CHIMPANZEE CXCR4 AND CCR5 ACT AS CORECEPTORS FOR HIV TYPE-1

Chemokine receptors are molecules involved in the fusion of immunodefi ciency viruses after their attachment, As chimpanzees are the animal m odel for infection by HIV-1, we cloned and sequenced chimpanzee CXCR4 and CCR5 from PBMCs. Chimpanzee CXCR4 was found to be identical to hum an CXCR4 which provides an explanation for the sensitivity of chimpanz ees to lymphotropic isolates of HIV-1, Chimpanzee CCR5 showed two subs titutions with respect to human CCR5. However, we show that the macrop hage-tropic isolate HIV-1-Ba-L can use chimpanzee CCR5 as a fusion rec eptor, Therefore, the resistance of chimpanzee PBMCs to infection by m acrophage-tropic isolates of HIV-1 is unlikely to be due to substituti ons in CCR5.