CHEMOKINE-INDEPENDENT IN-VITRO RESISTANCE TO HUMAN-IMMUNODEFICIENCY-VIRUS (HIV-1) CORRELATING WITH LOW VIREMIA IN LONG-TERM AND RECENTLY INFECTED HIV-1-POSITIVE PERSONS

Chemokines have been implicated as protective factors against human im munodeficiency virus (HIV) infection, competing for binding to recepto rs that also function as coreceptors for HIV. In this study of HIV-pos itive donors, peripheral blood mononuclear cell (PBMC) culture resista nce to endogenous and exogenous HIV correlated with low plasma viremia and high in vitro RANTES production. However, resistant cells were no t rendered susceptible by neutralization of C-C chemokines, and additi on of C-C chemokines did not consistently suppress endogenous virus or exogenous HIV-1(MN). In contrast, CD8 T cell depletion markedly decre ased the frequency of resistant cultures without reducing C-C chemokin e production, Among newly infected persons, half exhibited phenotype s witching from preinfection susceptibility to postinfection resistance, suggesting that genetically predetermined constitutive cytokine produ ction or allelic receptor expression are not generally responsible for in vitro resistance and nonprogression.