title: Immunogenicity of the ribosomal fraction of Salmonella typhimurium: analysis of humoral immunity.
abstract: The ribosomal fraction prepared from Salmonella typhimurium LT2 was further purified by gel filtration of Sepharose 4B and afforded excellent protection against homologous challenge. The highly effective immunogens were composed of several fractions which could give different types of protection to mice. The first type of protection was heat-labile antigens which could induce humoral immunity, and the second type of protection was heat-stable antigens capable of evoking cellular resistance in mice. The former were different from O-antigens and the latter were free of endotoxin and rich in ribonucleic acid. The third type of protection was heat-resistant substances of cell wall components, which were mainly composed of O-antigens. The high immunogenicity observed in this study could be obtained only by the heat-stable antigens rich in ribonucleic acid, and the immunity conferred by this kind of antigen was due to the cellular type of protection.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001426:Bacterial Proteins / Q000276:immunology*; D001770:Blood Bactericidal Activity; D005591:Chemical Fractionation; D005260:Female; D007111:Immunity, Cellular; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D051379:Mice; D012269:Ribosomal Proteins / Q000276:immunology / Q000302:isolation & purification; D012270:Ribosomes / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology* / Q000648:ultrastructure; D014165:Transfer Factor / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D012269:Ribosomal Proteins; D014165:Transfer Factor