Table 1.
The growing inhibitory receptor family
| Receptor/structure | Ligand | Cellular expression | Function | Likely effectors |
|---|---|---|---|---|
| FcγRIIB | IgG | B(T?)cells/mast cells, etc. | Inhibition of antigen/Fc receptor signaling | SHP-1, SHP-2, SHIP |
| CD22 | α2,6 sialogly- coproteins | B cells | Inhibition of antigen receptor signaling | SHP-1 |
| Killer inhibitory receptors (KIRs) (hp58/p70, mLy49, etc. >11 members) | MHC class I | T cells/NK cells | Inhibition of antigen/Fc receptor signaling | SHP-1, SHP-2 |
| CTLA4 | CD80, CD86 | T cells | Inhibition of antigen receptor signaling | SHP-2 |
| gp49B1 | ? | Mast cells/Nk cells | Inhibition of antigen/Fc receptor signaling | ? |
| PIR-B | ? | B cells | ?? | ? |
| Signal-regulatory Proteins (SIRPs) (SHPS-1, etc., >15 members) | ? | “Ubiquitous” | Inhibition of PDGF, EGF and insulin receptor signaling | SHP-1, SHP-2 |