Presence of IL-4-like molecules in larval excretory-secretory products andcrude extracts from Anisakis simplex

Acute symptoms of anisakidosis are caused by a type I allergic reaction in the gastrointestinal wall with elevated specific immunoglobulin (Ig)E. The purpose of this study was to investigate the presence of interleukin (IL)-4 in the larval antigens of Anisakis simplex. We detected concentrations of IL-4 in pg/ml when larval excretory-secretory products and crude extract fr om A. simplex were investigated by ELISA. Specific antibodies were obtained by immunization of rabbits with mouse IL-4 and tested in ELISA against A. simplex antigens obtaining higher values of optical density, that were conf irmed by western blot analysis. The absorption of these sera with A. simple x antigen resulted in a 70-80% inhibition of antigen binding when retested in ELISA. We demonstrated that A. simplex antigens react with antibodies ra ised against vertebrate IL-4. The results obtained by us support the hypoth esis that A. simplex shares several epitopes with IL-4, important for the T h2 response development in human anisnkiasis, where the parasite may modula te the Th1-Th2, dichotomy for its own benefit by mucosal inflammation contr ol in an attempt to avoid the larval expelling.