VIRUS OF HEPATITIS B

B肝炎病毒（HBV）是肝脏疾病的重要原因，包括 人类肝癌。它是一个病毒家族的成员， 有趣的结构，复制模式和生物学特性。 我们 建议通过综合分析HBV在肝癌中的作用， 病毒DNA序列，侧翼细胞DNA克隆自两个 肝细胞癌（HCC），每个都有单个整合位点。 我们 还将进一步研究NIH 3 T3细胞转化观察与 克隆的HBV DNA二聚体、HBV DNA的1850 bp BamHI片段和来自 HCC。 我们还将研究肝再生对病毒感染的影响。 整合和组建总部合同委员会。 我们将进一步表征高分子 血浆中病毒粒子中发现的HBV DNA形式（5和9 kd）的重量。 最终 目的是研究一种病毒疫苗策略， 抗原由肠道细菌菌株表达， 而不是疾病。 虽然这种方法可能为肠溶提供特别的优势， 病原体如轮状病毒对于其局部肠道免疫是重要的， 该方法对于其它试剂例如HBV形成同样有效 只有全身免疫才重要 我们已经引入了 B型肝炎表面（HBsAg）和核心（HBcAg）抗原和轮状病毒VP 7 转化到质粒表达载体中，并实现了HBsAg的表达， 在E. 杆菌 我们建议优化这些抗原在大肠杆菌中的表达。大肠杆菌; 将杂交质粒导入伤寒沙门氏菌菌株Ty 21 a和S. typhimurine 1479（具有减毒力的突变体， 作为活的口服沙门氏菌疫苗）;并测试转化的沙门氏菌 病毒抗原表达和诱导小鼠免疫应答的能力。 长期目标是在人类中获得轮状病毒和HBV的口服活疫苗。

Hepatitis B virus (HBV) is an important cause of liver disease including liver cancer in man. It is a member of a family of viruses which have interesting structure, mode of replication and biological properties. We propose to study the role of HBV in liver cancer by analyzing integrated viral DNA sequences with flanking cellular DNA cloned from two hepatocellular carcinomas (HCC), each with single integration sites. We will also further investigate NIH 3T3 cell transformation observed with a cloned HBV DNA dimer, an 1850 bp BamHI fragment of HBV DNA and DNA from HCC. We will also investigate the effect of liver regeneration on viral integration and HCC formation. We will further characterize high molecular weight HBV DNA forms (5 and 9 kd) found in virions from plasma. A final goal is to investigate a viral vaccine strategy by which relevant viral antigens are expressed by enteric bacterial strains which result in immune responses but not disease when live bacteria are ingested by mouth. Although this approach might offer a particular advantage for enteric pathogens such as rotavirus for which local enteric immunity is important, the approach could be equally effective for other agents such as HBV for which only systemic immunity is important. We have introduced genes for hepatitis B surface (HBsAg) and core (HBcAg) antigens and rotavirus VP7 into plasmid expression vectors and have achieved expression of HBsAg and rotavirus VP7 as fusion proteins and HBcAg as a discrete polypeptide in E. coli. We propose to optimize expression of these antigens in E. coli; introduce the hybrid plasmids into Salmonella typhi strain Ty 21a and S. typhimurine 1479 (mutants with attenuated virulence and successfully used as live, oral Salmonella vaccines); and test the transformed Salmonella for viral antigen expression and ability to induce immune responses in mice. The long-term goal is live oral vaccines for rotavirus and HBV in man.