Deciphering the Roles of Innate Lymphoid Cells in Cancer
Cancer is a complex disease and the role played by innate lymphoid cells (ILCs) in cancer development has begun to be uncovered over recent years. We aim to provide an exhaustive summary of the knowledge acquired on the role of ILCs in cancer. ILCs are classified into 3 different categories, ILC1s, ILC2s, and ILC3s, each encompassing specific and unique functions. ILC1s exhibit NK cells characteristics and can exert anti-tumor functions, but surprisingly their IFNγ production is not associated with a better immune response. In response to TGF-β or IL-12, ILC1s were shown to exert pro-tumor functions and to favor tumor growth. ILC2s role in cancer immune response is dependent on cytokine con…
Modulation of CD4 T Cell Response According to Tumor Cytokine Microenvironment
Simple Summary It is now accepted that CD4 T lymphocytes play an essential role in the anti-tumor response. CD4 T lymphocytes can activate and regulate several aspects of innate and adaptive immunity and participate in the rejection of tumors. Understanding the impact of the tumor, through cytokines present in the microenvironment, but also the effect of anti-cancer therapies are critical aspects of immunotherapy research aiming at improving the anti-tumor response dependent on CD4 T lymphocytes. Abstract The advancement of knowledge on tumor biology over the past decades has demonstrated a close link between tumor cells and cells of the immune system. In this context, cytokines have a majo…
Stat3 and Gfi-1 Transcription Factors Control Th17 Cell Immunosuppressive Activity via the Regulation of Ectonucleotidase Expression
International audience; Although Th17 cells are known to promote tissue inflammation and autoimmunity, their role during cancer progression remains elusive. Here, we showed that in vitro Th17 cells generated with the cytokines IL-6 and TGF-β expressed CD39 and CD73 ectonucleotidases, leading to adenosine release and the subsequent suppression of CD4(+) and CD8(+) T cell effector functions. The IL-6-mediated activation of the transcription factor Stat3 and the TGF-β-driven downregulation of Gfi-1 transcription factor were both essential for the expression of ectonucleotidases during Th17 cell differentiation. Stat3 supported whereas Gfi-1 repressed CD39 and CD73 expression by binding to thei…
Production of Adenosine by Ectonucleotidases: A Key Factor in Tumor Immunoescape
It is now well known that tumor immunosurveillance contributes to the control of cancer growth. Many mechanisms can be used by cancer cells to avoid the antitumor immune response. One such mechanism relies on the capacity of cancer cells or more generally of the tumor microenvironment to generate adenosine, a major molecule involved in antitumor T cell response suppression. Adenosine is generated by the dephosphorylation of extracellular ATP released by dying tumor cells. The conversion of ATP into adenosine is mediated by ectonucleotidase molecules, namely, CD73 and CD39. These molecules are frequently expressed in the tumor bed by a wide range of cells including tumor cells, regulatory T …
SOCS3 transactivation by PPARγ prevents IL-17-driven cancer growth.
Abstract Activation of the transcription factor PPARγ by the n-3 fatty acid docosahexaenoic acid (DHA) is implicated in controlling proinflammatory cytokine secretion, but the intracellular signaling pathways engaged by PPARγ are incompletely characterized. Here, we identify the adapter-encoding gene SOCS3 as a critical transcriptional target of PPARγ. SOCS3 promoter binding and gene transactivation by PPARγ was associated with a repression in differentiation of proinflammatory T-helper (TH)17 cells. Accordingly, TH17 cells induced in vitro displayed increased SOCS3 expression and diminished capacity to produce interleukin (IL)-17 following activation of PPARγ by DHA. Furthermore, naïve CD4…
Vascular Endothelial Growth Factor, a Key Modulator of the Anti-Tumor Immune Response
During tumor growth, angiogenesis is required to ensure oxygen and nutrient transport to the tumor. Vascular endothelial growth factor (VEGF) is the major inducer of angiogenesis and appears to be a key modulator of the anti-tumor immune response. Indeed, VEGF modulates innate and adaptive immune responses through direct interactions and indirectly by modulating protein expressions on endothelial cells or vascular permeability. The inhibition of the VEGF signaling pathway is clinically approved for the treatment of several cancers. Therapies targeting VEGF can modulate the tumor vasculature and the immune response. In this review, we discuss the roles of VEGF in the anti-tumor immune respon…
Bleomycin Exerts Ambivalent Antitumor Immune Effect by Triggering Both Immunogenic Cell Death and Proliferation of Regulatory T Cells
International audience; Bleomycin (BLM) is an anticancer drug currently used for the treatment of testis cancer and Hodgkin lymphoma. This drug triggers cancer cell death via its capacity to generate radical oxygen species (ROS). However, the putative contribution of anticancer immune responses to the efficacy of BLM has not been evaluated. We make here the observation that BLM induces immunogenic cell death. In particular, BLM is able to induce ROS-mediated reticulum stress and autophagy, which result in the surface exposure of chaperones, including calreticulin and ERp57, and liberation of HMBG1 and ATP. BLM induces anti-tumor immunity which relies on calreticulin, CD8(+) T cells and inte…
The receptor NLRP3 is a transcriptional regulator of TH2 differentiation.
The receptor NLRP3 is involved in the formation of the NLRP3 inflammasome that activates caspase-1 and mediates the release of interleukin 1β (IL-1β) and IL-18. Whether NLRP3 can shape immunological function independently of inflammasomes is unclear. We found that NLRP3 expression in CD4(+) T cells specifically supported a T helper type 2 (TH2) transcriptional program in a cell-intrinsic manner. NLRP3, but not the inflammasome adaptor ASC or caspase-1, positively regulated a TH2 program. In TH2 cells, NLRP3 bound the Il4 promoter and transactivated it in conjunction with the transcription factor IRF4. Nlrp3-deficient TH2 cells supported melanoma tumor growth in an IL-4-dependent manner and …
Immune effects of 5-fluorouracil
Cytotoxic anticancer drugs can promote antitumor immune responses. The anticancer activity of 5-fluorouracil (5FU) relies on the restoration of T-cell immunity following the elimination of myeloid-derived suppressor cells (MDSCs). We have recently discovered that the 5FU-driven activation of the NLRP3 inflammasome in MDSCs promotes tumor angiogenesis by eliciting TH17 responses that compromise anticancer immunity. This underscores the need to combine 5-FU with NLRP3 inhibitors to prevent tumor progression.
Dacarbazine-mediated upregulation of NKG2D ligands on tumor cells activates NK and CD8 T cells and restrains melanoma growth.
International audience; Dacarbazine (DTIC) is a cytotoxic drug widely used for melanoma treatment. However, the putative contribution of anticancer immune responses in the efficacy of DTIC has not been evaluated. By testing how DTIC affects host immune responses to cancer in a mouse model of melanoma, we unexpectedly found that both natural killer (NK) and CD8(+) T cells were indispensable for DTIC therapeutic effect. Although DTIC did not directly affect immune cells, it triggered the upregulation of NKG2D ligands on tumor cells, leading to NK cell activation and IFNγ secretion in mice and humans. NK cell-derived IFNγ subsequently favored upregulation of major histocompatibility complex cl…
Chemotherapy-triggered cathepsin B release in myeloid-derived suppressor cells activates the Nlrp3 inflammasome and promotes tumor growth
International audience; Chemotherapeutic agents are widely used for cancer treatment. In addition to their direct cytotoxic effects, these agents harness the host's immune system, which contributes to their antitumor activity. Here we show that two clinically used chemotherapeutic agents, gemcitabine (Gem) and 5-fluorouracil (5FU), activate the NOD-like receptor family, pyrin domain containing-3 protein (Nlrp3)-dependent caspase-1 activation complex (termed the inflammasome) in myeloid-derived suppressor cells (MDSCs), leading to production of interleukin-1β (IL-1β), which curtails anticancer immunity. Chemotherapy-triggered IL-1β secretion relied on lysosomal permeabilization and the relea…
5-Fluorouracil Selectively Kills Tumor-Associated Myeloid-Derived Suppressor Cells Resulting in Enhanced T Cell–Dependent Antitumor Immunity
AbstractMyeloid-derived suppressor cells (MDSC) accumulate in the spleen and tumor bed during tumor growth. They contribute to the immune tolerance of cancer notably by inhibiting the function of CD8(+) T cells. Thus, their elimination may hamper tumor growth by enhancing antitumor T-cell functions. We have previously reported that some anticancer agents relied on T cell–dependent anticancer responses to achieve maximal efficacy. However, the effect of anticancer agents on MDSC has remained largely unexplored. In this study, we observed that gemcitabine and 5-fluorouracil (5FU) were selectively cytotoxic on MDSC. In vivo, the treatment of tumor-bearing mice with 5FU led to a major decrease …
The transcription factor IRF1 dictates the IL-21-dependent anticancer functions of TH9 cells
The TH9 subset of helper T cells was initially shown to contribute to the induction of autoimmune and allergic diseases, but subsequent evidence has suggested that these cells also exert antitumor activities. However, the molecular events that account for their effector properties are elusive. Here we found that the transcription factor IRF1 enhanced the effector function of TH9 cells and dictated their anticancer properties. Under TH9-skewing conditions, interleukin 1β (IL-1β) induced phosphorylation of the transcription factor STAT1 and subsequent expression of IRF1, which bound to the promoters of Il9 and Il21 and enhanced secretion of the cytokines IL-9 and IL-21 from TH9 cells. Further…
Etude de NLRP3 dans les cellules myéloïdes immunosuppressives et les lymphocytes TCD4 dans un contexte de cancer
The inflammasome NLRP3 (NOD like receptor pyd containing 3) is a multiprotein complex notably responsible for IL-1β (interleukine-1β) production, an inflammatory cytokine. Negative effects have been observed in various diseases including cancer. My thesis focuses on the effects of NLRP3 in cancer.In my first project, I studied the NLRP3 inflammasome activation in MDSC (myeloïd derived suppressor cells) after a chemotherapy treatment. Two chemotherapies, 5-Fluorouracil and Gemcitabine, are selectively able to kill MDSC, an immunosuppressive population growing during cancer evolution. MDSC’s death restores anti-tumor immunity for a while but another immunosuppressive population is established…