Protection of human islets from the effects of interleukin-1β by adenoviral gene transfer of an IκB repressor

Interleukin-1β (IL-1β) is a pro-inflammatory cytokine that inhibits β cell function and promotes Fas-triggered apoptosis. IL-1β is thought to act early in the initiation of the autoimmune destruction of pancreatic β cells in type I diabetes. IL-1β promotes β cell impairment, in part, by activating NF-κB transcription factor-dependent signaling pathways. We have examined whether cells could be protected from the effects of IL-1β by overexpressing an inhibitor of NF-κB activity, IκB, by adenoviral gene transfer to intact human islets in culture. Infection of islets with an adenoviral vector encoding a non-phosphorylatable, non-degradable variant of IκBα resulted in normal insulin responses to glucose in the presence of IL-1β. Furthermore, nitric oxide production was prevented and, more importantly, Fas-triggered apoptosis was inhibited following IκBα gene transfer. These results suggest that blocking the NF-κB pathway might prevent cytokine-induced β cell impairment as a means of facilitating islet transplantation.