title: Proliferative and T-cell specific interleukin (IL-2/IL-4) production responses in spleen cells from mice vaccinated with aroA live attenuated Salmonella vaccines.
abstract: T-cell responses were studied in mice immunized with the Salmonella typhimurium aroA SL3261 live attenuated vaccine strain. T-cell responses in the spleen, both in whole cell populations and in nylon wool non-adherent (T-cell enriched) cells, were studied in vitro as proliferation by incorporation of tritiated thymidine and production of T-cell specific cytokines [IL-2 (interleukin-2)/IL-4]. Stimulating antigens included whole Salmonella lysates and purified lipopolysaccharide (LPS), both untreated and after alkaline hydrolysis to prevent the non-specific mitogenic effect of LPS. Strong proliferative responses were obtained with untreated whole cell extract and LPS, which were decreased by polymyxin B (PB). Alkaline detoxification of the antigens decreased the proliferative response of nylon-wool non-adherent populations to LPS, but greatly increased their response to the Salmonella extract. Surprisingly, PB also reduced proliferation to detoxified LPS. Little or no IL-2/IL-4 production was seen in response to LPS or purified polysaccharide antigens, while there was a strong IL-2/IL-4 response to whole cell lysate, again markedly increasing after alkaline treatment. The results suggest that the T-cell response elicited by immunization with live Salmonella aroA vaccines in mice recognizes antigens other than LPS determinants, and that estimation of T-cell responses to Salmonella antigens by proliferation alone may yield misleading results.
authors.affiliation: Department of Pathology, University of Cambridge, U.K.
authors.forename: B
authors.initials: B
authors.lastname: Villarreal
authors.forename: P
authors.initials: P
authors.lastname: Mastroeni
authors.forename: R D
authors.initials: RD
authors.lastname: de Hormaeche
authors.forename: C E
authors.initials: CE
authors.lastname: Hormaeche
mesh_terms: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D019883:Alkyl and Aryl Transferases; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001428:Bacterial Vaccines / Q000276:immunology*; D005260:Female; D007156:Immunologic Memory; D007376:Interleukin-2 / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D011112:Polymyxin B / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000235:genetics / Q000276:immunology*; D012972:Sodium Hydroxide / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D007376:Interleukin-2; D008070:Lipopolysaccharides; D014613:Vaccines, Attenuated; D015847:Interleukin-4; D012972:Sodium Hydroxide; D019883:Alkyl and Aryl Transferases; D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D011112:Polymyxin B