中国云南少数民族地区慢性乙型肝炎患者病毒基因在大肠杆菌中的表达及其抗原性

Expression in Escherichia coli of hepatitis B virus genes from minority nationality patients in Yunnan province with chronic hepatitis B and their antigenicity

目的研究不同民族慢性乙型肝炎(CHB)患者HBV前S2/S(preS2/S)和C(core,C)基因在大肠杆菌Escherichia coli(E.coli)中表达的稳定性和水平,并对其抗原性进行鉴定,为创制新型疫苗提供抗原材料。方法从中国云南少数民族地区50例慢性乙型肝炎患者血清中提取HBV基因组DNA,将聚合酶链反应(PCR)扩增-克隆-测序的HBV preS2/S和C基因插入到表达载体pλPR上,构建重组pλPR-S2S和pλPR-C表达质粒,并在大肠杆菌TOP10中表达。用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)测定表达产物非融合蛋白,并对其抗原性用Western印迹和ELISA方法进行检测。结果SDS-PAGE检测到全部慢性乙型肝炎患者pλPR-S2S和pλPR-C重组质粒在大肠杆菌TOP10中存在稳定性和高水平的表达,表达的非融合蛋白相对分子质量分别为31000和21000,非融合蛋白浓度约占16%,纯度达96%。Western印迹和ELISA分析,非融合蛋白能分别与HBVpreS2/S抗原单抗、C抗原单抗及慢性乙型肝炎患者血清发生反应,而与对照的甲型肝炎(HAV)患者血清、丙型肝炎(HCV)患者血清及正常血清之间无交叉反应。结论中国云南少数民族地区慢性乙型肝炎患者HBV preS2/S和C基因在大肠杆菌TOP10中有稳定性和高水平的表达,表达的非融合蛋白具有抗原性。这些发现为创制新型疫苗具有潜在应用价值。

Objective To investigate the expression in Escherichia coli （ E. coli） of hepatitis B virus （HBV） genes from minority nationality patients in Yunnan province with chronic hepatitis B （ CHB ） and their antigenicity. Methods Peripheral blood samples were collected from 25 minority nationality patients with CHB in Yunnan province. Twenty-five CHB patients of Han nationality in Yunnan were used as controls. The full length HBV preS2/S and C genes were amplified by PCR, cloned, sequenced, and inserted into the prokaryotic expression vector pλPR. The recombinant plasmids pλPR-S2S and pλPR-C were transfected into E. coli of the line TOP10. The expression of the non-fusion proteins encoded by the HBV preS2S and C genes was determined by sodium dodecyl sulphate polyacrolamide gel electrophoresis （ SDSPAGE） and Western blotting. The antigenicity of the non-fusion proteins was examined by ELASA. Fifty samples of serum of patients with hepatitis A, 50 samples of serum of patients with hepatitis C, and 50 samples of serum of healthy blood donors were used as controls in the study of the antigenicity of non-fusion proteins. Results SDS-PAGE showed that the recombinant plasmids pλPR-S2S and pλPR-C were both stably and highly expressed in the E. coli for all 50 CHB patients. The molecular weights of the expressed non-fusion proteins, with a concentration of 16% and a purity of 50%, were between 31 000 and 21 000. Western blotting and ELISA showed that the purified recombinant non-fusion proteins reacted strongly with the antibodies HBpreS2S/SAb and HBcAb and the serum of CHB patients, but there was no cross-activity between the non-fusion proteins and all the serum samples of controls with HA and HC, and normal controls. Conclusion The HBV preS2S and C genes from the minority nationality patients with CHB can be stably and highly expression in E. coll. The non-fusion proteins encoded by the HBV preS2S and C genes have high antigenicity. These findings have potential values in development of HB vaccines.