 242

    SufiawatiIHerreraRMayerWCaiXBorkakotiJLinVet al. Human immunodeficiency virus (HIV) and human cytomegalovirus (HCMV) coinfection of infant tonsil epithelium may synergistically promote both HIV-1 and HCMV spread and infection. J Virol. (2021) 95:e0092121. doi: 10.1128/JVI.00921-21

  • 243

    DeMerittIBMilfordLEYurochkoAD. Activation of the NF-kappaB pathway in human cytomegalovirus-infected cells is necessary for efficient transactivation of the major immediate-early promoter. J Virol. (2004) 78:4498–507. doi: 10.1128/JVI.78.9.4498-4507.2004

  • 244

    ChanGBivins-SmithERSmithMSYurochkoAD. Transcriptome analysis of NF-kappaB- and phosphatidylinositol 3-kinase-regulated genes in human cytomegalovirus-infected monocytes. J Virol. (2008) 82:1040–6. doi: 10.1128/JVI.00864-07

  • 245

    YurochkoADKowalikTFHuongSMHuangES. Human cytomegalovirus upregulates NF-kappa B activity by transactivating the NF-kappa B p105/p50 and p65 promoters. J Virol. (1995) 69:5391–400. doi: 10.1128/jvi.69.9.5391-5400.1995

  • 246

    JohnsonRAMaXLYurochkoADHuangES. The role of MKK1/2 kinase activity in human cytomegalovirus infection. J Gen Virol. (2001) 82:493–7. doi: 10.1099/0022-1317-82-3-493

  • 247

    MinCKShakyaAKLeeBJStreblowDNCaposioPYurochkoAD. The differentiation of human cytomegalovirus infected-monocytes is required for viral replication. Front Cell Infect Microbiol. (2020) 10:368. doi: 10.3389/fcimb.2020.00368

  • 248

    RodgersBCScottDMMundinJSissonsJG. Monocyte-derived inhibitor of interleukin 1 induced by human cytomegalovirus. J Virol. (1985) 55:527–32. doi: 10.1128/jvi.55.3.527-532.1985

  • 249

    RodgersBCScottDMSissonsJG. A monocyte-derived inhibitor of interleukin 1 induced by human cytomegalovirus. Trans Assoc Am Phys. (1985) 98:334–43. doi: 10.1128/jvi.55.3.527-532.1985

  • 250

    ScottDMRodgersBCFreekeCBuiterJSissonsJG. Human cytomegalovirus and monocytes: limited infection and negligible immunosuppression in normal mononuclear cells infected in vitro with mycoplasma-free virus strains. J Gen Virol. (1989) 70:685–94. doi: 10.1099/0022-1317-70-3-685

  • 251

    Taylor-WiedemanJSissonsJGBorysiewiczLKSinclairJH. Monocytes are a major site of persistence of human cytomegalovirus in peripheral blood mononuclear cells. J Gen Virol. (1991) 72:2059–64. doi: 10.1099/0022-1317-72-9-2059

  • 252

    ZhengAYuanFLiYZhuFHouPLiJet al. Claudin-6 and claudin-9 function as additional coreceptors for hepatitis C virus. J Virol. (2007) 81:12465–71. doi: 10.1128/JVI.01457-07

  • 253

    PlossAEvansMJGaysinskayaVAPanisMYouHde JongYPet al. Human occludin is a hepatitis C virus entry factor required for infection of mouse cells. Nature. (2009) 457:882–6. doi: 10.1038/nature07684

  • 254

    MaillyLBaumertTF. Hepatitis C virus infection and tight junction proteins: The ties that bind. Biochim Biophys Acta Biomembr. (2020) 1862:183296. doi: 10.1016/j.bbamem.2020.183296

  • 255

    SoCWSourisseauMSarwarSEvansMJRandallG. Roles of epidermal growth factor receptor, claudin-1 and occludin in multi-step entry of hepatitis C virus into polarized hepatoma spheroids. PloS Pathog. (2023) 19:e1011887. doi: 10.1371/journal.ppat.1011887

  • 256

    BartonESForrestJCConnollyJLChappellJDLiuYSchnellFJet al. Junction adhesion molecule is a receptor for reovirus. Cell. (2001) 104:441–51. doi: 10.1016/S0092-8674(01)00231-8

  • 257

    Torres-FloresJMSilva-AyalaDEspinozaMALopezSAriasCF. The tight junction protein JAM-A functions as coreceptor for rotavirus entry into MA104 cells. Virology. (2015) 475:172–8. doi: 10.1016/j.virol.2014.11.016

  • 258

    CoyneCBShenLTurnerJRBergelsonJM. Coxsackievirus entry across epithelial tight junctions requires occludin and the small GTPases Rab34 and Rab5. Cell Host Microbe. (2007) 2:181–92. doi: 10.1016/j.chom.2007.07.003

  • 259

    ChangYCesarmanEPessinMSLeeFCulpepperJKnowlesDMet al. Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi’s sarcoma. Science. (1994) 266:1865–9. doi: 10.1126/science.7997879

  • 260

    SternbachGVaronJ. Moritz Kaposi: idiopathic pigmented sarcoma of the skin. J Emerg Med. (1995) 13:671–4. doi: 10.1016/0736-4679(95)00077-N

  • 261

    EnsoliBBarillariGBuonaguroLGalloRC. Molecular mechanisms in the pathogenesis of AIDS-associated Kaposi’s sarcoma. Adv Exp Med Biol. (1991) 303:2738. doi: 10.1007/978-1-4684-6000-1_4

  • 262

    EnsoliBBarillariGGalloRC. Pathogenesis of AIDS-associated kaposi’s sarcoma. Hematol Oncol Clin North Am. (1991) 5:281–95. doi: 10.1016/S0889-8588(18)30441-6

  • 263

    EnsoliBGendelmanRMarkhamPFiorelliVColombiniSRaffeldMet al. Synergy between basic fibroblast growth factor and HIV-1 Tat protein in induction of Kaposi’s sarcoma. Nature. (1994) 371:674–80. doi: 10.1038/371674a0

  • 264

    EnsoliBSturzlMMoniniP. Reactivation and role of HHV-8 in Kaposi’s sarcoma initiation. Adv Cancer Res. (2001) 81:161200. doi: 10.1016/S0065-230X(01)81005-8

  • 265

    AlbiniABarillariGBenelliRGalloRCEnsoliB. Angiogenic properties of human immunodeficiency virus type 1 Tat protein. Proc Natl Acad Sci U S A. (1995) 92:4838–42. doi: 10.1073/pnas.92.11.4838

  • 266

    AlbiniABenelliRPrestaMRusnatiMZicheMRubartelliAet al. HIV-tat protein is a heparin-binding angiogenic growth factor. Oncogene. (1996) 12:289–97.

  • 267

    AlbiniAFontaniniGMasielloLTacchettiCBiginiDLuzziPet al. Angiogenic potential in vivo by Kaposi’s sarcoma cell-free supernatants and HIV-1 tat product: inhibition of KS-like lesions by tissue inhibitor of metalloproteinase-2. AIDS. (1994) 8:1237–44. doi: 10.1097/00002030-199409000-00004

  • 268

    AlbiniASoldiRGiunciuglioDGiraudoEBenelliRPrimoLet al. The angiogenesis induced by HIV-1 tat protein is mediated by the Flk-1/KDR receptor on vascular endothelial cells. Nat Med. (1996) 2:1371–5. doi: 10.1038/nm1296-1371

  • 269

    CoralliniACampioniDRossiCAlbiniAPossatiLRusnatiMet al. Promotion of tumour metastases and induction of angiogenesis by native HIV-1 Tat protein from BK virus/tat transgenic mice. AIDS. (1996) 10:701–10. doi: 10.1097/00002030-199606001-00003

  • 270

    VogelJHinrichsSHReynoldsRKLuciwPAJayG. The HIV tat gene induces dermal lesions resembling Kaposi’s sarcoma in transgenic mice. Nature. (1988) 335:606–11. doi: 10.1038/335606a0

  • 271

    ZhouFXueMQinDZhuXWangCZhuJet al. HIV-1 Tat promotes Kaposi’s sarcoma-associated herpesvirus (KSHV) vIL-6-induced angiogenesis and tumorigenesis by regulating PI3K/PTEN/AKT/GSK-3beta signaling pathway. PloS One. (2013) 8:e53145. doi: 10.1371/journal.pone.0053145

  • 272

    AokiYTosatoG. HIV-1 Tat enhances Kaposi sarcoma-associated herpesvirus (KSHV) infectivity. Blood. (2004) 104:810–4. doi: 10.1182/blood-2003-07-2533

  • 273

    Yen-MooreAHudnallSDRadyPLWagnerRFJr.MooreTOMemarOet al. Differential expression of the HHV-8 vGCR cellular homolog gene in AIDS-associated and classic Kaposi’s sarcoma: potential role of HIV-1 Tat. Virology. (2000) 267:247–51. doi: 10.1006/viro.1999.0125

  • 274

    PatiSFoulkeJSJr.BarabitskayaOKimJNairBCHoneDet al. Human herpesvirus 8-encoded vGPCR activates nuclear factor of activated T cells and collaborates with human immunodeficiency virus type 1 Tat. J Virol. (2003) 77:5759–73. doi: 10.1128/JVI.77.10.5759-5773.2003

  • 275

    GuoHGPatiSSadowskaMCharuratMReitzM. Tumorigenesis by human herpesvirus 8 vGPCR is accelerated by human immunodeficiency virus type 1 Tat. J Virol. (2004) 78:9336–42. doi: 10.1128/JVI.78.17.9336-9342.2004

  • 276

    YaoSHuMHaoTLiWXueXXueMet al. MiRNA-891a-5p mediates HIV-1 Tat and KSHV Orf-K1 synergistic induction of angiogenesis by activating NF-kappaB signaling. Nucleic Acids Res. (2015) 43:9362–78. doi: 10.1093/nar/gkv988

  • 277

    ChenXChengLJiaXZengYYaoSLvZet al. Human immunodeficiency virus type 1 Tat accelerates Kaposi sarcoma-associated herpesvirus Kaposin A-mediated tumorigenesis of transformed fibroblasts in vitro as well as in nude and immunocompetent mice. Neoplasia. (2009) 11:1272–84. doi: 10.1593/neo.09494

  • 278

    BeralVPetermanTABerkelmanRLJaffeHW. Kaposi’s sarcoma among persons with AIDS: a sexually transmitted infection? Lancet. (1990) 335:123–8. doi: 10.1016/0140-6736(90)90001-L

  • 279

    GalloRC. The enigmas of Kaposi’s sarcoma. Science. (1998) 282:1837–9. doi: 10.1126/science.282.5395.1837

  • 280

    La FerlaLPinzoneMRNunnariGMartellottaFLleshiATirelliUet al. Kaposi’ s sarcoma in HIV-positive patients: the state of art in the HAART-era. Eur Rev Med Pharmacol Sci. (2013) 17:2354–65.

  • 281

    RobeyRCBowerM. Facing up to the ongoing challenge of Kaposi’s sarcoma. Curr Opin Infect Dis. (2015) 28:3140. doi: 10.1097/QCO.0000000000000122

  • 282

    SilverbergMJChaoCLeydenWAXuLHorbergMAKleinDet al. HIV infection, immunodeficiency, viral replication, and the risk of cancer. Cancer Epidemiol Biomarkers Prev. (2011) 20:2551–9. doi: 10.1158/1055-9965.EPI-11-0777

  • 283

    Poizot-MartinILionsCCheretAReyDDuvivierCJacometCet al. Kaposi sarcoma in people living with HIV: incidence and associated factors in a French cohort between 2010 and 2015. AIDS. (2020) 34:569–77. doi: 10.1097/QAD.0000000000002450

  • 284

    Poizot-MartinIObry-RoguetVDuvivierCLionsCHuleuxTJacometCet al. Kaposi sarcoma among people living with HIV in the French DAT’AIDS cohort between 2010 and 2015. J Eur Acad Dermatol Venereol. (2020) 34:1065–73. doi: 10.1111/jdv.16204

  • 285

    PalichRVeyriMValantinMAMarcelinAGGuihotAPourcherVet al. Recurrence and occurrence of kaposi’s sarcoma in patients living with human immunodeficiency virus (HIV) and on antiretroviral therapy, despite suppressed HIV viremia. Clin Infect Dis. (2020) 70:2435–8. doi: 10.1093/cid/ciz762

  • 286

    RoystonLIsnardSCalmyARoutyJP. Kaposi sarcoma in antiretroviral therapy-treated people with HIV: a wake-up call for research on human herpesvirus-8. AIDS. (2021) 35:1695–9. doi: 10.1097/QAD.0000000000002933

  • 287

    MishraRSinghSK. HIV-1 Tat C modulates expression of miRNA-101 to suppress VE-cadherin in human brain microvascular endothelial cells. J Neurosci. (2013) 33:59926000. doi: 10.1523/JNEUROSCI.4796-12.2013

  • 288

    MishraRSinghSK. HIV-1 Tat C phosphorylates VE-cadherin complex and increases human brain microvascular endothelial cell permeability. BMC Neurosci. (2014) 15:80. doi: 10.1186/1471-2202-15-80

  • 289

    KimTAAvrahamHKKohYHJiangSParkIWAvrahamS. HIV-1 Tat-mediated apoptosis in human brain microvascular endothelial cells. J Immunol. (2003) 170:2629–37. doi: 10.4049/jimmunol.170.5.2629

  • 290

    ZhongYSmartEJWekslerBCouraudPOHennigBToborekM. Caveolin-1 regulates human immunodeficiency virus-1 Tat-induced alterations of tight junction protein expression via modulation of the Ras signaling. J Neurosci. (2008) 28:7788–96. doi: 10.1523/JNEUROSCI.0061-08.2008

  • 291

    ZhongYZhangBEumSYToborekM. HIV-1 Tat triggers nuclear localization of ZO-1 via Rho signaling and cAMP response element-binding protein activation. J Neurosci. (2012) 32:143–50. doi: 10.1523/JNEUROSCI.4266-11.2012

  • 292

    ZhouFLiuXGaoLZhouXCaoQNiuLet al. HIV-1 Tat enhances purinergic P2Y4 receptor signaling to mediate inflammatory cytokine production and neuronal damage via PI3K/Akt and ERK MAPK pathways. J Neuroinflamm. (2019) 16:71. doi: 10.1186/s12974-019-1466-8

  • 293

    BayerCVaraniSWangLWaltherPZhouSStraschewskiSet al. Human cytomegalovirus infection of M1 and M2 macrophages triggers inflammation and autologous T-cell proliferation. J Virol. (2013) 87:6779. doi: 10.1128/JVI.01585-12

  • 294

    XuRFengXXieXZhangJWuDXuL. HIV-1 Tat protein increases the permeability of brain endothelial cells by both inhibiting occludin expression and cleaving occludin via matrix metalloproteinase-9. Brain Res. (2012) 1436:13–9. doi: 10.1016/j.brainres.2011.11.052

  • 295

    NottetHS. Interactions between macrophages and brain microvascular endothelial cells: role in pathogenesis of HIV-1 infection and blood - brain barrier function. J Neurovirol. (1999) 5:659–69. doi: 10.3109/13550289909021294

  • 296

    AndrasIEPuHDeliMANathAHennigBToborekM. HIV-1 Tat protein alters tight junction protein expression and distribution in cultured brain endothelial cells. J Neurosci Res. (2003) 74:255–65. doi: 10.1002/jnr.10762

  • 297

    MahajanSDAalinkeelRSykesDEReynoldsJLBindukumarBFernandezSFet al. Tight junction regulation by morphine and HIV-1 tat modulates blood-brain barrier permeability. J Clin Immunol. (2008) 28:528–41. doi: 10.1007/s10875-008-9208-1

  • 298

    PuHTianJAndrasIEHayashiKFloraGHennigBet al. HIV-1 Tat protein-induced alterations of ZO-1 expression are mediated by redox-regulated ERK 1/2 activation. J Cereb Blood Flow Metab. (2005) 25:1325–35. doi: 10.1038/sj.jcbfm.9600125

  • 299

    Claesson-WelshLDejanaEMcDonaldDM. Permeability of the endothelial barrier: identifying and reconciling controversies. Trends Mol Med. (2021) 27:314–31. doi: 10.1016/j.molmed.2020.11.006

  • 300

    LeibrandCRParisJJGhandourMSKnappPEKimWKHauserKFet al. HIV-1 Tat disrupts blood-brain barrier integrity and increases phagocytic perivascular macrophages and microglia in the dorsal striatum of transgenic mice. Neurosci Lett. (2017) 640:136–43. doi: 10.1016/j.neulet.2016.12.073

  • 301

    JadhavSNemaV. HIV-associated neurotoxicity: the interplay of host and viral proteins. Mediators Inflamm. (2021) 2021:1267041. doi: 10.1155/2021/1267041

  • 302

    Debalkie AnimutMSorrieMBBirhanuYWTeshaleMY. High prevalence of neurocognitive disorders observed among adult people living with HIV/AIDS in Southern Ethiopia: A cross-sectional study. PloS One. (2019) 14:e0204636. doi: 10.1371/journal.pone.0204636

  • 303

    SunYCaiMLiangYZhangY. Disruption of blood-brain barrier: effects of HIV Tat on brain microvascular endothelial cells and tight junction proteins. J Neurovirol. (2023) 29:658–68. doi: 10.1007/s13365-023-01179-3

  • 304

    MaRYangLNiuFBuchS. HIV tat-mediated induction of human brain microvascular endothelial cell apoptosis involves endoplasmic reticulum stress and mitochondrial dysfunction. Mol Neurobiol. (2016) 53:132–42. doi: 10.1007/s12035-014-8991-3

  • 305

    ChandraPKRutkaiIKimHBraunSEAbdel-MageedABMondalDet al. Latent HIV-exosomes induce mitochondrial hyperfusion due to loss of phosphorylated dynamin-related protein 1 in brain endothelium. Mol Neurobiol. (2021) 58:2974–89. doi: 10.1007/s12035-021-02319-8

  • 306

    GasperiniPEspigol-FrigoleGMcCormickPJSalvucciOMaricDUldrickTSet al. Kaposi sarcoma herpesvirus promotes endothelial-to-mesenchymal transition through Notch-dependent signaling. Cancer Res. (2012) 72:1157–69. doi: 10.1158/0008-5472.CAN-11-3067

  • 307

    DingYChenWLuZWangYYuanY. Kaposi’s sarcoma-associated herpesvirus promotes mesenchymal-to-endothelial transition by resolving the bivalent chromatin of PROX1 gene. PloS Pathog. (2021) 17:e1009847. doi: 10.1371/journal.ppat.1009847

  • 308

    Xu-DuboisYCPeltierJBrocheriouISuberbielle-BoisselCDjamaliAReeseSet al. Markers of endothelial-to-mesenchymal transition: evidence for antibody-endothelium interaction during antibody-mediated rejection in kidney recipients. J Am Soc Nephrol. (2016) 27:324–32. doi: 10.1681/ASN.2014070679

  • 309

    LacunzaEAhujaACosoOAAbbaMRamosJCCesarmanEet al. Unveiling the role of KSHV-infected human mesenchymal stem cells in Kaposi’s sarcoma initiation. J Med Virol. (2024) 96:e29684. doi: 10.1002/jmv.29684

  • 310

    Piera-VelazquezSJimenezSA. Endothelial to mesenchymal transition: role in physiology and in the pathogenesis of human diseases. Physiol Rev. (2019) 99:1281–324. doi: 10.1152/physrev.00021.2018

  • 311

    Piera-VelazquezSMendozaFAJimenezSA. Endothelial to mesenchymal transition (EndoMT) in the pathogenesis of human fibrotic diseases. J Clin Med. (2016) 5. doi: 10.3390/jcm5040045

  • 312

    WermuthPJCarneyKRMendozaFAPiera-VelazquezSJimenezSA. Endothelial cell-specific activation of transforming growth factor-beta signaling in mice induces cutaneous, visceral, and microvascular fibrosis. Lab Invest. (2017) 97:806–18. doi: 10.1038/labinvest.2017.23

  • 313

    WermuthPJLiZMendozaFAJimenezSA. Stimulation of transforming growth factor-beta1-induced endothelial-to-mesenchymal transition and tissue fibrosis by endothelin-1 (ET-1): A novel profibrotic effect of ET-1. PloS One. (2016) 11:e0161988. doi: 10.1371/journal.pone.0161988

  • 314

    MaJvan der ZonGGoncalvesMvan DintherMThorikayMSanchez-DuffhuesGet al. TGF-beta-induced endothelial to mesenchymal transition is determined by a balance between SNAIL and ID factors. Front Cell Dev Biol. (2021) 9:616610. doi: 10.3389/fcell.2021.616610

Summary

Keywords

human immunodeficiency virus, Tat, mucosal epithelium, disruption of epithelial junctions, epithelial-mesenchymal transition

Citation

Tugizov S (2025) HIV-1 Tat-induced disruption of epithelial junctions and epithelial-mesenchymal transition of oral and genital epithelial cells lead to increased invasiveness of neoplastic cells and the spread of herpes simplex virus and cytomegalovirus. Front. Immunol. 16:1541532. doi: 10.3389/fimmu.2025.1541532

Received

08 December 2024

Accepted

28 January 2025

Published

13 February 2025

Volume

16 - 2025

Edited by

Aurelio Cafaro, National Institute of Health (ISS), Italy

Reviewed by

Guochun Jiang, University of North Carolina at Chapel Hill, United States

Cindy Anne Morris, Tulane University, United States

Updates

Copyright

*Correspondence: Sharof Tugizov,

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Outline

Figures

Cite article

Copy to clipboard


Export citation file


Share article

Article metrics