Trichinella spiralis: The Effect of Oral Immunization and the Adjuvancy of Cholera Toxin on the Mucosal and Systemic Immune Response of Mice

Abstract

The effect of oral immunization and the adjuvancy of cholera toxin (CT) were examined in mice infected with Trichinella spiralis. The mean of total muscle larvae was reduced by 36% in mice infected with Trichinella larvae in combination with CT. In mice fed soluble, particulate, or soluble/particulate antigens in combination with CT on Days 0, 14, and 21, and challenged with Trichinella larvae on Day 28, there was a significant reduction in adult worm fecundity (50%), worm size (20–30%), and the mean of total muscle larvae (75%) but no apparent effect on the rate of expulsion on Day 6 postchallenge. Following antigen feeding, but prior to challenge with Trichinella (Day 28), the immunoglobulin response was positive in only a small proportion of mice. On Day 6 following challenge with Trichinella larvae, the biliary immunoglobulin response was enhanced ∼10-fold (P <0.05) in all antigen-feeding treatments which included CT, compared with nonimmunized controls or antigen-feeding treatments which did not include CT. Similarly, the serum IgG response was enhanced following challenge with Trichinella larvae in treatments fed soluble, particulate, or soluble/particulate antigens with CT. The response was also enhanced in the particulate, but not in soluble or soluble/particulate antigen treatments without CT.