Table 2.

NOD-like receptors (NLR)^a

Subfamily	Select subfamily member	Ligand	Function	Signaling	Ref
NLRA	CIITA	IFNγ	Positive regulator of MHCII transcription	Transcription factor for MHC	[40]
NLRB	NAIP	Flagellin; T3SS	Anti-apoptosis	Caspase-1 mediated inflammasome	[41]
NLRC	NOD1	iE-DAP dipeptide	Inflammatory cytokine; antimicrobial proteins	RIP2, NFκB, MAPK	[42]
	NOD2	Muramyl dipeptide (MDP)	Inflammatory cytokine; antimicrobial proteins	RIP2, NFκB, MAPK	[43]
	NLRC3	Viral DNA & nucleic acids	Neg reg of NFκB; attenuates type I IFN	TRAF6	[44]
	NLRC4	Flagellin; T3SS; T4SS	Inflammasome formation	Caspase-1	[45]
	NLRC5	Nucleoside triophospate	Regulation of MHCI	MHCI transcription	[46]
	NLRX1	dsRNA, PUA, ESA, and DHA	Negatively regulates IFN-I and IL-6 responses; located on mitochondria	NFκB	[47]
NLRP	NLRP1	MDP, anthrax lethal toxin	Inflammasome formation	Caspase-1	[48]
	NLRP3	PAMPS and DAMPs associated with viral infection	Inflammasome formation	Caspase-1	[49]
	NLRP6	unknown	Poorly characterized inflammasome formation	Negative regulation of NFκB and MAPK	[50]
	NLRP7	lipopeptide	Putative inflammasome formation	unknown	[51]
	NLRP12	unknown	Unproven inflammasome formation	Negative regulation of NFκB and MAPK	[52]

^aSelect receptors with established role in innate immunity