Immunization of Laboratory Mice against Tetrathyridia of Mesocestoides corti (Cestoda) Using a Secretory and Excretory Antigen and a Soluble Somatic Antigen

Abstract

A secretory and excretory (ES) antigen was prepared by incubating tetrathyridia in Krebs-Ringer solution for 24 hr. A soluble somatic antigen was prepared by homogenization and subsequent centrifugation of M. corti larvae. Laboratory mice were given a series of injections of the antigen materials, and then challenged with 100 tetrathyridia of M. corti. Autopsy 10 days postinfection revealed that mice receiving ES antigen, and infected either orally or intraperitoneally, harbored approximately 60% fewer larvae as compared to control mice. Mice receiving somatic antigen and infected intraperitoneally showed no significant difference in worm burden as compared to control mice. Mice receiving somatic antigen and infected orally harbored 30.4% fewer larvae as compared to control mice. No precipitate was seen around larvae incubated in serum collected from uninfected mice immunized with somatic antigen; however, a light precipitate was seen around larvae incubated in serum collected from uninfected mice immunized with ES antigen. Several studies have demonstrated that antigen extracted from larval or adult cestode tissue can be used to stimulate levels of immunity to challenge with tissue-invading larvae or intestinal tapeworms (for references see Weinmann, 1970). Excretory and secretory (ES) antigens, however, have not been used to stimulate immunity against cestode infection. This is in spite of the fact that the effectiveness of ES antigen has been successfully demonstrated in nematode and trematode infections (Thorson, 1953; Kagan and Oliver-Gonzalez, 1958; Sadun and Lin, 1959). In this paper, we present our attempts to immunize mice against challenge infections with tetrathyridia of Mesocestoides corti using ES and somatic antigens. MATERIALS AND METHODS