Expression of CD25 defines peripheral blood mononuclear cells with productive versus latent HIV infection
Borvak, J.; Chou, C.S.; Bell, K.; Van Dyke, G.; Zola, H.; Ramilo, O.; Vitetta, E.S.
Journal of Immunology 155(6): 3196-3204
1995
ISSN/ISBN: 0022-1767 PMID: 7673732 Document Number: 447419
The present studies were designed to further determine whether the CD25 marker could distinguish between cells productively and latently infected with HIV. This was accomplished by combining immunotoxin (IT)-mediated killing of CD25+ cells, highly sensitive indirect immunofluorescence to detect remaining CD25+ cells, and PCR-mediated amplification of proviral DNA in immunotoxin-treated vs untreated HIV-infected cells. Our results demonstrate that: 1) By direct immunofluorescence 3 to 8% of PBMCs are CD25+, whereas by indirect immunofluorescence 30% are CD25+. The increased number of CD25+ cells is due to their detection by the highly sensitive indirect immunofluorescence assay. Up to 60% of the CD25+ cells are CD4+ and 12% are CD8+. 2) Treatment of HIV-infected PBMCs with an anti-CD25 IT for 6 days eliminated both CD25-high and CD25-low cells and decreased the production of p24 by 99%. 3) Differences in the HIV proviral genome were detected in the unfractionated PBMCs vs PBMCs from which CD25+ cells had been eliminated by IT treatment. Hence, PBMCs containing both CD25+ and CD25- cells express all intermediate proviral species and full-length double-stranded proviral DNA. In contrast CD25- quiescent cells contain predominantly intermediate species. These results confirm and extend our previous observations that expression of CD25 can distinguish latently infected cells from cells producing virus.