Pilot Scale Production and Characterization of Paramyosin, a Vaccine Candidate for Schistosomiasis japonica

Center for International Health Research, Rhode Island Hospital, Providence, Rhode Island, USA; Pathobiology Graduate Program, Brown University, Providence, Rhode Island, USA; Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, P.R. China; Department of Pediatrics, Rhode Island Hospital, Providence, Rhode Island, USA; Research Institute for Tropical Medicine, Alabang, Muntinlupa City, Metro Manila, Philippines; Department of Pathology and Laboratory Medicine, Rhode Island Hospital, Providence, Rhode Island, USA

^* To whom correspondence should be addressed. Email: Haiwei_Wu{at}brown.edu.

	Abstract

Despite effective chemotherapy, schistosomiasis remains a major public health problem in the developing world with at least 200 million active infections resulting in significant morbidity. Rapid reinfection after treatment accompanied by extensive residual morbidity mandate alternative control strategies including vaccine development. Paramyosin, a myofibrillar protein found only in invertebrates, has been widely studied as a vaccine candidate in both Schistosoma mansoni and Schistosoma japonicum. Recently, we demonstrated that Th2-biased immune responses to paramyosin are associated with resistance to reinfection with S. japonicum in humans; however, challenges in pilot-scale production of schistosome paramyosin have hampered further studies of this promising vaccine candidate. Here we report a method for the pilot scale expression and purification of recombinant S. japonicum paramyosin (rSj97). rSj97 was extracted from E. coli inclusion bodies and purified with sequential anion-exchange, hydroxyappatite, and size exclusion chromatography. The purified rSj97 was greater than 95% pure as judged by SDS-PAGE analysis and free of significant endotoxin contamination. We demonstrate that, like native paramyosin, rSj97 adopts an alpha helical coiled-coil tertiary structure and binds immunoglobulin and collagen. Naïve mice infected with S. japonicum produce IgG anti-rSj97 antibodies as early as 4 weeks post infection, while sera collected from S. japonicum infected individuals contain IgE anti-rSj97 antibodies. Our method for pilot scale production of recombinant full-length paramyosin will facilitate pre-clinical evaluation of paramyosin as a vaccine for schistosomiasis.