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Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens
Published on: April 5, 2019
Bactericidal monoclonal antibody against Moraxella catarrhalis lipooligosaccharide cross-reacts with Haemophilus Spp
Raina T Gergova1, Ianko D Iankov, Iana H Haralambieva
1Department of Microbiology, Medical University, Sofia, Bulgaria. renigergova@mail.bg
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.
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