title: Continuous expression of I-A antigen by peritoneal macrophages from mice resistant to Mycobacterium bovis (strain BCG).
abstract: Monoclonal antibodies were used to monitor the expression of I-A antigen on the surface of macrophages obtained from mice immunized to Mycobacterium bovis (strain BCG). Unlike the transient nature of I-A expression by macrophages from Listeria-injected mice, peritoneal macrophages from mice injected 28 days previously with 10(4) BCG expressed I-A continuously. The continued expression was not due to the presence of antigen or of contaminating lymphocytes. When we compared the kinetics of I-A expression from different strains of mice, the continuous expression of I-A correlated with the genetic resistance of the mice to BCG. Macrophages from mice that were resistant to BCG expressed I-A continuously, while macrophages from BCG susceptible mice expressed I-A transiently. Injection of resistant mice with Salmonella typhimurium did not result in the induction of a population of macrophages that expressed I-A continuously. This suggests that the Bcg gene may not be the same as that responsible for resistance to Salmonella (Ity) or Leishmania (Lsh).
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000008:administration & dosage*; D003352:Corynebacterium / Q000276:immunology; D004198:Disease Susceptibility / Q000276:immunology; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D008087:Listeria / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009163:Mycobacterium bovis / Q000235:genetics; D010529:Peritoneal Cavity / Q000166:cytology; D014376:Tuberculosis / Q000276:immunology*
chemical_list: D001500:BCG Vaccine; D000949:Histocompatibility Antigens Class II