Human KIRs
| KIR . | Identified ligand . |
|---|---|
| 2DL1 | HLA-CLys80 (C2 epitope) (eg, HLA-Cw4) |
| 2DL2* | HLA-CAsn80 (C1 epitope) (eg, HLA-Cw3) |
| 2DL3* | HLA-CAsn80 (C1 epitope) (eg, HLA-Cw3) |
| 2DL4 | HLA-G |
| 2DL5 | ? |
| 2DS1 | HLA-CLys80 (C2 epitope) |
| 2DS2 | ? |
| 2DS3 | ? |
| 2DS4 | HLA-A11 and subsets of C1+ C2+ HLA-C |
| 2DS5 | ? |
| 3DL1 | HLA-BBw4 (eg, HLA-B27), and HLA-ABw4 (eg, HLA-A32) |
| 3DL2 | HLA-A3, -A11 and CpG-ODN |
| 3DL3 | ? |
| 3DS1 | ? |
| KIR . | Identified ligand . |
|---|---|
| 2DL1 | HLA-CLys80 (C2 epitope) (eg, HLA-Cw4) |
| 2DL2* | HLA-CAsn80 (C1 epitope) (eg, HLA-Cw3) |
| 2DL3* | HLA-CAsn80 (C1 epitope) (eg, HLA-Cw3) |
| 2DL4 | HLA-G |
| 2DL5 | ? |
| 2DS1 | HLA-CLys80 (C2 epitope) |
| 2DS2 | ? |
| 2DS3 | ? |
| 2DS4 | HLA-A11 and subsets of C1+ C2+ HLA-C |
| 2DS5 | ? |
| 3DL1 | HLA-BBw4 (eg, HLA-B27), and HLA-ABw4 (eg, HLA-A32) |
| 3DL2 | HLA-A3, -A11 and CpG-ODN |
| 3DL3 | ? |
| 3DS1 | ? |
In general, KIRs with inhibitory activity are long-tailed, whereas short tails are present in the activating KIRs.
2D and 3D indicate the number of Ig-like domains; L (long) and S (short) indicate the length of the intracytoplasmic portion; and ? indicates that the ligand is still undefined.
2DL2 and 2DL3 bind also C2 alleles, although with low affinity. In addition, these 2 KIRs have been shown to recognize few HLA-B alleles that bear the C1 epitope (eg, HLA-B*4601 and HLA-B*7301).