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Pachynski, R.

Publications and source records attributed to Pachynski, R..

2 recordsLinked to original sources
bioRxiv2023

High dimensional analyses reveal activation of lymphocyte subsets and reversal of immunoresistance by cytokine enhancement of adoptive cellular vaccine therapy in prostate cancer.

Engineered cell therapies have emerged as a potent therapeutic option for the hematologic malignancies, however solid tumor responses to similar approaches have been modest. The outlier is Sipuleucel-T (sip-T), an FDA-approved autologous cellular immunotherapy for metastatic castration-resistant prostate cancer (mCRPC). To elucidate parameters of the response profile to this therapy, we report the first high dimensional cellular analyses of sip-T using mass cytometry (CyTOF) and show a lymphoid predominance, with CD3+ T cells constituting the highest proportion (median [~]60%) of sip-T, followed by B-cells, and natural killer (NK) and NKT cells. We hypothesized that treatment of sip-T with homeostatic cytokines known to activate/expand effector lymphocytes could augment efficacy against prostate cancer. Of cytokines tested, IL-15 treated sip-T showed the most significant activation and proliferation of effector lymphocytes, as well as augmentation of tumor cytotoxicity in vitro. Co-culture of sip-T with IL-15 and control or prostate-relevant antigens showed significant activation and expansion of CD8 T and NKT cells in an antigen-specific manner. Adoptive transfer of IL-15 treated sip-T into NSG mice resulted in potent prostate tumor growth inhibition compared with control sip-T. Evaluation of tumor-infiltrating lymphocytes revealed a 2 to 14-fold higher influx of sip-T and a significant increase in interferon (IFN)-{gamma} producing CD8+ T and NKT cells within the tumor microenvironment (TME) in the IL-15 group. In conclusion, we put forward the first evidence that IL-15 treatment can enhance the functional anti-tumor efficacy of sip-T, providing rationale for combining IL-15 or IL-15 agonists with sip-T to treat mCRPC patients. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/550213v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@130adb0org.highwire.dtl.DTLVardef@db2567org.highwire.dtl.DTLVardef@174a953org.highwire.dtl.DTLVardef@18c049_HPS_FORMAT_FIGEXP M_FIG C_FIG One sentence summaryIL-15 treatment can enhance the efficacy/anti-tumor immunity of sipuleucel-T by modulating CD8+ T-cell and CD56+ NKT subsets.

immunology↗
bioRxiv2019

Chemerin increases T-cell mediated cytotoxicity of human tumors via modulation of a novel CMKLR1/PTEN/PD-L1 axis

Chemerin (RARRES2) is an endogenous leukocyte chemoattractant known to recruit innate immune cells through its chemotactic receptor, CMKLR1. RARRES2 is often downregulated in prostate cancer and across multiple tumor types compared to normal tissue. Additionally, a methylome-wide analysis identified RARRES2 as one of the most hypermethylated genes in sarcoma. Recent studies have shown that augmenting chemerin in the tumor microenvironment significantly suppresses tumor growth, at least in part by recruitment of immune effector cells. However, as tumor cells have been shown to express functional chemokine receptors that can impact their phenotype, we hypothesized that chemerin might have additional, tumor-intrinsic effects. Here, we show for the first time that human cancer cells exposed to exogenous chemerin significantly upregulate PTEN expression and activity. Additionally, chemerin-induced PTEN expression correlated with a concomitant reduction in PD-L1 mRNA and protein expression. Chemerin treatment of tumor cells led to significantly reduced tumor cell migration/invasion, as well as significantly increased cytotoxicity by T cells. siRNA knockdown of tumor expressed CMKLR1 abrogated chemerin-induced modulation of PTEN and PD-L1 expression and activity, supporting the presence of a CMKLR1/PTEN/PD-L1 signaling cascade. We then compared chemerin treatment to PD-L1 inhibition by siRNA knockdown or the antagonistic antibody atezolizumab in T cell cytotoxicity assays and surprisingly found chemerin treatment was as effective as both PD-L1 knockdown and atezolizumab treatment in mediating tumor lysis. Collectively, our data show a novel link between chemerin, PTEN and PD-L1 in human tumor lines, with functional consequences that may have a role in improving T cell-mediated immunotherapies.

cancer biology↗