Abstract: OBJECTIVE: To study the effects of human apolipoprotein B mRNA_editing enzyme catalytic_polypeptide (APOBEC)_3F (hA3F) and _3G (hA3G) on the replication and mutation of influenza viruses. METHODS: A549 and MDCK were transfected using hA3F and hA3G plasmids, and the expression of recombinant proteins was detected using Western blotting and immunofluorescence assay. The titers of influenza virus, which replicated on the hA3F and hA3G expressing and control cells, were measured using TCID50 and plaque assay. The viral growth curves were drawn. The expression levels of hA3F and hA3G in influenza infected cells were detected using Western blotting. The mutation frequency of influenza viruses was detected using RT_PCR and DNA sequencing. RESULTS: The viral titers and viral growth curves indicated that there were no significant differences in replication of influenza virus between APOBEC proteins expressing cells and the control cells. Western blotting indicated that hA3F and hA3G were both over_expressed during the infection of influenza viral. DNA sequencing showed that there was no hypermutation in influenza viral genome induced by hA3F or hA3G. CONCLUSION: hA3F and hA3G have no obvious effects on the replication and mutation of influenza virus in A549 and MDCK cells.

Key words: hA_3F, hA_3G, influenza virus, replication, mutation, A549