{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE294nnn/GSE294274/"]},"type":"primary"},"statusCode":"OK","statusCodeValue":200}],"scores":null,"additional":{"omics_type":["Other"],"species":["Homo sapiens"],"gds_type":["Other"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE294274"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"Tumor-resident T cells and dendritic cells form an in situ archetype for immunotherapy response in melanoma [scTCR-seq]","description":"Tumor-resident (TR) T cells participate in immunosurveillance of melanoma, but their role in determining response to immune checkpoint inhibitors (ICI) has not been comprehensively explored. We performed spatial and single-cell profiling on 32 metastatic melanoma lymph node samples, from treatment-naïve, ICI-resistant, or ICI-responsive patients. In responders, we found enrichment for early differentiation (TCF1+) CD8+ and CD4+ TR which co-localized with melanoma cells. CD8+ TR were hyperexpanded, and both CD8+ and CD4+ TR upregulated cytotoxicity-related gene expression, suggesting functional anti-tumor immunity. Conversely, ICI-resistant tumors displayed chronic IFN-γ responses within the tumor microenvironment to potentiate T cell exhaustion. In ICI-responsive melanoma tumors, CD8⁺ TR interact with CD4⁺ TR cells (via the CCL4-CCR5 axis) and engage with type-3 dendritic cells (DC3) (via IL15-IL15R interaction). This intratumoral immune triad (CD8⁺ TR – CD4⁺ TR – DC) is exclusive to responders. This study illustrates the role of TR cells and their crosstalk with DCs in effective ICI responses.","dates":{"publication":"2026/06/08"},"accession":"GSE294274","cross_references":{"GSM":["GSM8901635","GSM8901634","GSM8901626","GSM8901637","GSM8901636","GSM8901631","GSM8901630","GSM8901633","GSM8901632","GSM8901628","GSM8901627","GSM8901629"],"GPL":["24676"],"GSE":["294274"],"taxon":["Homo sapiens"]}}