PROTECTIVE IMMUNITY INDUCED BY A YERSINIA-ENTEROCOLITICA SEROVAR 0 8 CELLULAR EXTRACT/

The purpose of this study was to investigate the protective power of a cellular extract (CE) from Y. enterocolitica O:8 grown in condition o f expression of chromosomal antigens. Mice were immunized by s.c. rout e and challenged with 10 LD(50) (1x10(4) CFU/ml). Immunoblotting showe d that CE-specific serum reacted with several CE antigens. Prominent b ands, of molecular weights 60 and 35.5, were present in cytoplasmic an d membrane fraction, respectively. The lipopolysaccharide (LPS) was de tected in CE. These findings suggest that chromosomally-encoded antige ns present in CE may induce protection against I: enterocolitica infec tion. Both humoral and cellular immune response contribute to protecti on in mice.