Zaikos TD, Terry VH, Sebastian Kettinger NT, Lubow J, Painter MM, Virgilio MC, Neevel A, Taschuk F, Onafuwa-Nuga A, McNamara LA, Riddell Jt, Bixby D, Markowitz N, and Collins KL. Hematopoietic stem and progenitor cells are a distinct HIV reservoir that contributes to persistent viremia in suppressed patients. Cell Rep 2018; 25(13):3759-3773.e9
Long-lived reservoirs of persistent HIV are a major barrier to a cure. CD4+ hematopoietic stem and progenitor cells (HSPCs) have the capacity for lifelong survival, self-renewal, and the generation of daughter cells. Recent evidence shows that they are also susceptible to HIV infection in vitro and in vivo. Whether HSPCs harbor infectious virus or contribute to plasma virus (PV) is unknown. Here, we provide strong evidence that clusters of identical proviruses from HSPCs and their likely progeny often match residual PV. A higher proportion of these sequences match residual PV than proviral genomes from bone marrow and peripheral blood mononuclear cells that are observed only once. Furthermore, an analysis of near-full-length genomes isolated from HSPCs provides evidence that HSPCs harbor functional HIV proviral genomes that often match residual PV. These results support the conclusion that HIV-infected HSPCs form a distinct and functionally significant reservoir of persistent HIV in infected people.