Protection conferred on mice by combinations of monoclonal antibodies directed against outer-membrane proteins or smooth lipopolysaccharide of Brucella (original) (raw)
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Infection and Immunity
In contrast to immunity against some other facultative intracellular parasites, protective immunity against Brucella abortus is mediated in mice by antibodies as well as by cell-mediated immune responses. It was the purpose of this study to determine whether antibody alone would prevent infection with B. abortus. The majority (82%) of CD-1 outbred mice infected with 100 CFU of virulent B. abortus 2308 preincubated with graded quantities of an O polysaccharide-specific IgG2a monoclonal antibody (MAb) were free of infection 1. 2, 4, and 6 weeks later, based on detection limits of 13 brucellae per spleen and 39 per liver. Infection was present in 95% of control animals. Similar results were obtained with a challenge dose of 500 CFU, but with a challenge dose of 5,000 CFU, infection became established even with the highest concentration of MAb used (50 micrograms of MAb per 5,000 brucellae). Pretreatment with an O polysaccharide-specific IgG1 MAb or with convalescent-phase serum diminis...
Veterinary World, 2018
Aim: The major objective of the investigation was to evaluate the hitherto uncharacterized potential of Brucella-specific antibodies to win the battle against virulent Brucella abortus infection. Materials and Methods: Brucella-specific immune serum was raised in mice. The antibody titer of serum was determined by standard tube agglutination test and indirect enzyme-linked immunosorbent assays (iELISA). Groups of mice and guinea pigs were passively immunized with serum containing specific agglutinin titers. 24 h after immunization, all animals along with unimmunized controls were challenged with B. abortus S544. Total B. abortus S544 counts in the spleen of each animal collected on the 7th day of challenge was determined to evaluate the protective index (PI) of anti-Brucella serum by statistical analysis. Results: A dose-dependent protective response to immune mice serum was observed in both experimental models though the values of PI of mice were higher than those obtained for guinea pigs. The PI values in mice passively immunized with 50 IU or 25 IU antibodies were 1.38 and 0.69, respectively. In guinea pigs, however, animals passively immunized with 50 IU or 25 IU antibodies showed PI values equivalent to 0.79 and 0.41, respectively. Conclusion: The observations support our hypothesis that the presence of antibodies inhibits the initial multiplication and eventual colonization of systemic organs by B. abortus. Therefore, a predominant antibody-mediated response induced by a vaccine is expected to protect the animal against the most severe clinical outcome of infection.
Humoral Immunity in mice Mediated by Monoclonal Antibodies Against the A and M Antigens of Brucella
Journal of Medical Microbiology, 1989
All smooth strains of Brucella bear two lipopolysaccharide (LPS) antigens in a ratio that defines the classification of strains in serovars, A (A > M), M (M >A) and A.M (A = M). Anti-LPS-A monoclonal antibodies (MAb-A) were previously shown to convey protection to mice against B. abortus (A) strain 544, as shown by lower spleen counts than in controls at days 7 and 21 after challenge. Anti-LPS-M monoclonal antibodies (MAb-M) were obtained and tested for M-specificity with LPS from reference strains by ELISA, by agglutination of LPS-coated latex particles, and by inhibition of this agglutination. Antigens A and M of three strains were quantified by a homologous LPS-latex and MAb agglutination inhibition assay. Protection conferred by MAb-A and MAb-M against three strains, B. abortus 544 (A), B. abortus 292 (M) and B. melitensis H38 (M)
Infection and immunity, 1994
A study was conducted to determine whether the covalent chemical modification of Brucella abortus 19 salt-extractable proteins (BCSP) and BCSP derivatives would modulate the immune responses in BALB/c mice. Salt-extractable proteins BCSP 0-70 and BCSP 70-100 were modified with acetoacetic anhydride, and recombinant proteins rBCSP20 (20 kDa), rBCSP31 (31 kDa), and rBCSP45 (45 kDa) were modified with succinic and dodecanoyl anhydrides. Four weeks after mice were vaccinated with the different preparations, principal and control mice were challenge exposed with a virulent culture of B. abortus 2308, and mice were necropsied 2 weeks later. Serum samples were obtained immediately before mice were challenge exposed and at necropsy. Sera were tested for specific immunoglobulin M (IgM) and G (IgG) antibodies by using an enzyme-linked immunosorbent assay. Acylation decreased the immune responses (increased IgG antibodies and reduced spleen CFU and splenomegaly) induced by both BCSP 0-70 and B...
Iraqi Journal of Veterinary Medicine, 2015
The aim of this study was to evaluate the cellular immune responses of salt-Extractable Brucella abortus S19 antigens with immunoadjuvant soluble βeta-glucan in BALB/C mice later challenged with B. abortus virulent strain. The 0.72mg/ml of SEBA was used according to the results obtained from experiment to determine the macrophages Nitric oxide production and delayed type hypersensitivity test. One hundred BALB/C mice were divided into four groups. G1 were injected i.p with 0.2 ml of saline, G2 were vaccinated S.C with 0.1ml (108 CFU/mouse) of B. abortus S19, G3 were vaccinated i.p. with 0.2 ml of salt-Extractable Brucella abortus S19 antigens and G4 were vaccinated i.p. with 0.2 ml of salt-Extractable Brucella abortus S19 antigens and 0.2ml βeta glucan. At 27 days after immunization the delayed type hypersensitivity test was conducted with the significant (P<0.05) an increase in the foot pad thickness of the G4 as compared to G3, G2 and G1. At day 30 of immunization all rema...
Veterinary Microbiology, 1991
A study was conducted to determine whether the protection induced in mice by a primary inoculation of lipopolysaccharide from Brucella abortus would be enhanced by a second inoculation given at different time intervals. Protection was challenged by exposure of the mice to a virulent culture of B. abortus strain 2308. Reduced mean viable count and/or splenic weights were the criteria of protection. There was no significant difference (P> 0.05) in the protective responses among mice given a single inoculation. Vaccinated mice were significantly (P<0.05) better protected than were nonvaccinated mice. Mice given vaccinal inoculations simultaneous with challenge exposure were less protected (P < 0.001) than were mice vaccinated prior to challenge, but were better protected (P < 0.010) than were nonvaccinated mice.
Induction of Specific Cytotoxic Lymphocytes in Mice Vaccinated with Brucella abortus RB51
Infection and Immunity, 2001
A safe, more sensitive, nonradioactive, neutral red uptake assay was adopted to replace the traditional 51 Cr release assay for detection of Brucella-specific cytotoxic T lymphocyte (CTL) activity. Our studies indicated that Brucella abortus strain RB51 vaccination of mice induced specific CTLs against both strain RB51-and strain 2308-infected J774.A1 macrophages but not against Listeria monocytogenes-infected J774.A1 cells. The antigenspecific cytotoxic activity was exerted by T lymphocytes but not by NK cells. CD3 ؉ CD4 ؉ T cells secreted the highest level of gamma interferon (IFN-␥) and were able to exert a low but significant level of specific lysis of Brucella-infected macrophages. They also exerted a low level of nonspecific lysis of noninfected macrophages. In contrast, CD3 ؉ CD8 ؉ T cells secreted low levels of IFN-␥ but demonstrated high levels of specific lysis of Brucella-infected macrophages with no nonspecific lysis. These findings indicate that B. abortus strain RB51 vaccination of mice induces specific CTLs and suggest that CD3 ؉ CD4 ؉ and CD3 ؉ CD8 ؉ T cells play a synergistic role in the anti-Brucella activity.
Protection of Mice against Brucella Abortus by Immunization with Polyclonal Anti-Idiotype Antibodies
Immunobiology, 1990
Polyclonal goat anti-idiotypic antibodies containing internal images which mimic Brucella abortus antigens were generated from rabbit polyclonal idiotypes specific for partially purified extract of B. abortus (PX III). The anti-idiotypic antibodies were purified using two-step immunoaffinity column chromatography. The presence of internal images was demonstrated by competitive inhibition analysis using an enzyme-linked immunosorbent assay. Several groups of BALB/c mice were vaccinated with the anti-idiotypic antibodies. The vaccinated mice showed a high serum titer of antibodies specific for B. abortus. When the vaccinated mice were challenged with a virulent B. abortus strain 2308, > 90 % reduction of bacteria in the spleen as compared to the unvaccinated control groups was seen. Immunoblotting experiments using antiserum from vaccinated mice demonstrate the ability to distinguish vaccinated mice from B. abortus infected mice. Our data indicate that the anti-idiotypic antibody containing internal images of B. abortus may be used as a vaccine and the induced antibody can be distinguished by immunoblotting from antibodies generated by natural infection with B. abortus.