2/19/91 MJ Dr. A. Fauci NIAID [stamped, FEB 17 1991] re MHC and HIV. Dear Tony: For a long time I have wondered whether the MHC polymorphism was related to virus transmission. In re HIV, it could go either way: T-cell-anti MHC might be an additional receptor for initial infection by HIV from a heterologous source. (That would select against the polymorphism). Do you know of any evidence on this hypothesis, viz. how MHC compatibility affects HIV transmission between spouses (or, less likely, mother to child)? I'm delighted you'll be on our program at 10M on Feb. 25. See you then. Joshua.