Effect of a Single Amino Acid Change in MHC Class I Molecules on the Rate of Progression to AIDS

A single amino acid substitution in HLA molecules has a substantial effect on the rate of progression from HIV-1 infection to AIDS. HLA class I molecules present antigenic epitopes to T lymphocytes, thereby initiating a specific immune response and the clearance of foreign material. 1 – 3 The genes encoding HLA class I molecules are highly polymorphic. The great diversity of these genes appears to have been selected over time so that mammals can resist a wide variety of pathogens. 4 , 5 If this model accurately explains the diversity of class I molecules, alleles encoding functionally distinct molecules should provide a range of protection against a given pathogen. However, accurately assigning HLA alleles or loci to the defense against a particular infectious disease has been . . .