Molecular evolution of hepatitis A virus in a human diploid cell line.
OBJECTIVE
To investigate the hotspots, direction, and the time course of evolution of hepatitis A virus in the process of consecutive cell culture passage in human KMB17 diploid cells.


METHODS
Wild type hepatitis A virus H2w was serially propagated in KMB17 cells until passage 30, and the full-length genomes of H2w and its six chosen progenies were determined by directly sequencing RT-PCR products amplified from viral genomic RNA. Alignment comparison of sequences from H2w with its six progenies and phylogenetic analysis of the whole VP1 region from H2w, progenies of H2w, and other cell culture adapted hepatitis A virus were then carried out to obtain data on the molecular evolution of hepatitis A virus in the process of consecutive passage in KMB17 cells.


RESULTS
Most of the mutations occurred by passage 5 and several hotspots related to adaptation of the virus during cell growth were observed. After that stage, few additional mutations occurred through the remaining duration of passage in KMB17 cells except for mutation in the virulence determinants, which occurred in the vicinity of passage 15. The phylogenetic analysis of the whole VP1 region suggested that the progenies of H2w evolved closely to other cell culture adapted hepatitis A virus, i.e. MBB, L-A-1, other than its progenitor H2w.


CONCLUSIONS
Hepatitis A virus served as a useful model for studying molecular evolution of viruses in a given environment. The information obtained in this study may provide assistance in cultivating the next generation of a seed virus for live hepatitis A vaccine production.
Tang
Cai-Hua
CH
Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang Province, China.
Mao
Jiang-Sen
JS
Chai
Shao-Ai
SA
Chen
Yong
Y
Zhuang
Fang-Cheng
FC
D002460:Cell Line; D049109:Cell Proliferation; D004252:DNA Mutational Analysis; D030541:Databases, Genetic; D004171:Diploidy; D019143:Evolution, Molecular; D030041:Hepatitis A virus / Q000235:genetics* / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D008168:Lung / Q000166:cytology / Q000196:embryology / Q000821:virology*; D009154:Mutation; D010802:Phylogeny; D012367:RNA, Viral; D013997:Time Factors; D014761:Viral Hepatitis Vaccines / Q000096:biosynthesis / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics; D014779:Virus Replication
D012367:RNA, Viral; D014761:Viral Hepatitis Vaccines; D037521:Virulence Factors