Table 2.

Cytosolic pattern recognition receptors (PRRs).

Cytosolic PRRs	Potential ligands
CIITA
NALP	Flagellin from Legionella
NOD1	GM-tripeptide, γ-d-Glu-DAP (iEDAP), d-lactyl-l-Ala-γ-Glu-meso-DAP-Gly (FK156), hepatonoyl-γ-Glu-meso-DAP-Ala (FK565)
NOD2	MDP, MurNAc-l-Ala-g-d-Glu-l-Lys (M-TRILys)
NLRC3	NLRC
NLRC4 (IPAF)	Flagellin from salmonella, Legionella, Listeria, Pseudomonas
NLRC5
NLRP1	MDP, Lethal Toxin
NLRP2
NLRP3	Sendai virus, Influenza virus, Adenovirus, Candida albicans, Saccharomyces cerevisiae, MDP, Nigericin, Maitotoxin, ATP, MSU, Silica, Asbestos, Alum, Amyloid β, Fatty acid, HIV
NLRP4–14
NLRX1
AIM2	DNA
MNDA	DNA(?)
IFI16	DNA(?)
IFIX	DNA(?)

Listed are the known human cytosolic PRRs, including NLRC4 (IPAF), NLRP1, NLRP3 and AIM2 that assemble to form large multiprotein complexes referred to as inflammasomes (in bold).

Abbreviations: AIM, absent in melanoma; ATP, adenosine triphosphate; CIITA, class II, major histocompatibility complex, transactivator; DNA, deoxyribonucleic acid; HIV, human immunodeficiency virus; IFI, IFN-inducible protein; IPAF, ICE-protease activating factor; MDP, muramyl dipeptide; MNDA, myeloid nuclear differentiation antigen; MSU, monosodium urate crystals; NALP, NACHT, LRR and PYD domains-containing protein; NLRC, NLR family CARD domain-containing protein; NLRP, NLR family, pyrin domain-containing; NLRX, NLR family member X; NOD, nucleotide-binding oligomerization domain.