CD4 T cell subsets in human metastatic melanoma

We used single-cell RNA-sequencing (scRNA-seq) to define CD4+ T-cell subsets in melanoma tumors from patients undergoing tumor resection. All patients received immune checkpoint blockade prior to surgery. We identified multiple subsets in the tumor with transcriptional features of suppressive function, including TR1 cells and FOXP3+ Treg cells. Based on transcriptional profiles, classical helper T cell subsets were not prevalent.