New Approaches to Attenuated Hepatitis a Vaccine Development: Cloning and Sequencing of Cell-Culture Adapted Viral cDNA
Abstract
An infectious cDNA clone derived from virulent HAV would be of considerable value in experiments designed to determine the molecular basis of attenuation, and would provide the basis for new approaches to developing candidate attenuated viruses. In an effort to assemble such a clone, partial inserts from ten HM175 cDNA clones were assembled into a single construct containing the consensus of p16 HM175 sequence. Flanking homopolymeric dC-dG tails derived from the original cloning procedure were removed, and the full length sequence of p16 HAV cDNA was inserted between the HindIII and XbaI sites of the transcription vector pGEM3. At the conclusion of the contract period, the infectivity of this construct (pHAV/p16) was under evaluation. The sequence of the p1 genomic regions of two plaque-purified, cytopathic variants of HM175 virus was determined from virion RNA; one of these variants was shown to be a spontaneous neutralization escape mutant. A novel immunoaffinity-linked nucleic acid amplification system (antigen-capture/polymerase chain reaction, or AC/PCR) capable of the strain-specific detection of HAV in clinical specimens was developed and evaluated. Molecular cloning and partial sequencing of the genome of PA21 strain HAV was undertaken in an effort to determine the extent of genetic divergence from human HAV.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1989
- Accession Number
- ADA220225
Entities
People
- Stanley M. Lemon
Organizations
- University of North Carolina at Chapel Hill