title: The capsular polysaccharide Vi from Salmonella typhi is a B1b antigen.
abstract: Vaccination with purified capsular polysaccharide Vi Ag from Salmonella typhi can protect against typhoid fever, although the mechanism for its efficacy is not clearly established. In this study, we have characterized the B cell response to this vaccine in wild-type and T cell-deficient mice. We show that immunization with typhoid Vi polysaccharide vaccine rapidly induces proliferation in B1b peritoneal cells, but not in B1a cells or marginal zone B cells. This induction of B1b proliferation is concomitant with the detection of splenic Vi-specific Ab-secreting cells and protective Ab in Rag1-deficient B1b cell chimeras generated by adoptive transfer-induced specific Ab after Vi immunization. Furthermore, Ab derived from peritoneal B cells is sufficient to confer protection against Salmonella that express Vi Ag. Expression of Vi by Salmonella during infection did not inhibit the development of early Ab responses to non-Vi Ags. Despite this, the protection conferred by immunization of mice with porin proteins from Salmonella, which induce Ab-mediated protection, was reduced postinfection with Vi-expressing Salmonella, although protection was not totally abrogated. This work therefore suggests that, in mice, B1b cells contribute to the protection induced by Vi Ag, and targeting non-Vi Ags as subunit vaccines may offer an attractive strategy to augment current Vi-based vaccine strategies.
authors.affiliation: Medical Research Council Centre for Immune Regulation, School of Immunity and Infection, Institute for Biomedical Research, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Marshall
authors.forename: Adriana
authors.initials: A
authors.lastname: Flores-Langarica
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kingsley
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Hitchcock
authors.forename: Ewan A
authors.initials: EA
authors.lastname: Ross
authors.forename: Constantino
authors.initials: C
authors.lastname: López-Macías
authors.forename: Jeremy
authors.initials: J
authors.lastname: Lakey
authors.forename: Laura B
authors.initials: LB
authors.lastname: Martin
authors.forename: Kai-Michael
authors.initials: KM
authors.lastname: Toellner
authors.forename: Calman A
authors.initials: CA
authors.lastname: MacLennan
authors.forename: Ian C
authors.initials: IC
authors.lastname: MacLennan
authors.forename: Ian R
authors.initials: IR
authors.lastname: Henderson
authors.forename: Gordon
authors.initials: G
authors.lastname: Dougan
authors.forename: Adam F
authors.initials: AF
authors.lastname: Cunningham
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000502:physiology; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000382:microbiology* / Q000637:transplantation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010529:Peritoneal Cavity / Q000166:cytology / Q000382:microbiology; D010537:Peritoneum / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D018272:Porins; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000096:biosynthesis / Q000276:immunology; D012485:Salmonella typhi / Q000276:immunology*; D014435:Typhoid Fever / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; D018272:Porins; D022562:Salmonella Vaccines; C054154:capsular polysaccharide, Salmonella