Project description:B cells potentially play a role in the immune response to melanoma, including during treatment with immune modulators. We profiled (transcriptome analysis) effects of anti-PD-L1 antibody therapy on gene expression in B16 melanoma tumors of B cells depleted and WT syngeneic mice. After 7 days of B16 tumors implantation, mice were treated or untreated with anti-PD-L1 antibody (every three days).
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.
Project description:The effects of AKT/WEE1 inhibitors or ALDH inhibitor combined with PD-1 antibody on melanoma were examined. Mouse B16F10 melanoma cells were subcutaneously injected into C57/B6 mice. When tumors were well-vascularized, mice were treated with anti-PD-1, AKT I (AZD5363)+WEE1 I (MK1775), AZD5363+MK1775+anti-PD-1, ALDH I (KS100), KS100+ anti-PD-1 daily. Mice were sacrificed when tumors in the control group (DMSO treated) reached 2000 mm3 and tumors were removed. RNA was extracted from tumor samples and gene expression was analized using RNAseq analysis.
Project description:PD-1 immune checkpoint blockade provides significant clinical benefits for cancer patients. However, factors influencing innate sensitivity remain incompletely catalogued. We analyzed the somatic mutanomes and transcriptomes of pretreatment melanoma biopsies. Mutations in cell adhesion genes and the DNA repair gene BRCA2 were enriched in responding tumors, and a high mutational load associated with improved survival. Innately resistant tumors displayed frequent transcriptomic up-expression of genes that enriched for mesenchymal transition, cell adhesion, ECM organization, wound-healing and angiogenesis. The transcriptomes of innate resistance also enriched for signatures indicating up-regulation of these processes. Notably, MAPK-targeted therapy (MAPKi) induced similar signatures in melanoma, suggesting that a form of MAPKi resistance mediates cross-resistance to anti-PD-1 therapy. Co-enrichment of IPRIM (Innate anti-PD-1 Resistance Induced by MAPKi) signatures defined a transcriptomic subset across advanced cancers, suggesting that attenuating processes underlying these signatures may augment anti-PD1 responses. Thus, multi-factorial determinants influence anti-PD-1 patterns in melanoma.
Project description:Response to immune checkpoint inhibitors may be improved through combinations with each other and other therapies, raising questions about non-redundancy and resistance. We report results from parallel studies of melanoma patients and mice treated with anti-CTLA4 and radiation (RT). Although combined treatment improved responses, resistance was common. Computational analyses of immune and transcriptomic profiles (provided here) revealed that resistance in mice was due to upregulation of tumor PD-L1 that drives T cell exhaustion. Accordingly, optimal response requires RT, anti-CTLA4, and anti-PD-L1. Anti-CTLA4 inhibits Tregs, RT diversifies and shapes the TCR repertoire, and anti-PD-L1 reinvigorates exhausted T cells. Together, all three therapies promote the expansion of clonotypes with distinct TCR traits. Similar to mice, patients with melanoma showing high PD-L1 did not respond to RT + anti-CTLA4, demonstrated persistent T cell exhaustion, and rapidly progressed. Thus, the combination of RT, anti-CTLA4, and anti-PD-L1 promotes response through distinct mechanisms.
Project description:Disrupting PD-1/PD-L1 interaction rejuvenates antitumor immunity. Clinical successes by blocking PD-1/PD-L1 binding have grown across wide-ranging cancer histologies, but innate therapy resistance is evident in the majority of treated patients1. Cancer cells can express robust surface levels of PD-L1 to tolerize tumor-specific T cells, but regulation of PD-L1 protein levels in the cancer cell is poorly understood. Quasi-mesenchymal tumor cells up-regulate PD-L1/L2 and induce an immune-suppressive microenvironment, including expansion of M2-like macrophages and regulatory T cells and exclusion of CD8+ T-cell infiltration2. Targeted therapy, including MAPK inhibitor therapy in melanoma, leads to quasi-mesenchymal transitions and resistance3, and both MAPK inhibitor treatment and mesenchymal signatures are associated with innate anti-PD-1 resistance4,5. Here we identify ITCH as an E3 ligase that downregulates tumor cell-surface PD-L1/L2 in PD-L1/L2-high cancer cells, including MAPK inhibitor-resistant melanoma, and suppresses acquired MAPK inhibitor resistance in and only in immune-competent mice. ITCH interacts with and poly-ubiquitinates PD-L1/L2, and ITCH deficiency increases cell-surface PD-L1/L2 expression and reduces T cell activation. Mouse melanoma tumors grow faster with Itch knockdown only in syngeneic hosts but not in immune-deficient mice. MAPK inhibitor therapy induces tumor cell-surface PD-L1 expression in murine melanoma, recapitulating the responses of clinical melanoma3, and this induction is more robust with Itch knockdown. Notably, suppression of ITCH expression first elicits a shift toward an immune-suppressive microenvironment and then accelerates resistance development. These findings collectively identify ITCH as a critical negative regulator of PD-L1 tumor cell-surface expression and provide insights into previously unexplained role of PD-L1 in adaptive resistance to therapy.
Project description:Programmed death-ligand 1 (PD-L1) is predominantly expressed in the antigen-presenting cells (APCs) that are originated and abundant in bone marrow. The roles of PD-L1 in bone cell differentiation and cancer bone metastasis remain unclear. Here we show that PD-L1 antibody or PD-L1 conditional knockout in the hematopoietic or myeloid lineage suppresses osteoclast differentiation in vitro and in vivo. Bone metastases of breast cancer and melanoma are diminished by PD-L1 antibody or PD-L1 deletion in the myeloid lineage. Transcriptional profiling of bone marrow cells reveals that PD-L1 deletion in the myeloid cells up-regulates immune stimulatory genes, leading to increased macrophage M1 polarization, decreased M2 polarization, enhanced IFN? signaling, and elevated T cell recruitment and activation. All these alterations result in heightened anti-tumor immunity in the cancer microenvironment. Our findings support PD-L1 antibody as a potent therapy for bone metastasis of breast cancer and melanoma by simultaneously suppressing osteoclast and enhancing immunity.
2022-03-07 | GSE190715 | GEO
Project description:Effect of treatment of Melanoma with SAM, Anti-PD-1 antibody and combination
Project description:Immune checkpoint inhibitors (ICIs) have transformed the treatment of melanoma. However, the majority of patients have primary or acquired resistance to ICIs, limiting durable responses and patient survival. Interferon-gamma (IFNg) signaling and the expression of IFNg-stimulated genes correlate with either response or resistance to ICIs, in a context-dependent manner. While IFNg-inducible immunostimulatory genes are required for response to ICIs, chronic IFNg signaling induces the expression of immunosuppressive genes, promoting resistance to these therapies. Here, we show that high levels of ULK1 correlate with poor survival in melanoma patients and overexpression of ULK1 in melanoma cells enhances IFNg-induced expression of immunosuppressive genes, with minimal effects on the expression of immunostimulatory genes. In contrast, genetic or pharmacological inhibition of ULK1 reduces expression of IFNg-induced immunosuppressive genes. ULK1 binds IRF1 in the nuclear compartment of melanoma cells, controlling its binding to the PD-L1 promoter region. Additionally, pharmacological inhibition of ULK1 in combination with anti-PD-1 therapy further reduces melanoma tumor growth and enhances anti-tumor immune responses in vivo. Our data suggest that targeting ULK1 represses IFNg-dependent immunosuppression. These findings support the combination of ULK1 drug-targeted inhibition with ICIs for the treatment of melanoma patients to improve response rates and patient outcomes.