Fc receptor

Receptors for the Fc region of IgG are found on a number of cell types and are associated with a variety of functions including phagocytosis (monocytes, macrophages, neutrophils), antibody-dependent cellular cytotoxicity (monocytes, mac- 

Until recently, the conventional wisdom was that complement interacts with the CH2 domain and cellular Fc receptors with the CH3 domain of IgG. This has been challenged by a number of workers [25]. The binding of IgG to the human monocyte Fc receptor (FcRI) will be briefly discussed. 

Finally molecules secreted or shed by T cells which have specificity for IgG (IgG binding factors, IgG-BF) have been described [108], 

Fc receptors present on the cell membrane of macrophages, monocytes, granulocytes, lymphocytes, and some other cells may, in theory, non-specifically bind Fc portion of antibodies used for immunolabeling. Typically, blocking endogenous Fc receptors involves using normal serum derived from the same species used to produce the secondary antibody. To block endogenous Fc receptors, incubate sections for 15 30 min with normal serum (2 5% v/v) from the host species of the secondary antibody. 

Normal Serum Blocking Solution 2 5% normal serum (blocking) 

05% Tween 20 (detergent and surface tension reducer optional) 

05% sodium azide (preservative, if you intend to store this solution for a long time) 

Buchwalow and W. Bocker, Immunohistochemistry Basics and Methods, DOI 10.1007/978 3 642 04609 4 5, Springer Verlag Berlin Heidelberg 2010 

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Inhibition of inflammatory cytokines (Fig. 2) Humanized monoclonal anti-TNF antibodies (Infliximab (Remicade ), Adalimumab (Humira )) bind with high selectivity to human TNF-a and neutralize its activity. Thereby, infliximab decreases the effects of enhanced TNF levels during inflammatory disease such as production of proteases, chemokines, adhesion molecules, cyclooxygenase products (prostaglandins), and proinflammatory molecules such as interleukin-1 and -6. The antibodies may also recognize membrane-bound TNF-a on lymphocytes and other immune cells. These cells may subsequently become apoptotic or are eliminated via Fc-receptor-mediated phagocytosis. 

Large granular lymphocytes, not belonging to either the T- or B-cell lineage. Natural killer (NK) cells are considered part of the innate defense system since, in contrast to cytotoxic T-cells, they are able to kill certain tumor cells in vitro without prior sensitization. The basal activity of NIC cells increases dramatically following stimulation with type I IFNs. In addition, NK cells display Fc-receptors for IgG and are important mediators of Antibody-Dependent-Cell-mediated-Cytotoxicity (ADCC). 

Panax ginseng X Macrophage Fc receptor expression enhancer, lL-6 production enhancer, nerve growth factor secretion enhancer [3, 67-69]... 

Aragnol, D., and Leserman, L. D. (1986). Immune clearance of liposomes inhibited by an anti-Fc receptor antibody in vivo,... 

Comparison of the Fc receptors for IgE on human lymphocytes and monocytes. J Immunol 1982 129 ... 

Mast cells express high-affinity IgE Fc receptors (FceRI) on their surface, contain cytoplasmic granules which are major sources of histamine and other inflammatory mediators, and are activated to release and generate these mediators by IgE-dependent and non-IgE-dependent mechanisms [1]. Disturbances either in the release of mast cell mediators or in mast cell proliferation are associated with clonal mast cell disorders including monoclonal mast cell activation syndrome (MMAS) and mastocytosis respectively, which are in turn associated with some cases of anaphylaxis [2], Molecular mechanisms have been identified which may link increased releasability of mast cell mediators and conditions leading to increased mast cell numbers [3]. Patients with mastocytosis have an increased risk to develop anaphylaxis [4, 5] and those with anaphylaxis may suffer from unrecognized mastocytosis or may display incomplete features of the disease [6-8]. 

Fc receptor up-regulation on macrophages (enhancing activity of immune complex clearance)... 

Structural characterization of a novel rhamnogalactm onan II with macrophage Fc receptor expression enhancing activity from the leaves of Panax ginseng C.A. Meyer... 

Kayaba, Y., Hiwatashi, N., Toyota, T. and Majima, T. (1991). Studies on functions of peripheral phagocytes from patients with Crohn s disease - with special reference to expressions of IgG Fc receptors and chemiluminescence. Gastroenterology 100, A589. 

Fc Crystallizable fraction of immunoglobulin molecule Fey Receptor for Fc portion of IgG FeyRI Ig Fc receptor I also known as CD64... 

Conrod, D.H., Ben-Sassort, S.Z., Le Gros, G., Finkelman, F.D. and Paul, W.E. (1990) Injection with anti-IgD antibodies markedly enhances Fc receptor mediated interleukin 4 production by non B, non T cells. Journal of Experimental Medicine 171,1497-1508. 

Dower, S.K., PeLisi, C., Titus, J.A., and Segal, D.M. (1981) Mechanism of binding of multivalent immune complexes to Fc receptors. 1. Equilibrium binding. Biochemistry 20, 6326-6334. 

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