Molecular cloning, purification and immunological responses of recombinants GroEL and DnaK from Streptococcus pyogenes

To better understand the roles of heat shock proteins in streptococcal dise ases, the groEL and dnaK genes from Streptococcus pyogenes were cloned and their products (GroEL and DnaK) and derivatives (F2GroEL, F3GroEL and C1Dna K) purified as His-tagged fusion proteins. Western blot analysis of the pur ified proteins with sera from individuals with streptococcal diseases demon strated that 29 out of 36 sera tested were reactive with GroEL and eight re cognized DnaK. Rabbit antiserum against myosin recognized both GroEL and Dn aK. Antibodies raised against purified F2GroEL and DnaK reacted with myosin in the ELISA but not in a Western immunoblot. These data indicate that the S. pyogenes GroEL and DnaK may be important immunogens during streptococca l infections. Furthermore, we provide evidence of an immunogenic relatednes s of the GroEL and DnaK proteins with myosin that could play a role in the pathogenesis of streptococcal non-suppurative sequelae. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.