Vaccination Against Taenia Solium Cysticercosis In Pigs Using Recombinant Oncosphere Antigen TSOL18

Cysticercosis caused by Taenia solium larval Cysticercus cellulosae, which can infect human and pigs, is a parasitic zoonsis and this disease is one of six eradicated diseases issued by WHO. At present, it is extensively focused on development of vaccine against cysticercosis.Total RNA was extracted from Taenia solium oncospheres hatched and activated in vitro and vaccine candidate TSOL18 gene was amplified by RT-PCR. The positive recombinant plasmid, designed as pPIC9K-TSOL18, was constructed and transformed into GS115 by electroporation and selected using G418 with gradient concentration. The results of SDS-PAGE and Western blot of the positive GS115 induced with methanol indicated that there were 12ku and 16ku target proteins in supernatant and the latter was of glycosylation determined by Endo-H. Under adjustment of pH, temperature, oxygen content and so on, the amount of TSOL18 secreted by Pichia pastoris was up to 2.54 g/L, accounting for more than 80% in total supernatant proteins.In this studies, it was the first time that secreted TSOL18 antigen with native protein's traits had used for development of cysticercosis vaccines. There was high level of antibodies against recombinant TSOL18 in both 1 and 2 trails and the positive antibodies reached at peak 40d after immunization and retained for 150d. In trail 1, immune increasers cytokines (IL-4 and IFN-γ) and CpG DNA were added into TSOL18 vaccine emulsified with 206 adjuvant, respectively, and pigs were challenged 15d after immunization. Statistic data showed that the group of TSOL18 plus 206 was of 70% protection less than that of coarse antigens. In trail 2, the immunized dose of TSOL18 was increased and eggs challenge was performed during periods of high titer of antibodies and the TSOL18+206 group (94%) was more higher that coarse antigens group in protection (89%). These results suggest that TSOL18 vaccine has promising prospects and is a new bio-product for prevention of cysticercosis.The group, in which pcDNA3.1/IFN-γwas used as a immune increaser, had obvious lymphocyte proliferation and increase in protection (94%) as the same as the coarse antigens group but not high antibody level. The groups using pcDNA3.1/IL-4 and pUC18/CpG were just the way around, 68.7% and 67% protection, respectively. Together with above data, it is recommended that IFN-γis used for development ofTSOL18 vaccine against cysticercosis.