CD133+ Hematopoietic Progenitor Cells Harbor HIV Genomes in a Subset of Optimally Treated People With Long-Term Viral Suppression

Background. Hematopoietic progenitor cells (HPCs) in the bone marrow of human immunodeficiency virus (HIV)-infected individuals have been proposed as a persistent reservoir of virus. However, some studies have suggested that HIV genomes detected in HPCs arise from T-cell contamination. Methods. CD133-sorted HPCs and CD133-depleted bone marrow cells were purified from bone marrow specimens obtained from 11 antiretroviral-treated donors in whom the HIV load had been < 48 copies/mL for at least 6 months. CD133 and CD3 expression on the cells was assessed by flow cytometry. HIV DNA was quantified by real-time polymerase chain reaction analysis. Results. HIV genomes were detected in CD133-sorted samples from 6 donors, including 2 in whom viral loads were undetectable for > 8 years. CD3(+) T cells represented < 1% of cells in all CD133-sorted samples. For 5 of 6 CD133-sorted samples with detectable HIV DNA, the HIV genomes could not be explained by contaminating CD3(+) T cells. Donors with detectable HIV DNA in HPCs received their diagnosis significantly more recently than the remaining donors but had had undetectable viral loads for similar periods. Conclusions. HIV genomes can be detected in CD133-sorted cells from a subset of donors with long-term viral suppression and, in most cases, cannot be explained by contamination with CD3(+) T cells.