Studies on the Pathogenesis of Hepatitis A and Feasibility Studies on a Hepatitis A Vaccine
Abstract
The objectives of this work are to produce hepatitis A virus (HAV) antigens by recombinant DNA technology to identify antigens that may induce a protective immune response, and to construct vectors that can be used to stimulate enteric mucosal immunity against HAV. Viral cDNA sequences encoding capsid proteins or selected parts of capsid proteins VP1 and VP3 have been cloned into several bacterial expression vectors, and have been shown to direct the synthesis of high levels of HAV capsid protein sequences in E. coli and in one case, in Salmonella typhimurium. Large amounts of HAV protein have also been produced in cultured insect cells infected with recombinant baculoviruses. The recombinant HAV proteins have been used to raise antisera in rabbits. In the case of one protein containing VP1 sequence, the antiserum recognized VP1 from purified virus, but it did not neutralize virus infectivity. The immunized rabbit, however, appeared to have been primed to produce a secondary, anamnestic response, which was neutralizing, to challenge with a sub-immunogenic dose of intact virus. An in situ hybridization procedure has been developed, using the plasmids constructed for antigen production as a source of probes to detect viral nucleic acid in infected cells and tissues. The procedure has been used to measure virus growth in cell culture, and for the analysis of liver and other biopsy material from HAV-infected Aotus monkeys.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 14, 1988
- Accession Number
- ADA201683
Entities
People
- Donald F. Summers
- Elvera Ehrenfeld
- Oliver R. Richards
Organizations
- University of Utah