ANTIGENIC CROSS-REACTIVITY OF OUTER MEMBRANE PROTEINS OFESCHERICHIA COLIANDPROTEUSSPECIES

Background and Aim: An accurate diagnosis of Brucella-infected animals is one of the critical measures in eradication programs. Conventional serological tests based on whole-cell (WC) antigens and detecting antibodies against pathogen-associated lipopolysaccharide might give false-positive results due to the cross-reactivity with other closely related bacteria. This study evaluated the serological potential of Brucella spp. chimeric outer membrane proteins (Omps) as antigens in an indirect enzyme-linked immunosorbent assay (i-ELISA). Materials and Methods: The chimeric gene constructs of the most immunodominant regions of Brucella Omps 25+31, 25+19, and 19+31 were cloned into the pET28a expression vectors and transformed into Escherichia coli BL21 (DE3). The serological potential of chimeric proteins compared with single recombinant Omps (rOmps)19, 25, and/or 31 were studied on blood serum samples of (i) a rabbit immunized with killed Brucella abortus 19WC, (ii) mice immunized with single rOmps, (iii) cows seropositive for brucellosis by rose Bengal test, and (iv) cattle naturally and/or experimentally infected with brucellosis. Results: E. coli BL21 actively produced Brucella chimeric rOmps, the concentration of which reached a maximum level at 6 h after isopropyl-β-D-1-thiogalactopyranoside stimulation. Target proteins were antigenic and expressed in an active state, as recognized by rabbit anti-B. abortus antibodies in an i-ELISA and western blotting. Murine antibodies against the single rOmps reacted with chimeric antigens, and conversely, antichimeric antibodies found their epitopes in single proteins. Brucella chimeric rOmps showed higher antigenicity in blood sera of seropositive cattle kept in the hotbed of the infection and/or experimentally challenged with brucellosis than single proteins. Conclusion: Brucella chimeric recombinant outer membrane proteins could be a potential antigen candidate for developing an ELISA test for accurate diagnosis of bovine brucellosis.

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Antigenic cross-reactivity between outer membrane proteins ofNeisseria meningitidisand commensalNeisseriaspecies

FEMS Immunology & Medical Microbiology ◽

10.1111/j.1574-695x.2000.tb01419.x ◽

2000 ◽

Vol 27 (2) ◽

pp. 103-109 ◽

Cited By ~ 27

Author(s):

G Troncoso ◽

S SÃ¡nchez ◽

M Moreda ◽

M.T Criado ◽

C.M FerreirÃ³s

Keyword(s):

Membrane Proteins ◽

Outer Membrane ◽

Outer Membrane Proteins ◽

Cross Reactivity

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Evaluation of a Western Blot Method for the Detection of Yersinia Antibodies: Evidence of Serological Cross-Reactivity between Yersinia Outer Membrane Proteins and Borrelia burgdorferi

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.11.1269-1274.2005 ◽

2005 ◽

Vol 12 (11) ◽

pp. 1269-1274 ◽

Cited By ~ 10

Author(s):

Mindy L. Rawlins ◽

Cecilia Gerstner ◽

Harry R. Hill ◽

Christine M. Litwin

Keyword(s):

Membrane Proteins ◽

Borrelia Burgdorferi ◽

Western Blot ◽

Outer Membrane ◽

Sensitivity And Specificity ◽

Reactive Arthritis ◽

Outer Membrane Proteins ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Western Blot Assay

ABSTRACT Yersinia enterocolitica and Yersinia pseudotuberculosis have been identified as causative organisms of reactive arthritis in humans. We evaluated a Western blot assay which uses Yersinia outer membrane proteins as antigens for the detection of Yersinia antibodies as a replacement for the complement fixation (CF) assay. Clinical agreement, sensitivity, and specificity were determined by testing 19 positive and 21 negative serum samples by the CF assay, Western blot assay, and enzyme-linked immunosorbent assay (ELISA). The CF assay and ELISA were compared to the Western blot assay, which was the reference method used in this study. Sera with antibodies that could potentially cross-react with Yersinia were also tested by the Western blot assay. The agreement, sensitivity, and specificity of the CF method were 61%, 26%, and 95%, respectively; and those for the ELISA were 89%, 95%, and 82%, respectively. The prevalences of Yersinia antibodies in 50 healthy donors were 6% for immunoglobulin G (IgG), 2% for IgA, and 2% for IgM. Sera positive for Bartonella henselae, Brucella, Chlamydia pneumoniae, and Rickettsia rickettsii antibodies showed cross-reactivity by the Western blot assay. The highest cross-reactivity was observed with Borrelia burgdorferi; 5 of 11 (45%) specimens were cross-reactive by the IgM-specific assay. Overall, the Western blot assay performs acceptably and is more sensitive than the CF assay, warranting replacement of the CF assay in the laboratory. Due to the evidence of cross-reactivity, particularly with B. burgdorferi, which can cause an oligoarthritis similar to reactive arthritis, the diagnosis of reactive arthritis should be based on clinical findings and complete serologic analysis of the potential causative infectious pathogens.

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The immunogenicity of the liposome-associated outer membrane proteins (OMPs) of Moraxella catarrhalis

Cellular & Molecular Biology Letters ◽

10.2478/s11658-009-0035-z ◽

2010 ◽

Vol 15 (1) ◽

Cited By ~ 7

Author(s):

Daria Augustyniak ◽

Józef Mleczko ◽

Jan Gutowicz

Keyword(s):

Immune Response ◽

Membrane Proteins ◽

Outer Membrane ◽

Moraxella Catarrhalis ◽

Outer Membrane Proteins ◽

Cross Reactivity ◽

Healthy Children ◽

Whole Cells ◽

Liposomal Formulations ◽

Human Sera

AbstractThe outer membrane proteins (OMPs) are the most immunogenic and attractive of the Moraxella catarrhalis vaccine antigens that may induce the protective immune response. The aim of this study was to determine the effectiveness of two types of OMP-associated phosphatidylcholine (PC) liposomal formulations (OMPs-PC, PC-OMPs) and of Zwittergent-based proteomicelles (OMPs-Z) in potentiating an anti-OMP systemic immune response in mice. The immunogenicities of the above preparations were evaluated by assessing serum anti-OMP IgG and IgA reactivity in the post-immunized mouse antisera using ELISA and Western blotting. Additionally, the cross-reactivity of the most effective anti-OMP response was determined using heterologous sera from both humans and mice. Both the proteoliposomes and the proteomicelles showed high immunogenic properties and did not elicit any distinct quantitative differences in the antibody titer or qualitative differences in the pattern of the mouse antisera. The post-immunized mouse antisera predominantly recognized a ∼60-kDa OMP of M. catarrhalis. That protein was also found to be a highly cross-reactive antigen interacting with a panel of pooled mouse antisera produced by immunization either with whole cells or the purified OMPs of heterologous M. catarrhalis strains. Furthermore, normal sera collected from healthy children were found to be preferentially reactive with the 60-kDa OMP. The serum-specific IgG, IgA and IgM were respectively detected via immunoblotting in 90%, 85% and 30% of heterologous human sera. This similar immunogenic effectiveness of both OMP-associated liposomal formulations could contribute to the practical use of such formulations in the future in human vaccination. Moreover, the highly cross-reactive 60-kDa OMP seems to be an important antigenic marker of M. catarrhalis, and, as it is responsible for the induction of an antibody-mediated and long-lasting immune response, studying it may partially aid us in understanding the relatively low degree of pathogenicity of the bacterium in immunocompetent individuals.

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