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.
Published by Oxford University Press for the Infectious Diseases Society of America 2021. This work is written by (a) US Government employee(s) and is in the public domain in the US.