Hematopoietic precursor cells isolated from patients on long-term suppressive HIV therapy did not contain HIV-1 DNA

Abstract

Background. We address the key emerging question of whether Lin -/CD34 + hematopoietic precursor cells (HPCs) represent an important latent reservoir of human immunodeficiency virus type 1 (HIV-1) during long-term suppressive therapy. Methods. To estimate the frequency of HIV-1 infection in bone marrow, we sorted Lin -/CD34 + HPCs and 3 other cell types (Lin -/CD34 -, Lin -/CD4 +, and Lin +/CD4 +) from 8 patients who had undetectable viral loads for 3-12 years. Using a single-proviral sequencing method, we extracted, amplified, and sequenced multiple single HIV-1 DNA molecules from these cells and memory CD4 + T cells from contemporaneous peripheral blood samples. Results. We analyzed 100 000-870 000 bone marrow Lin -/CD34 + HPCs from the 8 patients and found no HIV-1 DNA. We did isolate HIV-1 DNA from their bone marrow Lin +/CD4 + cells that was genetically similar to HIV-1 DNA from lymphoid cells located in the peripheral blood, indicating an exchange of infected cells between these compartments. Conclusions. The absence of infected HPCs provides strong evidence that the HIV-1 infection frequency of Lin -/CD34 + HPCs from bone marrow, if it occurred, was