Hepatitis A virus (HAV) causes one of the most prevalent infections of man, and remains a worldwide public health problem. The ability to propagate the virus in cultured cells, as well as the recent construction of cDNA clones and the determination of the nucleotide sequence of the viral genome, have made possible numerous new approaches to understanding the biology and pathogenesis of HAV infection and provided insight towards the development of potential subunit vaccines. In this application, we propose experiments designed to identify specific viral sequences that are responsible for the slow and protracted replication cycle of this virus, a characteristic that distinguishes it from all other members of its genus (enterovirus) and family (Picornaviridae). Recombinant viruses will be constructed that are composed of HAV 5' end regulatory sequences and poliovirus coding sequences, or HAV polymerase coding sequences replacing the homologous polio sequences. The efforts of the insertion of these potentially down-regulating HAV sequences into a rapidly-growing, lytic poliovirus will be evaluated by examining plaque size and morphology, temperature sensitivity, viral RNA and protein synthesis, and virus yields. Another uncharacterized HAV gene, the 2A protease coding region, will be analyzed for functions dealing with host cell interaction and virus morphogenesis by expressing genetically engineered proteins containing 2A sequences, both in vivo and in vitro. Finally, we have produced HAV capsid protein (VP1) antigens in both prokaryotic (E. coli) and eukaryotic (baculovirus-infected SF9) cells. We plan to systematically evaluate the ability of different antigenic proteins, expressed from a variety of different vectors and purified by different procedures, to induce neutralizing antibodies and/or to prime the immune system for a neutralizing anamnestic response. We hope that these studies will identify a recombinant protein that will be effective as a candidate immunogen for a subunit vaccine.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI026350-01
Application #
3140128
Study Section
Virology Study Section (VR)
Project Start
1988-04-01
Project End
1993-03-31
Budget Start
1988-04-01
Budget End
1989-03-31
Support Year
1
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Utah
Department
Type
Schools of Medicine
DUNS #
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112
Graff, J; Richards, O C; Swiderek, K M et al. (1999) Hepatitis A virus capsid protein VP1 has a heterogeneous C terminus. J Virol 73:6015-23
Graff, J; Ehrenfeld, E (1998) Coding sequences enhance internal initiation of translation by hepatitis A virus RNA in vitro. J Virol 72:3571-7
Graff, J; Cha, J; Blyn, L B et al. (1998) Interaction of poly(rC) binding protein 2 with the 5' noncoding region of hepatitis A virus RNA and its effects on translation. J Virol 72:9668-75
Jia, X Y; Van Eden, M; Busch, M G et al. (1998) trans-encapsidation of a poliovirus replicon by different picornavirus capsid proteins. J Virol 72:7972-7
Davis, H L; McCluskie, M J; Gerin, J L et al. (1996) DNA vaccine for hepatitis B: evidence for immunogenicity in chimpanzees and comparison with other vaccines. Proc Natl Acad Sci U S A 93:7213-8
Jia, X Y; Tesar, M; Summers, D F et al. (1996) Replication of hepatitis A viruses with chimeric 5' nontranslated regions. J Virol 70:2861-8
Ehrenfeld, E; Brown, D; Jia, X Y et al. (1995) Antibodies against viral nonstructural proteins in response to infection with poliovirus. J Infect Dis 171:845-50
Harmon, S A; Emerson, S U; Huang, Y K et al. (1995) Hepatitis A viruses with deletions in the 2A gene are infectious in cultured cells and marmosets. J Virol 69:5576-81
Tesar, M; Pak, I; Jia, X Y et al. (1994) Expression of hepatitis A virus precursor protein P3 in vivo and in vitro: polyprotein processing of the 3CD cleavage site. Virology 198:524-33
Jia, X Y; Summers, D F; Ehrenfeld, E (1993) Primary cleavage of the HAV capsid protein precursor in the middle of the proposed 2A coding region. Virology 193:515-9

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