CTLA-4(+)PD-1(-) Memory CD4(+) T Cells Critically Contribute to Viral Persistence in Antiretroviral Therapy-Suppressed, SIV-Infected Rhesus Macaques.
Research paper by
Colleen S CS McGary, Claire C Deleage, Justin J Harper, Luca L Micci, Susan P SP Ribeiro, Sara S Paganini, Leticia L Kuri-Cervantes, Clarisse C Benne, Emily S ES Ryan, Robert R Balderas, Sherrie S Jean, Kirk K Easley, Vincent V Marconi, Guido G Silvestri, Jacob D JD Estes, Rafick-Pierre RP Sekaly, Mirko M Paiardini
Antiretroviral therapy (ART) suppresses viral replication in HIV-infected individuals but does not eliminate the reservoir of latently infected cells. Recent work identified PD-1(+) follicular helper T (Tfh) cells as an important cellular compartment for viral persistence. Here, using ART-treated, SIV-infected rhesus macaques, we show that CTLA-4(+)PD-1(-) memory CD4(+) T cells, which share phenotypic markers with regulatory T cells, were enriched in SIV DNA in blood, lymph nodes (LN), spleen, and gut, and contained replication-competent and infectious virus. In contrast to PD-1(+) Tfh cells, SIV-enriched CTLA-4(+)PD-1(-) CD4(+) T cells were found outside the B cell follicle of the LN, predicted the size of the persistent viral reservoir during ART, and significantly increased their contribution to the SIV reservoir with prolonged ART-mediated viral suppression. We have shown that CTLA-4(+)PD-1(-) memory CD4(+) T cells are a previously unrecognized component of the SIV and HIV reservoir that should be therapeutically targeted for a functional HIV-1 cure.