TIGIT expression on CD8+ T cells correlates with higher cytotoxic capacity

J Infect Dis. 2021 Mar 21;jiab155. doi: 10.1093/infdis/jiab155. Online ahead of print.

Abstract

Persistent exposure to antigen leads to T cell exhaustion and immunologic dysfunction. We examined the immune exhaustion markers TIGIT and PD-1 in HIV-infected and healthy individuals and the relationship with cytotoxic CD8 + T lymphocyte (CTL) activity. Frequencies of TIGIT but not PD-1 positively correlated with CTL activity in HIV-aviremic and healthy individuals; however, there was no correlation in HIV-viremic individuals. Transcriptome analyses revealed upregulation of genes associated with antiviral immunity in TIGIT + versus TIGIT -CD8 + T cells. Our data suggest that TIGIT +CD8 + T cells do not necessarily represent a state of immune exhaustion and maintain an intrinsic cytotoxicity in HIV-infected individuals.

Keywords: Human immunodeficiency virus; TIGIT; cytotoxic T lymphocytes; immune exhaustion.