title: CD34+ progenitor cells from asymptomatic patients are not a major reservoir for human immunodeficiency virus-1.
abstract: Controversy exists as to whether hematopoietic progenitor cells are infected by human immunodeficiency virus-1 (HIV-1) in vivo. Most studies have focused on patients with acquired immunodeficiency syndrome (AIDS)/AIDS-related complex, and little data are available on asymptomatic patients with well preserved CD4+ T-cell counts. To determine if CD34+ hematopoietic progenitor cells are infected early in the course of HIV-1 disease, we evaluated 10 asymptomatic HIV-1 seropositive (HIV-1+) patients. The CD34+ cell fraction was purified by a two-step procedure consisting of both affinity chromatography and fluorescence-activated cell sorting that resulted in a median purity of over 99%. Using conventional and nested polymerase chain reaction (PCR) assays, we evaluated the presence and frequency of HIV-1 proviral DNA. Both bone marrow mononuclear cells and CD34- cells from all 10 patients were strongly positive for the HIV-1 pol and/or gag gene sequences. In contrast, sorted CD34+ cells from only two of 10 patients were positive, and the number of copies of proviral DNA in these samples was estimated to be from 2 to 5 per 250,000 cells. To test the in vitro functional capacity of CD34+ progenitors, these cells were assayed in both methylcellulose and long-term stromal culture. We found no significant reduction in the number of colony-forming unit-erythroid (CFU-E), burst-forming unit-erythroid (BFU-E), or colony-forming unit-granulocyte macrophage (CFU-GM) colonies, or in the frequency of cobblestone area forming cells from limit dilution analysis in HIV-1+ asymptomatic patients. Pooled methylcellulose colonies generated from CD34+ cells were HIV-1- in nine of 10 samples. All progeny from long-term cultures of CD34+ cells were HIV-1-. We conclude that the CD34+ hematopoietic progenitor compartment is not infected in the majority of asymptomatic HIV-1+ patients, and that these cells may represent a suitable target for strategies designed to protect developing CD4+ T cells from infection.
authors.affiliation: Department of Medicine, Emory University, Atlanta, GA 30322, USA.
authors.forename: T F
authors.initials: TF
authors.lastname: Neal
authors.forename: H K
authors.initials: HK
authors.lastname: Holland
authors.forename: C M
authors.initials: CM
authors.lastname: Baum
authors.forename: F
authors.initials: F
authors.lastname: Villinger
authors.forename: A A
authors.initials: AA
authors.lastname: Ansari
authors.forename: R
authors.initials: R
authors.lastname: Saral
authors.forename: J R
authors.initials: JR
authors.lastname: Wingard
authors.forename: W H
authors.initials: WH
authors.lastname: Fleming
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34; D001483:Base Sequence; D001853:Bone Marrow / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002469:Cell Separation; D002846:Chromatography, Affinity / Q000379:methods; D017931:DNA Primers; D004279:DNA, Viral / Q000032:analysis* / Q000235:genetics; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015658:HIV Infections / Q000276:immunology / Q000473:pathology*; D006679:HIV Seropositivity / Q000276:immunology / Q000473:pathology*; D015497:HIV-1 / Q000302:isolation & purification / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000473:pathology / Q000502:physiology* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000302:isolation & purification / Q000502:physiology
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D017931:DNA Primers; D004279:DNA, Viral