title: Anti-idiotypic immunization provides protection against lethal endotoxaemia in BALB/c mice.
abstract: Against lipid A (the conserved moiety of lipopolysaccharides from Gram-negative bacteria) neutralizing IgM monoclonal antibodies (mAb) 8-2 and 26-20 anti-idiotypic (Ab2) mAb were produced: Ab2 mAb KM-04 (IgG1) against mAb 8-2, and Ab2 mAb PW-1 (IgG2a) and PW-2 (IgG1) against mAb 26-20. The binding of Ab2 mAb KM-04 to 8-2 (Ab1) was strongly inhibited by a lipopolysaccharide (LPS) extract from either Salmonella minnesota R595 (Re LPS) or Escherichia coli J5 (Rc LPS), whereas the binding of Ab2 mAb PW-1 and PW-2 to 26-20 (Ab1) was only marginally inhibited by both Re LPS and Rc LPS. The results indicated that Ab2 mAb KM-04 recognizes a lipid A-binding site related idiotope on mAb 8-2 and therefore KM-04 might bear the internal image of a neutralization determining epitope of lipid A. Consequently Ab2 KM-04 might induce antibodies to lipid A. Indeed anti-idiotypic immunization of syngeneic BALB/c mice with Ab2 mAb KM-04 resulted in development of lipid A-binding anti-anti-idiotypic (Ab3) antibodies in serum. Similar immunizations with Ab2 mAb PW-1 and PW-2 were unsuccessful. However, induction of lipid A-binding Ab3 by mAb KM-04 proved to be genetically restricted to BALB/c mice. DBA/2 mice, Swiss mice and rabbits did not develop lipid A-binding antibodies upon immunization with mAb KM-04. In protection experiments, it was shown that BALB/c mice vaccinated with mAb KM-04 showed significantly enhanced survival from challenge with either rough (Re) LPS from Salmonella minnesota or smooth LPS from E. coli 0111:B4 when compared to BALB/c mice immunized with a non-relevant Ab2 mAb. The results suggest that mAb KM-04 constitutes a non-internal image vaccine to the lethal effect of lipid A in BALB/c mice. Furthermore an Ab3 mAb was prepared against Ab2 mAb KM-04 that showed reactivity with Re LPS. This Ab3 mAb, designated LE-21 (IgG2a) protected mice against an otherwise lethal challenge of Re LPS.
authors.affiliation: Department of Haematology, University Hospital Utrecht, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Cornelissen
authors.forename: K
authors.initials: K
authors.lastname: Maassen
authors.forename: L
authors.initials: L
authors.lastname: van Emst
authors.forename: P M
authors.initials: PM
authors.lastname: Weers
authors.forename: M
authors.initials: M
authors.lastname: Harmsen
authors.forename: B J
authors.initials: BJ
authors.lastname: Benaissa-Trouw
authors.forename: T A
authors.initials: TA
authors.lastname: Oosterlaken
authors.forename: C A
authors.initials: CA
authors.lastname: Kraaijeveld
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D003432:Cross-Linking Reagents; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D008050:Lipid A / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits; D014115:Toxemia / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008050:Lipid A; D008070:Lipopolysaccharides