Submitted April 18, 2007
Accepted July 26, 2007
Infection of hematopoietic progenitor cells by HIV-1 subtype C, and its association with anemia in southern Africa
Andrew D Redd, Ava Avalos, and M. Essex*
Department of Immunology and Infectious Diseases, Harvard School of Public Health Aids Initiative, Harvard School of Public Health, Boston, MA, United States
Infectious Disease Care Clinic, Princess Marina Hospital, Gaborone, Botswana
* Corresponding author; email: messex{at}hsph.harvard.edu.
Reports from southern Africa, an area in which HIV-1 infection is caused almost exclusively by subtype C (HIV-1C), have shown increased rates of anemia in HIV-infected populations when compared to similar AIDS patients in the U.S., an area predominantly infected with subtype B (HIV-1B). Recent findings by our group demonstrated a direct association between HIV-1 infection and hematopoietic progenitor cell health in Botswana. Therefore, using a single-colony infection assay and quantitative proviral analysis we examined whether HIV-1C could infect hematopoietic progenitor cells (HPC) and whether this phenotype was associated with the higher rates of anemia found in southern Africa. The results show that a significant number of HIV-1C, but not HIV-1B, isolates can infect HPC in vitro (P < 0.05). In addition, a portion of HIV-1C positive Africans had infected progenitor cell populations in vivo, which associated with higher rates of anemia in these patients (P < 0.05). This represents a difference in cell tropism between two geographically separate and distinct HIV-1 subtypes. The association of this hematotropic phenotype with higher rates of anemia should be considered when examining anti-HIV drug treatment regimens in HIV-1C predominant areas, such as southern Africa.
