This work builds on the work by Yamanaka
and others showing that relatively short periods of exposure and/or sequential exposure to reprogramming signals is sufficient to transform cells into pluripotent cells. This raised the possibility that episomal/transient vectors, protein transduction strategies and small molecules may work.
In this manuscript the authors have shown that inducible adenovirus persists for sufficiently long periods to reprogram cells and as such minimizes risks associated with nonrandom integration and disruption of potentially important genes. These induced cells appeared similar to cells derived by other integrating methods and were capable of robust chimera formation.
While clearly an important step forward, several issues remain. The authors note that adenovirus infection efficiency is variable in different cell types. Persistence and levels of expression are variable as well, and both of these likely reduce the efficiency of reprogramming. Indeed, the authors used liver cells for their experiments as...