. 2016 Oct 20;91(4):1595–1612. doi: 10.1007/s00204-016-1876-7

Table 2.

IgG receptors and effector functions

	Function	Binding affinity		Expression	Important AA residues	Impact of glycosylation^b
		IgG subclass	Ka (10⁶ M⁻¹)
C1q	CDC	** * ******* –	NA NA NA NA	Present in serum	L235, D265, D270, K322, P329, P331, H433	Galactose: ↑ CDC; Mannose: ↓ CDC
FcγRI	Activation	***** – ****	65 – 61 34	Monocytes, macrophages Dendritic Cells Neutrophils^I Mast Cells^I	E233, L235, G236	Unclear
FcγRIIA (H131)	Activation	***** ******	5.2 0.45 *0.89* 0.17	Monocytes, macrophages Dendritic Cells Neutrophils Mast Cells Basophils Eosinophils	L234, L235, G236, A327	Unclear
FcγRIIA (R131)	Activation	******* * ******	3.5 0.10 *0.91* 0.21		L234, L235, G236, A327	Unclear
FcγRIIB/C	Inhibition	* – ** *	0.12 0.02 *0.17* 0.20	B cells Dendritic cells Basophils Monocytes^a Macrophages^a Neutrophils^a	Unclear	Unclear
FcγRIIIA (F158)	Activation	– ****** –	1.2 0.03 *7.7* 0.20	Natural killer cells Monocytes Macrophages	E233, L234, L235G236	Mannose, Bisecting GlcNac:↑ ADCC; Sialic acid, fucose: ↓ ADCC
FcγRIIIA (V158)	Activation	******* * ******	2.0 0.07 *9.8* 0.25	Natural killer cells Monocytes Macrophages	E233, L234, L235G236
FcγRIIIB	Unclear	***** – ****** –	0.2 – *1.1* –	Neutrophils Basophils	L234, L235G236, G237, P238	Unclear
FcRn	Transcytosis Catabolism Antigen uptake	***** *** /** *****	80 NA NA NA	Monocytes, macrophages, Dendritic Cells Neutrophils Endothelium Syncytiotrophoblast	H433, N434, H435, Y436	Galactose, Mannose, GlcNAc: ↑ Clearance

Bold: IgG1, italic IgG2

Bolditalic: IgG3

Underline: IgG4

NA not applicable, AA amino acid

**** Very high affinity

*** High affinity

** Moderate affinity

* Low affinity;—no binding

^IInducible expression

^aLow percentages

^bLiu (2015)