The 14-3-3 protein as a vaccine candidate against schistosomiasis

We have previously reported on the cloning of the 14-3-3 protein of Schisto soma mansoni. Here, we evaluate the potential use of this protein as a vacc ine candidate against infection by S. mansoni Sm14-3-3 was expressed and pu rified either as a free protein or as a fusion protein to SjGST or MBP. Ser a from mice infected with S. mansoni recognized both SjGST and 14-3-3 indic ating that antibodies against these two proteins are induced in the course of the natural infection. Furthermore, mice immunized with either 14-3-3, G ST or 14-3-3-GST; reacted with cercaria lysate. A cellular immune response was also detected particularly in mice immunized with 14-3-3-GST: With resp ect to the effect on biological functions, antibodies to 14-3-3 and 14-3-3- GST caused 23-32% complement-mediated cytotoxcity of S. mansoni schistosomu la compared to only 10-11% induced by either normal mouse serum or GST alon e. In challenge infection with S. mansoni, immunization with 14-3-3, either as a fusion protein or as a free protein, led to protection ranging from 2 5-46%, as determined by reduction of adult worm burden, while SjGST alone e licited only 0-8% protection and MBP alone did not elicit any protection.