Increased Expression of the NK Cell Receptor KLRG1 by Virus-Specific CD8 T Cells during Persistent Antigen Stimulation

Abstract

ABSTRACT The killer cell lectin-like receptor G1 (KLRG1) is a natural killer cell receptor expressed by T cells that exhibit impaired proliferative capacity. Here, we determined the KLRG1 expression by virus-specific T cells. We found that repetitive and persistent antigen stimulation leads to an increase in KLRG1 expression of virus-specific CD8 + T cells in mice and that virus-specific CD8 + T cells are mostly KLRG1 + in chronic human viral infections (human immunodeficiency virus, cytomegalovirus, and Epstein-Barr virus) but not in resolved infection (influenza virus). Thus, by using KLRG1 as a T-cell marker, our results suggest that the differentiation status and function of virus-specific CD8 + T cells are directly influenced by persistent antigen stimulation.