The Kinase RIPK3 Promotes Neuronal Survival by Suppressing Excitatory Neurotransmission During Central Nervous System Viral Infection

While recent work has identified roles for immune mediators in regulating neural activity, how innate immune signaling within neurons influences neurotransmission remains poorly understood. Emerging evidence suggests that the modulation of neurotransmission may serve important roles in host protection during infection of the central nervous system. Here, we showed that receptor-interacting protein kinase-3 (RIPK3) preserved neuronal survival during flavivirus infection through the suppression of excitatory neurotransmission. These effects occurred independently of the traditional functions of RIPK3 in promoting necroptosis and inflammatory transcription. Instead, RIPK3 promoted phosphorylation of the neuronal regulatory kinase calcium/calmodulin-dependent protein kinase II (CaMKII), which in turn activated the transcription factor cyclic AMP response element-binding protein (CREB) to drive a neuroprotective transcriptional program and suppress deleterious glutamatergic signaling. These findings identify an unexpected function for a canonical cell death protein in promoting neuronal survival during viral infection through the modulation of neuronal activity, highlighting mechanisms of neuroimmune crosstalk.