Complement activation in progressive renal disease

Table 1 Properties of complement receptors

Receptor	Alternative name(s)	Location	Specificity	Role
CR1	CD35	Macrophages Neutrophils B-cells Some T-cells Renal epithelium	C3b C4b	Binding of opsonised immune complexes for transport to phagocytes
CR2	CD21	B-cells Some T-cells Dendritic cells Epithelia	C3d	Link between innate and acquired immune response on B-cells Presentation of immune complexes to B-cells
CR3	CD11b/18	Macrophages Natural killer cells Neutrophils	iC3b	Cellular-extracellular matrix linkage Promotes phagocytosis of opsonised complexes
CR4	CD11c/18	Macrophages Neutrophils	iC3b C3dg	Receptor for iC3b-opsonised particles
C3aR	-	Renal epithelium Macrophages	C3a	Mediation of inflammation
C5aR	CD88	Neutrophils	C5a
C1qR	CD93	Leukocytes Platelets Monocytes Neutrophils	C1q	Up-regulation of phagocytic capacity Protein chaperone

Adapted from Morgan et al[94] 1999.