PRODUCTION OF IGE ANTIBODIES AGAINST THE 22 KDA TEGUMENTAL MEMBRANE-ASSOCIATED ANTIGEN OF SCHISTOSOMES IS DIRECTED BY THE ANTIGEN ITSELF

It has previously been reported that the predominant target of immunog lobulin E (IgE) recognition in sera from humans infected with Schistos oma japonicum in the Philippines or with S. mansoni in Kenya, is a 22 kDa tegumental membrane-associated schistosome antigen. In the present study, we demonstrate that the 22 kDa antigen can direct the producti on of antigen-specific IgE antibodies independently of schistosome inf ection and in the absence of any other parasite components of adjuvant . These strains of mice were immunized using the purified recombinant 22 kDa antigen of S. japonicum without the use of any adjuvant. Sera f rom all three strains of immunized mice, but not control animals, gene rated IgE antibodies specific for the native 22 kDa schistosome antige n in Western blots. Thus, the 22 kDa antigen itself must contain signa ls (presumably encoded by the primary amino acid sequence or by the se condary or tertiary structures of the molecule, or by a combination of these) which are sufficient to direct the isotype switch required for production of antigen-specific IgE.