title: Immunostimulatory activity of Bacillus spores.
abstract: Bacillus species, typically Bacillus subtilis, are being used as probiotics and mounting evidence indicates that Bacillus species are important for development of a robust gut-associated lymphoid system (GALT). We used a number of gut isolates of Bacillus incorporating three species, B. subtilis, Bacillus licheniformis and Bacillus flexus to evaluate the nature of interaction between spores and the GALT. In mice orally administered with spores, evidence of cell proliferation was determined in the germinal centers of Peyer's patches. Stimulation of antigen-presenting cells and T lymphocytes was also markedly enhanced. Cytokines were shown to be induced in spleens and mesenteric lymph nodes of mice including the proinflammatory cytokines, tumour necrosis factor-alpha and IL-6. We also demonstrated that vegetative cells of B. subtilis can stimulate expression of the toll-like receptor (TLR) genes for TLR2 and TLR4. However, we were able to show that spores could not stimulate either and must, by default, interact with another TLR and by this mechanism help activate innate immunity.
authors.affiliation: School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK.
authors.forename: Jen-Min
authors.initials: JM
authors.lastname: Huang
authors.forename: Roberto M
authors.initials: RM
authors.lastname: La Ragione
authors.forename: Alejandro
authors.initials: A
authors.lastname: Nunez
authors.forename: Simon M
authors.initials: SM
authors.lastname: Cutting
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000284:Administration, Oral; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001407:Bacillus / Q000276:immunology*; D015169:Colony Count, Microbial; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D020869:Gene Expression Profiling; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008198:Lymph Nodes / Q000276:immunology; D008643:Mesentery / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013170:Spores / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D051195:Toll-Like Receptor 2 / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000235:genetics
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4