HEMATOPOIETIC POTENTIAL AND RETROVIRAL TRANSDUCTION OF CD34(-1(+) PERIPHERAL-BLOOD STEM-CELLS FROM ASYMPTOMATIC HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1-INFECTED INDIVIDUALS MOBILIZED WITH GRANULOCYTE-COLONY-STIMULATING FACTOR()THY)

The potential of hematopoietic stem cells (HSCs) from human immunodefi ciency virus type-1 (HIV-l)-infected individuals, eg, self-renewal and multilineage differentiative capacity, might be perturbed due to the underlying disease. In this study, we assessed the HSC activity in the CD34(+) Thy-1(+) cell population of peripheral blood stem cells (PBSC s) of three asymptomatic HIV-l-infected individuals after granulocyte colony-stimulating factor (G-CSF; 10 mu g/kg/d) mobilization, On day 4 of G-CSF treatment, 0.8% to 1% of the total blood mononuclear cells w ere CD34(+), Leukapheresis followed by a two-step cell isolation proce ss yielded a CD34(+)Thy-1(+) cell population of high purity (76% to 92 % CD34(+)Thy-1(+) cells). This cell population showed no evidence of H IV-1-containing cells based on a semiquantitative HIV-1 DNA polymerase chain reaction. Furthermore, the purified cells showed normal hematop oietic potential in in vitro clonogenic assays. Successful gene transf er into committed progenitor cells (colony-forming units-cells) and mo re primitive stem/progenitor cells (long-term culture colony-forming c ells) could be shown after amphotropic retroviral transduction. These data provide evidence that the CD34(+)Thy-1(+) stem cell compartment c an be mobilized and enriched in early stage HIV-l-infected patients. F urthermore, successful transduction of this cell population as a prere quisite for stem cell-based clinical gene therapy protocols was demons trated. (C) 1997 by The American Society of Hematology.