Project description:We developed a multi-paratopic VEGF decoy receptor (Ate-Grab) by fusing the scFv of atezolizumab to VEGF-Grab to target PD-L1 expressing cells in tumor microenvironment. We compared the single-cell transcriptomes of gemcitabine-treated and Ate-Grab with Gemcitabine-treated Pan02 tumors. We confirmed the subtype of cancer-associated fibroblasts(CAFs) that modulates the collagen inside the tumor microenvrionment. In the Ate-Grab+Gemcitabine group, it was confirmed that new CAFs were regulated.
Project description:Blocking the PD-1/PD-L1 immunosuppressive pathway has shown promise in the treatment of certain cancers including melanoma. This study investigates differences in the gene expression profiles of human melanomas that do or do not display the immunosuppressive protein PD-L1. Further understanding of genes expressed within the tumor microenvironment of PD-L1+ tumors may lead to improved rationally designed treatments. Gene expression profiling was performed on total RNA extracted by laser capture microdissection from 11 archived formalin-fixed paraffin-embedded (FFPE) melanoma specimens, 5 of which were PD-L1 positive and 6 PD-L1 negative. Details of the design, and the gene signatures found are given in the paper associated with this GEO Series: Janis M. Taube, Geoffrey D. Young, Tracee L. McMiller, Shuming Chen, January T. Salas, Theresa S. Pritchard, Haiying Xu, Alan K. Meeker, Jinshui Fan, Chris Cheadle, Alan E. Berger, Drew M. Pardoll, and Suzanne L. Topalian, Differential expression of immune-regulatory genes associated with PD-L1 display in melanoma: implications for PD-1 pathway blockade, Clin Cancer Res 2015, in press.
Project description:Prostate cancers (PC) are largely unresponsive to immune checkpoint inhibitors and there is strong evidence that PD-L1 expression itself must be inhibited to activate anti-tumor immunity. Here, we report that neuropilin-2 (NRP2), which functions as a VEGF receptor on tumor cells, is an attractive target to activate anti-tumor immunity in prostate cancer because we demonstrate that VEGF/NRP2 signaling sustains PD-L1 expression. NRP2 depletion increased T cell activation in vitro. Inhibition of the binding of VEGF to NRP2 using a mouse specific anti-NRP2 mAb in a syngeneic model of prostate cancer that is resistant to checkpoint inhibition resulted in significant necrosis and tumor regression compared to both an anti-PD-L1 mAb and control IgG. This therapy also decreased tumor PD-L1 expression and increased immune cell infiltration. We also observed that the NRP2, VEGF-A, and VEGF-C genes are amplified in metastatic castration resistant and neuroendocrine prostate cancer (NEPC) and that NRP2high PD-L1high population in metastatic tumors had a significantly lower AR and higher NEPC scores than other populations. Therapeutic inhibition of VEGF binding to human NRP2 with a high affinity humanized mAb, which is suitable for clinical use, in organoids derived from NEPC patients also diminished PD-L1 expression and caused a significant increase in immune-mediated tumor cell killing consistent with the animal studies. These findings provide justification for the initiation of clinical trials using this novel function-blocking NRP2 mAb in prostate cancer, especially for patients with aggressive primary and metastatic cancers, where blocking NRP2-VEGF signaling shows potential in mitigating the morbidity and mortality associated with these cancers.
Project description:Anti-PD-L1-based combination immunotherapy has become the first-line treatment for unresectable hepatocellular carcinoma (HCC). However, the objective response rate is lower than 40%, highlighting the need to identify mechanisms of tolerance to immune checkpoint inhibitors and accurate biomarkers of response. Here, we employed next-generation sequencing to analyze HCC samples from 10 patients receiving anti-PD-L1 therapy. Activation of the renin-angiotensin system was elevated in nonresponders compared with responders, and ACE2 expression was significantly downregulated in nonresponders. ACE2 deficiency promoted HCC development and anti-PD-L1 resistance, whereas ACE2 overexpression inhibited HCC progression in immune competent mice. Mass cytometry by time of flight (CyTOF) revealed that ACE2 deficient murine orthotopic tumor tissues featured elevated M2-like tumor-associated macrophages (TAMs), displayed a CCR5+PD-L1+ immunosuppressive phenotype, and exhibited high VEGFα expression. ACE2 downregulated tumor intrinsic CCL5 expression by suppressing NF-κB signaling through the ACE2/angiotensin-(1–7)/Mas receptor axis. The lower CCL5 levels led to reduced activation of the JAK-STAT3 pathway and suppressed PD-L1 and VEGFα expression in macrophages, blocking macrophage infiltration and M2-like polarization. Pharmacological targeting of CCR5 using maraviroc enhanced the tumor suppressive effect of anti-PD-L1 therapy. Together, these findings suggest that activation of the ACE2 axis overcomes the immunosuppressive microenvironment of HCC and may serve as an immunotherapeutic target and predictive biomarker of response to PD-L1 blockade.
Project description:Alzheimer’s disease (AD) is a heterogeneous disorder with multiple etiologies. Harnessing the immune system by blocking the programmed cell death receptor (PD)-1 pathway in an amyloid beta mouse model was shown to evoke a sequence of immune responses that lead to disease modification. Here, blocking PD-L1, a PD-1 ligand, was found to have similar efficacy to that of PD-1 blocking in disease modification, in both animal models of AD and of tauopathy. Targeting PD-L1 in a tau-driven disease model resulted in increased immunomodulatory monocyte-derived macrophages within the brain parenchyma. Single cell RNA-seq revealed that the homing macrophages expressed unique scavenger molecules including macrophage scavenger receptor 1 (MSR1), which was shown here to be required for the effect of PD-L1 blockade in disease modification. Overall, our results demonstrate that immune checkpoint blockade targeting the PD-1/PD-L1 pathway leads to modification of common factors that go awry in AD and dementia, and thus can potentially provide an immunotherapy to help combat these diseases.
Project description:Purpose: Use RNA-seq to characterize the anti-tumor immune response induced by ALPN-202 and compare to that of anti-PD-L1 treatment alone. Methods: mRNA was isolated from MC38/hPD-L1 tumors 72 hours after a single dose of ALPN-202 (n=4), anti-PD-L1 mAb (durvalumab) (n=4), or Fc control (n=4). Results: ALPN-202 treatment resulted in elevated expression of multiple T cell, NK cell, myeloid cell genes. Additionally, there was a strong increase in genes commonly associated with a proinflammatory response including cytokines, chemokines and surface markers. Conclusions: ALPN-202 treatment resulted in a strong anti-tumor immune response that was more potent than that generated by blockade of PD-L1 alone.
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:Only a subset of patients responds to immune checkpoint blockade in melanoma. A preclinical model recapitulating the clinical activity of ICB would provide a valuable platform for mechanistic studies. We used melanoma tumors arising from an Hgftg;Cdk4R24C/R24C genetically engineered mouse (GEM) model to evaluate the efficacy of an anti-mouse PD-L1 antibody similar to the anti-human PD-L1 antibodies durvalumab and atezolizumab. Consistent with clinical observations for ICB in melanoma, anti-PD-L1 treatment elicited complete and durable response in a subset of melanoma-bearing mice. We also observed tumor growth delay or regression followed by recurrence. For early treatment assessment, we analyzed gene expression profiles, T cell infiltration, and T cell receptor (TCR) signatures in regressing tumors compared to tumors exhibiting no response to anti-PD-L1 treatment. We found that CD8+ T cell tumor infiltration corresponded to response to treatment, and that anti-PD-L1 gene signature response indicated an increase in antigen processing and presentation, cytokine-cytokine receptor interaction, and natural killer cell-mediated cytotoxicity. TCR sequence data suggest that an anti-PD-L1-mediated melanoma regression response requires not only an expansion of the TCR repertoire that is unique to individual mice, but also tumor access to the appropriate TCRs. Thus, this melanoma model recapitulated the variable response to ICB observed in patients and exhibited biomarkers that differentiate between early response and resistance to treatment, providing a valuable platform for prediction of successful immunotherapy.
Project description:Only a subset of patients responds to immune checkpoint blockade in melanoma. A preclinical model recapitulating the clinical activity of ICB would provide a valuable platform for mechanistic studies. We used melanoma tumors arising from an Hgftg;Cdk4R24C/R24C genetically engineered mouse (GEM) model to evaluate the efficacy of an anti-mouse PD-L1 antibody similar to the anti-human PD-L1 antibodies durvalumab and atezolizumab. Consistent with clinical observations for ICB in melanoma, anti-PD-L1 treatment elicited complete and durable response in a subset of melanoma-bearing mice. We also observed tumor growth delay or regression followed by recurrence. For early treatment assessment, we analyzed gene expression profiles, T cell infiltration, and T cell receptor (TCR) signatures in regressing tumors compared to tumors exhibiting no response to anti-PD-L1 treatment. We found that CD8+ T cell tumor infiltration corresponded to response to treatment, and that anti-PD-L1 gene signature response indicated an increase in antigen processing and presentation, cytokine-cytokine receptor interaction, and natural killer cell-mediated cytotoxicity. TCR sequence data suggest that an anti-PD-L1-mediated melanoma regression response requires not only an expansion of the TCR repertoire that is unique to individual mice, but also tumor access to the appropriate TCRs. Thus, this melanoma model recapitulated the variable response to ICB observed in patients and exhibited biomarkers that differentiate between early response and resistance to treatment, providing a valuable platform for prediction of successful immunotherapy.