Hep3B human hepatoma cells support replication of the wild-type and a 5'-end deletion mutant GB virus B replicon.
Hepatitis C virus (HCV) and GB virus B (GBV-B) replicons have been reported to replicate only in Huh7 cells. Here we demonstrate that subpopulations of another human hepatoma cell line, Hep3B, are permissive for the GBV-B replicon, showing different levels of enhancement of replication from those of the unselected parental cell population. Adaptive mutations are not required for replication of the GBV-B replicon in these cells, as already demonstrated for Huh7 cells. Nonetheless, we identified a mutant replicon in one of the selected cell lines, which, although lacking the 5' end proximal stem-loop, is able to replicate in Hep3B cells as well as in Huh7 cells. This mutant indeed shows a higher replication efficiency than does wild-type replicon, especially in the Hep3B cell clone from which it was originally recovered. This indicates that the stem-loop Ia is not necessary for replication of the GBV-B replicon in human cells, unlike what occurs with HCV, and that its absence can even provide a selective advantage.
Istituto di Ricerche di Biologia Molecolare P. Angeletti, 00040 Pomezia (Rome), Italy.
Amedeo
A
De Tomassi
Maura
M
Pizzuti
Cinzia
C
Traboni
D020121:5' Untranslated Regions / Q000737:chemistry; D006528:Carcinoma, Hepatocellular / Q000821:virology*; D045744:Cell Line, Tumor; D029406:GB virus B / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008113:Liver Neoplasms / Q000821:virology*; D009154:Mutation; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000737:chemistry; D012093:Replicon; D014779:Virus Replication
D020121:5' Untranslated Regions; D012367:RNA, Viral