Molecular characterization of a virulence-associated epitope on the lipopolysaccharide of Legionella pneumophila serogroup 1.
For identification of lipopolysaccharide (LPS)-associated epitopes of Legionella pneumophila serogroup 1, LPS of strain Philadelphia 1 was investigated using monoclonal antibodies (MAbs). The O-specific chain of LPS is a homopolymer of 5-acetamidino-7-acetamido-8-O-acetyl-3,5,7,9-tetradeoxy-D-glycero- L-galacto- nonulosonic acid. At least four immunoaccessible epitopes were recognized by different MAbs on the intact LPS. After O-deacetylation of LPS, the reactivity of one of the MAbs (MAb 3/1) was lost, indicating thus that the corresponding epitope is associated with the 8-O-acetyl group. Since the reactivity pattern of the MAb 3/1 is identical with those of the MAb 2 which was considered as a virulence marker for serogroup 1, this epitope may be involved in mediating virulence in L. pneumophila. Four MAbs specific to strains of serogroup 1 other than the monoclonal subtype Philadelphia recognized epitopes on the O-deacetylated LPS of strain Philadelphia 1 and, therefore, the virulence-associated epitope blocks recognition of the immunodeterminants that are accessible on the intact LPS of the strains lacking this epitope.
Helbig
J H
JH
Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum der TU Dresden, Germany.
Lück
P C
PC
Knirel
Y A
YA
Witzleb
W
W
Zähringer
U
U
D000911:Antibodies, Monoclonal; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000032:analysis*; D016952:Legionella pneumophila / Q000145:classification / Q000276:immunology* / Q000472:pathogenicity; D008070:Lipopolysaccharides / Q000145:classification / Q000276:immunology*; D012703:Serotyping; D014774:Virulence / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D008070:Lipopolysaccharides