Table 1

The growing inhibitory receptor family

Receptor/structureLigandCellular expressionFunctionLikely effectors
FcγRIIBIgGB(T?)cells/mast cells, etc.Inhibition of antigen/Fc receptor signalingSHP-1, SHP-2, SHIP
CD22α2,6 sialogly- coproteinsB cellsInhibition of antigen receptor signalingSHP-1
Killer inhibitory receptors (KIRs) (hp58/p70, mLy49, etc. >11 members)MHC class IT cells/NK cellsInhibition of antigen/Fc receptor signalingSHP-1, SHP-2
CTLA4CD80, CD86T cellsInhibition of antigen receptor signalingSHP-2
gp49B1?Mast cells/Nk cellsInhibition 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 signalingSHP-1, SHP-2