Table 1.

Role of IFN-α, IFN-β, and IFN-γ in pain and the underlying mechanisms.

IFNs	Doses	Routes	Species	Conditions	Actions	Mechanisms	References
IFN-α	500 U	Intracerebral	Mouse	Naïve	Antinociception	Opioid receptor dependent	32
	4, 8, 16 pmole	Intracranial ventricle	Rat	Naïve	Antinociception	μ-opioid receptor dependent	33
	100 ng	Intrathecal	Rat	Naïve, CFA	Antinociception	Opioid receptor dependent	9
	100 ng	Intrathecal	Rat	Naïve, CFA	Antinociception	Inhibits EPSC and capsaicin-induced P-ERK	34
	300 U	Intraplantar	Mouse	Naïve	Hyperalgesia	Activation of MAPK and MNK-eIF4e translation	35
	100 U	Intrathecal	Mouse	Naïve	Antinociception	IFNAR-1 mediated actions; inhibition of Nav 1.7 and calcium channel activities	11
IFN-β	100 ng	Intrathecal	Mouse	LPS	Antinociception	IFNAR-1 mediated and TLR-mediated actions	36
	3600 U	Intrathecal	Mouse	Arhtritis	Co-injection with TNF antibody produces long-term pain relief	Induction of IL-10 expression	37
	1000, 5000, 10000 U	Intrathecal	Mouse	Spared nerve injury	Antinociception	Induction of ISG-15 and inhibition of MAPK	38
	300 U	Intraplantar	Mouse	Naïve	Hyperalgesia	Activation of MAPK and MNK-eIF4e translation	35
	100 U	Intrathecal	Mouse	Naïve	Antinociception	IFNAR-mediated actions; inhibition of Nav 1.7 and calcium channel activities	8
IFN-γ	20000 U/mL	Incubation 14d	Rat	Dorsal horn neuron	Increase EPSC	decrease inhibitory neuron GluR 1	39
	1000U	Intrathecal	Rat	Naïve	Hyperalgesia	Activation of IFN-γ receptor in Microglia	7
	1000U	Spinal dorsal nerve	Rat	Naïve	Hyperalgesia	Increase C-fiber response	40
	1000U	Intrathecal	Rat	Naïve	Hyperalgesia	Activation of astrocyte	41
	2000 U/mL	Incubation 4-8h	Rat	Spinal cord slice	Increase C-fiber EPSC	Activation of Microglia	42