Simian immunodeficiency viruses of diverse origin can use CXCR4 as a coreceptor for entry into human cells

Primary simian immunodeficiency virus (SIV) isolated from sooty mangabey (S IVsm [n = 6]), stumptail (SIVstm [n = 1]), mandrill (SIVmnd [n = 1]), and A frican green (SIVagm [n = 1]) primates were examined for their ability to i nfect human cells and for their coreceptor requirements. All isolates infec ted human peripheral blood mononuclear cells (PBMCs) from a CCR5(+/+) donor , and seven of eight isolates tested also infected CCR5(-/-) PBMCs. Analysi s of coreceptor utilization using GHOST and U87 cell lines revealed that al l of the isolates tested used CCR5 and the orphan receptors STRL33 and GPR1 5. Coreceptors such as CCR2b, CCR3, CCR8, and CX3CR1 were also utilized by some primary SIV isolates. More importantly, we found that CXCR4 was used a s a coreceptor by the SIVstm, the SIVagm, and four of the SIVsm isolates in GHOST and U87 cells. These data suggest that primary SIV isolates from div erse primate species can utilize CXCR4 for viral entry, similar to what has been described for human immunodeficiency viruses.