REVIEW article

Front. Immunol., 15 November 2022

Sec. Cancer Immunity and Immunotherapy

Volume 13 - 2022 | https://doi.org/10.3389/fimmu.2022.1050484

The effects of dendritic cell-based vaccines in the tumor microenvironment: Impact on myeloid-derived suppressor cells

  • 1. Department of Medical Biochemistry and Molecular Biology, School of Medicine, University of Seville, Seville, Spain

  • 2. Medical Oncology Service, Virgen Macarena University Hospital, Seville, Spain

  • 3. Department of Laboratory Medicine, Virgen Macarena University Hospital, Seville, Spain

  • 4. Laboratorio de Tecnología Inmunológica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe capital, Argentina

  • 5. Laboratorio de Células Presentadoras de Antígeno y Respuesta Inflamatoria, Instituto de Medicina Experimental (IMEX) - CONICET, Academia Nacional de Medicina, Buenos Aires, Argentina

Abstract

Dendritic cells (DCs) are a heterogenous population of professional antigen presenting cells whose main role is diminished in a variety of malignancies, including cancer, leading to ineffective immune responses. Those mechanisms are inhibited due to the immunosuppressive conditions found in the tumor microenvironment (TME), where myeloid-derived suppressor cells (MDSCs), a heterogeneous population of immature myeloid cells known to play a key role in tumor immunoevasion by inhibiting T-cell responses, are extremely accumulated. In addition, it has been demonstrated that MDSCs not only suppress DC functions, but also their maturation and development within the myeloid linage. Considering that an increased number of DCs as well as the improvement in their functions boost antitumor immunity, DC-based vaccines were developed two decades ago, and promising results have been obtained throughout these years. Therefore, the remodeling of the TME promoted by DC vaccination has also been explored. Here, we aim to review the effectiveness of different DCs-based vaccines in murine models and cancer patients, either alone or synergistically combined with other treatments, being especially focused on their effect on the MDSC population.

Introduction

The success of current cancer therapies depends on the knowledge of the tumor microenvironment (TME), which is a complex signaling network consisting of tumor, immune and stromal cells, as well as non-cellular components such as exosomes or the extracellular matrix (). Immune cells such as regulatory T cells (Tregs), tumor-associated macrophages (TAMs) or myeloid-derived suppressor cells (MDSCs) expand systematically and play a key role by inhibiting effector T-cell responses and favoring tumor progression through the release of a variety of factors, such as arginase-1 (ARG-1), reactive oxygen species (ROS), interleukin (IL)-6, IL-10, transforming growth factor (TGF)-β, vascular endothelial growth factor (VEGF), or the expression of different proteins in their surface, including programmed cell death protein 1 (PD-1) or cytotoxic T-lymphocyte antigen 4 (CTLA-4), among many others ().

Specifically, MDSCs are a heterogenous population of immature myeloid cells with a potent immunosuppressive capacity (as shown in Figure 1) that leads to tumor growth, development of pre-metastatic niches, resistance to immunotherapy, and poor outcomes (). MDSCs are recruited into the TME via C-C motif chemokine ligand 2 (CCL2)/C-C motif chemokine receptor 2 (CCR2), CCL3/CCR5, CC15/CCR1, or CXC motif chemokine ligand 13 (CXCL13)/CXC motif receptor 5 (CXCR5) pathways (), and other mediators such as granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, or prostaglandin E2 (PGE2) participate to expand MDSCs. There are two main populations of MDSCs that share some phenotypic, morphological, and functional characteristics with inflammatory, immunosuppressive monocytes and neutrophils, called monocytic MDSCs (M-MDSCs) and granulocytic MDSCs (G-MDSCs) (). Mouse and human MDSCs share some phenotypic expression, such a CD11b. However, mouse MDSCs are commonly defined as Gr1+CD11b+ cells characterized by the expression of Ly6ChighLy6G- (M-MDSCs) and Ly6ClowLy6G+ (G-MDSCs), whereas human MDSCs are CD11b+HLA-DRlow/- cells that also express CD14+CD15- (M-MDSCs) or CD14-CD15+ (G-MDSCs). Of note, G-MDSCs can also express high levels of CD66b ().

Figure 1

MDSCs mainly inhibit antitumor T-cell responses through a variety of mechanisms (). In this sense, MDSCs promote the loss of T-cell receptor (TCR) ζ-chain and cell cycle arrest in T cells by up-taking L-cysteine and L-arginine, two essential amino acids for proliferation and expansion of T cells (, ). MDSCs release ROS to provoke the loss of the TCR ζ-chain, and promote nitrosylation and nitration of components of the TCR complex (). MDSCs are also known to downregulate the cytotoxicity of natural killer (NK) cells by releasing TGF-β or indoleamine 2,3-dyoxygenase (IDO) (). The recruitment of other immunosuppressor cells by releasing IL-10 and TGF-β are also carried out by MDSCs, including M2 macrophages () and regulatory T cells (Tregs) ().

In this context, conventional treatments such as chemotherapy activate multiple signaling pathways and promote the secretion of inflammatory mediators, but it may have dual roles and is not considered as an efficient option to eradicate tumors completely (), and radiation therapy (RT) causes DNA damage in tumor cells to inhibit their proliferation, but it may also affect to adjacent healthy cells (). Also, RT, at least under some settings, can promote favorable conditions for immunoevasion by stimulating the recruitment of immunosuppressive cell populations, including MDSCs (). However, a different approach to treat cancer is based on immunotherapies, which target specific cellular or non-cellular components to boost the potential of the immune system to kill cancer cells. Different immunotherapies have been developed in last decades, including treatments to target stromal cells (), cell surface proteins (), or angiogenic factors (), among others.

Particularly, targeting DC activation using DC-based vaccines can be therapeutically beneficial because DCs are the most potent type of antigen presenting cells and are able to activate their immunogenic machinery ex profeso to sample and present tumor-associated antigens (TAAs) to CD4+ T cells on major histocompatibility complex (MHC) class II molecules and CD8+ T cells on MHC class I molecules, in order to activate T cells to recognize similar TAAs within the TME (), a process called “cancer-immunity cycle” (). It has been described that immunogenic tumor cell death (ICD) improves T-cell immunity since it promotes the migration of tumor-infiltrating DCs to draining lymph nodes (). In addition, ICD determinants have an effect on DCs. For example, proinflammatory mediators of tumor cells such as the high mobility group box 1 (HMGB1) protein or the 70 kilodalton heat shock protein (HSP70) facilitate TAA processing and presentation, whereas plasma membrane components such as calreticulin or phosphatidylserine residues promote phagocytosis or TAA recognition, respectively (). In line with this, conventional DCs (cDCs) have demonstrated a preferential capacity to promote antigen presentation to T cells () rather than monocyte-derived DCs (moDCs) or plasmacytoid DCs (pDCs), which may have dual roles in anti-tumor immunity (, ).

Here, we explain the current knowledge regarding the impact of DC-based vaccines on MDSCs in both preclinical tumor models and oncological patients, either alone or combined with other treatments.

Dendritic cell vaccines and myeloid-derived suppressor cells.

Immunotherapies have demonstrated to improve outcomes in cancer (). DC infiltration into tumors has been positively correlated with prognosis and survival (), leading to the design of DC-based immunotherapies. DC vaccines emerged as a promising alternative to further improve anti-tumor immunity (). Specifically, cDC vaccines and pDC have shown better anti-tumor efficacy compared to moDC vaccines (). Another interesting approach is the so-called in vivo vaccination to target DCs with DC receptor ligands, adjuvants, or other types of molecules that can accurately bind to DCs to exert better anti-tumor responses (). Of note, DC-based immunotherapy could be inefficient due to the MDSC accumulation within the TME, so the combination of DC vaccines with other treatments may be a feasible approach to deplete MDSCs (, ), as shown in Figure 2.

Figure 2

Dendritic cell vaccines and myeloid-derived suppressor cells in preclinical tumor models.

The use of DC vaccines has been widely investigated in murine models over the last decades. Although vaccination with DCs has demonstrated effectiveness in certain oncological settings in vivo (), it has been extensively shown that the inhibition of immunosuppressive conditions has been slight. In this sense, combinatorial treatments have improved the efficacy of DC vaccines reducing tumor growth significantly, enhancing survival rates, and activating stronger tumor-specific T cell responses (), thus overcoming immune tolerance. A growing preclinical literature illustrates the immunomodulatory capacity of DC vaccines combined with treatments such as IMiDs, inhibitors, or chemotherapeutic agents to reduce the proportion of MDSCs in cancer murine models (Table 1).

Table 1

Type of cancerTumor modelType of DC vaccineGroups of treatmentEffect on MDSCs after treatmentsReference
Breast4T1 cells
  • - DC cells

  • - Adenovirus-null DCs

  • - VE-cadherin gene modified DCs

Group 1: control
Group 2: DC vaccine
Group 3: Adenovirus-null DC vaccine
Group 4: VE-cadherin gene modified DC vaccine
Not only MDSCs, but also regulatory T cells, mildly decreased within the tumor tissues of Group 4 compared with the other groups(63)
  • - Tumor lysate-pulsed DCs

Group 1: control
Group 2: CD73-specific siRNA-loaded NPs
Group 3: DC vaccine
Group 4: DC vaccine + CD73-specific siRNA-loaded NPs
Groups 2 and 3 exhibited non-significant reductions of tumor MDSCs, whereas Group 4 showed a remarkable decrease, and their levels were significantly correlated with the frequency of CD73+ cells in tumor tissue(64)
ColonCT26 cells
  • - DC cells

  • - Adenovirus-null DCs

  • - VE-cadherin gene modified DCs

Group 1: control
Group 2: DC vaccine
Group 3: Adenovirus-null DC vaccine
Group 4: VE-cadherin gene modified DC vaccine
Not only MDSCs, but also regulatory T cells, mildly decreased within the tumor tissues of Group 4 compared with the other groups(63)
MC-38 cells
  • - Tumor antigen-loaded DCs

Group 1: control
Group 2: LEN
Group 3: DC vaccine
Group 4: LEN + DC vaccine
Group 4 showed the lowest percentage of splenic MDSCs()
  • - Tumor antigen-loaded DCs

Group 1: control
Group 2: TA-DC vaccine
Group 3: Rv2299c
Group 4: TA-DC vaccine + Rv2299c
Proportions of MDSCs increased in Group 1, remained unchanged in Groups 2 and 3, and significantly decreased in Group 4(65)
GliomaGL261 cells
  • - Lysate-pulsed mature DCs

Group 1: Control
Group 2: freeze-thaw necrosis (FT) + DC vaccine
Group 3: FT + radiation + DC vaccine
There was a decrease of both MDSC subsets and TAMs in Group 3 compared to Groups 1 and 2 (66)
HepatocellularHepa1-6 cells
  • - DC/tumor cell fusion vaccine

Group 1: control
Group 2: folate-modified chitosan/mouse interferon-induced protein-10 (FC/MIP10)
Group 3: FC/MIP10 + DC vaccine
Group 3 significantly reduced MDSCs in spleen, tumor, and bone marrow and increased tumor-specific IFN-γ responses compared with the other groups.(67)
KidneyHEK293 cells
  • - DC cells

  • - Adenovirus-null DCs

  • - VE-cadherin gene modified DCs

Group 1: control
Group 2: DC vaccine
Group 3: Adenovirus-null DC vaccine
Group 4: VE-cadherin gene modified DC vaccine
Not only MDSCs, but also regulatory T cells, mildly decreased within the tumor tissues of Group 4 compared with the other groups(63)
LungLewis Lung Carcinoma cells
  • - Rose Bengal (RB)-immature DCs

  • - RB-mature DCs

Group 1: control
Group 2: RB
Group 3: RB-immature DC vaccine
Group 4: RB- mature DC vaccine
MDSCs significantly decreased in groups 3 and 4 within the tumor microenvironment compared to control groups, whereas MDSC levels remained unchanged in the spleens.()
  • - TAA-derived MHC class I peptide- mature DCs

Group 1: healthy
Group 2: Control
Group 3: DC vaccine
Group 4: anti-cancer-associated fibroblasts (CAFs)
Group 5: anti-CAFs + DC vaccine
Groups 3, 4, and 5 showed a decrease of MDSCs, but it was significant in Group 5, reaching levels of Group 1(68)
LymphomaA20 B cells
  • - CFSE-labeled DCs 

Group 1: control
Group 2: Gemcitabine
Group 3: DC vaccine
Group 4: Gemcitabine + DC vaccine
Groups 2 and 3 did not inhibit tumor growth. However, the addition of gemcitabine to the vaccine (Group 4) significantly reduced MDSCs and improved efficacy()
E.G7 cells- TAA-derived MHC class I peptide- mature DCsGroup 1: healthy
Group 2: Control
Group 3: DC vaccine
Group 4: anti-CAFs
Group 5: anti-CAFs + DC vaccine
Groups 3, 4, and 5 showed a decrease of MDSCs, but it was significant in Group 5, reaching levels of Group 1(68)
MelanomaB16F10 cells
  • - Mature DCs

Group 1: control
Group 2: DC vaccine
Group 3: low-dose 5-fluorouracil (5FU)
Group 4: DC vaccine + low-dose 5FU
MDSCs similarly decreased in groups 2, 3 and 4 compared with the control group.(69)
  • - Tyrosinase related protein (TRP)-1/Tyrosine (Tyr) DCs

Group 1: DC vaccine
Group 2: DC vaccine + paclitaxel
Group 3: DC vaccine + anti-PD-1
Groups 2 and 3 experienced stronger cytotoxic T-cell activation and significantly decreased MDSCs in tumor-bearing mice, which led to improved survival rates(70)
  • - Mature DCs

Group 1: control
Group 2: DC vaccine
Group 3: low-dose 5FU
Group 4: DC vaccine + low-dose 5FU
Group 4 showed a reduced number of MDSCs and tumor growth, as well as increased survival, compared with the other groups()
B16F1 cells
  • - TAA-derived MHC class I peptide- mature DCs

  • - 

Group 1: healthy
Group 2: Control
Group 3: DC vaccine
Group 4: anti-CAFs
Group 5: anti-CAFs + DC vaccine
Groups 3, 4, and 5 showed a decrease of MDSCs, but it was significant in Group 5, reaching levels of Group 1(68)
B16.OVA cells
  • - OVA peptide-pulsed DC.IL12 cells

Group 1: Control
Group 2: DC vaccine
Group 3: Dasatinib
Group 4: Dasatinib + DC vaccine
MDSCs were especially depleted in Group 4, which was associated with a reduction of hypoxic signalling()
MO5-B16 cells
  • - Tyrosinase related protein (TRP)-1/Tyrosine (Tyr) DCs

Group 1: DC vaccine
Group 2: DC vaccine + paclitaxel
Group 3: DC vaccine + anti-PD-1
Groups 2 and 3 experienced stronger cytotoxic T-cell activation and significantly decreased MDSCs in tumor-bearing mice, which led to improved survival rates(70)
MyelomaMOPC-315 cells
  • - Dying tumor cell-loaded DCs

Group 1: control
Group 2: DC vaccine
Group 3: pomalidomide + dexamethasone (POM/DEX)
Group 4: DC vaccine + POM/DEX
Group 4 exhibited the lowest generation of splenic MDSCs, which was associated with a greater inhibition of tumor growth(71)
  • - Dying tumor cell-loaded DCs

Group 1: control
Group 2: DC vaccine + POM/DEX
Group 3: POM/DEX + anti-PD-1
Group 4: DC vaccine + POM/DEX + anti-PD-1
Pomalidomide with dexamethasone + PD-L1 from Groups 3 and 4 decreased the generation of MDSCs and Tregs in both the spleen and TME compared to Groups 1 and 2()
  • - Dying tumor cell-loaded DCs

Group 1: control
Group 2: DC vaccine
Group 3: DC vaccine + lenalidomide (LEN)
Group 4: DC vaccine + anti-PD-1
Group 5: DC vaccine + LEN + anti-PD-1
Splenic MDSCs were dramatically reduced in all treatment groups compared to control, but Group 5 showed the lowest proportion of these cells()
YAC-1 cells
  • - Dying tumor cell-loaded DCs

Group 1: control
Group 2: DC vaccine + POM/DEX
Group 3: POM/DEX + anti-PD-1
Group 4: DC vaccine + POM/DEX + anti-PD-1
Pomalidomide with dexamethasone + PD-L1 from Groups 3 and 4 decreased the generation of MDSCs and Tregs in both the spleen and TME compared to Groups 1 and 2()
PancreaticUNKC6141 PaCa cells
  • - Tumor cell-derived exosomes-loaded DCs

Group 1: control
Group 2: Gemcitabine, ATRA, Sunitinib (GAS)
Group 3: tumor exosome-loaded (TEX) DC vaccine
Group 4: GAS + TEX DC vaccine
Group 2 experienced a significant reduction of both MDSCs, and tumor cells compared with the other groups. However, Group 3 and 4 prolonged the survival time, but persisting drug application promoted tumor reappearance in the last group.(72)
PancreaticPanc02 cells
  • - Mature DCs

Group 1: control
Group 2: Gemcitabine
Group 3: DC vaccine
Group 4: Gemcitabine + DC vaccine
Gemcitabine decreased MDSCs in spleens and tumors of Group 2. Its addition to DC vaccination (Group 4) also improved survival rates in mice(73)

Preclinical studies involving the use of dendritic cell-based vaccines (alone and combined with other treatments) and their effects on the myeloid-derived suppressor cell population.

IMiDs

Lenalidomide (LEN) and pomalidomide (POM) are IMiDs derived from thalidomide that increase cytotoxic responses driven by T cells and NK cells against tumors (74, 75). LEN has promoted the depletion of MDSCs in lymphoma patients with good response to the treatment (76) and in lymphoma-bearing mice, in which have been demonstrated an additive therapeutic antitumor effect when combined with a fusion DNA vaccine (77). In combination with TAA-loaded DC vaccine, LEN showed a remarkable tumor growth inhibition and significantly reduced MDSCs compared to LEN alone and DC vaccine alone in a colon mouse model ().

Promising results were obtained with POM combined with dexamethasone in multiple myeloma (MM) (78, 79), although the combination with different inhibitors could further improve cell cycle arrest, deregulation of metabolic pathways, and tumor cell apoptosis in proliferative phases(8082). When added to a DC vaccine, POM and dexamethasone synergistically improved antitumor immunity in MM mouse models due to the increased proportion of effector lymphoid cells and the depletion of not only splenic MDSCs, but also VEGF (71), which usually promotes angiogenesis and MDSC migration into the blood (83, 84).

Inhibitors

The use of blockade agents has also improved the efficacy of different types of vaccines (85, 86). Specifically, immune checkpoint inhibitors have successfully targeted MDSCs in melanoma-bearing mice treated with the tyrosinase related protein (TRP)1/tyrosine DC vaccine (70). Similar results were obtained in myeloma murine models after combining a DC vaccine and anti-PD-1 with IMiDs (, ).

In addition, DC vaccines has improved the effects of other inhibitors such as tranilast (TRA) or dasatinib (DAS) in lung and melanoma mouse models, respectively, because the combinatorial treatment reduced the number of MDSCs (, 68). TRA is an anti-fibrotic agent to inhibit not only cancer-associated fibroblasts (CAFs; which are one of the most abundant and critical components of the tumor mesenchyme to promote carcinogenesis), but also tumor cell interactions, and the modulation of immune factors (87, 88), including MDSC differentiation and recruitment (89, 90). In the same line, DAS allows the blockade of the SRC kinase family (91) and has shown to improve T-cell responses after decreasing MDSCs in head and neck squamous cell carcinoma (92). Of note, M-MDSCs have been suggested as a promising prognostic biomarker in patients with myeloid leukemia treated with DAS (93).

Antimetabolite drugs

Analogs of biological compounds to inhibit metabolic routes also reduced the proportion of MDSCs when combined with DC-based vaccines. 5-fluorouracil (5-FU) is a fluoropyrimidine that inhibits essential biosynthetic processes and RNA and DNA functions by incorporating their metabolites into the nucleic acids and inhibiting the enzyme thymidylate synthase (94), which promotes the depletion of MDSCs (95). 5-FU in combination with a DC vaccine showed a greater MDSC reduction and improved survival rates in melanoma-bearing mice compared with DC vaccination alone (which maintained MDSC levels), and/or 5-FU alone (which significantly depleted MDSCs, although survival rates were lower compared to the combinatorial treatment) (). Interestingly, these schedules were used in a melanoma-bearing mice to stablish an agent-based model to simulate the interactions between tumor and immune cells, as well as comparing different scenarios to determine the role of each component (including MDSCs) during tumor progression (69).

Also, rose bengal (RB), a staining agent and an inhibitor of ribonucleic acid chain elongation some decades ago (96), induced not only the regression of injected tumors in melanoma murine models, but also immunogenic cell death and the release of HMGB1, which improved DC infiltration into draining lymph nodes and, consequently, the activation of T cell responses (97). Combined with a DC vaccine, RB reduced MDSCs and enhanced the activation of effector cells and the release of TNF-α, leading to the inhibition of tumor growth in lung cancer-bearing mice ().

Chemotherapeutic agents

DC vaccines have also been combined with chemotherapeutic agents such as gemcitabine (GEM). GEM is known to inhibit DNA synthesis of tumor cells (98) and has shown to inhibit MDSC expansion both in vitro and in vivo(99101). In line with this notion, DC vaccination improved the effects of low-dose GEM due to not only DC maturation, T-cell activation, and the production of IFN-γ, but also the reduction of tumor cells and MDSCs (GEM alone also did), and tumor growth inhibition, thus enhancing survival rates (GEM alone did not) in lymphoma-bearing mice (). GEM alone increased the apoptosis of splenic MDSCs significantly in pancreatic cancer-bearing mice, whereas the combination with a DC vaccine also enhanced the overall survival (73).

In a pancreatic cancer mouse model, overall survival was prolonged after using a tumor-exosome (TEX)-DC vaccine but both circulating and tumor-infiltrating MDSCs were only depleted in the group of mice treated with GEM, all-trans retinoic acid (ATRA), and/or sunitinib, or the combinatorial schedule with the vaccine. However, the latter group unexpectedly experienced tumor reappearance due to persisting drug application (72).

Other combinatorial treatments

Chitosan is a biological polysaccharide that play a role in multiple medical functions, such as absorption enhancer or drug releaser. In cancer, chitosan is mainly used in chemotherapeutic delivery and as an immunoadjuvant in vaccines (102). Folate (FA)-modified chitosan has demonstrated to enhance tumor targeting and cytotoxic T-cell responses in some oncological settings (103106). FA-modified chitosan nanoparticles carrying a plasmid of the mouse interferon-induced protein-10 (mIP-10) gene, a chemoattractant for cytotoxic T cells, reduced MDSCs from spleen, tumor, and bone marrow in combination with a DC/tumor cell fusion vaccine in hepatocellular carcinoma-bearing mice (67). In this context, neovascularization, metastasis, and survival of cancer cells can also be promoted by adenosine and its producing molecules, such as CD73, which has been proposed as one of the next-generation targets in cancer (107, 108). In line with this notion, CD73 expression is a biomarker of poor prognosis in breast cancer (109) and the use of chitosan-lactate nanoparticles to target CD73-specific small interfering RNA (siRNA) in combination with a DC vaccine have been successfully tested in breast cancer models after inhibiting tumor growth, and MDSCs (64). Interestingly, this combinatorial treatment also reduced the levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are pro-angiogenic factors released by MDSCs to facilitate extravasation processes and angiogenesis (110).

In addition, vascular endothelial (VE)-cadherin is an adhesion molecule with a key role in the development of the blood vascular system (111). VE-cadherin promotes tumor development and progression by enhancing angiogenesis (112) via interaction with VEGF receptor-2 and stimulation of TGF-β signaling pathway (113, 114). For these reasons, a VE-cadherin gene modified DC-based vaccine was developed and successfully tested in kidney, breast, and colon cancer models, resulting in delayed tumor progression and enhancing survival rates by the production of a large amounts of immunoglobulins, and the increase of T effector cells and cytotoxicity against VE-cadherin, as well as the reduction of immunosuppressor cells, including MDSCs (63).

The protein Rv2299c has also demonstrated to induce DC activation and maturation, and enhance the expression of MHC molecules, CD80, and CD86 proteins in vitro to promote naïve-T-cell proliferation (115). Combined with a DC vaccine, Rv2299c reduced tumor growth in a colon cancer murine model and improved antitumor immunity by activating T-cell responses and reducing MDSCs (65).

Interestingly, a DC vaccine with irradiated freeze-thaw-necrotic cells has also been tested and it increased tumor rejection and reduced the number of immunosuppressive cells, including MDSCs (66).

Dendritic cell vaccines and myeloid-derived suppressor cells in cancer patients.

Immunotherapy consisting in DC vaccination alone or combined with other treatments has also been tested in a variety of clinical trials (116123). Most of them has been focused on drug effectiveness and efficacy rather than the analysis of immunosuppressive cell populations. Therefore, the impact of DC vaccination on human MDSCs (Table 2) has been little studied.

Table 2

Type of cancerType of DC vaccineGroups of treatmentEffect on MDSCs after treatmentsReference
BrainGBM6-AD/DCsDC vaccinePatients with stable disease experienced a significant decrease of early stage MDSCs and M-MDSCs. Also, a significant increase of G-MDSCs in patients with non-stable disease was observed.(124)
BreastMonocyte-derived autologous DCsGroup 1: Control
Group 2: DC vaccine + neoadjuvant chemotherapy (NAC)
MDSCs significantly decreased in Group 2 after treatment(125)
BreastWilms tumor gene (WT) 1 peptide-pulsed DCsDC vaccine+ NACPatients who had immunological response to treatment had a significant depletion of MDSCs(126)
EsophagealWT1 peptide-pulsed DCsDC vaccine + docetaxelPositive immune responses were significantly correlated with a low concentration of MDSCs(127)
GastricWT1 peptide-pulsed DCsDC vaccine+ NACPatients who had immunological response to treatment had a significant depletion of MDSCs(126)
LungWild-type p53-transduced DCsGroup 1: Control
Group 2: DC vaccine
Group 3: DC vaccine + ATRA
MDSC levels were similar in all groups before starting treatments. After vaccinations, MDSCs did not vary in Group 2, whereas they decreased more than two-fold in Group 3(128)
MelanomaTumor-associated antigen (TAA)-loaded monocyte-derived autologous DCsGroup 1: Healthy control
Group 2: DC vaccine
M-MDSCs were significantly higher in Group 2 compared to Group 1. After treatment, MDSC frequency was associated with short survival.(129)
MelanomaAdVTMM2-transduced DCsGroup 1: Healthy control
Group 2: DC vaccine
Group 3: DC vaccine + IFNα
In group 2, there was a decreased of HLA-DRCD11b+CD33+ MDSCs, although M-MDSCs and G-MDSCs were not reduced. Group 3 experienced a slightly decreased of MDSC subsets(130)
OvarianWT1 peptide-pulsed DCsDC vaccine+ NACPatients who had immunological response to treatment had a significant depletion of MDSCs(126)
ProstateAutologous DCsGroup 1: Docetaxel
Group 2: Docetaxel + DC vaccine
MDSC levels were similar before treatments in both groups. However, Group 2 had a significant MDSC decrease during treatment compared to Group 1(131)
RenalTumor lysate-loaded DCDC vaccine + sunitinibPatients who responded to treatment showed decreased levels of MDSCs, whereas those who failed to develop tumor-reactive T cell responses did not show consistent reductions of MDSCs(132)
SarcomaTAA-monocyte-derived DCsDC vaccineMDSC levels varied in every patient after vaccination. One of those patients had low levels of M-MDSCs and experienced a remarkable regression of metastatic lesions(133)

Clinical studies involving the use of dendritic cell-based vaccines (alone and combined with other treatments) and their effects on the myeloid-derived suppressor cell population.

DC vaccines alone have shown conflicting results in terms of MDSC levels. MoDC vaccines loaded with TAAs demonstrated the stimulation of a preexisting immune response against TAAs in children, adolescents, and young adults with sarcoma tumors in a phase I/II clinical trial. Interestingly, one of those patients had low levels of MDSCs and Tregs prior to vaccination and experienced significant regression of metastatic lesions after a second disease relapse (133). A similar vaccine was tested in a clinical trial involving metastatic melanoma patients, but M-MDSCs increased after vaccination and were inversely associated with survival (129), demonstrating their immunosuppressive role.

Another anti-tumor target is the stromal tumor suppressor p53, since its loss showed to modify cytokine secretion to increase myeloid infiltration (134), including MDSCs (135). In this sense, the deletion of stromal p53 demonstrated to increase the proliferation of fibroblasts and epithelial cells in KrasG12D-bearing mammary glands together with DNA damage and replication stress, which finally reduced apoptosis of tumor cells and increased the frequency of MDSCs (136). The DC vaccine transduced with wild-type p53 was tested in small cell lung cancer patients without previous positive p53 responses and only 20% of them developed p53-specific responses, with no significant variations in the levels of granzyme B-positive CD8 T cells and MDSCs (128).

In addition, promising results have been shown after using a adenovirus (AdV)-loaded DC vaccine with the TAAs tyrosinase, melanoma-associated antigen recognized by T cells (MART-1), and melanoma-antigen gene (MAGE)-A6 (collectively known as TMM2) since it produced the depletion of blood HLA-DRCD11b+CD33+ MDSCs (130). Even better, a DC-based vaccine loaded with the glioma stem cell line GBM6-AD promoted a significant decrease of both M-MDSCs and e-MDSCs in patients with stable disease, whereas their non-stable counterparts experienced an increase of G-MDSCs (124).

Conversely, DC-based vaccines combined with other treatments have notably improved clinical responses and were associated with a significant MDSC reduction compared to DC vaccination alone:

Targeted therapies

IFNα, which belongs to the IFN1 family, is downregulated in the MDSC gene expression profile (137), suggesting that IFN-α signaling may be a key pathway to restrict the suppressive activity of MDSCs (138). Also, nitric oxygen produced by MDSCs may reduce the IFN responsiveness in other immune cells in vivo (139). Therefore, IFN-α therapies began to be tested, demonstrating an increment of the antibody-dependent cellular cytotoxicity in tumor-bearing mice (140), but adverse effects were also reported and they should be taken into consideration (141). When combined with an AdVTMM2-transduced DC vaccine in melanoma patients, IFN-α slightly decreased both M-MDSCs and G-MDSCs compared to DC vaccination alone and did not improve clinical responses (130).

Contrarily, sunitinib, which is a multi-target tyrosine kinase inhibitor that blocks stem cell factor receptor c-KIT, platelet-derived growth factor receptors, CSF receptors, and VEGF receptors 1, 2 and 3, has been extensively described as a treatment for renal cell carcinoma (142144). Sunitinib reduced the level of MDSCs (145, 146), mainly due to the inhibition of the signal transducer and activator of transcription (STAT)3 signaling pathway (147). TAA-loaded DC-based vaccine improved the effects of sunitinib due to the reduction in the percentage of MDSCs in patients with renal cell carcinoma (132).

Another compound, ATRA, which is a targeted therapy for peptidylprolyl cis/trans isomerase, NIMA-Interacting 1 (best known as Pin1) in breast cancer and acute promyelocytic leukemia (148), is an active metabolite of vitamin A and exerts important effects not only in cell growth, differentiation, and apoptosis (149), but also in enhancing the influx of DCs into the draining lymph nodes (150) and promoting the maturation of MDSCs into neutrophils and monocytes (151). Specifically, vaccination with p53-transduced DCs combined with ATRA in lung cancer patients resulted in a significant depletion of MDSCs in more than twofold, that was accompanied by more p53-specific responses compared to vaccination alone (128).

Chemotherapeutic agents

When combined with vaccines, chemotherapeutic agents may be promising strategies (152) because they improve the efficacy of DC vaccination synergistically in cancer patients (153, 154). Neoadjuvant chemotherapy (NAC) demonstrated to increase the levels of MDSCs in breast cancer (155, 156), whereas DC vaccination with conventional NAC was suggested to be more effective in cancer patients with lower MDSCs and Tregs prior to treatment because they may develop beneficial immunological responses (126). However, other studies have reported pathological complete responses after depleting MDSCs in breast cancer patients (157, 158), similarly to the combination with an autologous Mo-DC vaccine (125).

Also, the chemotherapeutic drug docetaxel, which has shown to boost immune responses after inducing M1 macrophages and antigen presentation in vitro (159) and inhibiting MDSCs in breast cancer in vivo (160), depleted MDSCs and promoted positive immune responses when combined with DC vaccines in esophageal and prostate cancers (127, 131).

Conclusions and future perspectives

DC vaccines emerged two decades ago as alternative strategies to overcome tumor resistance and improve survival rates in cancer. DC vaccination has demonstrated better (although still limited) results in terms of efficacy and overall survival compared with other treatments. Probably, cellular immune responses promoted by DC vaccines alone are not sufficiently strong to overcome immunosuppression. Despite this, DC vaccines are currently considered as promising therapeutic approaches to be still optimized. In this sense, the addition of different drugs may be needed to synergically improved the effects of this type of vaccination, what should be further tested in both murine models and clinical trials.

Tumor resistance is mainly led by cells with suppressive functions. Specifically, MDSCs are considered as the “queen-bee” cell population of the TME because they lead multiple mechanisms of resistance and finally protect tumor cells for their surveillance and proliferation (161). In this situation, a variety of therapeutic approaches are currently being used to target MDSCs in cancer, such as their direct elimination, preventing their recruitment into the TME, inhibiting their immunosuppressive role, or inducing their differentiation into mature myeloid cells (162).

The therapeutic benefit of DC vaccines as monotherapies may have been limited due to the resistance promoted by MDSCs, which is supported by the extensive literature that address the conflicting results regarding the levels of MDSCs after using DC vaccines. However, combinatorial approaches with other drugs such as IMiDs, antimetabolites, or chemotherapeutic agents have shown to reduce tumor growth and improve overall survivals in vivo compared to DC vaccines alone, which have been also associated with a significant depletion of MDSCs in clinical trials. Therefore, it seems clear that targeting MDSCs with combinatorial regimens based on DC vaccination plus different types of treatment may be therapeutically useful. However, we should take into consideration some aspects, including (a) the type of DCs used in the vaccine (e.g., cDCs can initiate effective immune responses, whereas moDCs seems to play a dual role in cancer) (b), the type of adjuvant (e.g., some vaccines have been loaded with TAAs, but others with dying tumor cells or RB) (c), the dosage used, that may depends on the status of the patients (e.g. levels of blood lymphocytes or MDSCs) and may be personalized, and (d) adverse effects (e.g., as it is with the use of IFN-α therapies). Altogether, some therapeutic approaches to overcome MDSC-mediated immunosuppression and improve survival rates may be focused on DC vaccination combined with MDSC inhibitors (e.g., receptor antagonists of cytokines or chemokines that recruit MDSC into the tumor), which may be promising, alternative strategies to be tested in vitro and in vivo in the future.

Funding

CJ-C is supported by a Margarita Salas fellowship, granted by the University of Seville (Seville, Spain).

Publisher’s note

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

Statements

Author contributions

MLS-L, C-J-C, GC, MV, LC-M, and VS-M contributed to conceptualization, literature search, and reviewing of the draft. MLS-L, and CJ-C wrote the draft. All authors have read and agreed to publish this version of the manuscript.

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

    AndersonNMSimonMC. The tumor microenvironment. Curr Biol (2020) 30(16):R921–5. doi: 10.1016/j.cub.2020.06.081

  • 2

    LindauDGielenPKroesenMWesselingPAdemaGJ. The immunosuppressive tumour network: myeloid-derived suppressor cells, regulatory T cells and natural killer T cells. Immunology (2013) 138(2):105–15. doi: 10.1111/imm.12036

  • 3

    DavidovVJensenGMaiSChenSHPanPY. Analyzing one cell at a TIME: Analysis of myeloid cell contributions in the tumor immune microenvironment. Front Immunol (2020) 11:1842. doi: 10.3389/fimmu.2020.01842

  • 4

    Labani-MotlaghAAshja-MahdaviMLoskogA. The tumor microenvironment: A milieu hindering and obstructing antitumor immune responses. Front Immunol (2020) 11:940. doi: 10.3389/fimmu.2020.00940

  • 5

    GaoDJoshiNChoiHRyuSHahnMCatenaRet al. Myeloid progenitor cells in the premetastatic lung promote metastases by inducing mesenchymal to epithelial transition. Cancer Res (2012) 72(6):1384–94. doi: 10.1158/0008-5472.CAN-11-2905

  • 6

    SceneayJChowMTChenAHalseHMWongCSAndrewsDMet al. Primary tumor hypoxia recruits CD11b+/Ly6Cmed/Ly6G+ immune suppressor cells and compromises NK cell cytotoxicity in the premetastatic niche. Cancer Res (2012) 72(16):3906–11. doi: 10.1158/0008-5472.CAN-11-3873

  • 7

    SicaABronteV. Altered macrophage differentiation and immune dysfunction in tumor development. J Clin Invest (2007) 117(5):1155–66. doi: 10.1172/JCI31422

  • 8

    LiBHGarstkaMALiZF. Chemokines and their receptors promoting the recruitment of myeloid-derived suppressor cells into the tumor. Mol Immunol (2020) 117:201–15. doi: 10.1016/j.molimm.2019.11.014

  • 9

    BronteVBrandauSChenSHColomboMPFreyABGretenTFet al. Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards. Nat Commun (2016) 7:12150. doi: 10.1038/ncomms12150

  • 10

    GabrilovichDIOstrand-RosenbergSBronteV. Coordinated regulation of myeloid cells by tumours. Nat Rev Immunol (2012) 12(4):253–68. doi: 10.1038/nri3175

  • 11

    SrivastavaMKSinhaPClementsVKRodriguezPOstrand-RosenbergS. Myeloid-derived suppressor cells inhibit T-cell activation by depleting cystine and cysteine. Cancer Res (2010) 70(1):6877. doi: 10.1158/0008-5472.CAN-09-2587

  • 12

    RodriguezPCOchoaAC. Arginine regulation by myeloid derived suppressor cells and tolerance in cancer: mechanisms and therapeutic perspectives. Immunol Rev (2008) 222:180–91. doi: 10.1111/j.1600-065X.2008.00608.x

  • 13

    OhlKTenbrockK. Reactive oxygen species as regulators of MDSC-mediated immune suppression. Front Immunol (2018) 9:2499. doi: 10.3389/fimmu.2018.02499

  • 14

    BrunoAMortaraLBaciDNoonanDMAlbiniA. Myeloid derived suppressor cells interactions with natural killer cells and pro-angiogenic activities: Roles in tumor progression. Front Immunol (2019) 10:771. doi: 10.3389/fimmu.2019.00771

  • 15

    BeuryDWParkerKHNyandjoMSinhaPCarterKAOstrand-RosenbergS. Cross-talk among myeloid-derived suppressor cells, macrophages, and tumor cells impacts the inflammatory milieu of solid tumors. J Leukoc Biol (2014) 96(6):1109–18. doi: 10.1189/jlb.3A0414-210R

  • 16

    HuangBPanPYLiQSatoAILevyDEBrombergJet al. Gr-1+CD115+ immature myeloid suppressor cells mediate the development of tumor-induced T regulatory cells and T-cell anergy in tumor-bearing host. Cancer Res (2006) 66(2):1123–31. doi: 10.1158/0008-5472.CAN-05-1299

  • 17

    BehranvandNNasriFZolfaghari EmamehRKhaniPHosseiniAGarssenJet al. Chemotherapy: a double-edged sword in cancer treatment. Cancer Immunol Immunother (2022) 71(3):507–26. doi: 10.1007/s00262-021-03013-3

  • 18

    BaskarRLeeKAYeoRYeohKW. Cancer and radiation therapy: current advances and future directions. Int J Med Sci (2012) 9(3):193–9. doi: 10.7150/ijms.3635

  • 19

    Jimenez-CorteganaCGalassiCKlappVGabrilovichDIGalluzziL. Myeloid-derived suppressor cells and radiotherapy. Cancer Immunol Res (2022) 10(5):545–57. doi: 10.1158/2326-6066.CIR-21-1105

  • 20

    BarrettRLPureE. Cancer-associated fibroblasts and their influence on tumor immunity and immunotherapy. Elife (2020) 9:e57243. doi: 10.7554/eLife.57243

  • 21

    BuchbinderEIDesaiA. CTLA-4 and PD-1 pathways: Similarities, differences, and implications of their inhibition. Am J Clin Oncol (2016) 39(1):98106. doi: 10.1097/COC.0000000000000239

  • 22

    Lopes-CoelhoFMartinsFPereiraSASerpaJ. Anti-angiogenic therapy: Current challenges and future perspectives. Int J Mol Sci (2021) 22(7):3765. doi: 10.3390/ijms22073765

  • 23

    EisenbarthSC. Dendritic cell subsets in T cell programming: location dictates function. Nat Rev Immunol (2019) 19(2):89103. doi: 10.1038/s41577-018-0088-1

  • 24

    ChenDSMellmanI. Oncology meets immunology: the cancer-immunity cycle. Immunity (2013) 39(1):110. doi: 10.1016/j.immuni.2013.07.012

  • 25

    MoriyaTKitagawaKHayakawaYHemmiHKaishoTUehaSet al. Immunogenic tumor cell death promotes dendritic cell migration and inhibits tumor growth via enhanced T cell immunity. iScience (2021) 24(5):102424. doi: 10.1016/j.isci.2021.102424

  • 26

    TesniereAPanaretakisTKeppOApetohLGhiringhelliFZitvogelLet al. Molecular characteristics of immunogenic cancer cell death. Cell Death Differ (2008) 15(1):312. doi: 10.1038/sj.cdd.4402269

  • 27

    GardnerARuffellB. Dendritic cells and cancer immunity. Trends Immunol (2016) 37(12):855–65. doi: 10.1016/j.it.2016.09.006

  • 28

    AzeemWBakkeRMAppelSOyanAMKallandKH. Dual pro- and anti-inflammatory features of monocyte-derived dendritic cells. Front Immunol (2020) 11:438. doi: 10.3389/fimmu.2020.00438

  • 29

    HernandezSSJakobsenMRBakRO. Plasmacytoid dendritic cells as a novel cell-based cancer immunotherapy. Int J Mol Sci (2022) 23(19):11397. doi: 10.3390/ijms231911397

  • 30

    StevenAFisherSARobinsonBW. Immunotherapy for lung cancer. Respirology (2016) 21(5):821–33. doi: 10.1111/resp.12789

  • 31

    BilusicMMadanRAGulleyJL. Immunotherapy of prostate cancer: Facts and hopes. Clin Cancer Res (2017) 23(22):6764–70. doi: 10.1158/1078-0432.CCR-17-0019

  • 32

    BasuARamamoorthiGJiaYFaughnJWienerDAwshahSet al. Immunotherapy in breast cancer: Current status and future directions. Adv Cancer Res (2019) 143:295349. doi: 10.1016/bs.acr.2019.03.006

  • 33

    JohdiNASukorNF. Colorectal cancer immunotherapy: Options and strategies. Front Immunol (2020) 11:1624. doi: 10.3389/fimmu.2020.01624

  • 34

    MiyagawaSSoedaJTakagiSMiwaSIchikawaENoikeT. Prognostic significance of mature dendritic cells and factors associated with their accumulation in metastatic liver tumors from colorectal cancer. Hum Pathol (2004) 35(11):1392–6. doi: 10.1016/j.humpath.2004.07.018

  • 35

    MelaiuOChiericiMLucariniVJurmanGContiLADe VitoRet al. Cellular and gene signatures of tumor-infiltrating dendritic cells and natural-killer cells predict prognosis of neuroblastoma. Nat Commun (2020) 11(1):5992. doi: 10.1038/s41467-020-19781-y

  • 36

    SzporJStrebJGlajcarAFraczekPWiniarskaATyrakKEet al. Dendritic cells are associated with prognosis and survival in breast cancer. Diagnostics (Basel) (2021) 11(4):702. doi: 10.3390/diagnostics11040702

  • 37

    GardnerAde Mingo PulidoARuffellB. Dendritic cells and their role in immunotherapy. Front Immunol (2020) 11:924. doi: 10.3389/fimmu.2020.00924

  • 38

    BlockMSDietzABGustafsonMPKalliKRErskineCLYoussefBet al. Th17-inducing autologous dendritic cell vaccination promotes antigen-specific cellular and humoral immunity in ovarian cancer patients. Nat Commun (2020) 11(1):5173. doi: 10.1038/s41467-020-18962-z

  • 39

    CarrenoBMMagriniVBecker-HapakMKaabinejadianSHundalJPettiAAet al. Cancer immunotherapy. a dendritic cell vaccine increases the breadth and diversity of melanoma neoantigen-specific T cells. Science (2015) 348(6236):803–8. doi: 10.1126/science.aaa3828

  • 40

    LiauLMAshkanKTranDDCampianJLTrusheimJECobbsCSet al. First results on survival from a large phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma. J Transl Med (2018) 16(1):142. doi: 10.1186/s12967-018-1507-6

  • 41

    RibasAComin-AnduixBChmielowskiBJalilJde la RochaPMcCannelTAet al. Dendritic cell vaccination combined with CTLA4 blockade in patients with metastatic melanoma. Clin Cancer Res (2009) 15(19):6267–76. doi: 10.1158/1078-0432.CCR-09-1254

  • 42

    EsmailyMMasjediAHallajSNabi AfjadiMMalakotikhahFGhaniSet al. Blockade of CTLA-4 increases anti-tumor response inducing potential of dendritic cell vaccine. J Control Release (2020) 326:6374. doi: 10.1016/j.jconrel.2020.06.017

  • 43

    KodumudiKNRamamoorthiGSnyderCBasuAJiaYAwshahSet al. Sequential anti-PD1 therapy following dendritic cell vaccination improves survival in a HER2 mammary carcinoma model and identifies a critical role for CD4 T cells in mediating the response. Front Immunol (2019) 10:1939. doi: 10.3389/fimmu.2019.01939

  • 44

    ZhouYSloneNChrisikosTTKyrysyukOBabcockRLMedikYBet al. Vaccine efficacy against primary and metastatic cancer with in vitro-generated CD103(+) conventional dendritic cells. J Immunother Cancer (2020) 8(1):e000474. doi: 10.1136/jitc-2019-000474

  • 45

    JohnsonPRosendahlNRadfordKJ. Conventional type 1 dendritic cells (cDC1) as cancer therapeutics: challenges and opportunities. Expert Opin Biol Ther (2022) 22(4):465–72. doi: 10.1080/14712598.2022.1994943

  • 46

    BolKFSchreibeltGRaboldKWculekSKSchwarzeJKDzionekAet al. The clinical application of cancer immunotherapy based on naturally circulating dendritic cells. J Immunother Cancer (2019) 7(1):109. doi: 10.1186/s40425-019-0580-6

  • 47

    BaldinAVSavvateevaLVBazhinAVZamyatninAAJr. Dendritic cells in anticancer vaccination: Rationale for ex vivo loading or In vivo targeting. Cancers (Basel) (2020) 12(3):590. doi: 10.3390/cancers12030590

  • 48

    ChiangCLKandalaftLE. In vivo cancer vaccination: Which dendritic cells to target and how? Cancer Treat Rev (2018) 71:88101. doi: 10.1016/j.ctrv.2018.10.012

  • 49

    ArabSKheshtchinNAjamiMAshurpoorMSafvatiANamdarAet al. Increased efficacy of a dendritic cell-based therapeutic cancer vaccine with adenosine receptor antagonist and CD73 inhibitor. Tumour Biol (2017) 39(3):1010428317695021. doi: 10.1177/1010428317695021

  • 50

    KhosravianfarNHadjatiJNamdarABoghozianRHafeziMAshourpourMet al. Myeloid-derived suppressor cells elimination by 5-fluorouracil increased dendritic cell-based vaccine function and improved immunity in tumor mice. Iran J Allergy Asthma Immunol (2018) 17(1):4755.

  • 51

    ZhuXJYangZFZhouJYLiuLSunXMFanZFet al. Progression of Large lymphoma is significantly impeded with a combination of gemcitabine chemotherapy and dendritic cells intra-tumor vaccination. PloS One (2015) 10(7):e0132799. doi: 10.1371/journal.pone.0132799

  • 52

    VoMCJungSHChuTHLeeHJLakshmiTJParkHSet al. Lenalidomide and programmed death-1 blockade synergistically enhances the effects of dendritic cell vaccination in a model of murine myeloma. Front Immunol (2018) 9:1370. doi: 10.3389/fimmu.2018.01370

  • 53

    ChuTHVoMCParkHSLakshmiTJJungSHKimHJet al. Potent anti-myeloma efficacy of dendritic cell therapy in combination with pomalidomide and programmed death-ligand 1 blockade in a preclinical model of multiple myeloma. Cancer Immunol Immunother (2021) 70(1):3145. doi: 10.1007/s00262-020-02654-0

  • 54

    VoMCNguyen-PhamTNLeeHJJaya LakshmiTYangSJungSHet al. Combination therapy with dendritic cells and lenalidomide is an effective approach to enhance antitumor immunity in a mouse colon cancer model. Oncotarget (2017) 8(16):27252–62. doi: 10.18632/oncotarget.15917

  • 55

    ZhangLDuJSongQZhangCWuX. A novel In situ dendritic cell vaccine triggered by rose Bengal enhances adaptive antitumour immunity. J Immunol Res (2022) 2022:1178874. doi: 10.1155/2022/1178874

  • 56

    LoweDBBoseATaylorJLTawbiHLinYKirkwoodJMet al. Dasatinib promotes the expansion of a therapeutically superior T-cell repertoire in response to dendritic cell vaccination against melanoma. Oncoimmunology (2014) 3(1):e27589. doi: 10.4161/onci.27589

  • 57

    NairSKSnyderDRouseBTGilboaE. Regression of tumors in mice vaccinated with professional antigen-presenting cells pulsed with tumor extracts. Int J Cancer (1997) 70(6):706–15. doi: 10.1002/(SICI)1097-0215(19970317)70:6<706::AID-IJC13>3.0.CO;2-7

  • 58

    CasatiAZimmermannVSBenigniFBertilaccioMTBelloneMMondinoA. The immunogenicity of dendritic cell-based vaccines is not hampered by doxorubicin and melphalan administration. J Immunol (2005) 174(6):3317–25. doi: 10.4049/jimmunol.174.6.3317

  • 59

    ShihNYYangHYChengHTHungYMYaoYCZhuYHet al. Conditioning vaccination site with irradiated MIP-3alpha-transfected tumor cells enhances efficacy of dendritic cell-based cancer vaccine. J Immunother (2009) 32(4):363–9. doi: 10.1097/CJI.0b013e31819d29d8

  • 60

    WeiSMFeiJXTaoFPanHLShenQWangLet al. Anti-CD27 antibody potentiates antitumor effect of dendritic cell-based vaccine in prostate cancer-bearing mice. Int Surg (2015) 100(1):155–63. doi: 10.9738/INTSURG-D-14-00147.1

  • 61

    LapentaCDonatiSSpadaroFLattanziLUrbaniFMacchiaIet al. Lenalidomide improves the therapeutic effect of an interferon-alpha-dendritic cell-based lymphoma vaccine. Cancer Immunol Immunother (2019) 68(11):1791–804. doi: 10.1007/s00262-019-02411-y

  • 62

    FerrisSTOharaRAOuFWuRHuangXKimSet al. cDC1 vaccines drive tumor rejection by direct presentation independently of host cDC1. Cancer Immunol Res (2022) 10(8):920–31. doi: 10.1158/2326-6066.CIR-21-0865

  • 63

    ZhouJXiYMuXZhaoRChenHZhangLet al. Antitumor immunity induced by VE-cadherin modified DC vaccine. Oncotarget (2017) 8(40):67369–79. doi: 10.18632/oncotarget.18654

  • 64

    Jadidi-NiaraghFAtyabiFRastegariAKheshtchinNArabSHassanniaHet al. CD73 specific siRNA loaded chitosan lactate nanoparticles potentiate the antitumor effect of a dendritic cell vaccine in 4T1 breast cancer bearing mice. J Control Release (2017) 246:4659. doi: 10.1016/j.jconrel.2016.12.012

  • 65

    VoMCLeeHJKimJSHoangMDChoiNRRheeJHet al. Dendritic cell vaccination with a toll-like receptor agonist derived from mycobacteria enhances anti-tumor immunity. Oncotarget (2015) 6(32):33781–90. doi: 10.18632/oncotarget.5281

  • 66

    VandenberkLGargADVerschuereTKoksCBelmansJBeullensMet al. Irradiation of necrotic cancer cells, employed for pulsing dendritic cells (DCs), potentiates DC vaccine-induced antitumor immunity against high-grade glioma. Oncoimmunology (2016) 5(2):e1083669. doi: 10.1080/2162402X.2015.1083669

  • 67

    HuZChenJZhouSYangNDuanSZhangZet al. Mouse IP-10 gene delivered by folate-modified chitosan nanoparticles and dendritic/tumor cells fusion vaccine effectively inhibit the growth of hepatocellular carcinoma in mice. Theranostics (2017) 7(7):1942–52. doi: 10.7150/thno.16236

  • 68

    OhshioYTeramotoKHanaokaJTezukaNItohYAsaiTet al. Cancer-associated fibroblast-targeted strategy enhances antitumor immune responses in dendritic cell-based vaccine. Cancer Sci (2015) 106(2):134–42. doi: 10.1111/cas.12584

  • 69

    RahbarSShafiekhaniSAllahverdiAJamaliAKheshtchinNAjamiMet al. Agent-based modeling of tumor and immune system interactions in combinational therapy with low-dose 5-fluorouracil and dendritic cell vaccine in melanoma B16F10. Iran J Allergy Asthma Immunol (2022) 21(2):151–66. doi: 10.18502/ijaai.v21i2.9223

  • 70

    GreesMSharbi-YungerAEvangelouCBaumannDCafriGTzehovalEet al. Optimized dendritic cell vaccination induces potent CD8 T cell responses and anti-tumor effects in transgenic mouse melanoma models. Oncoimmunology (2018) 7(7):e1445457. doi: 10.1080/2162402X.2018.1445457

  • 71

    VoMCYangSJungSHChuTHLeeHJLakshmiTJet al. Synergistic antimyeloma activity of dendritic cells and pomalidomide in a murine myeloma model. Front Immunol (2018) 9:1798. doi: 10.3389/fimmu.2018.01798

  • 72

    XiaoLErbUZhaoKHackertTZollerM. Efficacy of vaccination with tumor-exosome loaded dendritic cells combined with cytotoxic drug treatment in pancreatic cancer. Oncoimmunology (2017) 6(6):e1319044. doi: 10.1080/2162402X.2017.1319044

  • 73

    GhansahTVohraNKinneyKWeberAKodumudiKSpringettGet al. Dendritic cell immunotherapy combined with gemcitabine chemotherapy enhances survival in a murine model of pancreatic carcinoma. Cancer Immunol Immunother (2013) 62(6):1083–91. doi: 10.1007/s00262-013-1407-9

  • 74

    McDanielJMPinilla-IbarzJEpling-BurnettePK. Molecular action of lenalidomide in lymphocytes and hematologic malignancies. Adv Hematol (2012) 2012:513702. doi: 10.1155/2012/513702

  • 75

    Chanan-KhanAASwaikaAPaulusAKumarSKMikhaelJRRajkumarSVet al. Pomalidomide: the new immunomodulatory agent for the treatment of multiple myeloma. Blood Cancer J (2013) 3:e143. doi: 10.1038/bcj.2013.38

  • 76

    Jimenez-CorteganaCPalazon-CarrionNMartin Garcia-SanchoANogales-FernandezECarnicero-GonzalezFRios-HerranzEet al. Circulating myeloid-derived suppressor cells and regulatory T cells as immunological biomarkers in refractory/relapsed diffuse large b-cell lymphoma: translational results from the R2-GDP-GOTEL trial. J Immunother Cancer (2021) 9(6):e002323. doi: 10.1136/jitc-2020-002323

  • 77

    SakamakiIKwakLWChaSCYiQLermanBChenJet al. Lenalidomide enhances the protective effect of a therapeutic vaccine and reverses immune suppression in mice bearing established lymphomas. Leukemia (2014) 28(2):329–37. doi: 10.1038/leu.2013.177

  • 78

    RychakEMendyDShiTNingYLeistenJLuLet al. Pomalidomide in combination with dexamethasone results in synergistic anti-tumour responses in pre-clinical models of lenalidomide-resistant multiple myeloma. Br J Haematol (2016) 172(6):889901. doi: 10.1111/bjh.13905

  • 79

    OcioEMFernandez-LazaroDSan-SegundoLLopez-CorralLCorcheteLAGutierrezNCet al. In vivo murine model of acquired resistance in myeloma reveals differential mechanisms for lenalidomide and pomalidomide in combination with dexamethasone. Leukemia (2015) 29(3):705–14. doi: 10.1038/leu.2014.238

  • 80

    PainoTGonzalez-MendezLSan-SegundoLCorcheteLAHernandez-GarciaSDiaz-TejedorAet al. Protein translation inhibition is involved in the activity of the pan-PIM kinase inhibitor PIM447 in combination with pomalidomide-dexamethasone in multiple myeloma. Cancers (Basel) (2020) 12(10):2743. doi: 10.3390/cancers12102743

  • 81

    Hernandez-GarciaSSan-SegundoLGonzalez-MendezLCorcheteLAMisiewicz-KrzeminskaIMartin-SanchezMet al. The kinesin spindle protein inhibitor filanesib enhances the activity of pomalidomide and dexamethasone in multiple myeloma. Haematologica (2017) 102(12):2113–24. doi: 10.3324/haematol.2017.168666

  • 82

    SanchezELiMWangCSTangGGillespieAChenHet al. Anti-angiogenic and anti-multiple myeloma effects of oprozomib (OPZ) alone and in combination with pomalidomide (Pom) and/or dexamethasone (Dex). Leuk Res (2017) 57:4554. doi: 10.1016/j.leukres.2017.03.002

  • 83

    KoinisFVetsikaEKAggourakiDSkalidakiEKoutoulakiAGkioulmpasaniMet al. Effect of first-line treatment on myeloid-derived suppressor cells' subpopulations in the peripheral blood of patients with non-small cell lung cancer. J Thorac Oncol (2016) 11(8):1263–72. doi: 10.1016/j.jtho.2016.04.026

  • 84

    HorikawaNAbikoKMatsumuraNHamanishiJBabaTYamaguchiKet al. Expression of vascular endothelial growth factor in ovarian cancer inhibits tumor immunity through the accumulation of myeloid-derived suppressor cells. Clin Cancer Res (2017) 23(2):587–99. doi: 10.1158/1078-0432.CCR-16-0387

  • 85

    SalewskiIKuntoffSKuemmelAFeldtmannRFelixSBHenzeLet al. Combined vaccine-immune-checkpoint inhibition constitutes a promising strategy for treatment of dMMR tumors. Cancer Immunol Immunother (2021) 70(12):3405–19. doi: 10.1007/s00262-021-02933-4

  • 86

    DuYLiuYWangDBaiHWangZHeXet al. Peptidic microarchitecture-trapped tumor vaccine combined with immune checkpoint inhibitor or PI3Kgamma inhibitor can enhance immunogenicity and eradicate tumors. J Immunother Cancer (2022) 10(2):e003564. doi: 10.1136/jitc-2021-003564

  • 87

    LiuTHanCWangSFangPMaZXuLet al. Cancer-associated fibroblasts: an emerging target of anti-cancer immunotherapy. J Hematol Oncol (2019) 12(1):86. doi: 10.1186/s13045-019-0770-1

  • 88

    SahaiEAstsaturovICukiermanEDeNardoDGEgebladMEvansRMet al. A framework for advancing our understanding of cancer-associated fibroblasts. Nat Rev Cancer (2020) 20(3):174–86. doi: 10.1038/s41568-019-0238-1

  • 89

    LinYCaiQChenYShiTLiuWMaoLet al. CAFs shape myeloid-derived suppressor cells to promote stemness of intrahepatic cholangiocarcinoma through 5-lipoxygenase. Hepatology (2022) 75(1):2842. doi: 10.1002/hep.32099

  • 90

    PereiraBAVenninCPapanicolaouMChambersCRHerrmannDMortonJPet al. CAF subpopulations: A new reservoir of stromal targets in pancreatic cancer. Trends Cancer (2019) 5(11):724–41. doi: 10.1016/j.trecan.2019.09.010

  • 91

    AppelCKGallego-PedersenSAndersenLBlancheflor KristensenSDingMFalkSet al. The src family kinase inhibitor dasatinib delays pain-related behaviour and conserves bone in a rat model of cancer-induced bone pain. Sci Rep (2017) 7(1):4792. doi: 10.1038/s41598-017-05029-1

  • 92

    YuGTMaoLWuLDengWWBuLLLiuJFet al. Inhibition of SRC family kinases facilitates anti-CTLA4 immunotherapy in head and neck squamous cell carcinoma. Cell Mol Life Sci (2018) 75(22):4223–34. doi: 10.1007/s00018-018-2863-3

  • 93

    GiallongoCParrinelloNLLa CavaPCamioloGRomanoAScaliaMet al. Monocytic myeloid-derived suppressor cells as prognostic factor in chronic myeloid leukaemia patients treated with dasatinib. J Cell Mol Med (2018) 22(2):1070–80. doi: 10.1111/jcmm.13326

  • 94

    LongleyDBHarkinDPJohnstonPG. 5-fluorouracil: mechanisms of action and clinical strategies. Nat Rev Cancer (2003) 3(5):330–8. doi: 10.1038/nrc1074

  • 95

    VincentJMignotGChalminFLadoireSBruchardMChevriauxAet al. 5-fluorouracil selectively kills tumor-associated myeloid-derived suppressor cells resulting in enhanced T cell-dependent antitumor immunity. Cancer Res (2010) 70(8):3052–61. doi: 10.1158/0008-5472.CAN-09-3690

  • 96

    WuFYWuCW. Rose Bengal: an inhibitor of ribonucleic acid chain elongation. Biochemistry (1973) 12(22):4343–8. doi: 10.1021/bi00746a007

  • 97

    LiuHInnamaratoPPKodumudiKWeberANemotoSRobinsonJLet al. Intralesional rose bengal in melanoma elicits tumor immunity via activation of dendritic cells by the release of high mobility group box 1. Oncotarget (2016) 7(25):37893–905. doi: 10.18632/oncotarget.9247

  • 98

    KramerEDAbramsSI. Granulocytic myeloid-derived suppressor cells as negative regulators of anticancer immunity. Front Immunol (2020) 11:1963. doi: 10.3389/fimmu.2020.01963

  • 99

    LeHKGrahamLChaEMoralesJKManjiliMHBearHD. Gemcitabine directly inhibits myeloid derived suppressor cells in BALB/c mice bearing 4T1 mammary carcinoma and augments expansion of T cells from tumor-bearing mice. Int Immunopharmacol (2009) 9(7-8):900–9. doi: 10.1016/j.intimp.2009.03.015

  • 100

    GargettTChristoSNHercusTRAbbasNSinghalNLopezAFet al. GM-CSF signalling blockade and chemotherapeutic agents act in concert to inhibit the function of myeloid-derived suppressor cells in vitro. Clin Transl Immunol (2016) 5(12):e119. doi: 10.1038/cti.2016.80

  • 101

    WangZLiuYZhangYShangYGaoQ. MDSC-decreasing chemotherapy increases the efficacy of cytokine-induced killer cell immunotherapy in metastatic renal cell carcinoma and pancreatic cancer. Oncotarget (2016) 7(4):4760–9. doi: 10.18632/oncotarget.6734

  • 102

    BabuARameshR. Multifaceted applications of chitosan in cancer drug delivery and therapy. Mar Drugs (2017) 15(4):96. doi: 10.3390/md15040096

  • 103

    YuBTangCYinC. Enhanced antitumor efficacy of folate modified amphiphilic nanoparticles through co-delivery of chemotherapeutic drugs and genes. Biomaterials (2014) 35(24):6369–78. doi: 10.1016/j.biomaterials.2014.04.095

  • 104

    DuanSSongMHeJZhouNZhouSZhaoJet al. Folate-modified chitosan nanoparticles coated interferon-inducible protein-10 gene enhance cytotoxic T lymphocytes' responses to hepatocellular carcinoma. J BioMed Nanotechnol (2016) 12(4):700–9. doi: 10.1166/jbn.2016.2216

  • 105

    ZhuHCaoJCuiSQianZGuY. Enhanced tumor targeting and antitumor efficacy via hydroxycamptothecin-encapsulated folate-modified n-succinyl-N'-octyl chitosan micelles. J Pharm Sci (2013) 102(4):1318–32. doi: 10.1002/jps.23470

  • 106

    HeJDuanSYuXQianZZhouSZhangZet al. Folate-modified chitosan nanoparticles containing the IP-10 gene enhance melanoma-specific cytotoxic CD8(+)CD28(+) T lymphocyte responses. Theranostics (2016) 6(5):752–61. doi: 10.7150/thno.14527

  • 107

    de LeveSWirsdorferFJendrossekV. Targeting the immunomodulatory CD73/Adenosine system to improve the therapeutic gain of radiotherapy. Front Immunol (2019) 10:698. doi: 10.3389/fimmu.2019.00698

  • 108

    AllardDAllardBGaudreauPOChrobakPStaggJ. CD73-adenosine: a next-generation target in immuno-oncology. Immunotherapy (2016) 8(2):145–63. doi: 10.2217/imt.15.106

  • 109

    LoiSPommeySHaibe-KainsBBeavisPADarcyPKSmythMJet al. CD73 promotes anthracycline resistance and poor prognosis in triple negative breast cancer. Proc Natl Acad Sci USA (2013) 110(27):11091–6. doi: 10.1073/pnas.1222251110

  • 110

    VetsikaEKKoukosAKotsakisA. Myeloid-derived suppressor cells: Major figures that shape the immunosuppressive and angiogenic network in cancer. Cells (2019) 8(12):1647. doi: 10.3390/cells8121647

  • 111

    DuongCNVestweberD. Mechanisms ensuring endothelial junction integrity beyond VE-cadherin. Front Physiol (2020) 11:519. doi: 10.3389/fphys.2020.00519

  • 112

    WallezYVilgrainIHuberP. Angiogenesis: the VE-cadherin switch. Trends Cardiovasc Med (2006) 16(2):55–9. doi: 10.1016/j.tcm.2005.11.008

  • 113

    LabelleMSchnittlerHJAustDEFriedrichKBarettonGVestweberDet al. Vascular endothelial cadherin promotes breast cancer progression via transforming growth factor beta signaling. Cancer Res (2008) 68(5):1388–97. doi: 10.1158/0008-5472.CAN-07-2706

  • 114

    YuWYangLLiTZhangY. Cadherin signaling in cancer: Its functions and role as a therapeutic target. Front Oncol (2019) 9:989. doi: 10.3389/fonc.2019.00989

  • 115

    ChoiHGChoiSBackYWPaikSParkHSKimWSet al. Rv2299c, a novel dendritic cell-activating antigen of mycobacterium tuberculosis, fused-ESAT-6 subunit vaccine confers improved and durable protection against the hypervirulent strain HN878 in mice. Oncotarget (2017) 8(12):19947–67. doi: 10.18632/oncotarget.15256

  • 116

    FucikovaJHenslerMKasikovaLLanickovaTPasulkaJRakovaJet al. An autologous dendritic cell vaccine promotes anticancer immunity in patients with ovarian cancer with low mutational burden and cold tumors. Clin Cancer Res (2022) 28(14):3053–65. doi: 10.1158/1078-0432.CCR-21-4413

  • 117

    NicklesEDharmadhikariBYatingLWalshRJKohLPPoonMet al. Dendritic cell therapy with CD137L-DC-EBV-VAX in locally recurrent or metastatic nasopharyngeal carcinoma is safe and confers clinical benefit. Cancer Immunol Immunother (2022) 71(6):1531–43. doi: 10.1007/s00262-021-03075-3

  • 118

    VogelzangNJBeerTMGerritsenWOudardSWiechnoPKukielka-BudnyBet al. Efficacy and safety of autologous dendritic cell-based immunotherapy, docetaxel, and prednisone vs placebo in patients with metastatic castration-resistant prostate cancer: The VIABLE phase 3 randomized clinical trial. JAMA Oncol (2022) 8(4):546–52. doi: 10.1001/jamaoncol.2021.7298

  • 119

    HuJLOmofoyeOARudnickJDKimSTighiouartMPhuphanichSet al. A phase I study of autologous dendritic cell vaccine pulsed with allogeneic stem-like cell line lysate in patients with newly diagnosed or recurrent glioblastoma. Clin Cancer Res (2022) 28(4):689–96. doi: 10.1158/1078-0432.CCR-21-2867

  • 120

    TryggestadAMAAxcronaKAxcronaUBigalkeIBrennhovdBInderbergEMet al. Long-term first-in-man phase I/II study of an adjuvant dendritic cell vaccine in patients with high-risk prostate cancer after radical prostatectomy. Prostate (2022) 82(2):245–53. doi: 10.1002/pros.24267

  • 121

    OtaSMiyashitaMYamagishiYOgasawaraM. Baseline immunity predicts prognosis of pancreatic cancer patients treated with WT1 and/or MUC1 peptide-loaded dendritic cell vaccination and a standard chemotherapy. Hum Vaccin Immunother (2021) 17(12):5563–72. doi: 10.1080/21645515.2021.2003645

  • 122

    StorkusWJMaurerDLinYDingFBoseALoweDet al. Dendritic cell vaccines targeting tumor blood vessel antigens in combination with dasatinib induce therapeutic immune responses in patients with checkpoint-refractory advanced melanoma. J Immunother Cancer (2021) 9(11):e003675. doi: 10.1136/jitc-2021-003675

  • 123

    ChevallierPSaiaghSDehameVGuillaumeTPeterlinPBercegeaySet al. A phase I/II feasibility vaccine study by autologous leukemic apoptotic corpse-pulsed dendritic cells for elderly AML patients. Hum Vaccin Immunother (2021) 17(10):3511–4. doi: 10.1080/21645515.2021.1943991

  • 124

    OlinMRLowWMcKennaDHHainesSJDahlheimerTNasceneDet al. Vaccination with dendritic cells loaded with allogeneic brain tumor cells for recurrent malignant brain tumors induces a CD4(+)IL17(+) response. J Immunother Cancer (2014) 2:4. doi: 10.1186/2051-1426-2-4

  • 125

    SantistebanMSolansBPHatoLUrrizolaAMejiasLDSalgadoEet al. Final results regarding the addition of dendritic cell vaccines to neoadjuvant chemotherapy in early HER2-negative breast cancer patients: Clinical and translational analysis. Ther Adv Med Oncol (2021) 13:17588359211064653. doi: 10.1177/17588359211064653

  • 126

    ZhangWLuXCuiPPiaoCXiaoMLiuXet al. Phase I/II clinical trial of a wilms' tumor 1-targeted dendritic cell vaccination-based immunotherapy in patients with advanced cancer. Cancer Immunol Immunother (2019) 68(1):121–30. doi: 10.1007/s00262-018-2257-2

  • 127

    MatsudaTTakeuchiHSakuraiTMayanagiSBookaEFujitaTet al. Pilot study of WT1 peptide-pulsed dendritic cell vaccination with docetaxel in esophageal cancer. Oncol Lett (2018) 16(1):1348–56. doi: 10.3892/ol.2018.8734

  • 128

    IclozanCAntoniaSChiapporiAChenDTGabrilovichD. Therapeutic regulation of myeloid-derived suppressor cells and immune response to cancer vaccine in patients with extensive stage small cell lung cancer. Cancer Immunol Immunother (2013) 62(5):909–18. doi: 10.1007/s00262-013-1396-8

  • 129

    Van WigcherenGFDe HaasNMulderTAHorrevortsSKBloemendalMHins-DebreeSet al. Cisplatin inhibits frequency and suppressive activity of monocytic myeloid-derived suppressor cells in cancer patients. Oncoimmunology (2021) 10(1):1935557. doi: 10.1080/2162402X.2021.1935557

  • 130

    ButterfieldLHVujanovicLSantosPMMaurerDMGambottoALohrJet al. Multiple antigen-engineered DC vaccines with or without IFNalpha to promote antitumor immunity in melanoma. J Immunother Cancer (2019) 7(1):113. doi: 10.1186/s40425-019-0552-x

  • 131

    KongstedPBorchTHEllebaekEIversenTZAndersenRMetOet al. Dendritic cell vaccination in combination with docetaxel for patients with metastatic castration-resistant prostate cancer: A randomized phase II study. Cytotherapy (2017) 19(4):500–13. doi: 10.1016/j.jcyt.2017.01.007

  • 132

    MatsushitaHEnomotoYKumeHNakagawaTFukuharaHSuzukiMet al. A pilot study of autologous tumor lysate-loaded dendritic cell vaccination combined with sunitinib for metastatic renal cell carcinoma. J Immunother Cancer (2014) 2:30. doi: 10.1186/s40425-014-0030-4

  • 133

    FedorovaLMudryPPilatovaKSelingerovaIMerhautovaJRehakZet al. Assessment of immune response following dendritic cell-based immunotherapy in pediatric patients with relapsing sarcoma. Front Oncol (2019) 9:1169. doi: 10.3389/fonc.2019.01169

  • 134

    BlagihJZaniFChakravartyPHennequartMPilleySHoborSet al. Cancer-specific loss of p53 leads to a modulation of myeloid and T cell responses. Cell Rep (2020) 30(2):48196.e6. doi: 10.1016/j.celrep.2019.12.028

  • 135

    GuoGMarreroLRodriguezPDel ValleLOchoaACuiY. Trp53 inactivation in the tumor microenvironment promotes tumor progression by expanding the immunosuppressive lymphoid-like stromal network. Cancer Res (2013) 73(6):1668–75. doi: 10.1158/0008-5472.CAN-12-3810

  • 136

    WuJLiuXReeserJAWTrimboliAJPecotTSizemoreGMet al. Stromal p53 regulates breast cancer development, the immune landscape, and survival in an oncogene-specific manner. Mol Cancer Res (2022) 20(8):1233–46. doi: 10.1158/1541-7786.MCR-21-0960

  • 137

    YounJICollazoMShalovaINBiswasSKGabrilovichDI. Characterization of the nature of granulocytic myeloid-derived suppressor cells in tumor-bearing mice. J Leukoc Biol (2012) 91(1):167–81. doi: 10.1189/jlb.0311177

  • 138

    Alicea-TorresKSansevieroEGuiJChenJVegliaFYuQet al. Immune suppressive activity of myeloid-derived suppressor cells in cancer requires inactivation of the type I interferon pathway. Nat Commun (2021) 12(1):1717. doi: 10.1038/s41467-021-22033-2

  • 139

    Mundy-BosseBLLesinskiGBJaime-RamirezACBenningerKKhanMKuppusamyPet al. Myeloid-derived suppressor cell inhibition of the IFN response in tumor-bearing mice. Cancer Res (2011) 71(15):5101–10. doi: 10.1158/0008-5472.CAN-10-2670

  • 140

    EisenthalACameronRBRosenbergSA. Induction of antibody-dependent cellular cytotoxicity in vivo by IFN-alpha and its antitumor efficacy against established B16 melanoma liver metastases when combined with specific anti-B16 monoclonal antibody. J Immunol (1990) 144(11):4463–71.

  • 141

    SleijferSBanninkMVan GoolARKruitWHStoterG. Side effects of interferon-alpha therapy. Pharm World Sci (2005) 27(6):423–31. doi: 10.1007/s11096-005-1319-7

  • 142

    MotzerRJRiniBIBukowskiRMCurtiBDGeorgeDJHudesGRet al. Sunitinib in patients with metastatic renal cell carcinoma. JAMA (2006) 295(21):2516–24. doi: 10.1001/jama.295.21.2516

  • 143

    RizzoMPortaC. Sunitinib in the treatment of renal cell carcinoma: an update on recent evidence. Ther Adv Urol (2017) 9(8):195207. doi: 10.1177/1756287217713902

  • 144

    KollmannsbergerCSoulieresDWongRScaleraAGaspoRBjarnasonG. Sunitinib therapy for metastatic renal cell carcinoma: recommendations for management of side effects. Can Urol Assoc J (2007) 1(2 Suppl):S41–54. doi: 10.5489/cuaj.67

  • 145

    KoJSZeaAHRiniBIIrelandJLElsonPCohenPet al. Sunitinib mediates reversal of myeloid-derived suppressor cell accumulation in renal cell carcinoma patients. Clin Cancer Res (2009) 15(6):2148–57. doi: 10.1158/1078-0432.CCR-08-1332

  • 146

    FinkeJHRiniBIrelandJRaymanPRichmondAGolshayanAet al. Sunitinib reverses type-1 immune suppression and decreases T-regulatory cells in renal cell carcinoma patients. Clin Cancer Res (2008) 14(20):6674–82. doi: 10.1158/1078-0432.CCR-07-5212

  • 147

    XinHZhangCHerrmannADuYFiglinRYuH. Sunitinib inhibition of Stat3 induces renal cell carcinoma tumor cell apoptosis and reduces immunosuppressive cells. Cancer Res (2009) 69(6):2506–13. doi: 10.1158/0008-5472.CAN-08-4323

  • 148

    WeiSKozonoSKatsLNechamaMLiWGuarnerioJet al. Active Pin1 is a key target of all-trans retinoic acid in acute promyelocytic leukemia and breast cancer. Nat Med (2015) 21(5):457–66. doi: 10.1038/nm.3839

  • 149

    GuruvayoorappanCBerlin GraceVM. All trans retinoic acid and cancer. Immunopharmacol Immunotoxicol (2011) 33(2):241–9. doi: 10.3109/08923973.2010.521507

  • 150

    DarmaninSChenJZhaoSCuiHShirkoohiRKuboNet al. All-trans retinoic acid enhances murine dendritic cell migration to draining lymph nodes via the balance of matrix metalloproteinases and their inhibitors. J Immunol (2007) 179(7):4616–25. doi: 10.4049/jimmunol.179.7.4616

  • 151

    MirzaNFishmanMFrickeIDunnMNeugerAMFrostTJet al. All-trans-retinoic acid improves differentiation of myeloid cells and immune response in cancer patients. Cancer Res (2006) 66(18):9299–307. doi: 10.1158/0008-5472.CAN-06-1690

  • 152

    SaxenaMvan der BurgSHMeliefCJMBhardwajN. Therapeutic cancer vaccines. Nat Rev Cancer (2021) 21(6):360–78. doi: 10.1038/s41568-021-00346-0

  • 153

    BolKFSchreibeltGGerritsenWRde VriesIJFigdorCG. Dendritic cell-based immunotherapy: State of the art and beyond. Clin Cancer Res (2016) 22(8):1897–906. doi: 10.1158/1078-0432.CCR-15-1399

  • 154

    TruxovaIHenslerMSkapaPHalaskaMJLacoJRyskaAet al. Rationale for the combination of dendritic cell-based vaccination approaches with chemotherapy agents. Int Rev Cell Mol Biol (2017) 330:115–56. doi: 10.1016/bs.ircmb.2016.09.003

  • 155

    UruenaCLassoPBernal-EstevezDRubioDSalazarAJOlayaMet al. The breast cancer immune microenvironment is modified by neoadjuvant chemotherapy. Sci Rep (2022) 12(1):7981. doi: 10.1038/s41598-022-12108-5

  • 156

    WesolowskiRDugganMCStiffAMarkowitzJTrikhaPLevineKMet al. Circulating myeloid-derived suppressor cells increase in patients undergoing neo-adjuvant chemotherapy for breast cancer. Cancer Immunol Immunother (2017) 66(11):1437–47. doi: 10.1007/s00262-017-2038-3

  • 157

    LiFZhaoYWeiLLiSLiuJ. Tumor-infiltrating treg, MDSC, and IDO expression associated with outcomes of neoadjuvant chemotherapy of breast cancer. Cancer Biol Ther (2018) 19(8):695705. doi: 10.1080/15384047.2018.1450116

  • 158

    FallahJDiaz-MonteroCMRaymanPWeiWFinkeJHKimJSet al. Myeloid-derived suppressor cells in nonmetastatic urothelial carcinoma of bladder is associated with pathologic complete response and overall survival. Clin Genitourin Cancer (2020) 18(6):500–8. doi: 10.1016/j.clgc.2020.03.004

  • 159

    MillrudCRMehmetiMLeanderssonK. Docetaxel promotes the generation of anti-tumorigenic human macrophages. Exp Cell Res (2018) 362(2):525–31. doi: 10.1016/j.yexcr.2017.12.018

  • 160

    KodumudiKNWoanKGilvaryDLSahakianEWeiSDjeuJY. A novel chemoimmunomodulating property of docetaxel: suppression of myeloid-derived suppressor cells in tumor bearers. Clin Cancer Res (2010) 16(18):4583–94. doi: 10.1158/1078-0432.CCR-10-0733

  • 161

    TesiRJ. MDSC; the most important cell you have never heard of. Trends Pharmacol Sci (2019) 40(1):47. doi: 10.1016/j.tips.2018.10.008

  • 162

    LawAMKValdes-MoraFGallego-OrtegaD. Myeloid-derived suppressor cells as a therapeutic target for cancer. Cells (2020) 9(3):561. doi: 10.3390/cells9030561

Summary

Keywords

dendritic cells, myeloid-derived suppressor cells, vaccines, cancer, immunosuppression

Citation

Sánchez-León ML, Jiménez-Cortegana C, Cabrera G, Vermeulen EM, de la Cruz-Merino L and Sánchez-Margalet V (2022) The effects of dendritic cell-based vaccines in the tumor microenvironment: Impact on myeloid-derived suppressor cells. Front. Immunol. 13:1050484. doi: 10.3389/fimmu.2022.1050484

Received

22 September 2022

Accepted

27 October 2022

Published

15 November 2022

Volume

13 - 2022

Edited by

Fernando Aranda, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Spain

Reviewed by

Oliver Kepp, INSERM U1138 Centre de Recherche des Cordeliers (CRC), France; Diana Llopiz, University of Navarra, Spain

Updates

Copyright

*Correspondence: Carlos Jiménez-Cortegana,

†These authors have contributed equally to this work

This article was submitted to Cancer Immunity and Immunotherapy, a section of the journal Frontiers in Immunology

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.

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