Abstract
Although white AT can contribute to anti-infectious immune responses, it can also be targeted and perturbed by pathogens. The AT’s immune involvement is primarily due to strong pro-inflammatory responses (with both local and paracrine effects), and the large number of fat-resident macrophages. Adipocytes also exert direct antimicrobial responses. In recent years, it has been found that memory T cells accumulate in AT, where they provide efficient secondary responses against viral pathogens. These observations have prompted researchers to re-evaluate the links between obesity and susceptibility to infections. In contrast, AT serves as a reservoir for several persistence pathogens, such as human adenovirus Ad-36, Trypanosoma gondii, Mycobacterium tuberculosis, influenza A virus, and cytomegalovirus (CMV). The presence and persistence of bacterial DNA in AT has led to the concept of a tissue-specific microbiota. The unexpected coexistence of immune cells and pathogens within the specific AT environment is intriguing, and its impact on anti-infectious immune responses requires further evaluation. AT has been recently identified as a site of HIV persistence. In the context of HIV infection, AT is targeted by both the virus and the antiretroviral drugs. AT’s intrinsic metabolic features, large overall mass, and wide distribution make it a major tissue reservoir, and one that may contribute to the pathophysiology of chronic HIV infections. Here, we review the immune, metabolic, viral, and pharmacological aspects that contribute to HIV persistence in AT. We also evaluate the respective impacts of both intrinsic and HIV-induced factors on AT’s involvement as a viral reservoir. Lastly, we examine the potential consequences of HIV persistence on the metabolic and immune activities of AT.
Introduction
The three types of adipose tissue (AT: brown, white, and beige) each have specific functional properties (, ). Unless otherwise stated, the term “AT” will henceforth refer to white AT. The biology of AT is complex; this tissue exerts a range of metabolic, regenerative, immune, and other specific functions (; ). The immune potential of AT is currently under renewed scrutiny. Historically, the strong pro-inflammatory responses within AT (exerting both local and paracrine effects), and the high number of fat-resident macrophages suggested that AT contributed to anti-infectious innate immune responses. The presence and persistence of bacterial DNA further suggests that a broad range of pathogens persists in AT (). AT is a site of HIV persistence and appears as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection (; ). Concomitantly, studies on the AT’s immune compartment have highlighted the non-negligible contribution of resident immune cells [and particularly AT memory (Trm) CD8 T cells] to anti-infectious responses (). Here, we first review AT’s specific properties (independently of HIV infection) and, notably, its contribution to anti-infectious immune responses. We then discuss the changes in AT induced by HIV infection and/or antiretroviral therapy (ART). Lastly, we consider the potential consequences of HIV infection on the metabolic and immune functions of AT.
Specific Features of Adipose Tissue
The Anatomic and Functional Heterogeneity of Adipose Tissue
In healthy males and females, AT accounts for, respectively, 15 and 25% of the body weight, and is distributed across a large number of discrete anatomic sites (Shen et al., 2003; ; Table 1). Subcutaneous AT (SAT, accounting for over 80% of total body fat) and visceral AT (VAT) are the best-studied depots (Figure 1). The classification of the various types of AT reflects differences in the tissues’ ontogeny () and metabolic profiles. SAT and VAT differ with regard to their metabolic activity and immune cell content (Wajchenberg, 2000; ; ; Madani et al., 2009; ). Furthermore, SAT can be divided into superficial SAT and deep SAT, which again differ with regard to their metabolic properties (Smith et al., 2001). Likewise, VAT depots can be subclassified as omental fat (protective layer surrounding the intestine), retroperitoneal fat (near the kidney), and mesenteric fat (close to the intestine), which again have different activities (Wronska and Kmiec, 2012). In addition to SAT and VAT, AT is present in multiple locations, and may exhibit even more specialized functions related to the associated tissue. Dermal AT (dAT) is a specialized adipose depot that is distinct from SAT. Lastly, perivascular AT (pAT) has a role in the homeostasis of the cardiovascular system ().
TABLE 1
| Anatomical location/Sublocation | Functions | References |
| Major metabolic sites | ||
| Subcutaneous AT (SAT) | Metabolic activity | ; |
| Superficial SAT | Smith et al., 2001 | |
| Deep SAT | ||
| Visceral AT (VAT) | More active metabolically More strongly associated with metabolic diseases | Wronska and Kmiec, 2012 |
| Omental | ||
| Retroperitoneal | ||
| Mesenteric | ||
| Adipose tissue associated with primary and secondary immune sites | ||
| Bone marrow AT (MAT) | Contributing to hematopoiesis Deleterious in excess | ; Scheller et al., 2016 |
| AT embedding LN | Delivering nutrients to immune cells Favoring immune responses | |
| Thymic AT | Associated to age-associated thymic involution and the loss of thymic function | |
| Additional specialized adipose tissue | ||
| Dermal AT (dAT) | – Wound healing, hair follicle cycling, thermoregulation – Immune responses | ; Moffat, 1968; ; |
| Perivascular AT (pAT) | – Vascular homeostasis | Rajsheker et al., 2010; ; Szasz and Webb, 2012; |
The anatomical and functional heterogeneity of adipose tissues.
FIGURE 1
Adipose tissue can also surround lymphoid structures [notably lymph nodes (LNs)] or even infiltrate them [e.g., the bone marrow (BM) and thymus]. The physiologic impact of AT also differs from one lymphoid site to another. For example, the infiltration of fat into the thymus is always associated with age-associated thymic involution and the loss of thymic function (
From an immunologic point of view, AT is close to most of the physical barriers in the organism [i.e., the digestive tract, respiratory tract (
Metabolic Functions, Plasticity, and Expandability of Adipose Tissue
Physiological Metabolic Plasticity
Adipose tissue was initially defined as a metabolic site; it constitutes the body’s major energy storage site and is also an endocrine tissue that directly modulates systemic lipid and glucose metabolism and insulin sensitivity. AT is composed of two cell fractions: the adipocytes that represent approximately 80% of the volume of AT and 60% of the total cell population, and the stromal vascular fraction (SVF), both surrounded by extracellular matrix (ECM) (Figure 1). All these three compartments are responsible for the pleiotropic roles of AT. In physiological conditions, AT must be viewed primary as a protective tissue that stores and prevents excessive exposure of other organs to fatty acids. One key feature of AT is its ability to adapt and expand in response to energy needs or surpluses thanks to its cellular heterogeneity. The response to metabolic cues is based on adipocyte hypertrophy (increase in adipocyte volume) and/or hyperplasia (increase in adipocyte number by recruitment and proliferation of precursor cells and adipogenesis). Adipocyte volume reflects the specific function of adipocyte to store energy in the form of lipids, and thus, the cell capacity to dramatically modulate its size in response to changes in energy balance. Lipid accumulation is determined by the balance between lipogenesis and lipolysis. This plasticity also includes vascular remodeling and ECM remodeling to allow adequate tissue expansion, oxygenation, and mobilization of nutrients (Pellegrinelli et al., 2016).
The adipocyte’s metabolic activity is primarily modulated by insulin. When the energy balance is positive, insulin favors adipogenesis, lipogenesis from non-lipid precursor such as glucose, and the uptake of circulating free fatty acids (FFAs) to synthesize triacylglycerols (TGs) that will accumulate within the lipid droplets. In response to insulin, adipocytes secrete the lipoprotein lipase (that process TG into FFA and glycerol phosphate), but also favor glucose and glycerol influx by translocation of glucose transporter type 4 (GLUT4) to the plasma membrane and upregulation of glycerol channels. At the opposite, in time of energy shortage, adipocytes release FFA back in the circulation during lipolysis through the action of different lipases. It results in the efflux of glycerol-phosphate and FFA that serve as a source of energy for most tissues. Hence, under physiological conditions, adipocytes adapt rapidly to metabolic changes. Regional variations in the metabolic activity of adipocytes have been observed in healthy subjects, especially in regards to regulation of lipolysis and lipogenesis.
Even in non-expanding AT, adipocytes are renewed frequently to compensate for adipocyte death, with a turnover of approximately 10% annually (Spalding et al., 2008), indicating that committed adipocyte progenitors/precursors exist within AT. Adipose-derived mesenchymal stem cells (ASCs), defined as mesenchymal stem cells (MSCs) with similar clinical potential as MSCs from BM, were discovered. ASCs were identified as multipotent cells capable of in vitro differentiation into adipocytes, osteoblasts, chondrocytes, and myoblasts (Rodriguez et al., 2005;
FIGURE 2

Adipogenesis. Schematic figure of the regulation of adipogenesis from mesenchymal precursors. Adipogenesis is a sequential cascade of transcription factors leading to lipid accumulation and the acquisition of insulin sensitivity. Adipogenesis also involves extracellular matrix remodeling.
Studies of obesity have uncovered the presence of metabolically active immune cells within AT (Mathis et al., 2011). Under physiological conditions, immune cells in the AT [notably anti-inflammatory M2 macrophages (Morris et al., 2011) and CD4 regulatory T cells (Tregs) (
Defects in Adipose Tissue Expandability
When the AT’s buffering capacity is exceeded (as a consequence of sustained lipid/nutrient overload, for example), a wide range of disorders can result (
Adipose Tissue Senses and Sends Multiple Signals
Adipose tissue sense a number of hormonal, metabolic, and/or inflammatory signals (
FIGURE 3

The adipose tissue as a sensor: the AT immune and metabolic sides. Adipose tissue has many functional activities, including metabolic functions, immune responses, and regeneration. The large, ubiquitous depots of AT provide local storage for stem cell progenitors, and innate and adaptive immune cells. The adipocyte is the functional unit in the AT’s metabolic activity. Immune cells ensure adipose tissue homeostasis by providing a controlled environment that favors adipogenesis and metabolic homeostasis. Interestingly, AT components are also involved in anti-infectious immune responses: adipocytes exert an anti-infectious response by producing antimicrobial peptides such as the cathelicidins while both innate and adaptive immune cells contribute to anti-infectious responses. Another important feature of AT is its high sensitivity to environmental cues, such as metabolic and inflammatory signals, the microbiota, and infectious episodes.
The Accumulation of Hematopoietic Stem and Precursor Cells and Mesenchymal Stem Cells in Adipose Tissue
In addition to AT’s involvement in metabolic homeostasis, this tissue also contains large numbers of both hematopoietic stem and precursor cells (HSPCs) and ASCs (
The Intrinsic Coexistence of Metabolic Cells and Immune Cells in Adipose Tissue: The Concept of Immunometabolism
Immunometabolism refers to the interplay between immune processes and metabolic pathways (Mathis et al., 2011;
FIGURE 4

The detection of immune cells in adipose tissue: a time line. Adipose tissue was initially defined as a cushioning site, and subsequently as a metabolic site mainly composed of adipocytes. The AT’s immune function has emerged progressively. The first cell subset to be identified was the macrophage population (
Metabolic and immune cells obviously have different functional activities, and are also at opposite ends of the spectrum with regard to their metabolic strategies and energy needs. Whereas metabolic cells have large intracellular energy storage vesicles, immune cells mainly rely on external energy supplies. Indeed, immune cells and immune responses depend closely on external energy supplies. However, one can consider that this strategy is well suited to the rapid changes in metabolic status that accompany immune activation and proliferation.
Summary of the Biological Features of Adipose Tissue
In brief, AT comprises many different depots, some of which make specific contributes to the homeostasis of various tissues (BM, skin, blood vessels, etc.). The main AT depots (SAT and VAT) are capable of integrating signals from various sources and modulating their biology accordingly (Figure 1). A depot’s functional properties depend on its location (SAT vs. VAT) and may be partitioned within a given location. The AT’s sensitivity to metabolic and inflammatory signals also influences the tissue’s immune cell composition and properties. In rodent models of obesity, massive changes in the composition of the SVF has been described. One might think that adipocytes’ metabolic plasticity is related to changes in the AT’s immune functions. In fact, these two phenomena are relatively disconnected. Immune plasticity appears to be rather associated with the loss of adipocyte plasticity and the lipid spillover that initiates local inflammation. The AT’s high sensitivity to environmental cues complicates studies of human samples. The highly heterogeneous metabolic context and history of infections in clinical trial participants constitute a major limitation.
Adipose Tissue and Infections
As always in research on AT, the initial datasets emerged from studies of obesity. Interestingly, obesity and susceptibility to infections appears to have a two-way link, and AT has a key role in the dialog between metabolism and the immune system. On the one hand, it has been shown that infection impacts AT biology both indirectly (via the bystander effect of inflammation) and/or directly (via the impact of local pathogen persistence). These findings strengthen the “infectobesity” hypothesis, in which obesity has an infectious etiology. On the other hand, a growing body of evidence indicates that the obesity-induced disruption of AT direct influences the patients’ susceptibility to infection. AT therefore appears to contribute to anti-infectious immune responses and, at the same time, constitute a target for pathogens and a site at which infections induce perturbations. Both of these aspects will be reviewed below – firstly in contexts unrelated to HIV, and secondly in the specific context of HIV infection.
Our understanding of AT’s contribution to anti-infectious immune responses has changed over time (Figure 4). AT was initially considered to be an inert mechanical barrier – a buffer site that protects against mechanical trauma and thus protects organs from breach and subsequent infections. In the early 2000s, innate immune cells were found in AT (Zeyda and Stulnig, 2007; Schaffler and Scholmerich, 2010). In particular, the AT-resident macrophage fraction was found to contribute to strong pro-inflammatory responses with both local and paracrine effects (
FIGURE 5

The local and systemic anti-infectious properties of adipose tissue. The AT’s contribution to anti-infectious immune responses takes several forms. In addition to AT’s local anti-infectious activity, AT-resident memory T cells contributed immune defense against pathogens (as in other non-lymphoid tissues). Although it was initially considered to be a local barrier that protect other tissues after a mucosal breach, AT may also contribute to effective secondary adaptive immune responses. The AT’s local contribution to immune responses to infection includes (i) the maintenance of an effective physical barrier (by ensuring scarring and wound healing), (ii) the local secretion of anti- and pro-inflammatory cytokines (thus modulating both metabolic and immune components of metabolic homeostasis), (iii) immunosurveillance by AT-resident macrophages, and (iv) the direct production of antimicrobial peptides (such as cathelicidins) by adipocytes. Locally, both innate and adaptive immune cells contribute to anti-infectious responses. The systemic contribution of AT to immune responses against infection is mainly driven by the secretion of anti- or pro-inflammatory cytokines that modulate immune responses, regardless of the target antigen (i.e., pathogen, tumor, or self-antigens). However, the recent discovery of the systemic role played by resident memory T cells in non-lymphoid tissue means that one must consider a plethora of new ways in which immune cells in AT may contribute to memory immune response. The accumulation of memory T cells in AT close to interface and lymphoid structures may be a decisive factor in the development of a memory response against a secondary infection by a previously encountered pathogen.
TABLE 2
| Cell subsets | Modulation associated with obesity | Metabolic activity | Anti-infectious activity | References |
| Macrophages | ↗ Shift from M2 to M1 | Subset-dependent M2: Phagocytosis of dying adipocytes Lipid buffering Limiting inflammation M1: TNF-α production inducing insulin resistance in adipocytes Favoring angiogenesis | M1: TNF-α, MIP-1α producer | Weisberg et al., 2003; Lumeng et al., 2007; |
| CD4 T cells | Shift from Th2 to Th1 | Subset dependent Th2: maintaining glucose homeostasis Th1: promoting inflammation | ||
| CD8 T cells | ↗ | Rare at steady state, may contribute to the elimination of compromised adipocyte Early promoter of obesity-induced inflammation | Increased proportion in various contexts of AT infection Contributing to anti-infectious memory responses | Rausch et al., 2008; Nishimura et al., 2009b; |
| NKT cells | ↘ | Regulator of adipose tissue function Th2 cell type cytokine production | ||
| Treg | ↘ | Regulator of adipose tissue function | Control of adipocyte function Lipid uptake and metabolism | |
| NK cells | ↗ Stimulated phenotype | Subset dependent Early sensor of adipose stress – At steady state, eliminating macrophage – When activated, triggering M1 macrophage accumulation and adipose fibrosis | ||
| ILC2 | ↘ | Regulator of adipose tissue function Favoring beiging (Met-Enk, IL4) Favoring Type 2 innate immunity | Promoting B cell response, IgM production | Moro et al., 2010; |
Metabolic and anti-infectious activity of immune cells in adipose tissue.
Anti-infectious Immunity in Adipose Tissue
We will distinguish the local and systemic immune responses developed by AT. Indeed, the systemic activity of AT was initially related to the endocrine cytokine production but need to be reconsidered with the contribution of AT CD8 T cells to anti-infectious secondary responses.
Local Immunity
Soluble factors and adipokines
Adipose tissue produces a broad range of molecules referred to as adipokines. Although some adipokines (such as adiponectin) are produced solely by adipocytes, most (including cytokines and chemokines) are produced by AT-resident immune cells (
The stromal vascular fraction
Little information is available on the anti-infective properties of TA, as studies have mainly evaluated their contribution to metabolic functions (Table 3). Healthy AT is associated to an anti-inflammatory environment, that may theoretically limit the anti-infectious potential of AT. Among type 2 immune subsets present in AT, Tregs and ILC2 are central partners of AT regulation, providing anti-inflammatory signals by different pathways. One specific feature of non-obese VAT is the high proportion of CD4 Tregs, which account for up to 50–70% of CD4 T cells in VAT in 25-week-old male mice (
TABLE 3
| Pathogens | Species | Infected cell subset | Impact on AT biology | References |
| Human adenovirus | m | |||
| Trypanosoma gondii | m | Machado et al., 2012; Nagajyothi et al., 2012; Trindade et al., 2016; Tanowitz et al., 2017 | ||
| Plasmodium berghei | m | |||
| Plasmodium falciparum | Hu | Seydel et al., 2006 | ||
| Leishmania parasites | m | ASCs | ||
| Nippostrongylus brasiliensis | ↗ Eosinophils | Wu et al., 2011; | ||
| Mycobacterium tuberculosis | m, Hu | Adipocytes SVF cells | ↗ CD8 T cells and NK cells, ↗ IFN-g production | Neyrolles et al., 2006; |
| Microbiota/bacterial DNA | ||||
| Chlamydia pneumoniae | In vitro | |||
| Rickettsia prowazekii | ||||
| Staphylococcus aureus | In vitro | Adipocytes | ||
| Influenza virus | Hu | Nishimura et al., 2000 | ||
| Respiratory syncytial virus | In vitro | |||
| HIV | NHP, Hu | ↗ CD8 T cells | ||
| Cytomegalovirus | m | Adipocytes Endothelial cells | Metabolic changes ↗ CD8 T cells | Price et al., 1990; Sacher et al., 2011; |
Microbes detected in adipose tissue.
Species in which the microbes have been identified are indicated (m, mouse; Hu, human; NHP, non-human primate). When available, the cell subset targeted by the microbes and the impact on the immune compartment is indicated.
Group 2 innate lymphoid cells are also a crucial subset involved in the regulation of AT function (Molofsky et al., 2013). First described in FALCs in the mesentery, their identification has been extended to the whole AT. ILC2s contribute to the conversion of white to beige AT by directly impacting adipocyte progenitors (
Importantly, these cells are subjected and strongly regulated by the metabolic context. A detailed analysis of anti-infective immune responses would require the study of immune responses in both healthy and obese AT. Increases in macrophages, Th1 CD4 T cells, and CD8 T cells are described in most metabolic (McLaughlin et al., 2014;
Adipocytes: The Immune Side of the Metabolic Cells
A number of studies have found that adipocyte lineage cells possess innate immune activity. Early-stage adipocyte precursors (such as preadipocytes) are known to have certain macrophage-like properties (
Systemic Immunity
The endocrine activity of adipose tissue
Once the AT’s endocrine activity had been demonstrated, the impact of various adipokines (including hormones, cytokines, and chemokines produced in AT) on the immune system was widely documented. Leptin, IL-1, IL-6, IL-8, interferon gamma (IFN-γ), transforming growth factor beta (TGF-β), and chemokines (such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1) produced by AT interfere with the remote immune system. T cells and antigen-presenting cells are influenced by leptin, IL-6, and insulin. Conversely, in a context of calorie restriction and starvation, levels of pro-inflammatory adipokines fall and those of anti-inflammatory adipokines rise, which contributes to immunosuppression. Although not specific to the immune responses directed against pathogens, AT, by the secretion of various adipokines modulate immune responses.
Various murine models indicated that obesity (i.e., excessive adiposity) increases susceptibility to infection. Obese mice are more susceptible to bacterial infections due to greater microbial load and/or impaired clearance (Klebsiella, Mycobacterium tuberculosis, Staphylococcus) (Mancuso et al., 2002;
Adipose-tissue-resident memory T cells
It has been consistently observed that CD8 T cells accumulated in AT when the latter is exposed to metabolic or infectious insults. Whereas the clonal specificity of these cells is not clear in a metabolic context, pathogen-specific CD8 T cells have been found in AT. Although AT exhibits some very specific features, it is tempting to speculate that AT-Trm cells behave in much the same way as other memory T cells resident in non-lymphoid tissues. The literature on the biology of Trm cells is extensive (
The phenotypic characterization of Trm cells is ongoing (Walsh et al., 2019), and it is not yet clear whether or not the memory CD8 T cells found in AT are indeed resident. In non-lymphoid sites, the expression of surface markers like CD103 and CD69 is usually considered to be a marker of residency. CD69 is strongly expressed by CD4 and CD8 T cells in AT (
In conclusion, AT’s potential role in innate and adaptive immune responses to infection is based on the tissue’s immune cell content, pro-inflammatory potential, and proximity to sites with immune activity. Lastly, the recent realization that Trm T cells contribute to memory responses at lymphoid sites drastically broadens the anti-infectious potential of AT; this tissue might support local and systemic cell-based anti-infectious responses (Figure 4).
Adipose Tissue as a Pathogen Reservoir, and Pathogen-Induced Perturbations
Our group and others have demonstrated that AT is a reservoir for HIV (
Pathogens frequently reported in HIV co-infections [such as M. tuberculosis (
Mycobacterium tuberculosis in Adipose Tissue
Tuberculosis is one of the most common co-infections in people living with HIV. In non-treated patients with latent TB, the immunosuppression associated with HIV infection is particularly harmful because it may trigger the development of an active TB infection. Treating a TB and HIV co-infection is clinically challenging; drug interference and toxicity prevents the respective treatments from being combined, leading clinicians to favor one treatment over the other (
Mycobacterium tuberculosis can be detected in both SVF cells (macrophages) and adipocytes. Furthermore, the transfer of AT lysates from infected mice to naïve recipients can induce a TB infection. The local persistence of M. tuberculosis is associated with changes in the AT’s immune compartment, with infiltration of CD8 T cells and NK cells and the production of IFN-γ (Neyrolles et al., 2006;
Cytomegalovirus in Adipose Tissue
As mentioned above, CMV is a herpesvirus that infects most of the world’s population. The long-term impact of chronic CMV persistence has been extensively studied. Infection by CMV is associated with immune senescence, and is a prognostic component of the immune risk profile in elderly adults. CMV and HIV infections are interlinked; accentuated CMV-specific memory T-cell responses associated with an immune risk phenotype constitute a prominent immunologic feature of accelerated aging in HIV infection (
Cytomegalovirus infection of AT is also associated with the infiltration and/or local expansion of CD8 T cells, the development of pro-inflammatory responses, and metabolic alterations (
Human Immunodeficiency Virus in Adipose Tissue
The link between AT and HIV infection has long been known. People infected with HIV suffer from metabolic alterations (including dyslipidemia, insulin resistance, and lipodystrophy) that were initially considered to be adverse reactions to the first classes of antiretroviral drugs (ARVs) to be developed [i.e., nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors (PIs)] (Samaras et al., 2007;
Several research groups have confirmed that HIV infects CD4 T cells in AT (
TABLE 4
| Year | Species | Detection of viral nucleic acids in adipose tissue | References |
| 2002 | Hu | No HIV DNA in adipose tissue lysate | |
| 2015 | Hu | SHIV DNA in SVF cells | |
| Cyno Ms, Hu | SIV DNA and RNA in SVF cells, SVF CD4 T cells and SVF macrophages HIV DNA and RNA in SVF cells, SVF CD4 T cells in vitro reactivation assay | ||
| 2016 | Rh Ms | SHIV DNA in SVF cells | |
| 2017 | Rh Ms | SHIV RNA in SVF and SVF CD4 T cells at week 2 | |
| 2018 | Hu | HIV DNA in SVF CD4 T cells | |
| 2018 | Hu | In vitro reactivation assay |
Studies of the presence of HIV (or the simian form, SIV/SHIV) in adipose tissue in humans and simians, indicating the detection strategies and pathogens.
Cyno Ms, cynomolgus macaque; Rh Ms, rhesus macaques.
Mechanisms That May Favor the Persistence of HIV in Adipose Tissue
Very little information is available on the mechanisms that may favor HIV persistence but various hypotheses may be formulated (Table 5).
TABLE 5
| Parameters potentially favoring viral persistence in adipose tissue | References | |
| Immunological parameters | Mechanisms/observations | |
| AT as an Immunosuppressive environment | Wan et al., 2008; | |
| ASC | Limiting T cell proliferation | |
| Favoring Treg (generation and accumulation) | Yousefi et al., 2016 | |
| Th2-like cells and cytokines | ||
| Limited efficiency of Ag presenting cells | ||
| Distinct local distribution of CD4 and CD8 T cells | ||
| Defective T cell responses | Wronska and Kmiec, 2012 | |
| Exhaustion | High percentage of PD-1 expressing cells | Shirakawa et al., 2016; |
| Senescence | High percentage of CD57 expressing cells | |
| Metabolic reprogramming | ||
| Resident memory T cell | Pan et al., 2017 | |
| CD36 expression on AT T cell | ||
| Metabolic parameters | ||
| Interaction between adipocyte and immune cells The consequences of a lipid-rich environment | Mazzon and Mercer, 2014 | |
| Oxidative stress | Malmberg et al., 2001; | |
| Hypoxia in adipose tissue | Tao et al., 2015 | |
| Insulin sensitivity | Tsai et al., 2018 | |
| Viral and pharmacological parameters | ||
| HIV viral proteins | ||
| Adipose tissue remodeling and fibrosis | Sun et al., 2013; Vila et al., 2014; Marcelin et al., 2017 | |
| Antiretroviral diffusion (ARV) | ||
Mechanisms that may favor the persistence of HIV in adipose tissue.
Immunologic Parameters
Both of HIV’s main targets (CD4 T cells and macrophages) are present in AT. Both cell types are predominantly in a resting phase, which may favor the latency of HIV. The proximity to a major site of viral replication (such as the gut mucosae) may also contribute to the direct infection of AT. However, SAT or VAT do not differ significantly with regard to the level of HIV DNA in CD4 T cells (
Adipose Tissue as an Immunosuppressive Environment
One possible mechanism for HIV persistence in AT would involve local immunosuppression and thus failure to eliminate HIV-infected cells. An obvious candidate for this immunosuppression is the Foxp3+ CD4 Treg subset. We compared the distribution of the various cell subtypes associated with immunosuppression in the AT of mice, NHPs, and macaques (
T Cell Exhaustion and Senescence
Another intrinsic property of AT is the high surface expression of PD-1 (an exhaustion marker) on both CD4 and CD8 T cells. Although it is not known whether or not cells in AT cells express PD-L1 or PD-L2, the presence of PD-1 indicates high susceptibility to exhaustion. The difference in PD-1 expression between AT-resident T cells and circulating T cells is observed on both CD4 and CD8 T cell subsets, but reflect two distinct processes. Indeed, the high PD-1 expression on CD4 T cells in AT is due to the higher proportion of memory CD4 T cells which intrinsically express PD-1, and not to a higher expression level in CD4 T cells in AT compared with blood. At the opposite, memory CD8 T cells collected from AT or blood differ with regard to PD-1 expression – suggesting that a phenotypic change within CD8 T cell subsets is associated with the cells’ persistence in the AT environment. Regardless of the mechanisms, AT resident T cells exhibit high proportion of PD-1 expressing cells.
Similarly, AT resident CD4 and CD8 T cells also expressed high proportion of CD57 expressing cells (
CD4 and CD8 T Cells Are Not Colocalized in AT
We have studied the distribution of CD4 and CD8 T cells in AT from ART patients (
HIV Viral Proteins Affecting Immune Cells
The immune compartment can be modulated not only by AT’s intrinsic properties but also by HIV infection. It has been shown that the HIV proteins Tat, Nef, gp120, and Vpr can modulate immune cells, notably by inducing the apoptosis of non-infected CD4 T cells as a bystander effect (
Metabolic Reprogramming of Immune Cells in AT
Recent research has characterized the metabolic requirements of functionally effective immune cells. Metabolic reprogramming of immune cells is a crucial aspect related to their differentiation status. Resting, memory, and regulatory T cells have different metabolic requirements: activation of T cells is accompanied by a switch from oxidative metabolism to intensified glucose metabolism via aerobic glycolysis. Tregs have reduced ability to activate the PI3K/Akt pathway (Palmer et al., 2016a, b). Metabolic reprograming of immune cells is also described in non-lymphoid tissues: Trm cell survival depends on exogenous lipid uptake (Pan et al., 2017). T lymphocytes in AT express high levels of CD36, a scavenger receptor for lipid uptake (
Viruses are obligate parasites that are completely reliant on host cell metabolism. They manipulate cellular metabolism including glycolysis, fatty acid synthesis, and glutaminolysis to create an intracellular metabolic niche, which supports virion production and promotes survival of infected cells. Increased Glut1 expression on CD4 T cells in culture increases cellular permissivity to HIV-1 infection, while suppression of glucose metabolism by PI3K inhibitors inhibits infection (
In this respect, AT provides very specific metabolic cues whose effects on the local immune responses (and the virus cycle) requires further investigation. Whether AT immune cells in AT may be sensible to these HIV-induced reprogramming or favor viral latency remain to be evaluated.
Metabolic Parameters
Initially, the term “immunometabolism” referred to the two-way interaction between the metabolism and the immune system. This entity has now been subdivided into “tissue immunometabolism” (the impact of immune cells on both local and systemic metabolic homeostasis, and vice versa) (Matarese and La Cava, 2004;
The Consequences of a Lipid-Rich Environment
Lipids fulfill three general functions: (i) energy storage, principally as TG and steryl esters in lipid droplets, (ii) structural components of the cell (plasma and organelle membranes, and membrane component of budding and intracellular trafficking), and (iii) first and second messengers in signal transduction (van Meer et al., 2008). With regard to the latter point, several studies have found that the type and quantity of fatty acids and lipid mediators can influence the immune system in a potent manner (Pal et al., 2012). Saturated fatty acids are able to activate Toll-like receptors on adipocytes via endogenous ligand fetuin-A (Pal et al., 2012), and are involved in inflammation. Unsaturated fatty acids can be oxidized to generate potent pro-inflammatory or pro-resolving lipid mediators. High concentrations of fatty acids are toxic for T cells, whereas non-toxic concentrations can induce proliferation and cytokine production. This aspect of the interaction between immune cells and metabolic signals is probably the best documented (
Oxidative Stress
Adipose tissue produces reactive oxygen species (ROS) under various circumstances, and especially in a context of obesity. Both chronic and acute exposure to oxidative stress affects adipocyte and T cells (Malmberg et al., 2001), and also appears to impact HIV’s lifecycle (
Hypoxia in Adipose Tissue
As adipocytes expand, the interstitial oxygen tension falls. The subsequent activation of HIF-1 inhibits pre-adipocyte differentiation and initiates AT fibrosis. HIF-1 is also expressed by T cells and other immune cells, and is a potent regulator of T cell survival, activation, and differentiation (McNamee et al., 2013; Tao et al., 2015). It is known that HIF-1 drives pro-inflammatory Th17 cell function and longevity. Lastly, low oxygen levels inhibit the replication of HIV-1 and its reactivation from latent reservoirs (
Insulin Sensitivity
Insulin has a critical role in maintaining the homeostasis of energy metabolism, and coordinates the storage and utilization of fuel molecules in AT and in other insulin-sensitive peripheral tissues. Recent research has highlighted the two-way link between insulin and immune cells (
Adipose Tissue Remodeling and Fibrosis
In addition to intrinsic metabolic–immune interactions in healthy AT, metabolic and immune remodeling can also be induced by HIV infection and ART treatment. Remodeling of the ECM is a key event in HIV infection, and HIV infection has a specific role in AT fibrosis. Macrophages and ASCs are major players in the onset of AT fibrosis (Vila et al., 2014; Marcelin et al., 2017), notably by the production of TGF-β. It has been reported that SIV-infected macaques upregulated TGF-β expression in the SAT and VAT (
Pharmacologic Parameters
The adipose toxicity of the first generation of ARVs (notably in in vitro assays) has been extensively described (
Indeed, the penetration of ARVs into AT is influenced by several physiochemical and pharmacokinetics factors, including the blood perfusion rate, molecular size, ionization state, plasma protein binding, lipophilicity, and efflux/influx transporter affinity.
The perfusion rate varies considerably from one tissue to another. AT is a poorly vascularized compartment with a low perfusion rate [approximately 200 mL/min or 0.025 mL/g tissue) (
Other important factors include the complex structure of adipocyte tissue and the relationships between adipocytes and other cells. In SIV-infected macaques,
The low levels of ARVs in AT and the corresponding impact on HIV replication suggest that AT is a pharmacological sanctuary in which high tissue concentrations of ARVs are required to suppress local HIV replication.
Consequences of at Infection
Special focuses have been obviously given to the metabolic consequences of fat tissue infection that will be only briefly discussed in this review [see the excellent review on the subject (
Metabolic Alterations Associated With Viral Persistence in AT
In treatment-naïve patients infected with HIV, we observed a number of metabolic alterations: a decrease in the amount of AT (Visnegarwala et al., 2005), AT redistribution (Madge et al., 1999), changes in adipogenic markers (
Immune Effects of Viral Persistence in AT
In the cynomolgus macaque model of intravenous infection with SIVmac 251, major changes in the CD4 T cell compartment in SAT and VAT were not observed; the CD4 T cell counts were unchanged, suggesting that limited depletion occurs in AT (
In contrast to the changes observed in a context of obesity, viral persistence does not appear to greatly modify the macrophage count. Phenotypically, the macrophages shift toward an M1 profile but less so than in a context of obesity. This intermediate profile suggests that the local inflammation associated with HIV infection differs from the “metabolic inflammation” associated with obesity. Similarly, viral persistence does not lead to great changes in the level of pro-inflammatory cytokine secretion. Overall, HIV-associated inflammation in AT may differ qualitatively and/or quantitatively from that one observed in the extreme context of obesity. The characteristics of AT in HIV infection vs. obesity have recently been nicely reviewed (Wanjalla et al., 2018).
Accelerated Aging
Infection by HIV is thought to lead to the premature aging of AT, although further investigation is required. For example, the prevalence of comorbidities usually associated with aging (such as cardiometabolic disease) and the trunk fat accumulation phenotype are more prevalent in ART-treated HIV-infected patients (
Perspectives
The Immune Properties of Adipose Tissue
Due to the physical size of AT and its critical location close to immune sites (i.e., interface sites or lymphoid sites), a better understanding of the tissue’s local and systemic properties is essential. Both metabolic and infectious signals may change the homeostasis of AT and then directly impair the effectiveness of secondary immune responses. A growing body of evidence points to an anti-infectious role for AT. Research in this field may highlight novel mechanistic links between obesity and susceptibility to infections.
Another feature of AT is its potential modulation by pharmacologic modulators of metabolism. Indeed, AT is doubtless a valuable model in which strategies aimed at correcting viral-induced defects and/or reducing the size of the viral reservoir can be evaluated.
Therapeutic Strategies Based on Metabolic Pathways
At present, ART usually controls HIV replication in infected people. Nevertheless, cellular and tissue reservoirs of HIV are always present; it is still impossible to cure HIV and eradicate the virus from the body completely. The size of the HIV reservoir depends on several factors, including the time interval between the infection and the initiation of ART, the CD4/CD8 ratio, and the level of inflammation (even in patients on ART). To reduce systemic and local inflammation, pravastatin is already being used to treat HIV-infected patients (Toribio et al., 2017). Another possible treatment option is metformin, an antidiabetic, senolytic drug that might promote metabolic function in the AT, decrease inflammation, and modulate T cell activation (Moyo et al., 2014). Metformin’s effects have been studied in HIV-infected people with diabetes, and the drug is currently being tested clinically in non-diabetic HIV-infected patients (Routy et al., 2019). Another therapeutic strategy for controlling the HIV reservoir involves targeting immunometabolic checkpoints; metformin targets the 5′-adenosine monophosphate-activated protein kinase and the mammalian target of rapamycin (mTOR) (Routy et al., 2015), and the monoclonal antibody pembrolizumab targets PD-1 on infected CD4 T cells. This PD-1 blockade was initially used in cancer treatment but has been shown to reduce CD4 T cell HIV reservoirs ex vivo (
Conclusion
It is now well established that HIV infects AT, although the respective effects of the virus and ARVs on AT remain to be evaluated. This infection probably has more consequences than initially supposed. AT’s metabolic, immune, and regenerative properties mean that HIV infection triggers multiple defects in regenerative and/or immune functions. Regarding the mechanisms involved in HIV’s infection of (and then persistence in) AT, it is important to note that many pathogens are now known to persist in AT – suggesting the existence of an intrinsic mechanism that strongly favors their persistence. HIV persistence in AT may depend on various mechanisms; some may be intrinsic to the biology of AT, whereas others may be more closely related to virus-induced perturbations. Importantly, the AT’s metabolic activity may provide a means of therapeutically reducing or even eradicating the viral load in AT. A growing number of studies have demonstrated the effectiveness of metabolic approaches to immune modulation; this may be particularly relevant for decreasing the HIV reservoir in AT.
Statements
Author contributions
All authors, by their respective field of expertise (immunology, pharmacology, metabolism, and infectiology) contributed to the writing of the article.
Funding
This work was supported by instutitional funds from the INSERM and the Université Paris SUD, by grants from the ANRS and Sidaction, and financially by the Gilead Incorporation.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
1
AbayS. M.DeribeK.RedaA. A.BiadgilignS.DatikoD.AssefaT.et al (2015). The effect of early initiation of antiretroviral therapy in TB/HIV-coinfected patients.J. Int. Assoc. Provid. AIDS Care14560–570. 10.1177/2325957415599210
2
AdashekJ. J.JuniorP. N. A.GalaninaN.KurzrockR. (2019). Remembering the forgotten child: the role of immune checkpoint inhibition in patients with human immunod eficiency virus and cancer.J. Immunother. Cancer7:130. 10.1186/s40425-019-0618-9
3
AgarwalN.IyerD.PatelS. G.SekharR. V.PhillipsT. M.SchubertU.et al (2013). HIV-1 Vpr induces adipose dysfunction in vivo through reciprocal effects on PPAR/GR co-regulation. Sci.Transl. Med.5:213ra164. 10.1126/scitranslmed.3007148
4
AhmedD.RoyD.CassolE. (2018). Examining relationships between metabolism and persistent inflammation in HIV patients on antiretroviral therapy.Mediators Inflamm.20181–14. 10.1155/2018/6238978
5
AlcornJ. F.KollsJ. K. (2015). Killer fat.Science34726–27. 10.1126/science.aaa4567
6
AlexanderC. M.KaszaI.YenC.-L.ReederS. B.HernandoD.GalloR. L.et al (2015). Dermal white adipose tissue: a new component of the thermogenic response.J. Lipid Res.562061–2069. 10.1194/jlr.R062893
7
AllahverdiyevA. M.BagirovaM.ElcicekS.KocR. C.BaydarS. Y.FindikliN.et al (2011). Adipose tissue-derived mesenchymal stem cells as a new host cell in latent leishmaniasis.Am. J. Trop. Med. Hyg.85535–539. 10.4269/ajtmh.2011.11-0037
8
AltintasM. M.AzadA.NayerB.ContrerasG.ZaiasJ.FaulC.et al (2011). Mast cells, macrophages, and crown-like structures distinguish subcutaneous from visceral fat in mice.J. Lipid Res.52480–488. 10.1194/jlr.M011338
9
AppayV.AlmeidaJ. R.SauceD.AutranB.PapagnoL. (2007). Accelerated immune senescence and HIV-1 infection.Exp. Gerontol.42432–437. 10.1016/j.exger.2006.12.003
10
AppayV.FastenackelsS.KatlamaC.Ait-MohandH.SchneiderL.GuihotA.et al (2011). Old age and anti-cytomegalovirus immunity are associated with altered T-cell reconstitution in HIV-1-infected patients.AIDS251813–1822. 10.1097/QAD.0b013e32834640e6
11
AppayV.SauceD. (2008). Immune activation and inflammation in HIV-1 infection?: causes and consequences.J. Pathol.214231–241. 10.1002/path.2276
12
BaglioniS.FrancalanciM.SqueccoR.LombardiA.CantiniG.AngeliR.et al (2009). Characterization of human adult stem-cell populations isolated from. (visceral)and subcutaneous adipose tissue.FASEB J.233494–3505. 10.1096/fj.08-126946
13
BarrettL.FowkeK. R.GrantM. D. (2012). Cytomegalovirus, aging,. (and)HIV: a perfect storm.AIDS Rev.14159–167.
14
BastardJ.-P.CaronM.VidalH.JanV.AuclairM.VigourouxC.et al (2002). Association between altered expression of adipogenic factor SREBP1 in lipoatrophic adipose tissue from HIV-1-infected patients and abnormal adipocyte differentiation and insulin resistance.Lancet3591026–1031. 10.1016/s0140-6736(02)08094-7
15
BastardJ.-P.MaachiM.LagathuC.KimM. J.CaronM.VidalH.et al (2006). Recent advances in the relationship between obesity, inflammation, and insulin resistance.Eur. Cytokine Netw.174–12.
16
BeaupereC.GarciaM.LargheroJ.FèveB.CapeauJ.LagathuC. (2015). The HIV proteins Tat and Nef promote human bone marrow mesenchymal stem cell senescence and alter osteoblastic differentiation.Aging Cell14534–546. 10.1111/acel.12308
17
BechahY.PaddockC. D.CapoC.MegeJ.-L.RaoultD. (2010). Adipose tissue serves as a reservoir for recrudescent rickettsia prowazekii infection in a mouse model.PLoS One5:e8547. 10.1371/journal.pone.0008547
18
BeelenR. H. (1991). The greater omentum: physiology and immunological concepts.Neth. J. Surg.43145–149.
19
Beigier-BompadreM.MontagnaG. N.KühlA. A.LozzaL.WeinerJ.KupzA.et al (2017). Mycobacterium tuberculosis infection modulates adipose tissue biology.PLoS Pathog.13:e1006676. 10.1371/journal.ppat.1006676
20
BénézechC.Jackson-JonesL. H. (2019). ILC2 Orchestration of local immune function in adipose tissue.Front. Immunol.10:171. 10.3389/fimmu.2019.00171
21
BénézechC.LuuN.-T.WalkerJ. A.KruglovA. A.LooY.NakamuraK.et al (2015). Inflammation-induced formation of fat-associated lymphoid clusters.Nat. Immunol.16819–828. 10.1038/ni.3215
22
BéréziatV.CerveraP.Le DourC.VerpontM.-C.DumontS.VantyghemM.-C.et al (2011). LMNA mutations induce a non-inflammatory fibrosis and a brown fat-like dystrophy of enlarged cervical adipose tissue.Am. J. Pathol.1792443–2453. 10.1016/j.ajpath.2011.07.049
23
BertolaA.CiucciT.RousseauD.BourlierV.DuffautC.BonnafousS.et al (2012). Identification of adipose tissue dendritic cells correlated with obesity-associated insulin-resistance and inducing Th17 responses in mice and patients.Diabetes Metab. Res. Rev612238–2247. 10.2337/db11-1274
24
BeuraL. K.Fares-FredericksonN. J.SteinertE. M.ScottM. C.ThompsonE. A.FraserK. A.et al (2019). CD4 + resident memory T cells dominate immunosurveillance and orchestrate local recall responses.J. Exp. Med.2161214–1229. 10.1084/jem.20181365
25
BeuraL. K.WijeyesingheS.ThompsonE. A.MacchiettoM. G.RosatoP. C.PiersonM. J.et al (2018). T Cells in nonlymphoid tissues give rise to lymph-node-resident memory T Cells.Immunity48:327-338.e5. 10.1016/j.immuni.2018.01.015
26
BornsteinS. R.Abu-AsabM.GlasowA.PäthG.HaunerH.TsokosM.et al (2000). Immunohistochemical and ultrastructural localization of leptin and leptin receptor in human white adipose tissue and differentiating human adipose cells in primary culture.Diabetes Metab. Res. Rev.49532–538. 10.2337/diabetes.49.4.532
27
BoulenouarS.MicheletX.DuquetteD.AlvarezD.HoganA. E.DoldC.et al (2017). Adipose type one innate lymphoid cells regulate macrophage homeostasis through targeted cytotoxicity.Immunity46273–286. 10.1016/j.immuni.2017.01.008
28
BoulougouraA.SeretiI. (2016). HIV infection and immune activation.Curr. Opin. HIV AIDS11191–200. 10.1097/COH.0000000000000241
29
BourgiK.RebeiroP. F.TurnerM.CastilhoJ. L.HulganT.RaffantiS. P.et al (2019). Greater weight gain in treatment naïve persons starting dolutegravir-based antiretroviral therapy.Clin. Infect. Dis.10.1093/cid/ciz407[Epub ahead of print].
30
BouwmanJ. J.VisserenF. L.BouterK. P.DieperslootR. J. (2008). Infection-induced inflammatory response of adipocytes in vitro.Int. J. Obes.32892–901. 10.1038/ijo.2008.36
31
BoyaP.PauleauA.-L.PoncetD.Gonzalez-PoloR.-A.ZamzamiN.KroemerG. (2004). Viral proteins targeting mitochondria: controlling cell death.Biochim. Biophys. Acta Bioenerg.1659178–189. 10.1016/j.bbabio.2004.08.007
32
BrauneJ.WeyerU.HobuschC.MauerJ.BrüningJ. C.BechmannI.et al (2017). IL-6 regulates M2 polarization and local proliferation of adipose tissue macrophages in obesity.J. Immunol.1982927–2934. 10.4049/jimmunol.1600476
33
BrestoffJ. R.KimB. S.SaenzS. A.StineR. R.MonticelliL. A.SonnenbergG. F.et al (2015). Group 2 innate lymphoid cells promote beiging of white adipose tissue and limit obesity.Nature519242–246. 10.1038/nature14115
34
BrittonK. A.FoxC. S. (2011). Perivascular adipose tissue and vascular disease.Clin. Lipidol.679–91. 10.2217/clp.10.89
35
BurcelinR.SerinoM.ChaboC.GaridouL.PomiéC.CourtneyM.et al (2013). Metagenome and metabolism: the tissue microbiota hypothesis.Diabetes. Obes. Metab.15(Suppl. 3), 61–70. 10.1111/dom.12157
36
CaronM.AuclairM.DonadilleB.BéréziatV.GuerciB.LavilleM.et al (2007). Human lipodystrophies linked to mutations in A-type lamins and to HIV protease inhibitor therapy are both associated with prelamin A accumulation, oxidative stress and premature cellular senescence.Cell Death Differ.141759–1767. 10.1038/sj.cdd.4402197
37
Caron-DebarleM.LagathuC.BoccaraF.VigourouxC.CapeauJ. (2010). HIV-associated lipodystrophy: from fat injury to premature aging.Trends Mol. Med.16218–229. 10.1016/j.molmed.2010.03.002
38
CasteillaL.Planat-BenardV.LaharragueP.CousinB. (2011). Adipose-derived stromal cells: their identity and uses in clinical trials, an update.World J. Stem Cells325–33. 10.4252/wjsc.v3.i4.25
39
CatrysseL.van LooG. (2018). Adipose tissue macrophages and their polarization in health and obesity.Cell. Immunol.330114–119. 10.1016/j.cellimm.2018.03.001
40
CawthornW. P.SchellerE. L.MacDougaldO. A. (2012). Adipose tissue stem cells: the great WAT hope.Trends Endocrinol. Metab.23270–277. 10.1016/j.tem.2012.01.003
41
CharlesS.AmmosovaT.CardenasJ.FosterA.RotimiJ.JerebtsovaM.et al (2009). Regulation of HIV-1 transcription at 3% versus 21% oxygen concentration.J. Cell. Physiol.221469–479. 10.1002/jcp.21882
42
CharrièreG.CousinB.ArnaudE.AndréL.BacouF.PenicaudL.et al (2003). Preadipocyte conversion to macrophage. evidence of plasticity.J. Biol. Chem.2789850–9855. 10.1074/jbc.m210811200
43
ChaseH. B.MontagnaW.MaloneJ. D. (1953). Changes in the skin in relation to the hair growth cycle.Anat. Rec.11675–81. 10.1002/ar.1091160107
44
ChauY.-Y.BandieraR.SerrelsA.Martínez-EstradaO. M.QingW.LeeM.et al (2014). Visceral and subcutaneous fat have different origins and evidence supports a mesothelial source.Nat. Cell Biol.16367–375. 10.1038/ncb2922
45
ChenY.-Y.KaoT.-W.FangW.-H.WangC.-C.ChangY.-W.YangH.-F.et al (2019). Body fat percentage in relation to lung function in individuals with normal weight obesity.Sci. Rep.9:3066. 10.1038/s41598-019-38804-3
46
ChengC. K.BakarH. A.GollaschM.HuangY. (2018). Perivascular adipose tissue: the sixth man of the cardiovascular system.Cardiovasc. Drugs Ther.32481–502. 10.1007/s10557-018-6820-z
47
ChiJ.WuZ.ChoiC. H. J.NguyenL.TegegneS.AckermanS. E.et al (2018). Three-dimensional adipose tissue imaging reveals regional variation in beige fat biogenesis and PRDM16-dependent sympathetic neurite density.Cell Metab.27:226-236.e3. 10.1016/j.cmet.2017.12.011
48
CintiS. (2012). The adipose organ at a glance.Dis. Model. Mech.5588–594. 10.1242/dmm.009662
49
CintiS. (2018). Adipose Organ Development and Remodeling. In Comprehensive Physiology.Hoboken, NJ: John Wiley & Sons, Inc.
50
CipollettaD. (2014). Adipose tissue-resident regulatory T cells: phenotypic specialization, functions and therapeutic potential.Immunology142517–525. 10.1111/imm.12262
51
CipollettaD.CohenP.SpiegelmanB. M.BenoistC.MathisD. (2015). Appearance and disappearance of the mRNA signature characteristic of Treg cells in visceral adipose tissue: age, diet, and PPARγ effects.Proc. Natl. Acad. Sci. U.S.A.112482–487. 10.1073/pnas.1423486112
52
CipollettaD.FeuererM.LiA.KameiN.LeeJ.ShoelsonS. E.et al (2012). PPAR-γ is a major driver of the accumulation and phenotype of adipose tissue Treg cells.Nature486549–553. 10.1038/nature11132
53
CipollettaD.KolodinD.BenoistC.MathisD. (2011). Seminars in Immunology Tissular T regs?: a unique population of adipose-tissue-resident Foxp3 + CD4 + T cells that impacts organismal metabolism.Semin. Immunol.23431–437. 10.1016/j.smim.2011.06.002
54
ClarkE.NavaB.CaputiM. (2017). Tat is a multifunctional viral protein that modulates cellular gene expression and functions.Oncotarget827569–27581. 10.18632/oncotarget.15174
55
Coín AragüezL.MurriM.Oliva OliveraW.SalasJ.MayasM. D.Delgado-ListaJ.et al (2013). Thymus fat as an attractive source of angiogenic factors in elderly subjects with myocardial ischemia.Age351263–1275. 10.1007/s11357-012-9418-6
56
ContrerasN. A.SitnikK. M.JefticI.CoplenC. P.Èièin-ŠainL.Nikolich-ŽugichJ. (2019). Life-long control of cytomegalovirus (CMV) by T resident memory cells in the adipose tissue results in inflammation and hyperglycemia.PLoS Pathog.15:e1007890. 10.1371/journal.ppat.1007890
57
CotterE. J.ChewN.PowderlyW. G.DoranP. P. (2011). HIV type 1 alters mesenchymal stem cell differentiation potential and cell phenotype ex Vivo.AIDS Res. Hum. Retroviruses27187–199. 10.1089/aid.2010.0114
58
CousinB.CasteillaL.LaharragueP.LucheE.LorsignolA.CuminettiV.et al (2015). Immuno-metabolism and adipose tissue: the key role of hematopoietic stem cells.Biochimie12421–26. 10.1016/j.biochi.2015.06.012
59
CousinB.MunozO.AndreM.FontanillesA. M.DaniC.CousinJ. L.et al (1999). A role for preadipocytes as macrophage-like cells.FASEB J.13305–312. 10.1096/fasebj.13.2.305
60
CouturierJ.AgarwalN.NeheteP. N.BazeW. B.BarryM. A.Jagannadha SastryK.et al (2016). Infectious SIV resides in adipose tissue and induces metabolic defects in chronically infected rhesus macaques.Retrovirology13:30. 10.1186/s12977-016-0260-2
61
CouturierJ.LewisD. E. (2018). HIV persistence in adipose tissue reservoirs.Curr. HIV/AIDS Rep.1560–71. 10.1007/s11904-018-0378-z
62
CouturierJ.Nuotio-AntarA. M.AgarwalN.WilkersonG. K.SahaP.KulkarniV.et al (2019). Lymphocytes upregulate CD36 in adipose tissue and liver.Adipocyte8154–163. 10.1080/21623945.2019.1609202
63
CouturierJ.SuliburkJ. W.BrownJ. M.LukeD. J.AgarwalN.YuX.et al (2015). Human adipose tissue as a reservoir for memory CD4+ T cells and HIV.AIDS29667–674. 10.1097/QAD.0000000000000599
64
CouturierJ.WinchesterL. C.SuliburkJ. W.WilkersonG. K.PodanyA. T.AgarwalN.et al (2018). Adipocytes impair efficacy of antiretroviral therapy.Antiviral Res.154140–148. 10.1016/j.antiviral.2018.04.002
65
Cruz-MigoniS.CaamañoJ. (2016). Fat-associated lymphoid clusters in inflammation and immunity.Front. Immunol.7:612. 10.3389/fimmu.2016.00612
66
CumminsN. W.Sainski-NguyenA. M.NatesampillaiS.AboulnasrF.KaufmannS.BadleyA. D. (2017). Maintenance of the HIV reservoir is antagonized by selective BCL2 inhibition.J. Virol.91:e00012-17. 10.1128/JVI.00012-17
67
DalmasE.LehmannF. M.DrorE.WueestS.ThienelC.BorsigovaM.et al (2017). Interleukin-33-activated islet-resident innate lymphoid cells promote insulin secretion through myeloid cell retinoic acid production.Immunity47:928-942.e7. 10.1016/j.immuni.2017.10.015
68
DamoucheA.LazureT.Avettand-FènoëlV.HuotN.Dejucq-RainsfordN.SatieA.-P.et al (2015). Adipose tissue is a neglected viral reservoir and an inflammatory site during chronic HIV and SIV infection.PLoS Pathog.11:e1005153. 10.1371/journal.ppat.1005153
69
DamoucheA.PourcherG.PourcherV.BenoistS.BussonE.LatailladeJ.-J.et al (2017). High proportion of PD-1-expressing CD4 + T cells in adipose tissue constitutes an immunomodulatory microenvironment that may support HIV persistence.Eur. J. Immunol.472113–2123. 10.1002/eji.201747060
70
DattaP. K.DeshmaneS.KhaliliK.MeraliS.GordonJ. C.FecchioC.et al (2016). Glutamate metabolism in HIV-1 infected macrophages: role of HIV-1 Vpr.Cell Cycle152288–2298. 10.1080/15384101.2016.1190054
71
de FerrantiS.MozaffarianD. (2008). The perfect storm: obesity, adipocyte dysfunction, and metabolic consequences.Clin. Chem.54945–955. 10.1373/clinchem.2007.100156
72
de JongA. J.KloppenburgM.ToesE. M. R.Ioan-FacsinayA. (2014). Fatty acids, lipid mediators, and T-cell function.Front. Immunol.5:483. 10.3389/fimmu.2014.00483
73
DebaisieuxS.RayneF.YezidH.BeaumelleB. (2012). The ins and outs of HIV-1 Tat.Traffic13355–363. 10.1111/j.1600-0854.2011.01286.x
74
DekabanG. A.DikeakosJ. D. (2017). HIV-I Nef inhibitors: a novel class of HIV-specific immune adjuvants in support of a cure.AIDS Res. Ther.14:53. 10.1186/s12981-017-0175-6
75
DengT.LyonC. J.MinzeL. J.LinJ.ZouJ.LiuJ. Z.et al (2013). Article class II major histocompatibility complex plays an essential role in obesity-induced adipose inflammation.Cell Metab.17411–422. 10.1016/j.cmet.2013.02.009
76
DerendorfH.SchmidtS.PrecededM. (2019). Rowland. Rowland, and Tozer’s Clinical Pharmacokinetics, and. (Pharmacodynamics)?: Concepts and Applications.Philadelphia, PE: LWW.
77
DesruisseauxM. S.TrujilloM. E.TanowitzH. B.SchererP. E. (2007). Adipocyte, Adipose Tissue, and Infectious Disease.Infect Immun.751066–1078.
78
DhurandharN. V. (2011). A framework for identification of infections that contribute to human obesity.Lancet. Infect. Dis.11963–969. 10.1016/S1473-3099(11)70274-2
79
Díaz-DelfínJ.DomingoP.WabitschM.GiraltM.VillarroyaF. (2012). HIV-1 Tat protein impairs adipogenesis and induces the expression and secretion of proinflammatory cytokines in human SGBS adipocytes.Antivir. Ther.17529–540. 10.3851/IMP2021
80
DichampJ.BarreauC.GuissardC.CarrièreA.MartinezY.DescombesX.et al (2019). 3D analysis of the whole subcutaneous adipose tissue reveals a complex spatial network of interconnected lobules with heterogeneous browning ability.Sci. Rep.9:6684. 10.1038/s41598-019-43130-9
81
DjimeuE. W.HeardA. C. (2019). Treatment of HIV among tuberculosis patients: a replication study of timing of antiretroviral therapy for HIV-1-associated tuberculosis.PLoS One14:e0210327. 10.1371/journal.pone.0210327
82
DupinN.BuffetM.MarcelinA.-G.LamotteC.GorinI.Ait-ArkoubZ.et al (2002). HIV and antiretroviral drug distribution in plasma and fat tissue of HIV-infected patients with lipodystrophy.AIDS162419–2424. 10.1097/00002030-200212060-00006
83
Elgazar-CarmonV.RudichA.HadadN.LevyR. (2008). Neutrophils transiently infiltrate intra-abdominal fat early in the course of high-fat feeding.J. Lipid Res.491894–1903. 10.1194/jlr.M800132-JLR200
84
ElsheikhM. M.TangY.LiD.JiangG. (2019). Deep latency: a new insight into a functional HIV cure.EBio. Med.45624–629. 10.1016/j.ebiom.2019.06.020
85
EngelaA. U.HoogduijnM. J.BoerK.LitjensN. H.BetjesM. G.WeimarW.et al (2013). Human adipose-tissue derived mesenchymal stem cells induce functional de-novo regulatory T cells with methylated FOXP3 gene DNA.Clin. Exp. Immunol.173343–354. 10.1111/cei.12120
86
EvansV. A.van der SluisR. M.SolomonA.DantanarayanaA.McNeilC.GarsiaR.et al (2018). Programmed cell death-1 contributes to the establishment and maintenance of HIV-1 latency.AIDS321491–1497. 10.1097/QAD.0000000000001849
87
FainJ. N.MadanA. K.HilerM. L.CheemaP.BahouthS. W. (2004). Comparison of the release of adipokines by adipose tissue, adipose tissue matrix, and adipocytes from visceral and subcutaneous abdominal adipose tissues of obese humans.Endocrinology1452273–2282. 10.1210/en.2003-1336
88
FallerE. M.McVeyM. J.MacPhersonP. A. (2014). IL-7 receptor recovery on CD8 T-cells isolated from HIV+ patients is inhibited by the HIV Tat protein.PLoS One9:e102677. 10.1371/journal.pone.0102677
89
FalutzJ. (2011). HIV infection, body composition changes and related metabolic complications: contributing factors and evolving management strategies.Curr. Opin. Clin. Nutr. Metab. Care14255–260. 10.1097/MCO.0b013e3283457a8f
90
FerranteA. W.Jr. (2013). The immune cells in adipose tissue.Diabetes. Obes. Metab.15(Suppl. 3), 34–38. 10.1111/dom.12154
91
FeuererM.HerreroL.CipollettaD.NaazA.WongJ.NayerA.et al (2009). Lean, but not obese, fat is enriched for a unique population of regulatory T cells that affect metabolic parameters.Nat. Med.151–11.
92
FiumeG.VecchioE.De LaurentiisA.TrimboliF.PalmieriC.PisanoA.et al (2012). Human immunodeficiency virus-1 Tat activates NF-κB via physical interaction with IκB-α and p65.Nucleic Acids Res.403548–3562. 10.1093/nar/gkr1224
93
FlachM.DiefenbachA. (2015). Adipose tissue: ILC2 Crank Up the Heat.Cell Metab.21152–153. 10.1016/j.cmet.2015.01.015
94
Franke-FayardB.FonagerJ.BraksA.KhanS. M.JanseC. J. (2010). Sequestration and tissue accumulation of human malaria parasites: can we learn anything from rodent models of malaria?PLoS Pathog.6:e1001032. 10.1371/journal.ppat.1001032
95
FranquesaM.MensahF. K.HuizingaR.StriniT.BoonL.LombardoE.et al (2015). Human adipose tissue-derived mesenchymal stem cells abrogate plasmablast formation and induce regulatory B cells independently of T helper cells.Stem Cells33880–891. 10.1002/stem.1881
96
GarrabouG.LópezS.MorénC.MartínezE.FontdevilaJ.CardellachF.et al (2011). Mitochondrial damage in adipose tissue of untreated HIV-infected patients.AIDS25165–170. 10.1097/QAD.0b013e3283423219
97
GebhardtT.WakimL. M.EidsmoL.ReadingP. C.HeathW. R. (2009). Memory T cells in nonlymphoid tissue that provide enhanced local immunity during infection with herpes simplex virus.Nat. Immunol.10524–530. 10.1038/ni.1718
98
GiraltM.DomingoP.GuallarJ. P.Rodriguez de la ConcepciónM. L.AlegreM.DomingoJ. C. (2006). HIV-1 infection alters gene expression in adipose tissue, which contributes to HIV- 1/HAART-associated lipodystrophy.Antivir. Ther.11729–740.
99
GodfreyC.BremerA.AlbaD.ApovianC.KoetheJ. R.KoliwadS.et al (2019). Obesity and fat metabolism in HIV-infected individuals: immunopathogenic mechanisms and clinical implications.J.Infect.Dis.220420–431. 10.1093/infdis/jiz118
100
GorwoodJ.BourgeoisC.ManteconM.AtlanM.PourcherV.PourcherG.et al (2019). Impact of HIV/SIV infection and viral proteins on adipose tissue fibrosis and adipogenesis.AIDS33953–964. 10.1097/qad.0000000000002168
101
GuW.NowakW. N.XieY.Le BrasA.HuY.DengJ.et al (2019). Single-cell RNA-sequencing and metabolomics analyses reveal the contribution of perivascular adipose tissue stem cells to vascular remodeling.Arterioscler. Thromb. Vasc. Biol.392049–2066. 10.1161/ATVBAHA.119.312732
102
Guerrero-JuarezC. F.PlikusM. V. (2018). Emerging nonmetabolic functions of skin fat.Nat. Rev. Endocrinol.14163–173. 10.1038/nrendo.2017.162
103
GuzikT. J.SkibaD. S.TouyzR. M.HarrisonD. G. (2017). The role of infiltrating immune cells in dysfunctional adipose tissue.Cardiovasc. Res.1131009–1023. 10.1093/cvr/cvx108
104
HaleL. P. (2004). Histologic and molecular assessment of human thymus.Ann. Diagn. Pathol.850–60. 10.1016/j.anndiagpath.2003.11.006
105
HanS.-J.Glatman ZaretskyA.Andrade-OliveiraV.CollinsN.DzutsevA.ShaikJ.et al (2017). White adipose tissue is a reservoir for memory T Cells and promotes protective memory responses to infection.Immunity47:1154-1168.e. 10.1016/j.immuni.2017.11.009
106
HansesF.KoppA.BalaM.BuechlerC.FalkW.SalzbergerB.et al (2011). Intracellular survival of Staphylococcus aureus in adipocyte-like differentiated 3T3-L1 cells is glucose dependent and alters cytokine, chemokine, and adipokine secretion.Endocrinology1524148–4157. 10.1210/en.2011-0103
107
HardouinP.PansiniV.CortetB. (2014). Bone marrow fat.Joint. Bone Spine81313–319. 10.1016/j.jbspin.2014.02.013
108
HaridasV.PeanP.JasenoskyL. D.MadecY.LaureillardD.SokT.et al (2015). TB-IRIS, T-cell activation, and remodeling of the T-cell compartment in highly immunosuppressed HIV-infected patients with TB.AIDS29263–273. 10.1097/QAD.0000000000000546
109
HazanU.RomeroI. A.CancelloR.ValenteS.PerrinV.MariotV.et al (2002). Human adipose cells express CD4, CXCR4, and CCR5 [corrected] receptors: a new target cell type for the immunodeficiency virus-1?FASEB J.161254–1256. 10.1096/fj.01-0947fje
110
HolmbergV.SoiniH.KiveläP.OllgrenJ.RistolaM. (2019). Epidemiology and outcome of HIV patients in finland co-infected with tuberculosis 1998–2015.BMC Infect. Dis.19:264. 10.1186/s12879-019-3890-x
111
HotamisligilG. S. (2006). Inflammation and metabolic disorders.Nature44860–867.
112
HruskovaZ.BiswasS. K. (2013). Previews a new “‘Immunological”’ role for adipocytes in obesity.Cell. Metab.17315–317. 10.1016/j.cmet.2013.02.015
113
HsuD. C.WegnerM. D.SunyakumthornP.SilsornD.TayamunS.InthawongD. (2017). CD4+ Cell infiltration into subcutaneous adipose tissue is not indicative of productively infected cells during acute SHIV infection.J. Med. Primatol.46154–157. 10.1111/jmp.12298
114
HussaartsL.García-TardónN.van BeekL.HeemskerkM. M.HaeberleinS.vanG. C.et al (2015). Chronic helminth infection and helminth-derived egg antigens promote adipose tissue M2 macrophages and improve insulin sensitivity in obese mice.FASEB J.293027–3039. 10.1096/fj.14-266239
115
HuttunenR.SyrjänenJ. (2013). Obesity and the risk and outcome of infection.Int. J. Obes.37333–340. 10.1038/ijo.2012.62
116
IbrahimM. M. (2009). Subcutaneous and visceral adipose tissue: structural and functional differences.Obes. Rev.1111–18. 10.1111/j.1467-789X.2009.00623.x
117
IkejimaS.SasakiS.SashinamiH.MoriF.OgawaY.NakamuraT.et al (2005). Impairment of host resistance to Listeria monocytogenes infection in liver of db/db and ob/ob mice.Diabetes Metab. Res. Rev.54182–189. 10.2337/diabetes.54.1.182
118
IvanovA. V.Valuev-EllistonV. T.IvanovaO. N.KochetkovS. N.StarodubovaE. S.BartoschB.et al (2016). Oxidative stress during HIV Infection: mechanisms and consequences.Oxid. Med. Cell. Longev.2016:8910396.
119
IvanovS.MerlinJ.LeeM. K. S.MurphyA. J.GuinamardR. R. (2018). Biology and function of adipose tissue macrophages, dendritic cells and B cells.Atherosclerosis271102–110. 10.1016/j.atherosclerosis.2018.01.018
120
JacksonE.ShoemakerR.LarianN.CassisL. (2017). Adipose Tissue as a Site of Toxin Accumulation. In Comprehensive Physiology.Hoboken, NJ: John Wiley & Sons, Inc.
121
JacobR. A.JohnsonA. L.PawlakE. N.DirkB. S.Van NynattenL. R.HaeryfarS.et al (2017). The interaction between HIV-1 Nef and adaptor protein-2 reduces Nef-mediated CD4+ T cell apoptosis.Virology5091–10. 10.1016/j.virol.2017.05.018
122
JannehO.HoggardP. G.TjiaJ. F.JonesS. P.KhooS. H.MaherB.et al (2003). Intracellular disposition and metabolic effects of zidovudine, stavudine and four protease inhibitors in cultured adipocytes.Antivir. Ther.8417–426.
123
JannehO.OwenA.BrayP. G.BackD. J.PirmohamedM. (2010). The accumulation and metabolism of zidovudine in 3T3-F442A pre-adipocytes.Br. J. Pharmacol.159484–493. 10.1111/j.1476-5381.2009.00552.x
124
JonesD. D.RacineR.WittmerS. T.HarstonL.PapillionA. M.DishawL. M.et al (2015). The omentum is a site of protective IgM production during intracellular bacterial infection.Infect. Immun.832139–2147. 10.1128/IAI.00295-15
125
KarlssonE. A.BeckM. A. (2010). The burden of obesity on infectious disease.Exp. Biol. Med.2351412–1424. 10.1258/ebm.2010.010227
126
KerchbergerA. M.ShethA. N.AngertC. D.MehtaC. C.SummersN. A.OfotokunI.et al (2019). Weight gain associated with integrase stand transfer inhibitor use in women.Clin. Infect. Dis.10.1093/cid/ciz853[Epub ahead of print].
127
KhairounM.KorevaarS. S. (2013). Human bone marrow- and adipose tissue-derived mesenchymal stromal cells are immunosuppressive In vitro and in a humanized allograft rejection model.J. Stem Cell Res. Ther.6:20780.
128
KimH.DarwishI.MonroyM.-F.ProckopD. J.LilesW. C.KainK. C. (2014). Mesenchymal stromal (stem) cells suppress pro-inflammatory cytokine production but fail to improve survival in experimental staphylococcal toxic shock syndrome.BMC Immunol.15:1. 10.1186/1471-2172-15-1
129
KintscherU.HartgeM.HessK.Foryst-LudwigA.ClemenzM.WabitschM.et al (2008). T-lymphocyte infiltration in visceral adipose tissue: a primary event in adipose tissue inflammation and the development of obesity-mediated insulin resistance.Arterioscler. Thromb. Vasc. Biol.281304–1310. 10.1161/ATVBAHA.108.165100
130
KisO.RobillardK.ChanG. N. Y.BendayanR. (2010). The complexities of antiretroviral drug–drug interactions: role of ABC and SLC transporters.Trends Pharmacol. Sci.3122–35. 10.1016/j.tips.2009.10.001
131
KnightS. C. (2008). Specialized perinodal fat fuels and fashions immunity.Immunity28135–138. 10.1016/j.immuni.2008.01.003
132
KoetheJ. R. (2017). Adipose Tissue in HIV Infection. In Comprehensive Physiology.Hoboken, NJ: John Wiley & Sons, Inc.
133
KoetheJ. R.McDonnellW.KennedyA.AbanaC. O.PilkintonM.SetliffI.et al (2017). Adipose tissue is enriched for activated and late-differentiated CD8+ T cells, and shows distinct CD8+ receptor usage, compared to blood in HIV-infected persons.JAIDS J. Acquir. Immune Defic. Syndr.77:1. 10.1097/QAI.0000000000001573
134
KolodinD.van PanhuysN.LiC.MagnusonA. M.CipollettaD.MillerC. M.et al (2015). Antigen- and cytokine-driven accumulation of regulatory T cells in visceral adipose tissue of lean mice.Cell Metab.21543–557. 10.1016/j.cmet.2015.03.005
135
KuangX.BrockmanM. (2018). Implications of HIV-1 Nef for “Shock and Kill” strategies to eliminate latent viral reservoirs.Viruses10:677. 10.3390/v10120677
136
KugelbergE. (2015). Infection: double skin protection.Nat. Rev. Immunol.1568–69. 10.1038/nri3811
137
La CavaA.AlviggiC.MatareseG. (2004). Unraveling the multiple roles of leptin in inflammation and autoimmunity.J. Mol. Med.824–11. 10.1007/s00109-003-0492-1
138
LagathuC.CossarizzaA.BéréziatV.NasiM.CapeauJ.PintiM. (2017). Basic science and pathogenesis of ageing with HIV.AIDS31S105–S119. 10.1097/QAD.0000000000001441
139
LagathuC.EustaceB.ProtM.FrantzD.GuY.BastardJ.-P.et al (2007). Some HIV antiretrovirals increase oxidative stress and alter chemokine, cytokine or adiponectin production in human adipocytes and macrophages.Antivir. Ther.12489–500.
140
LagathuC.KimM.MaachiM.VigourouxC.CerveraP.CapeauJ.et al (2005). HIV antiretroviral treatment alters adipokine expression and insulin sensitivity of adipose tissue in vitro and in vivo.Biochimie8765–71. 10.1016/j.biochi.2004.12.007
141
LaparraA.TricotS.Le VanM.DamoucheA.GorwoodJ.VaslinB.et al (2019). The frequencies of immunosuppressive cells in adipose tissue differ in human, non-human primate, and mouse models.Front. Immunol.10:117. 10.3389/fimmu.2019.00117
142
Le BlancK.MougiakakosD. (2012). Multipotent mesenchymal stromal cells and the innate immune system.Nat. Rev. Immunol.12383–396. 10.1038/nri3209
143
LeeB.-C.KimM.-S.PaeM.YamamotoY.EberléD.ShimadaT.et al (2016). Adipose natural killer cells regulate adipose tissue macrophages to promote insulin resistance in obesity.Cell Metab.23685–698. 10.1016/j.cmet.2016.03.002
144
LeeE.-H.ItanM.JangJ.GuH.-J.RozenbergP.MinglerM. K.et al (2018). Eosinophils support adipocyte maturation and promote glucose tolerance in obesity.Sci. Rep.8:9894. 10.1038/s41598-018-28371-4
145
LeeM.-J.WuY.FriedS. K. (2013). Adipose tissue heterogeneity: implication of depot differences in adipose tissue for obesity complications.Mol. Aspects Med.341–11. 10.1016/j.mam.2012.10.001
146
LeeM.-W.OdegaardJ. I.MukundanL.QiuY.MolofskyA. B.NussbaumJ. C.et al (2015). Activated type 2 innate lymphoid cells regulate beige fat biogenesis.Cell16074–87. 10.1016/j.cell.2014.12.011
147
LeeY. S.WollamJ.OlefskyJ. M. (2018). An integrated view of immunometabolism.Cell17222–40. 10.1016/j.cell.2017.12.025
148
LinY.LeeH.BergA. H.LisantiM. P.ShapiroL.SchererP. E. (2000). The lipopolysaccharide-activated toll-like receptor (TLR)-4 induces synthesis of the closely related receptor TLR-2 in adipocytes.J. Biol. Chem.27524255–24263. 10.1074/jbc.m002137200
149
LionettiL.MollicaM. P.LombardiA.CavaliereG.GifuniG.BarlettaA. (2009). From chronic overnutrition to insulin resistance: the role of fat-storing capacity and inflammation.Nutr. Metab. Cardiovasc. Dis.19146–152. 10.1016/j.numecd.2008.10.010
150
LiuJ.DivouxA.SunJ.ZhangJ.ClémentK.GlickmanJ. N.et al (2009). Genetic deficiency and pharmacological stabilization of mast cells reduce diet-induced obesity and diabetes in mice.Nat. Med.15940–945. 10.1038/nm.1994
151
LiuR.NikolajczykB. S. (2019). Tissue immune cells fuel obesity-associated inflammation in adipose tissue and beyond.Front. Immunol.10:1587. 10.3389/fimmu.2019.01587
152
Loisel-MeyerS.SwainsonL.CraveiroM.OburogluL.MongellazC.CostaC.et al (2012). Glut1-mediated glucose transport regulates HIV infection.Proc. Natl. Acad. Sci. U.S.A.1092549–2554. 10.1073/pnas.1121427109
153
LolmèdeK.DuffautC.BouloumiéA. (2011). Immune cells in adipose tissue?: key players in metabolic disorders.Diabetes Metab.37283–290. 10.1016/j.diabet.2011.03.002
154
LucheE.SengenèsC.ArnaudE.LaharragueP.CasteillaL.CousinB. (2015). Differential hematopoietic activity in white adipose tissue depending on its localization.J. Cell. Physiol.2303076–3083. 10.1002/jcp.25045
155
LumengC. N.BodzinJ. L.SaltielA. R. (2007). Obesity induces a phenotypic switch in adipose tissue macrophage polarization.J. Clin. Invest.117175–184. 10.1172/jci29881
156
Luz-CrawfordP.KurteM.Bravo-AlegríaJ.ContrerasR.Nova-LampertiE.TejedorG.et al (2013). Mesenchymal stem cells generate a CD4+CD25+Foxp3+ regulatory T cell population during the differentiation process of Th1 and Th17 cells.Stem Cell Res. Ther.4:65. 10.1186/scrt216
157
LynchL.MicheletX.ZhangS.BrennanP. J.MosemanA.LesterC.et al (2015). Regulatory iNKT cells lack expression of the transcription factor PLZF and control the homeostasis of T(reg) cells and macrophages in adipose tissue.Nat. Immunol.1685–95. 10.1038/ni.3047
158
LynchL.NowakM.VargheseB.ClarkJ.HoganA. E.ToxavidisV.et al (2012). Adipose tissue invariant NKT cells protect against diet-induced obesity and metabolic disorder through regulatory cytokine production.Immunity37574–587. 10.1016/j.immuni.2012.06.016
159
MachadoF. S.DutraW. O.EsperL.GollobK. J.TeixeiraM. M.FactorS. M.et al (2012). Current understanding of immunity to Trypanosoma cruzi infection and pathogenesis of Chagas disease.Semin. Immunopathol.34753–770. 10.1007/s00281-012-0351-7
160
MadaniR.KarastergiouK.OgstonN. C.MiheisiN.BhomeR.HaloobN.et al (2009). RANTES release by human adipose tissue in vivo and evidence for depot-specific differences.Am. J. Physiol. Endocrinol. Metab.296E1262–E1268. 10.1152/ajpendo.90511.2008
161
MadgeS.Kinloch-de-LoesS.MerceyD.JohnsonM. A.WellerI. V. (1999). Lipodystrophy in patients naive to HIV protease inhibitors.AIDS13735–737.
162
MahlakõivT.FlamarA. L.JohnstonL. K.MoriyamaS.PutzelG. G.BryceP. J.et al (2019). Stromal cells maintain immune cell homeostasis in adipose tissue via production of interleukin-33.Sci. Immunol.4:eaax0416. 10.1126/sciimmunol.aax0416
163
MalmbergK. J.ArulampalamV.IchiharaF.PeterssonM.SekiK.AnderssonT.et al (2001). Inhibition of activated/memory (CD45RO(+)) T cells by oxidative stress associated with block of NF-kappaB activation.J. Immunol.1672595–2601. 10.4049/jimmunol.167.5.2595
164
MancusoP.GottschalkA.PhareS. M.Peters-GoldenM.LukacsN. W.HuffnagleG. B. (2002). Leptin-deficient mice exhibit impaired host defense in Gram-negative pneumonia.J. Immunol.1684018–4024. 10.4049/jimmunol.168.8.4018
165
MañesS.del RealG.MartínezC.-A. (2003). Pathogens: raft hijackers.Nat. Rev. Immunol.3557–568. 10.1038/nri1129
166
MarcelinG.FerreiraA.LiuY.AtlanM.Aron-WisnewskyJ.PellouxV.et al (2017). A PDGFRα-mediated switch toward CD9 high adipocyte progenitors controls obesity-induced adipose tissue fibrosis.Cell Metab.25673–685. 10.1016/j.cmet.2017.01.010
167
MatareseG.La CavaA. (2004). The intricate interface between immune system and metabolism.Trends Immunol.25193–200. 10.1016/j.it.2004.02.009
168
MathisD.ShoelsonS. E.LugusJ. J.WalshK.ShoelsonS. E.CantrellD. A. (2011). Immunometabolism: an emerging frontier.Nat. Rev. Immunol.11:81. 10.1038/nri2922
169
MattacksC. A.SadlerD.PondC. M. (2003). The cellular structure and lipid/protein composition of adipose tissue surrounding chronically stimulated lymph nodes in rats.J. Anat.202551–561. 10.1046/j.1469-7580.2003.00188.x
170
MaurinT.Saillan-BarreauC.CousinB.CasteillaL.DoglioA.PénicaudL. (2005). Tumor necrosis factor-alpha stimulates HIV-1 production in primary culture of human adipocytes.Exp. Cell Res.304544–551. 10.1016/j.yexcr.2004.12.003
171
MazzonM.MercerJ. (2014). Lipid interactions during virus entry and infection.Cell. Microbiol.161493–1502. 10.1111/cmi.12340
172
McLaughlinT.LiuL.-F.LamendolaC.ShenL.MortonJ.RivasH.et al (2014). T-cell profile in adipose tissue is associated with insulin resistance and systemic inflammation in humans.Arterioscler. Thromb. Vasc. Biol.342637–2643. 10.1161/ATVBAHA.114.304636
173
McNameeE. N.Korns JohnsonD.HomannD.ClambeyE. T. (2013). Hypoxia and hypoxia-inducible factors as regulators of T cell development, differentiation, and function.Immunol. Res.5558–70. 10.1007/s12026-012-8349-8
174
MeijerK.de VriesM.Al-LahhamS.BruinenbergM.WeeningD.DijkstraM.et al (2011). Human primary adipocytes exhibit immune cell function: adipocytes prime inflammation independent of macrophages.PLoS One6:e17154. 10.1371/journal.pone.0017154
175
Meza-PerezS.RandallT. D. (2017). Immunological Functions of the Omentum.Trends Immunol.38526–536. 10.1016/j.it.2017.03.002
176
MoffatG. H. (1968). The growth of hair follicles and its relation to the adjacent dermal structures.J. Anat.102527–540.
177
Mohamed-AliV.GoodrickS.RaweshA.KatzD. R.MilesJ. M.YudkinJ. S.et al (1997). Subcutaneous adipose tissue releases interleukin-6, but not tumor necrosis factor-alpha, in vivo.J. Clin. Endocrinol. Metab.824196–4200. 10.1210/jc.82.12.4196
178
MollinedoF.GajateC. (2015). Lipid rafts as major platforms for signaling regulation in cancer.Adv. Biol. Regul.57130–146. 10.1016/j.jbior.2014.10.003
179
MolofskyA. B.NussbaumJ. C.LiangH.-E.Van DykenS. J.ChengL. E.MohapatraA.et al (2013). Innate lymphoid type 2 cells sustain visceral adipose tissue eosinophils and alternatively activated macrophages.J. Exp. Med.210535–549. 10.1084/jem.20121964
180
MoroK.YamadaT.TanabeM.TakeuchiT.IkawaT.KawamotoH.et al (2010). Innate production of T(H)2 cytokines by adipose tissue-associated c-Kit(+)Sca-1(+) lymphoid cells.Nature463540–544. 10.1038/nature08636
181
MorrisD. L.ChoK. W.DelPropostoJ. L.OatmenK. E.GeletkaL. M.Martinez-SantibanezG.et al (2013). Adipose tissue macrophages function as antigen-presenting cells and regulate adipose tissue CD4 + T cells in mice.Diabetes Metab. Res. Rev.622762–2772. 10.2337/db12-1404
182
MorrisD. L.SingerK.LumengC. N. (2011). Adipose tissue macrophages: phenotypic plasticity and diversity in lean and obese states.Curr. Opin. Clin. Nutr. Metab. Care14341–346. 10.1097/MCO.0b013e328347970b
183
MoyoD.TanthumaG.CaryM. S.MushishaO.KwadibaG.ChikuseF.et al (2014). Cohort study of diabetes in HIV-infected adult patients: evaluating the effect of diabetes mellitus on immune reconstitution.Diabetes Res. Clin. Pract.103e34–e36. 10.1016/j.diabres.2013.12.042
184
MuellerS. N.GebhardtT.CarboneF. R.HeathW. R. (2013). Memory T cell subsets, migration patterns, and tissue residence.Annu. Rev. Immunol.31137–161. 10.1146/annurev-immunol-032712-095954
185
MunierS.BorjabadA.LemaireM.MariotV.HazanU. (2003). In vitro infection of human primary adipose cells with HIV-1: a reassessment.AIDS172537–2539. 10.1097/00002030-200311210-00019
186
MuthumaniK.ChooA. Y.PremkumarA.HwangD. S.ThieuK. P.DesaiB. M.et al (2005). Human immunodeficiency virus type 1 (HIV-1) Vpr-regulated cell death: insights into mechanism.Cell Death. Differ.12(Suppl. 1), 962–970. 10.1038/sj.cdd.4401583
187
NagajyothiF.DesruisseauxM. S.MachadoF. S.UpadhyaR.ZhaoD.SchwartzG. J.et al (2012). Response of adipose tissue to early infection with Trypanosoma cruzi (Brazil strain).J. Infect. Dis.205830–840. 10.1093/infdis/jir840
188
NekhaiS.KumariN.DhawanS. (2013). Role of cellular iron and oxygen in the regulation of HIV-1 infection.Future Virol.8301–311. 10.2217/fvl.13.6
189
NeyrollesO.Herná Ndez-PandoR.Pietri-RouxelF.FornèP.TailleuxL.BarriosJ. A. (2006). Is adipose tissue a place for mycobacterium tuberculosis persistence?PLoS One1:e43. 10.1371/journal.pone.0000043
190
NippeN.VargaG.HolzingerD.LöfflerB.MedinaE.BeckerK.et al (2011). Subcutaneous infection with S. aureus in mice reveals association of resistance with influx of neutrophils and Th2 response.J. Invest. Dermatol.131125–132. 10.1038/jid.2010.282
191
NishimuraH.ItamuraS.IwasakiT.KurataT.TashiroM. (2000). Characterization of human influenza A (H5N1) virus infection in mice: neuro-, pneumo- and adipotropic infection.J. Gen. Virol.812503–2510. 10.1099/0022-1317-81-10-2503
192
NishimuraS.ManabeI.NagaiR. (2009a). Adipose tissue inflammation in obesity and metabolic syndrome.Discov. Med.855–60.
193
NishimuraS.ManabeI.NagasakiM.EtoK.YamashitaH.OhsugiM.et al (2009b). CD8+ effector T cells contribute to macrophage recruitment and adipose tissue inflammation in obesity.Nat. Med.15914–920. 10.1038/nm.1964
194
NishimuraS.ManabeI.TakakiS.NagasakiM.OtsuM.YamashitaH.et al (2013). Adipose Natural Regulatory B cells negatively control adipose tissue inflammation.Cell Metab.18759–766. 10.1016/j.cmet.2013.09.017
195
NorwoodJ.TurnerM.BofillC.RebeiroP.ShepherdB.BebawyS.et al (2017). Brief report: weight gain in persons with HIV switched from efavirenz-based to integrase strand transfer inhibitor-based regimens.J. Acquir. Immune Defic. Syndr.76527–531. 10.1097/QAI.0000000000001525
196
OdegaardJ. I.ChawlaA. (2013). Pleiotropic actions of insulin resistance and inflammation in metabolic homeostasis.Science339172–177. 10.1126/science.1230721
197
O’SullivanT. E.RappM.FanX.WeizmanO.-E.BhardwajP.AdamsN. M.et al (2016). Adipose-resident group 1 innate lymphoid cells promote obesity-associated insulin resistance.Immunity45428–441. 10.1016/j.immuni.2016.06.016
198
OuchiN.ParkerJ. L.LugusJ. J.WalshK. (2011). Adipokines in inflammation and metabolic disease.Nat. Publ. Gr.1185–97. 10.1038/nri2921
199
PalD.DasguptaS.KunduR.MaitraS.DasG.MukhopadhyayS.et al (2012). Fetuin-A acts as an endogenous ligand of TLR4 to promote lipid-induced insulin resistance.Nat. Med.181279–1285. 10.1038/nm.2851
200
PalmerC. S.CherryC. L.Sada-OvalleI.SinghA.CroweS. M. (2016a). Glucose metabolism in T cells and monocytes: new perspectives in HIV pathogenesis.EBio. Med.631–41. 10.1016/j.ebiom.2016.02.012
201
PalmerC. S.HussainT.DuetteG.WellerT. J.OstrowskiM.Sada-OvalleI.et al (2016b). Regulators of glucose metabolism in CD4 + and CD8 + T cells.Int. Rev. Immunol.35477–488. 10.3109/08830185.2015.1082178
202
PanY.TianT.ParkC. O.LofftusS. Y.MeiS.LiuX.et al (2017). Survival of tissue-resident memory T cells requires exogenous lipid uptake and metabolism.Nature543252–256. 10.1038/nature21379
203
PangC.GaoZ.YinJ.ZhangJ.JiaW.YeJ. (2008). Macrophage infiltration into adipose tissue may promote angiogenesis for adipose tissue remodeling in obesity.Am. J. Physiol. Endocrinol. Metab.295E313–E322. 10.1152/ajpendo.90296.2008
204
PeirceV.CarobbioS.Vidal-PuigA. (2014). The different shades of fat.Nature51076–83. 10.1038/nature13477
205
PellegrinelliV.CarobbioS.Vidal-PuigA. (2016). Adipose tissue plasticity: how fat depots respond differently to pathophysiological cues.Diabetologia591075–1088. 10.1007/s00125-016-3933-4
206
PoglioS.De ToniF.LewandowskiD.MinotA.ArnaudE.BarrocaV.et al (2012). In situ production of innate immune cells in murine white adipose tissue.Blood1204952–4962. 10.1182/blood-2012-01-406959
207
PoglioS.De Toni-CostesF.ArnaudE.LaharragueP.EspinosaE.CasteillaL.et al (2010). Adipose tissue as a dedicated reservoir of functional mast cell progenitors.Stem Cells282065–2072. 10.1002/stem.523
208
PondC. M. (2002). Paracrine interactions of mammalian adipose tissue.J. Exp. Zool. Part A Comp. Exp. Biol.295A99–110. 10.1002/jez.a.10215
209
PossasC.AntunesA. M. S.Lins MendesF. M.VelosoV.MartinsR. M.HommaA. (2018). HIV cure: global overview of bNAbs’ patents and related scientific publications.Expert Opin. Ther. Pat.28551–560. 10.1080/13543776.2018.1495708
210
PriceP.EddyK. S.PapadimitriouJ. M.RobertsonT. A.ShellamG. R. (1990). Cytomegalovirus infection of adipose tissues induces steatitis in adult mice.Int. J. Exp. Pathol.71557–571.
211
ProckopD. J.OhJ. Y. (2012). Mesenchymal stem/stromal cells (MSCs): role as guardians of inflammation.Mol. Ther.2014–20. 10.1038/mt.2011.211
212
PuissantB.BarreauC.BourinP.ClavelC.CorreJ.BousquetC.et al (2005). Immunomodulatory effect of human adipose tissue-derived adult stem cells: comparison with bone marrow mesenchymal stem cells.Br. J. Haematol.129118–129. 10.1111/j.1365-2141.2005.05409.x
213
RajshekerS.MankaD.BlomkalnsA. L.ChatterjeeT. K.StollL. L.WeintraubN. L. (2010). Crosstalk between perivascular adipose tissue and blood vessels.Curr. Opin. Pharmacol.10191–196. 10.1016/j.coph.2009.11.005
214
Rangel-MorenoJ.Moyron-QuirozJ. E.CarragherD. M.KusserK.HartsonL.MoquinA.et al (2009). Omental milky spots develop in the absence of lymphoid tissue-inducer cells and support B and T cell responses to peritoneal antigens.Immunity30731–743. 10.1016/j.immuni.2009.03.014
215
RauschM. E.WeisbergS.VardhanaP.TortorielloD. V. (2008). Obesity in C57BL/6J mice is characterized by adipose tissue hypoxia and cytotoxic T-cell infiltration.Int. J. Obes.32451–463. 10.1038/sj.ijo.0803744
216
RodriguezA.-M.ElabdC.AmriE. Z.AilhaudG.DaniC. (2005). The human adipose tissue is a source of multipotent stem cells.Biochimie87125–128. 10.1016/j.biochi.2004.11.007
217
RosenE. D.MacDougaldO. A. (2006). Adipocyte differentiation from the inside out.Nat. Rev. Mol. Cell Biol.7885–896. 10.1038/nrm2066
218
RoutyJ.-P.IsnardS.MehrajV.OstrowskiM.ChomontN.AncutaP.et al (2019). Effect of metformin on the size of the HIV reservoir in non-diabetic ART-treated individuals: single-arm non-randomised Lilac pilot study protocol.BMJ Open9:e028444. 10.1136/bmjopen-2018-028444
219
RoutyJ. P.MehrajV.VybohK.CaoW.KemaI.JenabianM. A. (2015). Clinical relevance of kynurenine pathway in HIV/AIDS: an immune checkpoint at the crossroads of metabolism and inflammation.AIDS Rev.1796–106.
220
SacherT.AndrassyJ.KalninsA.DölkenL.JordanS.PodlechJ.et al (2011). Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.PLoS Pathog.7:e1002366. 10.1371/journal.ppat.1002366
221
Saillan-BarreauC.CousinB.AndréM.VillenaP.CasteillaL.PénicaudL. (2003). Human adipose cells as candidates in defense and tissue remodeling phenomena.Biochem. Biophys. Res. Commun.309502–505. 10.1016/j.bbrc.2003.08.034
222
SamarasK.WandH.LawM.EmeryS.CooperD.CarrA. (2007). Prevalence of metabolic syndrome in HIV-infected patients receiving highly active antiretroviral therapy using International diabetes foundation and adult treatment panel III criteria: associations with insulin resistance, disturbed body fat compartmental.Diabetes Care30113–119. 10.2337/dc06-1075
223
SathaliyawalaT.KubotaM.YudaninN.TurnerD.CampP.ThomeJ.et al (2013). Distribution and compartmentalization of human circulating and tissue-resident memory T cell subsets.Immunity38187–197. 10.1016/j.immuni.2012.09.020
224
SauceD.LarsenM.FastenackelsS.PauchardM.Ait-MohandH.SchneiderL.et al (2011). HIV disease progression despite suppression of viral replication is associated with exhaustion of lymphopoiesis.Blood1175142–5151. 10.1182/blood-2011-01-331306
225
SchafflerA.ScholmerichJ. (2010). Innate immunity and adipose tissue biology.Trends Immunol.31228–235. 10.1016/j.it.2010.03.001
226
SchellerE. L.CawthornW. P.BurrA. A.HorowitzM. C.MacdougaldO. A. (2016). Marrow adipose tissue: trimming the fat.Trends Endocrinol Metab.27392–403. 10.1016/j.tem.2016.03.016
227
SeydelK. B.MilnerD. A.Jr.KamizaS. B.MolyneuxM. E.TaylorT. E. (2006). The distribution and intensity of parasite sequestration in comatose malawian children.J. Infect. Dis.194208–215.
228
ShaoX.WangM.WeiX.DengS.FuN.PengQ.et al (2016). Peroxisome proliferator-activated receptor-γ: master regulator of adipogenesis and obesity.Curr. Stem Cell Res. Ther.11282–289. 10.2174/1574888x10666150528144905
229
ShenS.TianW.JiY.GaoY.ZhangM.HanX.et al (2019). Higher genetic diversity and viral evolution on key regions of envelope gene are associated with broader neutralizing antibody responses: report of two chronic HIV infected cases.JPN. J. Infect. Dis.72312–317. 10.7883/yoken.JJID.2018.336
230
ShenW.WangZ.PunyanitaM.LeiJ.SinavA.KralJ. G.et al (2003). Adipose tissue quantification by imaging methods: a proposed classification.Obes. Res.115–16. 10.1038/oby.2003.3
231
ShirakawaK.YanX.ShinmuraK.EndoJ.KataokaM.KatsumataY.et al (2016). Obesity accelerates T cell senescence in murine visceral adipose tissue.J. Clin. Invest.1264626–4639. 10.1172/JCI88606
232
ShrivastavS.KinoT.CunninghamT.IchijoT.SchubertU.HeinkleinP.et al (2008). Human immunodeficiency virus (HIV)-1 viral protein R suppresses transcriptional activity of peroxisome proliferator-activated receptor {gamma} and inhibits adipocyte differentiation: implications for HIV-associated lipodystrophy.Mol. Endocrinol.22234–247. 10.1210/me.2007-0124
233
SmithS. R.LovejoyJ. C.GreenwayF.RyanD.deJongeL.de la BretonneJ.et al (2001). Contributions of total body fat, abdominal subcutaneous adipose tissue compartments, and visceral adipose tissue to the metabolic complications of obesity.Metabolism50425–435. 10.1053/meta.2001.21693
234
SolanaR.TarazonaR.AielloA. E.AkbarA. N.AppayV.BeswickM.et al (2012). CMV and Immunosenescence: from basics to clinics.Immun. Ageing9:23. 10.1186/1742-4933-9-23
235
SpaldingK. L.ArnerE.WestermarkP. O.BernardS.BuchholzB. A.BergmannO.et al (2008). Dynamics of fat cell turnover in humans.Nature453783–787. 10.1038/nature06902
236
SpencerM.Yao-BorengasserA.UnalR.RasouliN.GurleyC. M.ZhuB.et al (2010). Adipose tissue macrophages in insulin-resistant subjects are associated with collagen VI and fibrosis and demonstrate alternative activation.Am. J. Physiol. Endocrinol. Metab.299E1016–E1027. 10.1152/ajpendo.00329.2010
237
SuganamiT.Tanimoto-KoyamaK.NishidaJ.ItohM.YuanX.MizuaraiS.et al (2007). Role of the Toll-like receptor 4/NF-kappaB pathway in saturated fatty acid-induced inflammatory changes in the interaction between adipocytes and macrophages.Arterioscler. Thromb. Vasc. Biol.2784–91. 10.1161/01.atv.0000251608.09329.9a
238
SunK.TordjmanJ.ClémentK.SchererP. E. (2013). Fibrosis and adipose tissue dysfunction.Cell Metab.18470–477. 10.1016/j.cmet.2013.06.016
239
SzaszT.WebbR. C. (2012). Perivascular adipose tissue: more than just structural support.Clin. Sci.1221–12. 10.1042/CS20110151
240
TangW.ZeveD.SuhJ. M.BosnakovskiD.KybaM.HammerR. E.et al (2008). White fat progenitor cells reside in the adipose vasculature.Science322583–586. 10.1126/science.1156232
241
TangX.LuH.DoonerM.ChapmanS.QuesenberryP. J.RamratnamB. (2018). Exosomal Tat protein activates latent HIV-1 in primary, resting CD4+ T lymphocytes.JCI Insight3:95676. 10.1172/jci.insight.95676
242
TanowitzH. B.SchererP. E.MotaM. M.FigueiredoL. M. (2017). Adipose tissue: a safe haven for parasites?Trends Parasitol.33276–284. 10.1016/j.pt.2016.11.008
243
TaoJ.-H.BarbiJ.PanF. (2015). Hypoxia-inducible factors in T lymphocyte differentiation and function. a review in the theme: cellular responses to hypoxia.Am. J. Physiol. Cell Physiol.309C580–C589. 10.1152/ajpcell.00204.2015
244
TchkoniaT.MorbeckD. E.Von ZglinickiT.Van DeursenJ.LustgartenJ.ScrableH.et al (2010). Fat tissue, aging, and cellular senescence.Aging Cell9667–684. 10.1111/j.1474-9726.2010.00608.x
245
ToribioM.FitchK. V.SanchezL.BurdoT. H.WilliamsK. C.SponsellerC. A.et al (2017). Effects of pitavastatin and pravastatin on markers of immune activation and arterial inflammation in HIV.AIDS31797–806. 10.1097/QAD.0000000000001427
246
TrezzaC.FordS. L.SpreenW.PanR.PiscitelliS. (2015). Formulation and pharmacology of long-acting cabotegravir.Curr. Opin. HIV AIDS10239–245. 10.1097/COH.0000000000000168
247
TrindadeS.Rijo-FerreiraF.CarvalhoT.Pinto-NevesD.GueganF.Aresta-BrancoF.et al (2016). Trypanosoma brucei parasites occupy and functionally adapt to the adipose tissue in mice.Cell Host Microbe19837–848. 10.1016/j.chom.2016.05.002
248
TsaiS.Clemente-CasaresX.ZhouA. C.LeiH.AhnJ. J.ChanY. T.et al (2018). Insulin receptor-mediated stimulation boosts T cell immunity during inflammation and infection.Cell Metab.281–13. 10.1016/j.cmet.2018.08.003
249
Valle-CasusoJ. C.AnginM.VolantS.PassaesC.MonceauxV.MikhailovaA.et al (2019). Cellular metabolism is a major determinant of HIV-1 reservoir seeding in CD4+ T cells and offers an opportunity to tackle infection.Cell Metab.29:611-626.e5. 10.1016/j.cmet.2018.11.015
250
van MeerG.VoelkerD. R.FeigensonG. W. (2008). Membrane lipids: where they are and how they behave.Nat. Rev. Mol. Cell Biol.9112–124. 10.1038/nrm2330
251
VernochetC.AzoulayS.DuvalD.GuedjR.CottrezF.VidalH.et al (2005). Human immunodeficiency virus protease inhibitors accumulate into cultured human adipocytes and alter expression of adipocytokines.J. Biol. Chem.2802238–2243. 10.1074/jbc.m408687200
252
VidalF.DomingoP.VillarroyaF.GiraltM.López-DuplaM.GutiérrezM.et al (2012). Adipogenic/lipid, inflammatory, and mitochondrial parameters in subcutaneous adipose tissue of untreated HIV-1-infected long-term nonprogressors: significant alterations despite low viral burden.J. Acquir. Immune Defic. Syndr.61131–137. 10.1097/qai.0b013e31825c3a68
253
VilaI. K.BadinP.-M.MarquesM.-A.MonbrunL.LefortC.MirL.et al (2014). Immune cell Toll-like receptor 4 mediates the development of obesity- and endotoxemia-associated adipose tissue fibrosis.Cell Rep.71116–1129. 10.1016/j.celrep.2014.03.062
254
VisnegarwalaF.RaghavanS. S.MullinC. M.BartschG.WangJ.KotlerD.et al (2005). Sex differences in the associations of HIV disease characteristics and body composition in antiretroviral-naive persons.Am. J. Clin. Nutr.82850–856. 10.1093/ajcn/82.4.850
255
WajchenbergB. (2000). Subcutaneous and visceral adipose tissue?: their relation to the metabolic syndrome.Endocr. Rev.21697–738. 10.1210/edrv.21.6.0415
256
WalkerG. E.MarzulloP.VertiB.GuzzaloniG.MaestriniS.ZurleniF.et al (2008). Subcutaneous abdominal adipose tissue subcompartments: potential role in rosiglitazone effects.Obesity161983–1991. 10.1038/oby.2008.326
257
WalshD. A.Borges da SilvaH.BeuraL. K.PengC.HamiltonS. E.MasopustD.et al (2019). The functional requirement for CD69 in establishment of resident memory CD8 + T cells varies with tissue location.J. Immunol.203946–955. 10.4049/jimmunol.1900052
258
WanC.-D.ChengR.WangH.-B.LiuT. (2008). Immunomodulatory effects of mesenchymal stem cells derived from adipose tissues in a rat orthotopic liver transplantation model.Hepatobil. Pancreat. Dis. Int.729–33.
259
WangQ.WuH. (2018). T Cells in adipose tissue: critical players in immunometabolism.Front. Immunol.9:2509. 10.3389/fimmu.2018.02509
260
WangY.ChenX.CaoW.ShiY. (2014). Plasticity of mesenchymal stem cells in immunomodulation: pathological and therapeutic implications.Nat. Immunol.151009–1016. 10.1038/ni.3002
261
WanjallaC. N.McDonnellW. J.BarnettL.SimmonsJ. D.FurchB. D.LimaM. C.et al (2019). Adipose tissue in persons With HIV Is enriched for CD4+ T effector memory and T effector memory RA+ cells, which show higher CD69 expression and CD57, CX3CR1, GPR56 Co-expression with increasing glucose intolerance.Front. Immunol.10:408. 10.3389/fimmu.2019.00408
262
WanjallaC. N.McDonnellW. J.KoetheJ. R. (2018). Adipose tissue T cells in HIV/SIV infection.Front. Immunol.9:2730. 10.3389/fimmu.2018.02730
263
WeisbergS. P.MccannD.DesaiM.RosenbaumM.LeibelR. L.FerranteA. W. (2003). Obesity is associated with macrophage accumulation in adipose tissue.J. Clin. Invest.1121796–1808. 10.1172/jci19246
264
WensveenF. M.JelenèiæV.ValentiæS.ŠestanM.WensveenT. T.TheurichS.et al (2015). NK cells link obesity-induced adipose stress to inflammation and insulin resistance.Nat. Immunol.16376–385. 10.1038/ni.3120
265
Wernstedt AsterholmI.TaoC.MorleyT. S.WangQ. A.Delgado-LopezF.WangZ. V.et al (2014). Adipocyte inflammation is essential for healthy adipose tissue expansion and remodeling.Cell Metab.20103–118. 10.1016/j.cmet.2014.05.005
266
WertheimerA. M.BennettM. S.ParkB.UhrlaubJ. L.MartinezC.PulkoV.et al (2014). Aging and cytomegalovirus infection differentially and jointly affect distinct circulating T cell subsets in humans.J. Immunol.1922143–2155. 10.4049/jimmunol.1301721
267
WielandC. W.FlorquinS.ChanE. D.LeemansJ. C.WeijerS.VerbonA.et al (2005). Pulmonary Mycobacterium tuberculosis infection in leptin-deficient ob/ob mice.Int. Immunol.171399–1408. 10.1093/intimm/dxh317
268
WinerD. A.WinerS.ShenL.WadiaP. P.YanthaJ.PaltserG.et al (2011). B cells promote insulin resistance through modulation of T cells and production of pathogenic IgG antibodies.Nat. Med.17610–617. 10.1038/nm.2353
269
WorodriaW.Massinga-LoembeM.MazakpweD.LuzindaK.MentenJ.Van LethF.et al (2011). Incidence and predictors of mortality and the effect of tuberculosis immune reconstitution inflammatory syndrome in a cohort of TB/HIV patients commencing antiretroviral therapy.J. Acquir. Immune Defic. Syndr.5832–37. 10.1097/QAI.0b013e3182255dc2
270
WorodriaW.SsempijjaV.HanrahanC.SsegonjaR.MuhofwaA.MazapkweD.et al (2018). Opportunistic diseases diminish the clinical benefit of immediate antiretroviral therapy in HIV–tuberculosis co-infected adults with low CD4+ cell counts.AIDS322141–2149. 10.1097/QAD.0000000000001941
271
WronskaA.KmiecZ. (2012). Structural and biochemical characteristics of various white adipose tissue depots.Acta Physiol.205194–208. 10.1111/j.1748-1716.2012.02409.x
272
WuD.MolofskyA. B.LiangH. E.Ricardo-GonzalezR. R.JouihanH. A.BandoJ. K.et al (2011). Eosinophils sustain adipose alternatively activated macrophages associated with glucose homeostasis.Science332243–247. 10.1126/science.1201475
273
WuH.GhoshS.PerrardX. D.FengL.GarciaG. E.PerrardJ. L.et al (2007). T-cell accumulation and regulated on activation, normal T cell expressed and secreted upregulation in adipose tissue in obesity.Circulation1151029–1038. 10.1161/circulationaha.106.638379
274
XiaoL.YangX.LinY.LiS.JiangJ.QianS.et al (2016). Large adipocytes function as antigen-presenting cells to activate CD4 + T cells via upregulating MHCII in obesity.Int. J. Obes.40112–120. 10.1038/ijo.2015.145
275
XuH.BarnesG. T.YangQ.TanG.YangD.ChouC. J.et al (2003). Chronic inflammation in fat plays a crucial role in the development of obesity-related insulin resistance.J. Clin. Invest.1121821–1830. 10.1172/jci200319451
276
YousefiF.EbtekarM.SoudiS.SoleimaniM.HashemiS. M. (2016). In vivo immunomodulatory effects of adipose-derived mesenchymal stem cells conditioned medium in experimental autoimmune encephalomyelitis.Immunol. Lett.17294–105. 10.1016/j.imlet.2016.02.016
277
ZeydaM.StulnigT. M. (2007). Adipose tissue macrophages.Immunol Lett.11261–67. 10.1016/j.imlet.2007.07.003
278
ZhangL.-J. L.Guerrero-JuarezC. F.HataT.BapatS. P.RamosR.PlikusM. V.et al (2015). Innate immunity. dermal adipocytes protect against invasive Staphylococcus aureus skin infection.Science34767–71. 10.1126/science.1260972
279
ZúñigaL. A.ShenW.-J.Joyce-ShaikhB.PyatnovaE. A.RichardsA. G.ThomC.et al (2010). IL-17 regulates adipogenesis, glucose homeostasis, and obesity.J. Immunol.1856947–6959. 10.4049/jimmunol.1001269
Summary
Keywords
adipose tissue, fat, HIV, infectious disease, resident memory T cells, T lymphocyte, reservoir, immune response
Citation
Bourgeois C, Gorwood J, Barrail-Tran A, Lagathu C, Capeau J, Desjardins D, Le Grand R, Damouche A, Béréziat V and Lambotte O (2019) Specific Biological Features of Adipose Tissue, and Their Impact on HIV Persistence. Front. Microbiol. 10:2837. doi: 10.3389/fmicb.2019.02837
Received
06 August 2019
Accepted
22 November 2019
Published
17 December 2019
Volume
10 - 2019
Edited by
Matthieu Perreau, Lausanne University Hospital (CHUV), Switzerland
Reviewed by
Ma Angeles Muñoz-Fernandez, Gregorio Marañón Hospital, Spain; Cristian Apetrei, University of Pittsburgh, United States
Updates

Check for updates
Copyright
© 2019 Bourgeois, Gorwood, Barrail-Tran, Lagathu, Capeau, Desjardins, Le Grand, Damouche, Béréziat and Lambotte.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Christine Bourgeois, christine.bourgeois@u-psud.fr
This article was submitted to Virology, a section of the journal Frontiers in Microbiology
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.