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: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.
Project description:CD38 and CD49d are associated negative prognosticators in chronic lymphocytic leukemia (CLL). Despite evidence that both molecules are involved in interactions occurring between CLL and normal cells in the context of CLL-involved tissues, a functional link is still missing. Using gene expression profiles comparing CD38+CD49d+ vs. CD38-CD49d- CLL cells, we demonstrated overexpression of the CCL3 and CCL4 chemokines in cells from the former group. These chemokines were also upregulated by CD38 signals in CLL; moreover, CCL3 was expressed by CLL cells from bone marrow biopsies (BMB) of CD38+CD49d+ but not CD38-CD49d- cases. High levels of CCR1 and, to a lesser extent, CCR5, the receptors for CCL3 and CCL4, were found in CLL-derived monocyte-macrophages. Consistently, CCL3 increased monocyte migration, and CD68+ macrophage infiltration was particularly high in BMB from CD38+CD49d+ CLL. Conditioned media from CCL3-stimulated macrophages induced endothelial cells to express VCAM-1, the CD49d ligand, likely through TNFα over-production. These effects were apparent in BMB from CD38+CD49d+CLL, where lymphoid infiltrates were characterized by a prominent meshwork of VCAM-1+ stromal/endothelial cells. Lastly, CD49d engagement by VCAM-1-transfectants increased viability of CD38+CD49d+ CLL cells. Altogether, CD38 and CD49d can be thought of as a part of a consecutive chain of events ultimately leading to improved survival of CLL cells.
Project description:CD38 expression is an important prognostic marker in CLL with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38+ and CD38- chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38+ and CD38- CLL cells derived from the same patient were shown to be monoclonal by VH gene sequencing but despite this, CD38+ CLL cells possessed a distinct gene expression profile when compared with their CD38- sub-clones. Keywords: Sub-clonal analysis of CLL cells derived from the same leukemia sample
Project description:Functional impairment of the immune response to chronic viral infections and malignancies is characterised by exhausted T cells, which do not respond to antigen. The cell surface receptor PD1 has been implicated in the maintenance of T cell exhaustion and is an attractive target for immunomodulatory approaches to the treatment of such conditions. However, the mechanisms by which PD1 signalling causes exhaustion and the exact response of T cells to PD1 activation are not clear although it has been suggested that PD1 up regulates a number of anti-proliferative factors. Here we perform cytokine and transcriptional profiling of uninfected primary human T cells to characterise these events. We find that PD1 completely prevents cytokine and transcrip- tional changes induced by CD3/28 stimulation. We do not see any factors specifically induced by PD1, including BATF or IL10 which have previously been linked to PD1 activity. Together with the work of others this confirms that PD1 is the sole effector of T cell exhaustion and that infection is responsible for BATF and IL10 up regulation. As a consequence future therapeutic strategies will be confined to the inhibition of PD1 and not a downstream effector.
Project description:We have identified a CD57+PD1- CD4 T cell phenotype at the time of transplantation that strongly correlates with subsequesnt development of belatacept-resistant rejection. In this study, we used microarray to determine which genes were upregulated in CD57+ compared to CD57- CD4 T cells. Peripheral blood obtained from 5 healthy controls was processed and sorted into CD4+CD57+PD1- and CD4+CD57-PD1- populations. Total RNA was extracted from the sorted populations and quality assessed. cDNA synthesis and amplification was performed, and fragmented and biotinylated samples were hybridized to the Affymetrix Human U133 plus 2.0 probe array. The arrays were scanned and probe intensity measurements were normalized across the samples using the robust multichip average (RMA) algorithm.