OBJECTIVE: To obtain peptide mimicking epitopes of Schistosoma japonicum (S. japonicum) through screening of a phage peptide library and to test their potential for induction of protection. METHODS: S. japonicum infected sera from Microtus fortis (IMFS) and normal sera from Microtus fortis (NMFS) were used respectively to screen a 12-mers random peptide library by testing the reactivity of anti-S. japonicum serum with the phagotopes. After three rounds of biopanning, the pooled phages were used to immunize mice, after which challenge infection was performed. RESULTS: Of 12 randomly picked clones, 10 clones selected using IMFS and 7 clones selected using NMFS were shown to be antigenic. Significant reduction in adult worms (22.6%) and a high reduction (68.9%) in liver eggs were achieved following immunization with phages screened with IMFS. However, no protection was elicited by those selected with NMFS. CONCLUSION: The results show that the phagotopes are both antigenic and immunogenic, suggesting a potential use of phage displayed peptide as novel vaccines against S. japonicum.
OBJECTIVE: To obtain peptide mimicking epitopes of Schistosoma japonicum (S. japonicum) through screening of a phage peptide library and to test their potential for induction of protection. METHODS:S. japonicum infected sera from Microtus fortis (IMFS) and normal sera from Microtus fortis (NMFS) were used respectively to screen a 12-mers random peptide library by testing the reactivity of anti-S. japonicum serum with the phagotopes. After three rounds of biopanning, the pooled phages were used to immunize mice, after which challenge infection was performed. RESULTS: Of 12 randomly picked clones, 10 clones selected using IMFS and 7 clones selected using NMFS were shown to be antigenic. Significant reduction in adult worms (22.6%) and a high reduction (68.9%) in liver eggs were achieved following immunization with phages screened with IMFS. However, no protection was elicited by those selected with NMFS. CONCLUSION: The results show that the phagotopes are both antigenic and immunogenic, suggesting a potential use of phage displayed peptide as novel vaccines against S. japonicum.