Canine monocytes express a receptor specific for murine Fc gamma 2a and Fc gamma 3 immunoglobulins.
Murine monoclonal antibodies (mAb) of IgM and IgG subclasses that do not bind to canine cells have been used to detect the expression of Fc receptors on canine peripheral blood mononuclear cells and the cell line MAXEY-DH82. Murine Ig of IgG2a and IgG3 isotypes bound specifically to canine peripheral blood monocytes and to MAXEY-DH82, whereas Ig of IgG1, IgG2b, and IgM did not. No other cell types, including resting and activated peripheral blood lymphocytes, expressed this canine Fc receptor (cFcR) specific for murine IgG2a and IgG3. MAXEY-DH82 was used to characterize this Fc gamma 2a/gamma 3 receptor. Binding of murine IgG2a and IgG3 is trypsin sensitive and partially suppressed by phosphatidyl inositol-phospholipase C (PI-PLC) treatment, indicating that this cFc gamma 2a/gamma 3 receptor is a lipid-anchored protein. Preincubation of MAXEY-DH82 with canine sera or canine IgG prevented the binding of murine gamma 2a/gamma 3 Ig, demonstrating that this receptor is a cFc receptor for canine IgG. The cFc gamma R expressed on canine monocytes and on MAXEY-DH82 is probably the analog of the murine and human Fc gamma RI. The specific expression of this analog by canine cells could be used in identifying and purifying canine monocytes.
Laboratoire d'Immunologie Faculté A. Carrel, Lyon, France.
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Caux
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Chabanne
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Rigal
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Monier
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002460:Cell Line; D004285:Dogs / Q000097:blood / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000145:classification / Q000378:metabolism; D051379:Mice; D009000:Monocytes / Q000737:chemistry*; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D017452:Receptors, IgG / Q000032:analysis* / Q000145:classification / Q000187:drug effects; D014357:Trypsin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D017452:Receptors, IgG; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D014357:Trypsin; D043265:Phosphatidylinositol Diacylglycerol-Lyase