CELL-PROLIFERATION IS NOT REQUIRED FOR PRODUCTIVE HIV-1 INFECTION OF MACROPHAGES

Lentiviruses, including HIV-1, are considered a rare example of retrov iruses which do not require cell proliferation for their replication. However, this notion was questioned in several publications where prod uctive HIV-1 infection was found to be restricted to a small fraction of macrophages with proliferative capacity. Since the mode of HIV-1 re plication in macrophages is of great clinical relevance, we performed a single-cell analysis of HIV-1 replication and [H-3]thymidine incorpo ration. Our results indicate that while 17% macrophages were detected as HIV-1 DNA-positive 12 hr after infection, only 2% of those cells ha d incorporated tritium, about the same percentage as in the uninfected cell population. Forty-eight hours after infection, 38% macrophages w ere HIV-1 DNA-positive and 47% of those had incorporated tritium, whil e the percentage of tritium-positive uninfected cells did not change ( 1%). These results demonstrate directly that HIV-1 DNA does not coloca lize with [H-3]thymidine and support the notion that cell proliferatio n is not required for HIV-1 infection of macrophages. (C) 1997 Academi c Press.