title: Bactericidal monoclonal antibody against Moraxella catarrhalis lipooligosaccharide cross-reacts with Haemophilus Spp.
abstract: Monoclonal antibodies (MAbs) against lipooligosaccharide (LOS) determinants after immunization of BALB/c mice with heat inactivated Moraxella catarrhalis serotype A were generated. MAb 219A9 was specific for a common epitope of A, B, and C M. catarrhalis serotypes in ELISA and immunofluorescent test (IFT). In both tests it also cross-reacted with whole bacteria and LPS antigens isolated from non-typeable H. influenzae and H. parainfluenzae strains. IgM antibody clone 219A9 possessed a strong bactericidal effect against the three serotypes in the presence of complement. Our results demonstrate that antibodies directed to a single LOS epitope common for A, B, and C serotype could be highly protective. This suggests that the common determinants are very promising in the development of LOS-based vaccine against M. catarrhalis. The cross-reactions of MAb 219A9 with Haemophilus spp. also show that immunization could result in immune response to epitopes conserved in other important respiratory pathogens.
authors.affiliation: Department of Microbiology, Medical University, Sofia, Bulgaria. renigergova@mail.bg
authors.forename: Raina T
authors.initials: RT
authors.lastname: Gergova
authors.forename: Ianko D
authors.initials: ID
authors.lastname: Iankov
authors.forename: Iana H
authors.initials: IH
authors.lastname: Haralambieva
authors.forename: Ivan G
authors.initials: IG
authors.lastname: Mitov
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D015169:Colony Count, Microbial; D003165:Complement System Proteins; D003429:Cross Reactions; D000939:Epitopes; D006168:Guinea Pigs; D006190:Haemophilus / Q000145:classification / Q000254:growth & development / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D001936:Moraxella catarrhalis / Q000145:classification / Q000254:growth & development / Q000276:immunology*; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000939:Epitopes; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides; D003165:Complement System Proteins