Project description:T cell receptor (TCR) signaling is a critical process in immunity to infectious disease and cancer. Recently, a genome-wide association study has implicated polymorphisms in the CISH locus with susceptibility to infectious diseases. However, the role of Cish in the immune responses and its molecular underpinnings remains unclear. Here we demonstrate that Cish deletion resulted in protection against viral infection and enhanced CD8+ T cell tumor immunity. Transcriptome profiling revealed a hyper-TCR activation signature in Cish-deficient CD8+ T cells. Subsequent analysis revealed an inhibitory role for Cish in PLCγ1 activation, ensuing Ca2+ release and downstream signaling. In the steady-state Cish was found to physically interact with PLCγ1, however, PLCγ1 was only found to be ubiquitinated after acute TCR stimulation in the presence of Cish. These data implicate Cish as a potent negative regulator of TCR signaling and T cell immunity to infection and cancer and may have significant clinical applications. 4 biological replicates from wild-type mice and 3 biological replicates from Cish knock-out (-/-) mice were analyzed.
Project description:T cell receptor (TCR) signaling is a critical process in immunity to infectious disease and cancer. Recently, a genome-wide association study has implicated polymorphisms in the CISH locus with susceptibility to infectious diseases. However, the role of Cish in the immune responses and its molecular underpinnings remains unclear. Here we demonstrate that Cish deletion resulted in protection against viral infection and enhanced CD8+ T cell tumor immunity. Transcriptome profiling revealed a hyper-TCR activation signature in Cish-deficient CD8+ T cells. Subsequent analysis revealed an inhibitory role for Cish in PLCγ1 activation, ensuing Ca2+ release and downstream signaling. In the steady-state Cish was found to physically interact with PLCγ1, however, PLCγ1 was only found to be ubiquitinated after acute TCR stimulation in the presence of Cish. These data implicate Cish as a potent negative regulator of TCR signaling and T cell immunity to infection and cancer and may have significant clinical applications.
Project description:Antibodies targeting “immune checkpoints” have revolutionized cancer therapy by reactivating tumor-resident cytotoxic lymphocytes, primarily CD8 T cells. Interest in targeting analogous pathways in other cytotoxic lymphocytes is growing. Natural killer (NK) cells are key to cancer immunosurveillance by eradicating metastases and driving solid tumor inflammation. NK cell anti-tumor function is dependent on the cytokine interleukin (IL)-15. Ablation of the IL-15 signaling inhibitor CIS (Cish) enhances NK cell anti-tumor immunity by increasing NK cell metabolism and persistence within the tumor microenvironment (TME). The TME has also been shown to impair NK cell fitness via the production of immunosuppressive TGF-b, a suppression which occurs even in the presence of high IL-15 signaling. Here, we identified an unexpected interaction between CIS and the TGF-b signaling pathway in NK cells. Independently, Cish- and Tgfbr2- deficient NK cells are both hyper-responsive to IL-15 and hypo-responsive to TGF-b, with dramatically enhanced anti-tumor immunity. Remarkably, when both these immunosuppressive genes are simultaneously deleted in NK cells, mice are largely resistant to tumor development, suggesting that combining suppression of these two pathways might represent a novel therapeutic strategy to enhance innate anti-cancer immunity.
Project description:RIG-I is a pattern recognition receptor involved in innate immunity, but its role in adaptive immunity remains unclear. Here, we demonstrate that RIG-I is upregulated in tumor infiltrating CD8+ T cells, where it functions as an intracellular checkpoint to negatively regulate CD8+ T cell function and limit antitumor immunity. Mechanically, up-regulation of RIG-I in CD8+ T cells is induced by retinoic acid (RA), a metabolite of vitamin A in TME, and direct inhibits the AKT/glycolysis signaling pathway. In addition, deletion of RIG-I enhances the efficacy of adoptively transferred T cells against solid tumors and inhibition of RIG-I enhances the response to PD-1 blockade. Our findings identify RIG-I as an intracellular checkpoint and a potential target for alleviating inhibitory constraints on T cells in cancer immunotherapy, either alone or in combination with immune checkpoint blockade.
Project description:We developed human CISH-knockout (CISH-/-) NK cells using an induced pluripotent stem cell-derived NK cell (iPSC-NK cell) platform. And compare transcriptomes of CISH-/- iPSC NK cells with wild type iPSC NK cells using RNA seq. RNA seq data suggested that genes involved in the JAK-STAT signaling pathway and lymphocyte activations were significantly activated in CISH-/- iPSC NK cells.
Project description:TGFb signaling is a major pathway associated with poor clinical outcome in patients with
advanced metastatic cancers and non-response to immune checkpoint blockade, particularly in the immune-excluded tumor phenotype. While previous pre-clinical studies demonstrated that converting tumors from an excluded to an inflamed phenotype and curative anti-tumor immunity require attenuation of both PD-L1 and TGFb signaling, the underlying cellular mechanisms remain unclear. Recent studies suggest that stem cell-like CD8 T cells (TSCL) can differentiate into non-exhausted CD8 T effector cells that drive durable anti-tumor immunity. Here, we show that TGFb and PD-L1 restrain TSCL expansion as well as replacement of progenitor exhausted and dysfunctional CD8 T cells with non-exhausted IFNghi CD8 T effector cells in the tumor microenvironment (TME). Blockade of TGFb and PD-L1 generated IFNghi CD8 T effector cells with enhanced motility, enabling both their accumulation in the TME and increased interaction with other cell types. Ensuing IFNg signaling markedly transformed myeloid, stromal, and tumor niches to yield a broadly immune-supportive ecosystem. Blocking IFNg completely abolished the effect of anti-PD-L1/ TGFb combination therapy. Our data suggest that TGFb works in concert with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells with fresh CD8
T effector cells, thereby maintaining the CD8 T cell compartment in a dysfunctional state.
Project description:GM-CSF paradoxically possesses ability to differentiate both classically activated macrophages (MØs) with dominant proinflammatory function (M1-like MØs) and alternative activated MØs with strong immunosuppressive function (M2-like MØs). The intrinsic regulatory mechanism responsible for functional polarization of MØs under GM-CSF signalling remains elusive. Here we revealed that cytokine-inducible SH2-containing protein (CIS), induced by GM-CSF, is a key determinant in controlling MØ polarization. Compared to WT MØs, Cish-/- MØs gained characteristics of alternative activated MØs (M2 MØs), showing high expression of prototypic M2 markers Arginase 1, Tgm2 and YM-1; strong suppression of T cell proliferation; and low production of IL-12 and other proinflammatory cytokines¬¬. Differing from canonical IL-4/STAT6/IRF4 signaling axis of M2 induction, development of M2 MØ characteristics in Cish-/- MØs was associated with intensified STAT5 activation and consequent IRF8 downregulation. Attenuation of GM-CSF signalling via JAK inhibition and IRF8 rescue corrected certain functional defects in Cish-/- MØs. As CIS inhibition in NK and T cells promotes anti-tumour immunity, we showed that CIS deficiency enhanced the development of intra-tumoural M2 MØs and reduced CTL induction within tumour microenvironment with elevated GM-CSF. Overall, we conclude that CIS acts as an intrinsic rheostat to control intense GM-CSF signalling in order to maintain proinflammatory functions of MØs. Targeting CIS as a checkpoint in cancer immunotherapy should consider its role in regulating myeloid cell function.
Project description:<p>Plasmacytoid dendritic cells (pDC) are a subset of dendritic cells with unique immunophenotypic properties and functions. While their role in antiviral immunity through production of type I interferons is well-established, their contributions to anti-tumor immunity are less clear. While some evidence demonstrates that pDC in the tumor microenvironment (TME) may drive CD4+ T cell to become <a href="https://www.ncbi.nlm.nih.gov/gene/50943">Foxp3</a>+ T regulatory cells, little is understood about the relationship of pDC with cytotoxic CD8+ T cell, the key player in antitumor immune responses.</p> <p>In this study, we perform comprehensive immunophenotyping and functional analysis of pDC from the TME and draining lymph nodes of patients with head and neck squamous cell carcinoma (HNSCC) and identify a novel pDC subset characterized by expression of the TNF receptor superfamily member <a href="https://www.ncbi.nlm.nih.gov/gene/?term=7293">CD134 (OX40)</a>. We show that OX40 expression is expressed on intratumoral pDC in both humans and mice in a tumor-model specific fashion and that this subset of pDC enhances tumor associated-antigen (TAA)-specific CD8+ T cell responses. Through transcriptomic profiling of OX40-expressing pDC from the TME, we further characterize gene signatures unique to this pDC subset that support its role as an important immunostimulatory immune population in the TME.</p>