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. 1991 Feb;83(2):257-61.
doi: 10.1111/j.1365-2249.1991.tb05624.x.

Characterization of three monoclonal antibodies to membrane co-factor protein (MCP) of the complement system and quantification of MCP by radioassay

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Characterization of three monoclonal antibodies to membrane co-factor protein (MCP) of the complement system and quantification of MCP by radioassay

S W Cho et al. Clin Exp Immunol. 1991 Feb.

Abstract

MCP is a widely distributed regulatory glycoprotein of the complement system which binds C3b and C4b and has factor I-dependent co-factor activity. Monoclonal antibodies raised to lymphocytes (E4.3), chorionic microvilli (GB24) and an embryonal carcinoma cell line (TRA-2-10) recognize MCP (CD46). GB24 inhibited both the binding of MCP to its ligand iC3 and co-factor activity; E4.3 and TRA-2-10 did not. The binding of GB24 to cells bearing MCP was not cross-inhibited by E4.3 or TRA-2.10, but TRA-2-10 blocked binding and displaced pre-bound E4.3. Using these antibodies, we developed a radioassay for quantifying the number of MCP molecules/cells. Human peripheral blood mononuclear (PBMC) and polymorphonuclear cells (PMN) had about 10,000 MCP cell; platelets had about 600/cell, and no MCP was found on erythrocytes. Neoplastic hematopoietic cell lines, of myelocytic and T lymphocytic origin, had several-fold more (20-60,000) molecules cell than peripheral blood cells or B cell lines (about 12,000). Malignant epithelial cell lines. HeLa (about 100,000/cell) and HEp-2 (about 250,000 cell) had the highest MCP expression of any cells examined. These monoclonal antibodies--especially GB24, which blocks MCP function--and the direct binding assay will facilitate the further analysis of the biology of this complement regulatory protein.

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References

    1. Arch Biochem Biophys. 1969 Nov;134(2):279-84 - PubMed
    1. Immunology. 1990 Jun;70(2):155-61 - PubMed
    1. Methods Enzymol. 1974;31:149-55 - PubMed
    1. J Immunol Methods. 1980;37(2):133-8 - PubMed
    1. Hum Immunol. 1983 May;7(1):1-15 - PubMed

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