A tale of 2 epidemics: Link discovered between smallpox and HIV resistance

"The protective mutation in the CCR5 chemokine receptor gene almost certainly emerged well before MV began to infect humans, just about 50 years ago," said Alshad Lalani, lead author of the Science article. "Based on genetic analysis, it has been speculated by HIV researchers that the CCR5 mutation probably evolved at least 700 years ago, possibly during the European smallpox plagues." The article reported that myxoma infection of CCR5 mouse cells could be inhibited by RANTES, a protein that normally binds to chemokine receptors, as well as by anti-CCR5 polyclonal antibody or herbimycin A. Pertussis toxin did not prevent infection, and neither did monoclonal antibodies that normally block HTV-1 infection. These findings raise hopes that some form of "blockade" therapy might be possible, McFadden said.