Cross-reaction: a common trait among helminthes.

Cross-reaction between three important zoonotic helminths, Fasciola gigantica, Trichinella spiralis and Echinococcus granulosus, was proved by ELISA. Cross-binding activities in the prepared antisera were strongly directed towards protoscolices and hydatid fluid antigens of E. granulosus rather than to F. gigantica and T. spiralis antigens. Two sets of polypeptides were identified in each antigen by immunoblot; species-specific and cross-reactive. Cross-reactive components in F. gigantica antigen were 205 KD, 178 KD, 166 KD, 106 KD, 100 KD, 65 KD, 45 KD and 32 KD. While, cross-reactive molecules in T. spiralis antigen were 205 KD, 191 KD, 166 KD, 148 KD, 132 KD, and 32 KD. In protoscolices antigen six cross-reactive components were identified, 205 KD, 191 KD, 149 KD, 106 KD, 45 and 32 KD. Moreover, 205 KD, 190 KD, 177 KD, 149 KD, 103 KD and 33 KD were detected in hydatid fluid antigen by heterologous antisera. Interestingly, three polypeptides of 205 KD, 149 KD and 32 KD showed broad immunogenicity with the developed antisera raising the prospect of being putative common immunoprophylactic components.