Hepatitis B virus (HBV) is an agent which infects man, integrates into the genome of a specific tissue (liver), and probably causes hepatocellular carcinoma (HCC). In the United States, there are over three quarters of a million individuals with persistent HBV infection and worldwide, HCC is one of the leading causes of death from cancer. The purpose of this proposal is to study the strategies and molecular mechanisms utilized by the hepatitis B virus (HBV) to understand its hepatotropism, genetic regulation, and association with pathologic conditions especially its role in liver carcinogenesis. Our underlying hypothesis is that the HBV genome has evolved mechanisms of gene regulation and expression similar to those utilized by host genes as an adaptation for an efficient symbiotic relationship with its host. Mouse embryo microinjection technology has been used to construct an animal model simulating the chronic carrier state. Such HBV transgenic mice, in which the newly acquired HBV genome is expressed and transmitted in kindreds of mice will allow the genetic dissection of HBV gene expression, regulation, and function. This system appears ideally suited to examine the influence of host genes on HBV expression, the developmental regulation of HBV sequences, and the associated factors potentially linking HBV to the multistep process of hepatocarcinogenesis. In addition, the viral genetic requirements for tissue specific expression will be examined in liver cells in vivo. Such an approach has broad applicability towards elucidating novel mechanisms of higher eukaryotic gene expression and regulation. Our program involves the isolation and characterization of nucleic acids by Southern blot analysis, Northern blot analysis, primer extension, cloning, and sequencing. Viral proteins will be identified and studied using monoclonal antibodies by immunohistochemistry and protein blotting. Hepatocarcinogenesis studies will examine the relationship of treating HBV transgenic mice with such agents as aflatoxin B1 and alcohol upon the development of liver pathology and the incidence of liver tumors in such mice followed over time.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA045476-02
Application #
3188546
Study Section
Experimental Virology Study Section (EVR)
Project Start
1987-08-01
Project End
1990-07-31
Budget Start
1988-08-01
Budget End
1989-07-31
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Type
Schools of Medicine
DUNS #
009095365
City
Bronx
State
NY
Country
United States
Zip Code
10461
Aragona, E; Burk, R D; Ott, M et al. (1996) Cell type-specific mechanisms regulate hepatitis B virus transgene expression in liver and other organs. J Pathol 180:441-9
Gupta, S; Vemuru, R P; Lee, C D et al. (1994) Hepatocytes exhibit superior transgene expression after transplantation into liver and spleen compared with peritoneal cavity or dorsal fat pad: implications for hepatic gene therapy. Hum Gene Ther 5:959-67
Gustin, K; Shapiro, M; Lee, W et al. (1993) Characterization of the role of individual protein binding motifs within the hepatitis B virus enhancer I on X promoter activity using linker scanning mutagenesis. Virology 193:653-60
Gupta, S; Kim, S K; Vemuru, R P et al. (1993) Hepatocyte transplantation: an alternative system for evaluating cell survival and immunoisolation. Int J Artif Organs 16:155-63
Gupta, S; Vemuru, R P; Yerneni, P R et al. (1993) Hepatocyte transplantation: prolonged cell survival following ex vivo manipulation and release from culture matrix components. Transplant Proc 25:2370-4
Breidbart, S; Burk, R D; Saenger, P (1993) Hormonal regulation of hepatitis B virus gene expression: influence of androgen receptor. Pediatr Res 34:300-2
Vemuru, R P; Davidson, A; Aragona, E et al. (1992) Immune tolerance to a defined heterologous antigen after intrasplenic hepatocyte transplantation: implications for gene therapy. FASEB J 6:2836-42
Gupta, S; Aragona, E; Vemuru, R P et al. (1991) Permanent engraftment and function of hepatocytes delivered to the liver: implications for gene therapy and liver repopulation. Hepatology 14:144-9
Akmal, M; el-Ghor, A; Burk, R D (1989) DNase I hypersensitive site maps to the HBV enhancer. Virology 172:478-88
DeLoia, J A; Burk, R D; Gearhart, J D (1989) Developmental regulation of hepatitis B surface antigen expression in two lines of hepatitis B virus transgenic mice. J Virol 63:4069-73

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