Reactivation of Nedd-2, a developmentally down-regulated apoptotic gene, in apoptosis induced by a street strain of rabies virus

A laboratory strain of rabies virus has been reported to induce apoptosis in experimental animals. The present study demonstrated that a bat strain and a primary canine rabies virus isolate also induced apoptosis in vivo. This death process involved reactivation of the caspase gene, Nedd-2, a developmentally down-regulated apoptotic gene. Expression of Nedd-2 was significantly up-regulated in infected adult and suckling mice. Reactivation of Nedd-2 in infected adult mice started at around day 3 and was prominent on day 5. The level of expression was constantly high up to the time that mice showed signs of illness. Expression of Nedd-2 correlated with the appearance of apoptotic nuclei within the infected brain, suggesting that reactivation of a developmentally down-regulated gene, Nedd-2, may be required for apoptotic elimination of cells damaged by infection.