关键词: 甲型, 沙门菌, 鼠伤寒, 疫苗, 减毒, 甲肝疫苗, 基因表达调控, 病毒

Abstract: Objective To construct hepatitis A virus vaccine with attenuated Salmonella typhimurium as vector, and study its immune response. Methods The plasmid pHAV5 containing hepatitis A virus genome cDNA was digested by restrict endonucleic acid enzyme, the 5′-non coding region was deleted, the remains were inserted into the high level expressive plasmid pBV221 and then were transformed into E.coli DH5α. The positive clone was screened and identified by DNA-probe and restrict endonucleic acid enzyme. The postive recombinant plasmid was used to transform attenuated Salmonella typhimurium BRD509 by electroporation. The transformed Salmonella typhimurium was screened in Amp-control medium. The aim-gene was expressed in Salmonella typhimurium by temperature-induced method. Results The expressed proteins reacted specifically with HAVIgG antibody were demonstrated by ELISA and Western blotting. The transformed Salmonella typhimurium was administrated to mice by oral or abdominal injection, HAVIgG antibody was found in the mice sera. Conclusion Hepatitis A vaccine with attenuated Salmonella typhimurium as vector can induce immune response.

Key words: Salmonella typhimurium, vaccines, attenuated, hepatitis A vaccines, gene expression regulation, viral