It is known that HIV, the causative agent of AIDS, is severely species restricted, and, to date, only humans and chimpanzees have been shown to be susceptible to infection.  Human infection by HIV is restricted to cells expressing the CD4 molecule.  In addition to CD4, productive HIV infection requires one of two different G protein–coupled receptors, namely CCR5 or CXCR4.  However, despite the prevalence of … Continue reading First-ever study proves HIV targets & replicates in human macrophages.