哺乳动物细胞分泌的乙型肝炎病毒表面抗原的理化和生物学性状

PHYSICAL CHEMICAL AND BIOLOGIC PROPERTIES OF HEPATITIS B VIRUS SURFACE ANTIGEN SECRETED BY MAMMALIAN CELLS

研究了哺乳动物细胞分泌的乙型肝炎病毒表面抗原(HBsAg)纯品的理化及生物学性状。结果表明:此种HBsAg在CsCl中的浮力密度是1.21g/cm^3;快速液相层析的SuperoseHR6层析柱上呈现3个峰,中间是一个主峰,两侧各一小峰;经Mono Q柱层析呈现一个对称峰,证明了HBsAg颗粒所带电荷的均一性;以SDS-PAGE和凝胶扫描方法分析HBsAg的多肽,P23、gp27和gp30各占65％、20％和10％,另有5％的二聚体存在;N-末端的氨基酸序列与转入细胞的目的基因所编码的序列相同;HBsAg在4℃和-20℃储存较稳定,室温条件保存时间不宜过长。动物实验证明:用与血源HBsAg疫苗同等剂量的基因工程HBsAg疫苗接种Balb/C小鼠,可获得比血源疫苗高2.64倍的免疫效果。此外,经过福尔马林处理的疫苗较未处理的疫苗有较强的免疫原性。

The physical, chemical and biologic properties of hepatitis B virus surface antigen ( HBsAg ) secreted by mammalian cells were studied. The buoyant density of HBsAg in CsCl is 1.21g/cm3. The pure HBsAg appeared as 3 peaks through FPLC Superose HR 6 column, one big peak and two small ones, indicating minor variation in particle size. All of them are specific HBsAg. Only one symmetric peak appeared through FPLC Mono Q column which shows that the electric charge of HBsAg particles is homogeneous. Scanning analysis of HBsAg polypeptides in SDS-pAGE after silver staining indicated that the percentages of p23, gp27 and gp30 were 65%, 20%, 10% respectively in addition to 5% dimer. The N-terminal amiao acid sequence of HBsAg is the same as the sequence coded by trans-fected gene. HBsAg is stable at 4℃ and -20℃ but not stable at room temperature for long time. The immunogenicity test in mice showed that cellular HBsAg was 1.55-2.64 times more potent than that blood-derived HBsAg. HBsAg treated with 0.025% formalin produced higher HBsAb than that without formalin. The above data indicate that HBsAg from mammalian cells are suitable for vaccine purpose.