Table 1 Characteristics of human and mouse Fc receptors
From: Beyond neutralization: Fc-dependent antibody effector functions in SARS-CoV-2 infection
Fc receptor | Function | ITAM, ITIM or ITAMi | Binding affinity for antibody isotypesa | Cell type-specific expression |
|---|---|---|---|---|
Human | ||||
FcμR | Endocytosis | None | IgM (+++) | B cells; subpopulations of T cells and NK cells |
Fcα/μR | Endocytosis | None | IgM (+++), IgA (+++) | Subpopulations of B cells and DCs |
FcαRI | Cell activation or inhibition | ITAM or ITAMi | IgA (++) | Neutrophils and eosinophils; subpopulations of monocytes/macrophages and DCs |
FcεRI | Cell activation | ITAM | IgE (+++) | Basophils, mast cells and platelets; subpopulations of monocytes/macrophages, DCs and eosinophils |
FcεRII | IgE regulation | None | IgE (++) | B cells, eosinophils and platelets; inducible expression on monocytes/macrophages and DCs |
FcγRI | Cell activation | ITAM | IgG1 (+++), IgG3 (+++), IgG4 (+++) | Monocytes/macrophages; inducible expression on neutrophils and mast cells |
FcγRIIA | Cell activation or inhibition | ITAM or ITAMi | IgG1 (++), IgG2 (++), IgG3 (++), IgG4 (++) | Monocytes/macrophages, neutrophils, DCs, basophils, mast cells, eosinophils and platelets |
FcγRIIB | Cell inhibition | ITIM | IgG1 (+), IgG2 (+), IgG3 (++), IgG4 (++) | B cells, DCs and basophils; majority of monocytes/macrophages (except alveolar macrophages); subpopulations of neutrophils |
FcγRIICb | Cell activation | ITAM | IgG1 (+), IgG2 (+), IgG3 (++), IgG4 (++) | NK cells |
FcγRIIIA | Cell activation or inhibition | ITAM or ITAMi | IgG1 (++), IgG2 (+), IgG3 (+++), IgG4 (++) | NK cells and monocytes/macrophages; uncertain expression on neutrophils |
FcγRIIIB | Cell activation or decoy receptor | None | IgG1 (++), IgG3 (++) | Neutrophils; subpopulations of basophils |
Mouse | ||||
FcμR | Endocytosis | None | IgM (+++) | B cells |
Fcα/μR | Endocytosis | None | IgM (+++), IgA (+++) | B cells; subpopulations of DCs |
FcεRI | Cell activation | ITAM | IgE (+++) | Basophils and mast cells; inducible expression on neutrophils and DCs |
FcεRII | IgE regulation | None | IgE (+++) | B cells; subpopulations of DCs |
FcγRI | Cell activation | ITAM | IgG2a (+++), IgG2b (++) | Neutrophils; subpopulations of monocytes/macrophages and DCs |
FcγRIIB | Cell inhibition | ITIM | IgG1 (++), IgG2a (++), IgG2b (++), IgE (+) | B cells, monocytes/macrophages, neutrophils, DCs, basophils, mast cells and eosinophils |
FcγRIII | Cell activation or inhibition | ITAM or ITAMi | IgG1 (++), IgG2a (++), IgG2b (++), IgE (+) | NK cells, monocytes/macrophages, neutrophils, DCs, basophils, mast cells and eosinophils |
FcγRIV | Cell activation | ITAM | IgG2a (+++), IgG2b (+++), IgE (++) | Monocytes/macrophages, neutrophils and DCs |
