CXCR4 AS A FUNCTIONAL CORECEPTOR FOR HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTION OF PRIMARY MACROPHAGES

The coreceptors used by primary Syncytium-inducing (SI) human immunode ficiency virus type 1 isolates for infection of primary macrophages we re investigated. SI strains using only CXCR4 replicated equally well i n macrophages with or without CCR5 and were inhibited by several diffe rent ligands for CXCR4 including SDF-1 and bicyclam derivative AMD3100 . SI strains that used a broad range of coreceptors including CCR3, CC R5, CCR8, CXCR4, and BONZO infected CCR5-deficient macrophages about 1 0-fold less efficiently than CCR5(+) macrophages. Moreover, AMD3100 bl acked infection of CCR5-negative macrophages by these strains. Our res ults therefore demonstrate that CXCR4, as well as CCR5, is used for in fection of primary macrophages but provide no evidence for the use of alternative coreceptors.