Human Fc receptors
. | Classical FcγR . | Nonclassical FcR . | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
FcγRI . | FcγRIIa . | FcγRIIb . | FcγRIIc . | FcγRIIIa . | FcγRIIIb . | FcRn . | DC-SIGN . | CD22 . | CD23 . | TRIM21 . | FCRL1-6 . | FCRLA . | FCRLB . | |
Other name | CD64 | CD32A | CD32B | CD32C | CD16A | CD16B | Brambell receptor | CD209; CLEC4L | SIGLEC2 | FcεRII | Ro52 | CD307a-f | ||
Cellular distribution | Surface plasma membrane | Surface and endosomes | Surface plasma membrane | Surface | Cytoplasmic | Surface | Intracellular compartments | |||||||
Functional outcome | Activation | Inhibition | Activation | IgG recycling; circulating immune complex responses | Ag presentation | Inhibition | Activation | Activation; viral degradation | Inhibition/ activation? | IgG retention during affinity maturation? | ||||
Cellular expression | Hematopoietic | Most nucleated cells | Myeloid | B cells | Hematopoietic; epithelia | Most nucleated cells | Lymphocytes; mainly B cells | Germinal center B cells | ||||||
Ig-binding affinity | IgG, high | IgG, low/medium | IgG, high; pH dependent | Sialylated IgG, medium | Sialylated glycans, surface IgM, CD45 | IgE, low | IgG, IgM, and IgA, medium | IgG aggregates, low/medium | IgG, low |
. | Classical FcγR . | Nonclassical FcR . | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
FcγRI . | FcγRIIa . | FcγRIIb . | FcγRIIc . | FcγRIIIa . | FcγRIIIb . | FcRn . | DC-SIGN . | CD22 . | CD23 . | TRIM21 . | FCRL1-6 . | FCRLA . | FCRLB . | |
Other name | CD64 | CD32A | CD32B | CD32C | CD16A | CD16B | Brambell receptor | CD209; CLEC4L | SIGLEC2 | FcεRII | Ro52 | CD307a-f | ||
Cellular distribution | Surface plasma membrane | Surface and endosomes | Surface plasma membrane | Surface | Cytoplasmic | Surface | Intracellular compartments | |||||||
Functional outcome | Activation | Inhibition | Activation | IgG recycling; circulating immune complex responses | Ag presentation | Inhibition | Activation | Activation; viral degradation | Inhibition/ activation? | IgG retention during affinity maturation? | ||||
Cellular expression | Hematopoietic | Most nucleated cells | Myeloid | B cells | Hematopoietic; epithelia | Most nucleated cells | Lymphocytes; mainly B cells | Germinal center B cells | ||||||
Ig-binding affinity | IgG, high | IgG, low/medium | IgG, high; pH dependent | Sialylated IgG, medium | Sialylated glycans, surface IgM, CD45 | IgE, low | IgG, IgM, and IgA, medium | IgG aggregates, low/medium | IgG, low |