The role of CD20⁺ T cells: Insights in human peripheral blood

Abstract

CD20+ T cells constitute a small subset of T cells. These are found among CD4+, CD8+, CD4+CD8+, CD4−CD8− T, and TCRγδ+ T cells, and have been poorly characterized. The aim of this study was to characterize peripheral blood (PB) CD20+ T cells and compare them to their PB CD20− T cell counterparts. PB from 17 healthy individuals was collected. The distribution of CD20+ T cells among maturation‐associated T cells compartments (naïve, central memory, transitional memory, effector memory, and effector T cells), their polarization, activation status, and expression of immune‐regulatory proteins were evaluated by flow cytometry. Their function was also assessed, by measuring IFN‐γ, TNF‐α, and IL‐17 production. Compared with CD20− T cells, CD20+ T cells represent a higher proportion of transitional memory cells. Furthermore, CD20+ T cells display a proinflammatory phenotype, characterized by the expansion of Th1, Th1/17, and Tc1 cell subsets , associated to a high expression of activation (CD25) and exhaustion (PD‐1) markers. In addition, the simultaneous production of the proinflammatory cytokines IFN‐γ, TNF‐α, and IL‐17 was also detected in CD4+CD20+ T cells. Our results show that CD20+ T cells are phenotypically and functionally different from CD20− T cells, suggesting that these cells are a distinct subset of T cells.