Enhancement by Endotoxin of the Primary Antibody Response to Bovine Serum Albumin in Chickens

Abstract

Purified lipopolysaccharide of Salmonella abortus equi (endotoxin) was shown to enhance the antibody response of chickens to a single, intravenous injection of bovine serum albumin. Simultaneous injection of 5 or 10 µg of endotoxin/kg body weight and bovine serum albumin markedly potentiated all phases of antibody synthesis. The induction period was shortened, antibody levels were several-fold greater and detectable serum antibodies persisted for longer periods than in animals given antigen alone. Enhancement was demonstrated when endotoxin was given 24 hr after, but not 24 hr before, antigenic stimulation. The results are discussed with respect to the animal species involved as well as the time interval between endotoxin and antigen administration.