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.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AI013526-12
Application #
3480749
Study Section
Virology Study Section (VR)
Project Start
1976-06-01
Project End
1991-05-31
Budget Start
1987-06-01
Budget End
1988-05-31
Support Year
12
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Stanford University
Department
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
He, X S; Rivkina, M; Robinson, W S (1996) Construction of adenoviral and retroviral vectors coexpressing the genes encoding the hepatitis B surface antigen and B7-1 protein. Gene 175:121-5
He, X S; Chen, H S; Chu, K et al. (1996) Costimulatory protein B7-1 enhances the cytotoxic T cell response and antibody response to hepatitis B surface antigen. Proc Natl Acad Sci U S A 93:7274-8
Rivkina, M; Cote, P J; Robinson, W S et al. (1996) Absence of mutations in the p53 tumor suppressor gene in woodchuck hepatocellular carcinomas associated with hepadnavirus infection and intake of aflatoxin B1. Carcinogenesis 17:2689-94
Rivkina, M B; Cullen, J M; Robinson, W S et al. (1994) State of the p53 gene in hepatocellular carcinomas of ground squirrels and woodchucks with past and ongoing infection with hepadnaviruses. Cancer Res 54:5430-7
He, X S; Rivkina, M; Stocker, B A et al. (1994) Hypervariable region IV of Salmonella gene fliCd encodes a dominant surface epitope and a stabilizing factor for functional flagella. J Bacteriol 176:2406-14
Sherker, A H; Twu, J S; Reyes, G R et al. (1993) Presence of viral replicative intermediates in the liver and serum of patients infected with hepatitis C virus. J Med Virol 39:91-6
Hung, L F; Brumbaugh, A E; Bhatia, G et al. (1991) Effects of purine nucleoside analogues with a cyclobutane ring and erythromycin A oxime derivatives on duck hepatitis B virus replication in vivo and in cell culture and HIV-1 in cell culture. J Med Virol 35:180-6
Wu, J Y; Zhou, Z Y; Judd, A et al. (1990) The hepatitis B virus-encoded transcriptional trans-activator hbx appears to be a novel protein serine/threonine kinase. Cell 63:687-95
Twu, J S; Wu, J Y; Robinson, W S (1990) Transcriptional activation of the human immunodeficiency virus type 1 long terminal repeat by hepatitis B virus X-protein requires de novo protein synthesis. Virology 177:406-10
Aoki, N; Robinson, W S (1989) State of hepatitis B viral genomes in cirrhotic and hepatocellular carcinoma nodules. Mol Biol Med 6:395-408

Showing the most recent 10 out of 18 publications