OBJECTIVETo investigate the genetic stability during the serial passages of non-replicating recombinant adenoviruses based on the novel AdEasy system.

METHODSFour non-replicating adenoviruses expressing rotavirus antigens, which were generated by the AdEasy system, were used as models and continuously propagated on 293 cells for 20 passages. Samples of the infected cells were collected at every 5 passages for the PCR analysis of the inserted rotavirus genes, replication-competent adenoviruses (RCAs) as well as the Western blot examination of the expression of the certain rotavirus genes.

RESULTSThe adenoviruses can be stably propagated on 293 cells. The existence and the stable expression of inserted rotavirus genes were able to be detected during the serial passage. The RCAs were not found within the first 10 passages, but the rvAdG2VP7(o) at passage 15 and the rvAdG2VP7(o) and rvAdG1VP7(o) at passage 20.

CONCLUSIONThe non-replicating adenoviruses showed promising genetic stability during the continuous passage on 293 cells. The RCAs normally will not be detectable within 10 continuous passages. The results indicated the potential of such recombinant adenoviruses in the research and development of the gene therapies and adenoviral-vectored vaccines.