ScRNAseq of orthotopic mismatch repair deficient (dMMR) or chromosomally instable (CIN) colorectal cancer
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ABSTRACT: Colorectal cancers (CRCs) deficient in DNA mismatch repair (dMMR) contain abundant CD8+ tumor infiltrating lymphocytes (TILs) responding to the abundant neoantigens from their unstable genomes. Priming of such tumor-targeted TILs first requires recruitment of CD8+ T cells into the tumors, implying that this is an essential prerequisite of successful dMMR anti-tumor immunity. We have discovered that selective recruitment and activation of systemic CD8+ T cells into dMMR CRCs strictly depends on overexpression of CCL5 and CXCL10 due to endogenous activation of cGAS/STING and IFN signaling by damaged DNA. TIL infiltration into orthotopic dMMR CRCs is neoantigen-independent and followed by induction of a resident memory-like phenotype key to the anti-tumor response. CCL5 and CXCL10 could be upregulated by common chemotherapies in all CRCs, indicating that facilitating CD8+ T cell recruitment underlies their efficacy. Induction of CCL5 and CXCL10 thus represents a tractable therapeutic strategy to induce TIL recruitment into CRCs where local priming can be maximized even in neoantigen-poor CRCs.
ORGANISM(S): Mus musculus
PROVIDER: GSE178706 | GEO | 2021/07/19
REPOSITORIES: GEO
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