Hematopoietic Potential and Retroviral Transduction of CD34+Thy-1+ Peripheral Blood Stem Cells From Asymptomatic Human Immunodeficiency Virus Type-1–Infected Individuals Mobilized With Granulocyte Colony-Stimulating Factor

Abstract

AbstractThe potential of hematopoietic stem cells (HSCs) from human immunodeficiency virus type-1 (HIV-1)–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 (PBSCs) of three asymptomatic HIV-1–infected individuals after granulocyte colony-stimulating factor (G-CSF; 10 μg/kg/d) mobilization. On day 4 of G-CSF treatment, 0.8% to 1% of the total blood mononuclear cells were CD34+. Leukapheresis followed by a two-step cell isolation process yielded a CD34+Thy-1+ cell population of high purity (76% to 92% CD34+Thy-1+ cells). This cell population showed no evidence of HIV-1–containing cells based on a semiquantitative HIV-1 DNA polymerase chain reaction. Furthermore, the purified cells showed normal hematopoietic potential in in vitro clonogenic assays. Successful gene transfer into committed progenitor cells (colony-forming units-cells) and more primitive stem/progenitor cells (long-term culture colony-forming cells) could be shown after amphotropic retroviral transduction. These data provide evidence that the CD34+Thy-1+ stem cell compartment can be mobilized and enriched in early stage HIV-1–infected patients. Furthermore, successful transduction of this cell population as a prerequisite for stem cell-based clinical gene therapy protocols was demonstrated.