Table 1.
Paired receptors and their ligands.
| Receptor | Function | Endogenous ligand | Non-self ligand |
|---|---|---|---|
| KIR2DL1 | Inhibitory | HLA-C (group 2) | |
| KIR2DL2 | Inhibitory | HLA-C (group 1, a subset of group 2), some HLA-B | |
| KIR2DL3 | Inhibitory | HLA-C (group 1, a subset of group 2), some HLA-B | |
| KIR2DL4 | Activating? | HLA-G | |
| KIR2DL5 | Inhibitory | ? | |
| KIR3DL1 | Inhibitory | HLA-Bw4, a subset of HLA-A | |
| KIR3DL2 | Inhibitory | HLA-A3, A11 | CpG ODN |
| KIR3DL3 | Inhibitory | ? | |
| KIR2DS1 | Activating | HLA-C (group 2) | |
| KIR2DS2 | Activating | HLA-C (group 1)? | |
| KIR2DS3 | Activating | HLA-C (group 2)? | |
| KIR2DS4 | Activating | A subset of HLA-Cw4, A11 | |
| KIR2DS5 | Activating | ? | |
| KIR3DS1 | Activating | HLA-Bw4, a subset of HLA-A? | |
| LILRB1 | Inhibitory | HLA-A, B, C, E, F, G | CMV UL18 |
| LILRB2 | Inhibitory | HLA-A, B, C, E, F, G, ANGPTLs (Zheng et al., 2012) | |
| LILRB3-5 | Inhibitory | ? | |
| LILRA1 | Activating | HLA-B27, HLA-CfHC | |
| LILRA2, 4–6 | Activating | ? | |
| LILRA3 | Soluble | HLA-CfHC, HLA-A, HLA-G | |
| PIR-B | Inhibitory | MHCI (Nakamura et al., 2004) | |
| Nogo, MAG, OMgp (Atwal et al., 2008) | |||
| ANGPTLs (Zheng et al., 2012) | |||
| PIR-A | Activating | MHCI (Nakamura et al., 2004) | |
| PILRα | Inhibitory | CD99, PANP, NPDC1, COLEC12 | HSV-1 gB |
| PILRβ | Activating | CD99 | HSV-1 gB |
| SIRPα | Inhibitory | CD47, SP-A, SP-D | |
| SIRPβ | Activating | SP-D | |
| SIRPγ | No signal | CD47 | |
| DCIR | Inhibitory | ? | |
| DCAR | Activating | ? | |
| NKRP1-A | Activating | LLT1 | |
| NKRP1-D | Inhibitory | Clrb (Iizuka et al., 2003) | |
| NKRP1-C, F | Activating | Clrg (Iizuka et al., 2003) | |
| Ly49A, C, I, etc | Inhibitory | H-2 | CMV m157 |
| Ly49D, H, etc | Activating | CMV m157, others? | |
| CD94/NKG2A | Inhibitory | HLA-E (Qa-1) | |
| CD94/NKG2C, E | Activating | HLA-E (Qa-1) | Others? |
| MAIR-I | Inhibitory | ? | |
| MAIR-II | Activating | ? | |
| CD200R1 | Inhibitory | CD200 (Wright et al., 2003) | |
| CD200R3,4 | Activating | ? |
ANGPTLs, angiopoietin-like proteins; fHC, free heavy chain; Nogo, neurite outgrowth inhibitor; MAG, myelin-associated glycoprotein; OMgp, oligodendrocyte myelin glycoprotein; Clrb, C-type lectin-related molecule b.