Detection and Characterization of a Novel Subset of CD8+CD57+ T Cells in Metastatic Melanoma with an Incompletely Differentiated Phenotype

Abstract

Our studies identified a novel subset of incompletely differentiated CD8(+) CTL coexpressing early effector memory and late CTL markers. This population resembles that found in patients with uncontrolled chronic viral infections. TGF-β1, frequently produced by melanoma tumors, may be a key cytokine inhibiting further maturation of this subset.