Human interleukin-2 could bind to opioid receptor and induce corresponding signal transduction

Interleukin-2 (IL-2) was found to have an analgesic effect in the peripheral nervous system. Both electrophysiological and behavioural experiments suggested an anti-noceiceptive effect of IL-2 in animals. Biochemical experiments revealed that IL-2 could displace diprenorphine binding in both NG 108-15 cells and HEK 293 cells transfected with pCDNA3-DOR (delta opioid receptor). Furthermore, IL-2 significantly inhibited cAMP production stimulated by forskolin in both NG 108-15 and transfected HEK 293 cells, indicating that the binding of IL-2 to the delta opioid receptor is functional.