title: Monoclonal antibodies to Brucella rough lipopolysaccharide: characterization and evaluation of their protective effect against B. abortus.
abstract: We characterized 4 monoclonal antibodies (mAb) specific for rough lipopolysaccharide (R-LPS) of Brucella. mAb were selected by enzyme-linked immunosorbent assay (ELISA) on whole B. abortus 45/20 rough cells and R-LPS from B. melitensis B115 rough cells. Specificity was confirmed by immunoblot analysis using R-LPS and smooth LPS (S-LPS) preparations. Anti-R-LPS revealed the low molecular mass R-LPS molecules below 20.1 kDa in the R-LPS and S-LPS preparations as well as the typical A and M patterns in high molecular mass S-LPS molecules (between 21.5 and 66 kDa) in the S-LPS preparations. An O-polysaccharide-specific mAb revealed only high molecular mass S-LPS molecules in the S-LPS preparation. In ELISA the anti-R-LPS mAb bound better on rough than on smooth B. abortus 544 whole cells, and this was confirmed by immunoelectron microscopy. Protective activity of anti-R-LPS mAb of different isotypes was tested on mice and compared with an S-LPS-specific mAb. Only the IgG3 mAb reduced significantly the splenic infection but did not reach the level of protection conferred by the S-LPS-specific mAb.
authors.affiliation: Institut National de la Recherche Agronomique, Centre de Recherches de Tours, Nouzilly, France.
authors.forename: A
authors.initials: A
authors.lastname: Cloeckaert
authors.forename: I
authors.initials: I
authors.lastname: Jacques
authors.forename: R A
authors.initials: RA
authors.lastname: Bowden
authors.forename: G
authors.initials: G
authors.lastname: Dubray
authors.forename: J N
authors.initials: JN
authors.lastname: Limet
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000302:isolation & purification*; D002003:Brucella abortus / Q000276:immunology* / Q000648:ultrastructure; D017347:Brucella melitensis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D015151:Immunoblotting; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008854:Microscopy, Electron; D013158:Splenic Diseases / Q000276:immunology / Q000382:microbiology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D008070:Lipopolysaccharides