Semipermissive replication of adenovirus 5 in rat brain cells and evidence for an induction of cellular DNA replication in vivo.

Human adenovirus type 5 is shown to cause a limited infection of the cells lining the ventricles of 2- to 3-week-old newborn rats. By the distribution of fluorescent antibody-labelled cells the infection appears to be confined to the ependymal cells. In these same (ependymal) cells autoradiographic labelling of [3H]thymidine-pulsed brains indicates that viral and possibly cellular DNA synthesis is occurring. Studies with the mutants dl 312 and dl 313 indicate that some cellular DNA synthesis is indeed occurring. No DNA synthesis is observed in cells after inoculation of brains with phosphate-buffered saline or infection of brains with Semliki Forest virus. These results suggest that expression of adenovirus early region genes stimulates differentiated (G0) brain cells to enter a cell cycle.