title: Intracellular fate and immunogenicity of B. subtilis spores.
abstract: To support our work on the development of bacterial spores as oral vaccines we examined the immunogenicity and intracellular fate of Bacillus subtilis endospores in a murine model. Mice dosed orally with spores developed systemic IgG and mucosal sIgA responses. Analysis of IgG subclasses revealed a predominance of the IgG2a subclass during the early stages of immunisation. Analysis of cytokine mRNA in GALT and lymphoid organs showed early induction of IFN-gamma, a Th1 cytokine, as well as the pro-inflammatory cytokine TNF-alpha. Significant levels of IgG antibodies were produced against vegetative bacilli following dosing with spores. This showed that spores could germinate in the GI tract. In vitro studies detailing the intracellular fate and persistence of spores in a macrophage-like cell line (RAW264.7) demonstrated that spores could germinate efficiently in macrophages, initiate gene expression as well as inducing pro-inflammatory cytokines.
authors.affiliation: School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK.
authors.forename: Le H
authors.initials: le H
authors.lastname: Duc
authors.forename: Huynh A
authors.initials: HA
authors.lastname: Hong
authors.forename: Nguyen Q
authors.initials: NQ
authors.lastname: Uyen
authors.forename: Simon M
authors.initials: SM
authors.lastname: Cutting
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001412:Bacillus subtilis / Q000276:immunology* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D018928:Immunity, Mucosal / Q000276:immunology; D007763:Lac Operon / Q000235:genetics; D008221:Lymphoid Tissue / Q000382:microbiology; D008264:Macrophages / Q000276:immunology / Q000382:microbiology / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D012333:RNA, Messenger / Q000096:biosynthesis / Q000276:immunology; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013171:Spores, Bacterial / Q000276:immunology* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D016207:Cytokines; D012333:RNA, Messenger; C030069:spore-specific proteins, Bacillus