Immune response of cattle to Haemophilus somnus lipid A-protein conjugate vaccine and efficacy in a mouse abortion model.
Immunogenicity of the lipid A component of Haemophilus somnus lipooligosaccharide in cattle and mice was examined after purification, detoxification, and covalent conjugation to a protein carrier. After 2 inoculations, a substantial antibody response was induced in most cattle to lipid A and the protein carrier. To determine whether antibodies to lipid A would be protective, 5 x 10(7) colony-forming units of H somnus strain 649 were administered IV to endotoxin-responsive (C3H/HeN) mice. In one study, 8 of 13 C3H/HeN mice aborted when inoculated. In contrast, abortion did not result when mice were inoculated with the same dose of an isolate of H somnus normally found in the prepuce or with the rough mutant Escherichia coli J5. In addition, endotoxin-nonresponsive (C3H/HeJ) mice were significantly (P = 0.03) more resistant to abortion by strain 649 than were C3H/HeN mice, but inoculated C3H/HeN mice were only slightly more resistant to H somnus abortion, compared with control mice. Although a large antibody response to lipid A was detected, there was no significant difference in the immunized group between mice that aborted and mice that delivered normally. Thus, lipooligosaccharide and other properties of virulent H somnus strains may contribute to abortion in mice.
Inzana
T J
TJ
Department of Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.
Todd
J
J
D000034:Abortion, Veterinary / Q000276:immunology / Q000517:prevention & control*; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D006190:Haemophilus / Q000276:immunology*; D006192:Haemophilus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D006433:Hemocyanins / Q000276:immunology; D008050:Lipid A / Q000276:immunology; D008647:Mesocricetus; D051379:Mice; D008809:Mice, Inbred C3H; D010047:Ovalbumin / Q000276:immunology; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D014614:Vaccines, Synthetic / Q000276:immunology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D008050:Lipid A; D014614:Vaccines, Synthetic; D010047:Ovalbumin; D006433:Hemocyanins