Project description:PD-1 blockade therapy, harnessing the cytotoxic potential of CD8+ T cells, has yielded clinical success in treating malignancies. However, its efficacy is often limited due to the progressive differentiation of intratumoral CD8+ T cells into a hypofunctional state known as terminal exhaustion. Despite identifying CD8+ T cell subsets associated with immunotherapy resistance, the molecular pathway triggering the resistance remains elusive. Given the clear association of CD38 with CD8+ T cell subsets resistant to anti-PD1 therapy, we investigated its role in inducing resistance. Phenotypic and functional characterization, along with single-cell RNA sequencing analysis of both in vitro chronically stimulated and intratumoral CD8+ T cells, revealed that CD38-expressing CD8+ T cells are terminally exhausted. Exploring the molecular mechanism, we discovered that CD38 expression was crucial in promoting terminal differentiation of CD8+ T cells by suppressing TCF1 expression, thereby rendering them unresponsive to anti-PD1 therapy. Genetic ablation of CD38 in tumor reactive CD8+ T cells restored TCF1 levels and improved the responsiveness to anti-PD1 therapy in mice. Mechanistically, CD38 expression on exhausted CD8+ T cells elevated intracellular Ca2+ levels through RyR2 calcium channel activation. This, in turn, promoted chronic AKT activation, leading to TCF1 loss. Knockdown of RyR2 or inhibition of AKT in CD8+ T cells maintained TCF1 levels, induced a sustained anti-tumor response, and enhanced responsiveness to anti-PD1 therapy. Thus, targeting CD38 represents a potential strategy to improve the efficacy of anti-PD1 treatment in cancer.
Project description:PD1 blockade therapy, harnessing the cytotoxic potential of CD8+ T cells, has yielded clinical success in treating malignancies. However, its efficacy is often limited due to the progressive differentiation of intratumoral CD8+ T cells into a hypofunctional state known as terminal exhaustion. Despite identifying CD8+ T cell subsets associated with immunotherapy resistance, the molecular pathway triggering the resistance remains elusive. Given the clear association of CD38 with CD8+ T cell subsets resistant to anti-PD1 therapy, we investigated its role in inducing resistance. Phenotypic and functional characterization, along with single-cell RNA sequencing analysis of both in vitro chronically stimulated and intratumoral CD8+ T cells, revealed that CD38-expressing CD8+ T cells are terminally exhausted. Exploring the molecular mechanism, we found that CD38 expression was crucial in promoting terminal differentiation of CD8+ T cells by suppressing TCF1 expression, thereby rendering them unresponsive to anti-PD1 therapy. Genetic ablation of CD38 in tumor-reactive CD8+ T cells restored TCF1 levels and improved the responsiveness to anti-PD1 therapy in mice. Mechanistically, CD38 expression on exhausted CD8+ T cells elevated intracellular Ca2+ levels through RyR2 calcium channel activation. This, in turn, promoted chronic AKT activation, leading to TCF1 loss. Knockdown of RyR2 or inhibition of AKT in CD8+ T cells maintained TCF1 levels, induced a sustained anti-tumor response, and enhanced responsiveness to anti-PD1 therapy. Thus, targeting CD38 represents a potential strategy to improve the efficacy of anti-PD1 treatment in cancer.
Project description:Despite remarkable achievements, majority of hepatocellular carcinoma (HCC) patients fail to respond to anti-PD1 therapy. Here, we showed that ZFP64 was frequently upregulated in HCC tissues of anti-PD1 resistance patients. Elevated ZFP64 levels triggered tumor progression and induced an immunosuppressive microenvironment. Mechanistically, ZFP64 transcriptionally activated colony-stimulating factor 1 (CSF1) by directly binding to its promoter, and secreted CSF1 driving the shift of macrophages into an alternatively activated phenotype. Importantly, the PKCα was revealed to phosphorylate ZFP64 at S226, resulting in its nuclear translocation to transcribe the CSF1 gene. Particularly, we proposed firstly that the PKCα/ZFP64/CSF1 axis was a critical pathway in fostering immune evasion and anti-PD1 tolerance and inhibiting this axis with lenvatinib or Gö6976 surmounted the anti-PD1 resistance in HCC. Our study indicates that the ZFP64 is an emerging indicator in predicting anti-PD1 efficacy, and reveals the PKCα/ZFP64/CSF1 axis is a suitable target for anti-PD1 combination therapy in HCC.
Project description:Despite remarkable achievements, majority of hepatocellular carcinoma (HCC) patients fail to respond to anti-PD1 therapy. Here, we showed that ZFP64 was frequently upregulated in HCC tissues of anti-PD1 resistance patients. Elevated ZFP64 levels triggered tumor progression and induced an immunosuppressive microenvironment. Mechanistically, ZFP64 transcriptionally activated colony-stimulating factor 1 (CSF1) by directly binding to its promoter, and secreted CSF1 driving the shift of macrophages into an alternatively activated phenotype. Importantly, the PKCα was revealed to phosphorylate ZFP64 at S226, resulting in its nuclear translocation to transcribe the CSF1 gene. Particularly, we proposed firstly that the PKCα/ZFP64/CSF1 axis was a critical pathway in fostering immune evasion and anti-PD1 tolerance and inhibiting this axis with lenvatinib or Gö6976 surmounted the anti-PD1 resistance in HCC. Our study indicates that the ZFP64 is an emerging indicator in predicting anti-PD1 efficacy, and reveals the PKCα/ZFP64/CSF1 axis is a suitable target for anti-PD1 combination therapy in HCC.
Project description:Despite remarkable achievements, majority of hepatocellular carcinoma (HCC) patients fail to respond to anti-PD1 therapy. Here, we showed that ZFP64 was frequently upregulated in HCC tissues of anti-PD1 resistance patients. Elevated ZFP64 levels triggered tumor progression and induced an immunosuppressive microenvironment. Mechanistically, ZFP64 transcriptionally activated colony-stimulating factor 1 (CSF1) by directly binding to its promoter, and secreted CSF1 driving the shift of macrophages into an alternatively activated phenotype. Importantly, the PKCα was revealed to phosphorylate ZFP64 at S226, resulting in its nuclear translocation to transcribe the CSF1 gene. Particularly, we proposed firstly that the PKCα/ZFP64/CSF1 axis was a critical pathway in fostering immune evasion and anti-PD1 tolerance and inhibiting this axis with lenvatinib or Gö6976 surmounted the anti-PD1 resistance in HCC. Our study indicates that the ZFP64 is an emerging indicator in predicting anti-PD1 efficacy, and reveals the PKCα/ZFP64/CSF1 axis is a suitable target for anti-PD1 combination therapy in HCC.
Project description:We report the gene expression profiles of FACS-sorted PD1-high, PD1-intermediate, and PD1-negative tumor-infiltrating CD8 T cells in hepatocellular carcinoma.
Project description:Recent success in cancer immunotherapy has come from the blockade of inhibitory receptors on T cells, such as programmed cell death-1, which can induce a state of T cell exhaustion upon constant antigen stimulation. Understanding miRNA regulation of PD1 can be useful to discover miRNAs for use in therapy or as prognostic markers in various diseases including cancer, autoimmunity and transplantation. We used microarrays to discover global miRNA expression changes upon PD1 upregulation and identified miRNAs that are both up- and down-regulated. B16F10 cells were injected subcutaneously into C57BL/6 mice and 16 days later CD4+PD1+ and CD4+PD1- were sorted from the lymph nodes and spleen for RNA extraction and hybridization on Affymetrix miRNA array.