PLX152658

GSE123813: Clonal replacement of tumor-specific T cells following PD-1 blockade [single cells]

• Organsim human
• Type RNASEQ
• Target gene
• Project ARCHS4

Immunotherapies that block inhibitory checkpoint receptors on T cells have transformed the clinical care of cancer patients. However, the clonal origin of tumor-specific T cells following checkpoint blockade in patients remains unclear. Here, we performed paired single-cell RNA- and T cell receptor (TCR)- sequencing on site-matched tumors from patients with basal cell carcinoma (BCC) pre- and post-anti-PD-1 therapy. Tracking TCR clonotypes and transcriptome phenotypes revealed a coupling of tumor-recognition, clonal expansion, and T cell dysfunction: the response to treatment was accompanied by a clonal expansion of CD8+CD39+ T cells, which co-expressed markers of chronic T cell activation and exhaustion. However, this response was not accompanied by an expansion of pre-existing tumor-specific T cell clonotypes; rather, expanded T cell clones post-therapy comprised novel clonotypes, which were not previously observed in the same tumor. Clonal replacement of T cells was preferentially observed in tumor-specific exhausted CD8+ T cells, compared to other distinct T cell phenotypes, and was more evident in patients who exhibited a clinical response to treatment. These results, enabled by single-cell multi-omic profiling of clinical samples, demonstrate that the chronic activation of pre-existing tumor-infiltrating T cells may limit their re-invigoration following checkpoint blockade, and that a successful response relies on the expansion of a distinct repertoire of tumor-specific T cell clones. SOURCE: Howard,Y,Chang (howchang@stanford.edu) - Howard Y. Chang Stanford University