Possible roles of infections and heat shock proteins in rheumatoid arthritis

: Heat shock protein, one of the most conserved proteins from prokaryotes to man, was shown to be strongly immunogenic in bacterial and helminthic infections. Evidences have accumulated suggesting that mycobacterial hsp65 plays a crucial role in the development of adjuvant arthritis induced in rats. By analogy, the pathogenetic roles of hsp were investigated in rheumatoid arthritis in man. The evidences obtained so far are highly suggestive but still circumstantial. Hsp's strong immunogenicity and high conservation, which seem to be mutually exclusive, make this molecule very mysterious. In this regard, Coutinho's new network theory or Cohen and Young's theory of immunological homunculus nicely reconciles these aspects.