Demonstration of anti-muscle immunity in murine trichinellosis.

Swiss mice infected with Trichinella spiralis (I mice), or immunized with straight Freund's complete adjuvant (A mice) or with rat muscle extract (RME) in Freund's complete adjuvant (MA mice) were tested for skin reactivity against RME and compared with uninfected, unimmunized, tested controls (C mice). C, A and I mice infected for 32 days did not show any reaction; MA mice exhibited significant enlargement of the foot-pads at 24 h of the skin inoculation when tested 7 days after immunization and at 0.5, 5, 24 and 48 h of inoculation when tested 18 days after immunization. I mice infected for 3 months produced skin reactions at 0.5, 5 and 48 h of the inoculation. RME is antigenic in mice when injected with adjuvant and 3 month old T. spiralis infection elicits immediate, intermediate and delayed skin reactivities to heterologous muscle components.