Is AIDS an Evolutionary Accident?

clipped from www.scientificblogging.com Is AIDS An Evolutionary Accident? AIDS may partly be the consequence of an evolutionary accident, said Professor Frank Kirchhoff from the University of Ulm in Germany “AIDS is a deadly disease in people that is caused by human immunodeficiency virus (HIV). But similar viruses such as simian immunodeficiency virus (SIV), which infects monkeys, usually don’t cause disease in their natural monkey hosts,” says Kirchhoff. The researchers found that the Nef protein of most SIVs removes a molecule from the cell surface that is critical to make T cells responsive to stimulation. Nef proteins in HIV-1 and its closest related SIVs lack this protective function natural SIV infections in monkeys, the ability of the Nef protein to remove a specific receptor means that it can still fight off other diseases. Only the Nef proteins of HIV-1 and its immediate SIV relatives do not perform this function. evolutionary loss of a protective function of Nef may contribute to the high virulence of HIV-1 in humans”