Mucosal immunization with non-living antigens usually requires the use of an adjuvant. The adjuvant activity of Bacillus firmus in the mucosal immunization of mice was described by our laboratory previously. In the present study, subcellular localization of B. firmus activities was followed. After mechanical disintegration, subcellular components of bacterium were fractionated by differential centrifugation and salting out. Bacterial cell walls, cytoplasmic membrane fraction, soluble cytoplasmic proteins, and ribosomal fractions were isolated. Their effect on the mouse immune system was studied. Lymphocyte proliferation and immunoglobulin formation in vitro were stimulated by bacterial cell wall (BCW), cytoplasmic membrane (CMF), and ribosomal fractions. BCW and CMF increased antibody formation after intratracheal immunization of mice with influenza A and B viruses, and increased protection against subsequent infection with influenza virus. The BCW fraction even induced intersubtypic cross-protection: Mice immunized with A/California/7/04 (H3N2) + BCW were resistant to the infection by the highly pathogenic A/PR/8/34 (H1N1) virus.

• MeSH
• Adjuvants, Immunologic administration & dosage   isolation & purification   MeSH
• Bacillus chemistry   MeSH
• Orthomyxoviridae Infections prevention & control   MeSH
• Cells, Cultured MeSH
• Lymphocytes drug effects   MeSH
• Disease Models, Animal MeSH
• Mice MeSH
• Cell Proliferation drug effects   MeSH
• Antibody Formation drug effects   MeSH
• Influenza Vaccines administration & dosage   MeSH
• Influenza A virus immunology   MeSH
• Influenza B virus immunology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adjuvants, Immunologic MeSH
• Influenza Vaccines MeSH

Intranasal immunization of guinea pigs with inactivated type B influenza virus plus inactivated Bacillus firmus as an adjuvant compared to the virus alone yields higher titers of serum hemagglutination-inhibiting antibodies and virus-neutralizing antibodies. This phenomenon could be useful in standard serology, especially in the preparation of immune sera against highly pathogenic strains for in vitro diagnosis.

• MeSH
• Adjuvants, Immunologic * MeSH
• Bacillus immunology   MeSH
• Guinea Pigs MeSH
• Antibodies, Viral analysis   MeSH
• Serologic Tests methods   MeSH
• Vaccination methods   MeSH
• Influenza Vaccines immunology   MeSH
• Influenza B virus immunology   MeSH
• Animals MeSH
• Check Tag
• Guinea Pigs MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adjuvants, Immunologic * MeSH
• Antibodies, Viral MeSH
• Influenza Vaccines MeSH

The effect of nonpathogenic G+ bacterium B. firmus (BF) on stimulation of mouse peritoneal cells in vitro was evaluated by testing nitric-oxide-synthesis induction and cytokine formation. The reactivity was compared of peritoneal cells from two inbred mouse strains, C57B1/6 and BALB/c, which differ in their immunological reactivity. Peritoneal macrophages from C57B1/6 produced more nitric oxide after a 1-d cultivation with inactivated BF than those of BALB/c mice. In both strains, production can be further increased by adding exogenous IFN-gamma to the culture. There were no significant differences between peritoneal cells of these two mouse strains in cytokine production after optimal in vitro stimulation with BF. BF effectively activated peritoneal cells for the production of TNF-alpha, IL-1beta and IL-10, delipidated bacterium (DBF) being more efficient than BF in induction of IL-10 and TNF-alpha. On the other hand, BF had only small effect on IFN-gamma production and no detectable effect on IL-12 production. Macrophage activation by BF/DBF can represent one of the mechanisms responsible for previously described immunomodulatory activity of BF.

• MeSH
• Macrophage Activation * MeSH
• Bacillus immunology   MeSH
• Cell Culture Techniques methods   MeSH
• Cytokines immunology   metabolism   MeSH
• Lipopolysaccharides pharmacology   MeSH
• Mice, Inbred BALB C MeSH
• Mice, Inbred C57BL MeSH
• Mice MeSH
• Organic Chemicals pharmacology   MeSH
• Nitric Oxide metabolism   MeSH
• Peritoneal Cavity cytology   MeSH
• Immunity, Innate MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Cytokines MeSH
• Lipopolysaccharides MeSH
• Nocardia delipidated cell mitogen MeSH Browser
• Organic Chemicals MeSH
• Nitric Oxide MeSH

Inactivated Bacillus firmus (BF), G+ nonpathogenic bacterium of the external environment, was coupled to ovalbumin (OVA) and used in immunization experiments as antigen carrier. Balb/c mice were immunized thrice intra-tracheally and intra-nasally with conjugates of OVA and BF. Surprisingly, administration of OVA-BF conjugates inhibited anti-OVA IgG response in both sera and mucosal secretions if compared to an exposure to OVA alone. The suppression of antigen-specific antibody production was accompanied by promotion of TH1 phenotype.

• MeSH
• Lymphocyte Activation MeSH
• Antigens administration & dosage   MeSH
• Administration, Intranasal MeSH
• Bacillus immunology   MeSH
• Immunization MeSH
• Immunoglobulin G biosynthesis   blood   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Drug Carriers MeSH
• Ovalbumin administration & dosage   immunology   MeSH
• Antibodies, Bacterial biosynthesis   blood   MeSH
• Immunity, Mucosal MeSH
• In Vitro Techniques MeSH
• Th1 Cells immunology   MeSH
• Trachea MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens MeSH
• Immunoglobulin G MeSH
• Drug Carriers MeSH
• Ovalbumin MeSH
• Antibodies, Bacterial MeSH

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.

• MeSH
• Lymphocyte Activation * drug effects   MeSH
• B-Lymphocytes drug effects   immunology   MeSH
• Bacillus chemistry   immunology   MeSH
• Enzyme-Linked Immunosorbent Assay MeSH
• Immunoglobulin G biosynthesis   drug effects   MeSH
• Cells, Cultured MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Antibodies, Bacterial biosynthesis   MeSH
• T-Lymphocytes immunology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Immunoglobulin G MeSH
• Antibodies, Bacterial MeSH

A nonpathogenic bacterium of external environment possessing remarkable immunomodulatory activity, Bacillus firmus (BF) inactivated with formaldehyde, was given intragastrically to two genetically different mouse strains BALB/c (H-2d) and B10.BR/SnPh (B10.BR, H-2k) reared in conventional (CV) and B10.BR strain also in germ-free (GF) conditions. Repeated intragastric administration of BF (500 micrograms every other day over two weeks, starting at the age of 3 months) significantly enhanced intestinal IgA levels in CV BALB/c mice but did not affect intestinal IgA in CV B10.BR mice. In GF B10.BR mice, IgG levels in sera and intestinal washings increased after BF administration compared to CV B10.BR mice. In CV BALB/c mice, specific activity of enterocyte brush-border enzymes (lactase, gamma-glutamyltransferase, alkaline phosphatase) decreased after BF treatment; sucrase (sucrose alpha-glucosidase) activity was not affected. On the other hand, in B10.BR mice, specific activity of gamma-glutamyltransferase and dipeptidyl peptidase IV were higher after administration of BF in both CV and GF groups relative to untreated controls. The activities of lactase and glucoamylase (glucan 1,4-alpha-glucosidase) were significantly stimulated only in the group of GF B10.BR mice treated with formolized BF. The stimulation of immunoglobulin production after BF treatment was accompanied by changes in the levels of enterocyte brush-border enzymes; this responsiveness to BF treatment was genetically regulated.

• MeSH
• Alkaline Phosphatase metabolism   MeSH
• Bacillus immunology   MeSH
• beta-Galactosidase metabolism   MeSH
• Dipeptidyl Peptidase 4 metabolism   MeSH
• Enterocytes enzymology   microbiology   MeSH
• Genetic Predisposition to Disease MeSH
• Glucan 1,4-alpha-Glucosidase metabolism   MeSH
• Germ-Free Life MeSH
• Immunoglobulin A biosynthesis   blood   MeSH
• Immunohistochemistry MeSH
• Lactase MeSH
• Microvilli enzymology   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Sucrase metabolism   MeSH
• Intestines enzymology   immunology   microbiology   MeSH
• Intestinal Mucosa enzymology   immunology   microbiology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alkaline Phosphatase MeSH
• beta-Galactosidase MeSH
• Dipeptidyl Peptidase 4 MeSH
• Glucan 1,4-alpha-Glucosidase MeSH
• Immunoglobulin A MeSH
• Lactase MeSH
• Sucrase MeSH