Immunoscreening of Schistosoma japonicum adult worm cDNA library by sera from infected Bubalus bubalis

Objective To explore the molecular mechanisms of the self-cure phenomenon of Bubalus bubalis (Bb) infected with Schistosomajaponicum (S. japonicum) and to find new vaccine candidates. Methods 5. japonicum adult worm cDNA library was screened with sera from infected Bb. The inserts of positive clones were amplified by PCR and the sequences were analyzed. Results Seven positive clones were obtained after rescreening. After automatically excised with helper phage, positive clones were further identified by PCR. The size of S. japonicum cDNA fragments in positive clones range from 0.8 to 2.0 kb. After DNA sequencing, it was discovered that there were two new S. japonicum genes of these clones. These new S. japonicum genes were designated Sj-IB1 and Sj-Rho GTP-like gene and registered in Gene Bank. Conclusions The serum of infected Bb could recognize S. japonicum specific antigens. It is worthwhile to further study immune protection of these cloned molecules.