The role of IgA immunoglobulins in the passive transfer of protection to Taenia taeniaeformis in the mouse.

Normal mice were protected against infection with metacestodes of Taenia taeniaeformis when administered intestinal, colostral or serum immunoglobulins obtained from adult mice previously orally infected with the parasitie. The protective capacity of these preparations was found to be associated mainly with IgA of colostrum and intestinal secretions and IgG of serum. The removal of IgA and IgG from immune colostrum and serum, respectively, abolished the protective effect. Neonatal mice were protected against infection with T. taeniaeformis when fed purified colostral IgA and serum IgG from immune donors. The intraduodenal injection of intestinal IgA from immune donors into 4-week-old mice passively protected the recipients against infection with T. taeniaeformis, but intestinal IgG from immune donors had no protective effect when given in this manner. The protective capacity of IgA and IgG was largely eliminated by prior absorption with T. taeniaeformis antigen or hatched, activated oncospheres of T. taeniaeformis.