[Examination of protein MPB 70 properties in BCG substrains used for the production of Polish antituberculosis vaccines].

The aim of the study was examination of MPB70 protein production by different BCG substrains and testing this protein as reagent in allergenic skin test on BCG vaccinated guinea pigs. Three BCG substrains: Danish 1331 (D), Japanese 172 (J) and Polish BCG Moreau (P) were used for the study. The protein MPB70 received from dr Nagai from Osaka University was used as reference preparation. It has been shown that MPB70 protein of molecular weight about 21,500 Da was present only in BCG Moreau (P) and Japanese (J) substrains. In immunoblotting test monoclonal antibodies reacted additionally with 43,000 Da protein in all tested substrains. We suspect that the detected additional molecule was a dimer of MPB70 protein. The development of skin reactions to MPB70 protein was seen in guinea pigs vaccinated with J and P substrains. The peak of alergy to MPB70 protein was observed 9 weeks after vaccination. In sera of vaccinated animals antibodies against MPB70 protein were detected by ELISA method. The possibility of using MPB70 protein for diagnostic purpose is discussed.