一种新型鱼病口服疫苗的研制和示踪研究

Development of A New Oral Vaccine for Fish Diseases

目的研制一种新型的鱼病口服疫苗,并进行鱼体内的示踪研究。方法通过物理方法(油/水/油)制备包裹模式蛋白的PLGA微粒;将FITC标记蛋白与PLGA结合,观察该新型疫苗在鱼体内的消化过程;将特异性尘螨Derf1蛋白结合PLGA口服给予鱼,不包裹PLGA的Derf1蛋白作为对照,运用ELISA方法测定该疫苗给予后不同时间在血液中的含量。结果PLGA包裹的荧光标记蛋白在消化道1h内即可被鱼小肠上皮细胞吸收,24h小肠消化道内残余很少。包裹特异性尘螨Derf1蛋白的PLGA微粒给予鱼1h后血液中特异性蛋白浓度最高,2、4和24h后仍在血液中保持一定浓度。而不给药对照或Derf1直接给予则在鱼血液中不能测到该特异性蛋白。结论以PLGA为佐剂的蛋白鱼病疫苗可通过消化道吸收入血,是一种新型的鱼病口服疫苗给药系统。

Objective To develop a new oral vaccine for fish disease, and to monitor the absorption in fish. Method Physical methods（oil/water/off） were used to prepare PLGA microparticles entrapped with the model protein. FITC labeled protein vaccine entrapped in microparticles was used to trace the digestive process of this new oral vaccine in fish. Specific protein-Der fl entrapped microparticles were orally given to fishes. Fishes in the control group were directly given with Der fl protein. The level of Der fl in fish sera at different time-point were measured by ELISA. Result FITC labeled protein-PLGA microparticles were taken up by fish epithelial cells in an hour, and there were little remains in small intestine after 24 hour. Specific Der fl can be detected in fish sera from PLGA encapsulated group in 1, 2, 4, 24 hours, and peaks at 1 hour, while the Der fl can not be detected in simple Der fl control group. Conclusion The protein vaccine with PLGA as adjuvant can be detected in fish sera after oral administration. This new method may be used in the development of oral vaccine for fish disease.