Project description:The anti-tumor effects of IFNγ are well-known as IFNγ binding to tumor cells increases antigen presentation and can cause cytostatic growth defects. Indeed, the inability of tumors to respond to IFNγ often renders tumors resistant to checkpoint blockade and other immunotherapies reliant on direct T cell cytotoxicity. We performed single-cell RNA-sequencing during virus therapy to get insight into the immune microenvironment of the tumor during treatment.
Project description:The anti-tumor effects of IFNγ are well-known as IFNγ binding to tumor cells increases antigen presentation and can cause cytostatic growth defects. Indeed, the inability of tumors to respond to IFNγ often renders tumors resistant to checkpoint blockade and other immunotherapies reliant on direct T cell cytotoxicity. We demonstrate through RNA-sequencing that IFNgR1-/- and STAT1-/- tumors are defective in their response to IFNγ compared to wild-type tumors.
Project description:Homeostatic programs maintain equilibrium between immune protection, and selftolerance. Such mechanisms impact autoimmunity and tumor formation, respectively. How tissue homeostasis is maintained, and impacts tumor surveillance is unknown. Here we identify that mononuclear phagocytes share conserved programming during homeostatic differentiation, and entry into tissue. IFNγ is necessary and sufficient to induce these transcripts, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify metastatic melanoma survival. Single-cell RNA-sequencing reveals enrichment of these modules in monocytes and DCs in human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2), a highly conserved transcript in this program is induced by IFNγ, and expressed in mononuclear phagocytes infiltrating primary melanoma. SOCS2 limits DC adaptive anti-tumoral immunity and T cell priming in vivo, indicating a critical regulatory role. Our findings link homeostasis in peripheral tissue to anti-tumoral immunity and escape, revealing coopting of tissue-specific immune development in the tumor microenvironment. The raw FASTQ sequence files are being deposited in dbGAP.
Project description:While immune checkpoint blockade therapy (ICBT) benefits cancer patients, many fail to maintain their response due to adaptive resistance mechanisms. IFNγ is critical for cellular immunity, but also promotes adaptive resistance to ICBT. We have established a role for PARP14 in mediating IFNγ-induced adaptive resistance. We confirm that chronic pre-treatment of tumour cells with IFNγ confers resistance to α-PD-1 antibodies in syngeneic mouse tumour models. We identified that PARP14 was consistently upregulated in cancer cells treated chronically with IFNγ as well as in IFNγ-high melanoma samples. Further, we showed that PARP14 knockdown or pharmacological inhibition restores sensitivity to α-PD-1 antibodies accompanied by increased immune cell infiltration into tumours but the decreased presence of regulatory T cells. RNA sequencing analysis of tumours and cultured cells treated with PARP14 inhibitor showed an upregulation of inflammatory-related pathways. In conclusion, PARP14 is an actionable target for reversing IFNγ-driven adaptive resistance to ICBT.
Project description:While immune checkpoint blockade therapy (ICBT) benefits cancer patients, many fail to maintain their response due to adaptive resistance mechanisms. IFNγ is critical for cellular immunity, but also promotes adaptive resistance to ICBT. We have established a role for PARP14 in mediating IFNγ-induced adaptive resistance. We confirm that chronic pre-treatment of tumour cells with IFNγ confers resistance to α-PD-1 antibodies in syngeneic mouse tumour models. We identified that PARP14 was consistently upregulated in cancer cells treated chronically with IFNγ as well as in IFNγ-high melanoma samples. Further, we showed that PARP14 knockdown or pharmacological inhibition restores sensitivity to α-PD-1 antibodies accompanied by increased immune cell infiltration into tumours but the decreased presence of regulatory T cells. RNA sequencing analysis of tumours and cultured cells treated with PARP14 inhibitor showed an upregulation of inflammatory-related pathways. In conclusion, PARP14 is an actionable target for reversing IFNγ-driven adaptive resistance to ICBT.
Project description:While immune checkpoint blockade therapy (ICBT) benefits cancer patients, many fail to maintain their response due to adaptive resistance mechanisms. IFNγ is critical for cellular immunity, but also promotes adaptive resistance to ICBT. We have established a role for PARP14 in mediating IFNγ-induced adaptive resistance. We confirm that chronic pre-treatment of tumour cells with IFNγ confers resistance to α-PD-1 antibodies in syngeneic mouse tumour models. We identified that PARP14 was consistently upregulated in cancer cells treated chronically with IFNγ as well as in IFNγ-high melanoma samples. Further, we showed that PARP14 knockdown or pharmacological inhibition restores sensitivity to α-PD-1 antibodies accompanied by increased immune cell infiltration into tumours but the decreased presence of regulatory T cells. RNA sequencing analysis of tumours and cultured cells treated with PARP14 inhibitor showed an upregulation of inflammatory-related pathways. In conclusion, PARP14 is an actionable target for reversing IFNγ-driven adaptive resistance to ICBT.
Project description:The cytokine IFNγ differentially impacts on tumors upon immune checkpoint blockade (ICB). Despite our understanding of downstream signaling events, less is known about 36 regulation of its receptor (IFNγ-R1). With an unbiased genome-wide CRISPR/Cas9 screen for critical regulators of IFNγ-R1 cell surface abundance, we identified STUB1 as an E3 ubiquitin ligase for IFNγ-R1 in complex with its signal-relaying kinase JAK1. STUB1 mediates ubiquitination-dependent proteasomal degradation of IFNγ-R1/JAK1 complex through IFNγ-R1K285 and JAK1K249. Conversely, STUB1 inactivation amplifies IFNγ signaling, sensitizing tumor cells to cytotoxic T cells in vitro. This was corroborated by an anticorrelation between STUB1 expression and IFNγ response in ICB-treated patients. Consistent with the context-dependent effects of IFNγ in vivo, anti-PD-1 response was increased in heterogenous tumors comprising both wildtype and STUB1-deficient cells but not full STUB1 knockout tumors. These results uncover STUB1 as a critical regulator of IFNγ-R1, and highlight the context-dependency of STUB1-regulated IFNγ signaling for ICB outcome.