Sequence homologies between hsp60 and autoantigens.

The human heat shock protein (hsp) 60 shares sequence homology with a wide range of autoantigens including those of insulin dependent diabetes mellitus, Hashimoto's thyroiditis, glomerulonephritis, scleroderma, pemphigoid, rheumatoid arthritis, multiple sclerosis, chronic active hepatitis, primary biliary cirrhosis and Addison's disease. Here we show the extent of this homology and suggest that it contributes to autoimmunity through cross-reactivity between hsp60 and tissue-specific proteins containing similar epitope motifs. Differences between individuals in MHC class II may influence the selection of a particular hsp60 epitope and the corresponding target antigen that gives rise to an autoimmune disease.