Production of a D-glycero-D-manno-heptosyltransferase mutant of Mannheimia haemolytica displaying a veterinary pathogen specific conserved LPS structure; development and functionality of antibodies to this LPS structure.
Previous structural studies of the lipopolysaccharides from the veterinary pathogens Mannheimia haemolytica (Mh), Actinobacillus pleuropneumoniae (Ap) and Pasteurella multocida (Pm) had identified a conserved inner core oligosaccharide structure that was present in all strains investigated. In order to examine the potential of this inner core structure as a vaccine, a mutagenesis strategy was adopted to interrupt a D-glycero-D-manno-heptosyltransferase gene (losB) of Mh. This gene encodes the enzyme responsible for the addition of a D-glycero-D-manno-heptose residue, the first residue beyond the conserved inner core, and its inactivation exposed the conserved inner core structure as a terminal unit on the mutant LPS molecule. Subsequent analyses confirmed the targeted structure of the mutant LPS had been obtained, and complementation with losB in trans confirmed that the losB gene encodes an alpha-1,6-D-glycero-D-manno-heptosyltransferase. Monoclonal antibodies raised in mice to this LPS structure were found to recognise LPS and whole-cells of the truncated mutant and wild-type Mh. The antibodies were bactericidal against a wild-type Mh strain and were able to passively protect mice in a model of Mh disease. This illustrates that it is possible to raise functional antibodies against the conserved inner core LPS structure.
Logan
Susan M
SM
Institute for Biological Sciences, National Research Council, Ottawa, Ont., Canada K1A 0R6.
Chen
Wangxue
W
Aubry
Annie
A
Gidney
Margaret Anne J
MA
Lacelle
Suzanne
S
St Michael
Frank
F
Kuolee
Rhonda
R
Higgins
Melanie
M
Neufeld
Sayre
S
Cox
Andrew D
AD
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D005260:Female; D016695:Glycosyltransferases / Q000235:genetics*; D008070:Lipopolysaccharides / Q000276:immunology*; D008168:Lung / Q000166:cytology / Q000473:pathology; D016978:Mannheimia haemolytica / Q000201:enzymology* / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D016871:Pasteurellaceae Infections / Q000517:prevention & control
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D008070:Lipopolysaccharides; D016695:Glycosyltransferases; C086735:heptosyltransferase