Autoimmunity to chaperonins in the pathogenesis of arthritis and diabetes

The immunology of the 65 kd heat shock protein (hsp65) is paradoxical. Microbial and mammalian hsp65 molecules are 50% identical in amino acid sequence and immunologically cross-reactive, so microbial hsp65 looks like self; yet hsp65 is a dominant antigen in infection. Immunity to hsp65 can cause autoimmune diabetes in mice and may be related to autoimmune arthritis in rats and humans, so immunity to hsp65 should be forbidden; yet healthy persons manifest T-cell responses to self-hsp65. The aim of this chapter is to explore the immunological dominance of hsp65 and its role in autoimmunity--benign and pernicious.