Opsonization with C3b or C4b

Stable Identifier
Reaction [omitted]
Gallus gallus
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C4b and C3b are opsonins, which are able to bind covalently to glycoproteins on the target cell surface. Opsonization by C3b or C4b leads to engagement of complement receptors (CR1, CR3 or Cr4) on acceptor phagocytic cells, thus targeting foreign particles for phagocytosis [Bohnsack JF et al 1985].

C3b and C4b have been reported to facilitate a clearance of immune complexes (IC) which begins with covalent attachment of C3b or C4b to IC. C3b/C4b-coated immune complexes are loaded on erythrocytes via C1R and are transferred to phagocytes in the liver and spleen [Hakansson L et al 1982; Taylor RP et al 1991; Pascual M and Schifferli JA 1992; Emlen W et al 1992].

Literature References
PubMed ID Title Journal Year
6981589 Kinetic studies of phagocytosis. III. The complement-dependent opsonic and anti-opsonic effects of normal and sle sera

Håkansson, L, Hällgren, R, Venge, P

Immunology 1982
1385769 Mechanism of transfer of immune complexes from red blood cell CR1 to monocytes

Emlen, W, Carl, V, Burdick, G

Clin. Exp. Immunol. 1992
1473961 The binding of immune complexes by the erythrocyte complement receptor 1 (CR1)

Pascual, M, Schifferli, JA

Immunopharmacology 0
1833104 Complement-opsonized IgG antibody/dsDNA immune complexes bind to CR1 clusters on isolated human erythrocytes

Taylor, RP, Pocanic, F, Reist, C, Wright, EL

Clin. Immunol. Immunopathol. 1991
3161946 Fibronectin-enhanced phagocytosis of an alternative pathway activator by human culture-derived macrophages is mediated by the C4b/C3b complement receptor (CR1)

Bohnsack, JF, O'Shea, JJ, Takahashi, T, Brown, EJ

J. Immunol. 1985
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