Selective inhibition of HIV replication in primary macrophages but not T lymphocytes by macrophage-derived chemokine

Macrophage-derived chemokine (MDC) has been reported to inhibit different H IV-1 strains in activated peripheral blood mononuclear cells (T cell blasts ), although other investigators have not confirmed these findings. Here we demonstrate that MDC inhibits the replication of CCR5-dependent (R5) HIV-1( BaL) in monocyte-derived macrophages (MDM), but not in T cell blasts, altho ugh with variable potency depending on donor variability. Analysis of HIV-1 (BaL) proviral DNA synthesis in MDM indicated that the suppressive effect o f MDC did not involve inhibition of early events such as entry or reverse t ranscription. Finally, an inverse correlation was observed between the leve ls of endogenous MDC secreted by uninfected MDM of different donors and the efficiency of different HIV strains, including two primary isolates with d ifferent coreceptor usage, to replicate in these cells. Thus, MDC represent s an example of a chemokine inhibiting HIV replication in macrophages actin g at one or more postentry levels in the virus life cycle.