EXPRESSION OF HEAT-SHOCK PROTEINS IN STREPTOCOCCUS-PYOGENES AND THEIRIMMUNOREACTIVITY WITH SERA FROM PATIENTS WITH STREPTOCOCCAL DISEASES

The heat-shock response of Streptococcus pyogenes following exposure t o elevated growth temperatures, and the immunological reactivity of he at-shock proteins (HSPs) in streptococcal infections were studied. Two major proteins of 65 and 75 kDa were expressed when a S. pyogenes str ain was shifted from 37 degrees C to heat-shock temperatures of 40, 42 and 45 degrees C, Such proteins are members of the GroEL and DnaK fam ilies recognised in a Western blot assay with polyclonal antibodies ag ainst Escherichia coli GroEL and E, coli DnaK, respectively. Two-dimen sional autoradiograms of polypeptides labelled at 37 or 42 degrees C s howed an increased intensity of three spots at 42 degrees C. A monoclo nal antibody (MAb) against HSP 63 of Bordetella pertussis also recogni sed the 65-kDa inducible protein, although MAbs against Mycobacterium tuberculosis HSP 65 failed to recognise this protein. Immunoblot analy sis of sera from individuals with rheumatic fever or uncomplicated str eptococcal diseases revealed seven major immunogenic protein bands, tw o of which also reacted with anti-E, coli GroEL and DnaK polyclonal an tibodies. Furthermore, antibodies to the GroEL and DnaK proteins were also detected in sera from patients with either rheumatoid arthritis o r systemic lupus erythematosus, These results demonstrated a heat-shoc k response of S. pyogenes, and indicated the presence of an immune res ponse against HSPs in streptococcal diseases.