Utilization of chimeras between human (HM-175) and simian (AGM-27) strains of hepatitis A virus to study the molecular basis of virulence.
Chimeras between human (HM-175) and simian (AGM-27) strains of hepatitis A virus (HAV) were constructed to evaluate the effect of the 2C gene of AGM-27 on HAV replication in cell culture and virulence in tamarins (Saguinus mystax) and chimpanzees (Pan troglodytes). Kinetic studies and radioimmunofocus assays demonstrated that replacement of the 2C gene of HAV/7, a cell culture-adapted strain of HM-175, with that of AGM-27 drastically reduced the ability of the virus to replicate in cultured cells. Intragenic chimeras containing AGM-27 sequences in either the 5' or 3' half of the 2C gene replicated in cell culture at an intermediate level. Whereas HAV/7 is attenuated for tamarins, a chimera containing the simian virus 2C gene in the HAV/7 background was virulent in tamarins, demonstrating that the simian virus 2C gene alone can confer the phenotype of virulence to an otherwise attenuated virus. Clusters of AGM-27-specific residues near both ends of the 2C protein were required for virulence since a chimera containing AGM-27 sequences in the carboxy-terminal half of 2C was partially attenuated for tamarins while one containing AGM-27 sequences only in the amino-terminal half of 2C was even more attenuated. Chimeras containing either the entire or only the 3' half of the simian virus 2C gene in the HAV/7 background were attenuated for chimpanzees.
Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892, USA. graychaudh@atlas.niaid.nih.gov
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G
Raychaudhuri
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S
Govindarajan
M
M
Shapiro
R H
RH
Purcell
S U
SU
Emerson
D000818:Animals; D002460:Cell Line; D004195:Disease Models, Animal; D006506:Hepatitis A / Q000821:virology*; D017957:Hepatitis A Virus, Human / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D006524:Hepatitis, Viral, Animal / Q000821:virology*; D006507:Hepatovirus / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D006801:Humans; D008253:Macaca mulatta; D002679:Pan troglodytes; D011863:Radioimmunoassay; D012452:Saguinus; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*; D014774:Virulence
D014764:Viral Proteins; C108899:protein 2C, Hepatitis A virus