%0 Journal Article %A Hamel, JOSÉE %A Brodeur, B. R. %A Larose, Yolande %A Tsang, Peggy S. %A Belmaaza, A. %A Montplaisir, S. %T A monoclonal antibody directed against a serotype-specific, outer-membrane protein of Haemophilus influenzae type b %D 1987 %J Journal of Medical Microbiology, %V 23 %N 2 %P 163-170 %@ 1473-5644 %R https://doi.org/10.1099/00222615-23-2-163 %I Microbiology Society, %X Summary Monoclonal antibodies (Mabs) were produced against outer-membrane proteins (OMPs) of Haemophilus influenzae type b. The clones were screened by ELISA with outer-membrane preparations of H. influenzae type b and untypable strains as coating antigens. Antibodies directed against the proteins of mol. wt (103) 43, 37 and 13 were identified by immunoblotting of SDS-PAGE patterns of OMPs. Proteolytic enzyme treatments of the OMPs resulted in reduction of Mab reactivity as measured by ELISA. Furthermore, the absence of reactivity of Mab Hb-2 with a preparation of lipopolysaccharide confirmed the protein nature of its corresponding epitope. Binding assays with live bacteria showed that Hb-2 reacted with a cell surface-exposed antigenic determinant. Mab Hb-2 was bactericidal in vitro in the presence of complement. The characterisation of Hb-2 (IgG2a) by Western immunoblotting analysis revealed that it was directed against the 37 × 103-mol. wt OMP. In a dot-enzyme immunoassay, Hb-2 reacted specifically with 326 strains of H. influenzae type b. It did not cross-react with the other serotypes or untypable strains of H. influenzae or with other bacterial species. This is the first report of a monoclonal antibody identifying a serotype—specific surface-exposed OMP of H. influenzae type b. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-23-2-163