Effect of human immunodeficiency virus type 1 on CD34+ cells

The effect of HIV-1 on the in vitro growth of enriched hematopoietic stem cells (CD34+ cells) obtained from normal peripheral blood samples was studied. In comparison to untreated controls, the number of viable CD34+ cells progressively and significantly decreased in liquid cultures containing interleukin-3 (IL-3, 100 U/ml) after inoculation with HIV-1. In inoculated samples there was a significant reduction of all the hematopoietic progenitors (CFU-GM, BFU-E, CFU-Meg) starting from the second day of culture, CFU-GM being the most affected. In spite of these findings, no evidence of viral replication was observed: the total amount of p24 in HIV-1-inoculated CD34+ cell cultures showed a plateau, slightly declining towards the end of the experimental observation period. Moreover, erythroid and granulomacrophage colonies harvested from inoculated CD34+ cell cultures were unable to infect susceptible cells.