DENDRITIC CELLS EXPRESS MULTIPLE CHEMOKINE RECEPTORS USED AS CORECEPTORS FOR HIV ENTRY

Cells of the dendritic lineage are thought to be among the first cells infected after mucosal exposure to HIV, Zn this study, we have identi fied the presence of multiple chemokine receptors on dendritic cells ( DC) that may function as coreceptors for HIV entry, DC effectively use d CCR5 far entry of macrophage (M)-tropic isolates. CCR3, the eotaxin receptor, initially identified on eosinophils, is expressed on DC and may be used as an entry coreceptor by certain dual-tropic strains, CXC R4 was not expressed on DC, although SDF-1 induced a calcium flux and DC could be infected by T cell line (T)-tropic HIV. Our findings pro,i de evidence for the presence of a non-CXCR4 SDF-1 receptor on DC that is used mainly by T-tropic strains of HIV. DC from individuals homozyg ous for a 32-bp deletion of the CCR5 gene are also infectable with M-t ropic strains of HIV-1, and this infection is inhibited by stromal cel l-derived factor (SDF)1, suggesting that this receptor can also be use d by hi-tropic HIV for entry, Delineation of the spectrum of corecepto r usage on DC may offer new approaches to interfere with the initiatio n and propagation of HIV infection.