Crossreactivity of SLE autoantibodies with 70 kDa heat shock proteins of Mycobacterium tuberculosis

Heat shock proteins (hsp) may be involved in the initiation and perpetuation of autoimmune diseases. In order to investigate the possible role of hsp and other intracellular proteins of Mycobacterium tuberculosis in the autoantibody production in SLE, the immuno-crossreactivity of SLE autoantibodies with Mycobacterium tuberculosis sonic extract and hsp-70 kDa was investigated. These proteins showed significant binding with Protein A-Sepharose isolated SLE IgG. Western blotting of hsp-70 with SLE IgG showed strong recognition, suggesting possible involvement of hsp and other intracellular proteins of Mycobacterium tuberculosis in the autoantibody induction in SLE.