title: Immunostimulatory effect of Bacillus firmus on mouse lymphocytes.
abstract: Bacillus firmus (a Gram-positive nonpathogenic and harmless bacterium), was shown to be a strong polyclonal activator of mouse B lymphocytes as estimated by ELISA testing of Ig concentrations in culture supernatants after incubation of BALB/c mouse splenocytes with inactivated bacillus. Synthesis of all main Ig classes and all IgG subclasses was stimulated in vitro, the considerable effect on IgA formation being the most interesting feature. B cell stimulation was T cell dependent, as was demonstrated by the effect of B. firmus on all Ig isotypes and by comparison of lymphocyte response of nu/nu mice and heterozygous nu/+ mice. The effect of B. firmus on splenocyte proliferation was stimulatory or suppressive depending on the dose of the bacterium. Increased synthesis of IFN-gamma and IL-10 (detected by ELISA in splenocyte culture supernatants) showed probable stimulation of Th1 and Th2 subpopulations. Considering the stimulatory effect on IgA formation and macrophage stimulation, B. firmus seems to be a prospective mucosal adjuvant and/or probiotic.
authors.affiliation: Institute of Immunology and Microbiology, 1st Faculty of Medicine, Charles University, 128 00 Prague, Czechia. lprok@lfl.cuni.cz
authors.forename: L
authors.initials: L
authors.lastname: Prokesová
authors.forename: P
authors.initials: P
authors.lastname: Mlcková
authors.forename: I
authors.initials: I
authors.lastname: Stanková
authors.forename: P
authors.initials: P
authors.lastname: Ladmanová
authors.forename: J
authors.initials: J
authors.lastname: Jezková
authors.forename: P
authors.initials: P
authors.lastname: Chalupná
authors.forename: O
authors.initials: O
authors.lastname: Novotná
authors.forename: D
authors.initials: D
authors.lastname: Cechová
authors.forename: J
authors.initials: J
authors.lastname: Julák
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D001407:Bacillus / Q000737:chemistry / Q000276:immunology*; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G