Table 1.
Human FcRs: their expression, function and allotypes.
| Name | Subclass binding | Expression | Functions | Alleles | Link to diseases |
|---|---|---|---|---|---|
| FcγRI (CD64) | IgG 1/3/4 | Monocytes/Macrophages Neutrophils/DCs/Mast cells | Activation | – | – |
| FcγRIIA (CD32a) | H131:lgG 1/2/3/4 R131:lgG l/(2) /3/4 | Monocytes/Macrophages Neutrophils/DCs/Basophils/Mast eells/Eosinophils | Activation/inhibition | H131/R131 | Kawasaki diseases (43), Ulcerative colitis (44). Childhood-onset ITP (71)/Lupus (46), IgAN (48), arthritis |
| FcγRIIB (CD32b) | lgG l/(2)/3/4 | B cells/DCs/Mast cells/Basophils | Inhibition | Promoter−3S6C or −120/T232 | Lupus (46)/lupus (42), Atopy (72) |
| FcγRIIC (CD32c) | IgG 1/(2)/3/4 | NK cells/ Monocytes/Macrophages /Neutrophils | Activation | Q13/stopl3 | Kawasaki disease (73) |
| FcγRIIIA (CD16) | V158: lgG l(2)/3/4 Fl58: lgG l/(2)/3/4 | NK cells/ Monocytes/Macrophages | Activation/Inhibition | V15S/F158 | IgAN (48), arthritis seventy (74), childhood chronic ITP (75)/Lupus (76), arthritis (58), Crohn's disease (77) |
| FcγRIIIB (CD16b) | IgG 1/3/4? | Neutrophils/ Eosinophils/ Basophils | Activation | Wegener's granulomatosis (78) | |
| FcαRI (CD89) | IgAl, lgA2, CRP | Monocytes/Macrophages Neutrophils/DCs/Kupffer cells (79) | Activation/Inhibition | 114T/C | IgA nephropathy (60), AIDS, ankylosing spondylitis, alcoholic liver cirrhosis, Henoth-Schonlem purpura (HSP) (26) |
| FcμR | IgM | B and T lymphocytes | Inhibition/? | Chronic Lymphocytic Leukemia (CLL) (80, 81) | |
| Fcα/μR | IgM and IgA | Germinal center B cell, Follicular dendritic cells | ? | ||
| FcεRI | IgE | Mast cells/Basophils | Activation | 66T/31SC | Atopic dermatitis.J asthma and chronic urticaria (66–71) |
| FcεRII (CD23) | IgE | B cells and macrophages | Activation | – | AIDS and B-CLL (82) |
| FcRn | IgG 1/2/3/4 | Monocytes/Macrophages Neutrophils/DCs/endothelium/Syncytiotrophoblasts | Recycling Transport uptake | VNTR1–5 | |
| PlgR | plgA | Mucosal epithelium | Transcytosis | 1739C to T | Nasopharyngeal cancer and infection (65) |
From left to right columns: names, function, alleles that include amino acid variations in immunoglobulin domains and the transmembrane domain, cellular expression of FcRs, and diseases linked to alleles and CNVs (reference numbers are shown), and binding abilities of IgG subclasses to each FcR allele. IgAN, IgA nephropathy; CLL, chronic lymphocytic Leukemia; FcRn, neonatal Fc receptor; AIDS, acquired immune deficiency syndrome; PIgR, Polymeric immunoglobulin receptor; DCs, dendritic cells.