Abstract
HIV subtype C has previously been shown to infect hematopoietic progenitor cells (HPCs) at a significantly higher rate than subtype B. To better understand the subtype-specific nature of HPC infection, we examined the prevalence of HPC infection in vivo by HIV-1 subtypes A and D. HIV-1 infection of HPC was examined in 40 individuals, 19 infected with subtype A and 21 with subtype D, using a single colony assay format. DNA from 1177 extracted colonies was tested for integrated viral DNA of the p24 gene. Four colonies were found to be stably infected, three of 462 colonies (0.65%) from HIV-1A-infected individuals (1/19 individuals) and one of 715 colonies (0.14%) from HIV-1D-infected individuals (1/22 individuals). These rates of colony infection were comparable to the rates observed in PBMCs from the same subjects. Additionally, no correlation was observed between cell colony density and circulating viral load or proviral load. Our findings suggest that HIV-1 subtypes A and D do not preferentially infect colony-forming HPCs over mature HIV target cells in vivo.