Immunization of Dairy Cows with an Escherichia coli J5 Lipopolysaccharide Vaccine

Abstract

Development of a lipopolysaccharide-protein conjugate vaccine and the immunological response to the vaccine were investigated. Lipopolysaccharide derived from Escherichia coli J5 was detoxified by mild alkaline hydrolysis. Detoxification reduced endotoxin activity 2500-fold compared with that of native J5 lipopolysaccharide. The conjugate vaccine was synthesized by covalently coupling detoxified lipopolysaccharide to chicken serum albumin by reductive amination. Dairy cows were immunized with 8.35 mg of conjugate (n = 3) or 5 x 109 heat-killed J5 bacterin (n = 5) at 215 DIM and received a secondary immunization 14 d later. Control cows were not immunized. Immunization enhanced serum antibody titer to J5 lipopolysaccharide antigens. Whey IgG and IgM titers to J5 lipopolysaccharide were not different among treatment groups. Serum and whey IgG titers to J5 whole-cell antigens were elevated in immunized cows within treatment groups. Immunization did not enhance whey IgM to J5 whole-cell antigens. Conjugate immunization elicited an immune response comparable with or greater than that of immunized cows with J5 bacterin. © 1995, American Dairy Science Association. All rights reserved.