A Mycobacterial 65 kD Heat-Shock Protein and T Cells in Experimental Arthritis

As a common characteristic, autoimmune disorders show a loss of self integrity due to a pernicious reactivity of the immune system directed against self structures. Since mycobacterial species are notoriously difficult to grow in vitro, molecular cloning of their antigens seemed the solution for the development of diagnostics and vaccines. From serology in mycobacterial diseases one antigen, the 65 kD protein, was already identified as a potent immunogen. By further subcloning of the latter coding gene an overproducing strain was obtained. From this strain, the 65 kD could easily be purified and subsequently further characterized. From in vivo cross-priming experiments, evidence was obtained for the immunologic relationship between the mycobacterial 65 kD and an antigen present in the streptococcal cell wall, presumably the streptococcal 65 kD homolog. The evidence in humans that autoimmune arthritis could be triggered by microbial antigens is supported by a number of experimental models. One of these models is the well-known model of adjuvant arthritis.