The involvement of survival signaling pathways in rubella-virus induced apoptosis

Cooray, Samantha; Jin, Li; Best, Jennifer M

The effect of PI3K and MEK1/2 inhibition on RV growth and replication Akt, GKS3β and PKCζ (another downstream target of PI3K signaling), has been demonstrated in Vero E6 cells early during infection with severe acute respiratory syndrome (SARS)-associated corona virus (CoV) [35] . However, unlike in this study the survival response due to PI3K-Akt signaling was deemed to be weak, as LY294002 treatment did not result in an increase in apoptotic DNA laddering. PI3K, Akt and NFκB have also been shown to be activated prior to epithelial cell apoptosis in RSVinfected cells [36] . As with RV, inhibition of PI3K increased the speed and magnitude of RSV-induced apoptosis, although host-cell survival was suggested to occur prior to apoptotic signaling, as opposed to RV where caspase activation and Akt phosphorylation occur concomitantly [6] . PI3K-Akt signaling has also been shown to reduce coxsackievirus B3 (CVB3)-induced apoptosis. However, in contrast to RSV, the replication of CVB3 was also reduced, suggesting that PI3K-Akt survival signals may also serve as a defense mechanism against virus infection [37] .