Evidence for a Human Immunodeficiency Virus Type 1-Mediated Suppression of Uninfected Hematopoietic (CD34⁺) Cells in AIDS Patients

Hematopoietic progenitor (CD34⁺) cells were purified from the bone marrow of 6 human immunodeficiency virus (HIV) type 1-seropositive cytopenic patients and 10 healthy donors. HIV-1-seropositive patients showed a reduced number of granulocyte/macrophage, erythroid, and megakaryocyte progenitors and also a progressive and significant decline of numbers of CD34+ cells in liquid culture, which did not result from a productive or latent HIV-1 infection of CD34⁺cells. However, all HIV-1-seropositive patients showed signs of active viral replication at the bone marrow level. Moreover, virus isolates from 3 HIV-l-seropositive patients showed a dose-dependent inhibition on growth of normal CD34⁺cells. This suppressive activity was almost completely reversed by incubating the virus isolates with an anti-gp120 polyclonal antibody before adding to normal CD34⁺cells.