Immunoglobulin basophils

Type I allergic reactions are inappropriate immune responses to an allergen with preferential synthesis of immunoglobulin E (IgE), a special antibody class, which binds to mast cells and basophilic granulocytes via Fee receptors. Binding of the allergen to the cell-bound IgE initiates the rapid release of allergic mediators, most prominently histamine, and the de novo synthesis of arachidonic acid metabolites and cytokines, which are responsible for the clinical symptoms. 

Shim JY, Kim BS, Cho SH, Min KU, Hong SJ Allergen-specific conventional immunotherapy decreases immunoglobulin E-mediated basophil histamine releasability. Clin Exp Allergy 2003 33 52-57. 

TsujimuraY, ObataK, Mukai K, Shindou H, Yoshida M, Nishikado H, Kawano Y, Minegishi Y, Shimizu X Karasuyama H Basophils play a pivotal role in SS immunoglobulin-G-mediated but not immuno-globulin-E-mediated systemic anaphylaxis. Immunity 2008 28 581-589. 

Immunoglobulin receptors, such as the high affinity receptor for IgE, are present on mast cells and bloodbome basophils. These receptors play an important role in hypersensitivity and the initiation of acute inflammatory responses. 

Histamine, an important mediator (local signaling substance) and neurotransmitter, is mainly stored in tissue mast cells and basophilic granulocytes in the blood. It is involved in inflammatory and allergic reactions. Histamine liberators such as tissue hormones, type E immunoglobulins (see p. 300), and drugs can release it. Histamine acts via various types of receptor. Binding to Hi receptors promotes contraction of smooth muscle in the bronchia, and dilates the capillary vessels and increases their permeability. Via H2 receptors, histamine slows down the heart rate and promotes the formation of HCl in the gastric mucosa. In the brain, histamine acts as a neurotransmitter. 

Mechanism of Action A monoclonal antibody that selectively binds to human immunoglobulin E (IgE) preventing it from binding to the surface of mast cells and basophils. Therapeutic Effect Prevents or reduces the number of asthmatic attacks. Pharmacokinetics Absorbed slowly after subcutaneous administration, with peak concentration in 7-8 days. Excreted in the liver, reticuloendothelial system, and endothelial cells. Half-life 26 days. 

Pramod, S. N., Venkatesh, Y. P, Mahesh, P. A. (2007). Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E. Clin. Exp. Immunol., 748,391 01. 

In nature, mammalian antibodies occur in five distinct classes IgG, IgA, IgM, IgD, and IgE. These differ in structure, size, amino acid composition, charge, and carbohydrate components. The basic structure of each of the classes of immunoglobulins consists of two identical polypeptide chains linked by disulfide bonds to two identical heavy chains. Differences between classes and subclasses are determined by the makeup of the respective heavy chains. IgG is the major serum immunoglobulin and occurs as a single molecule IgA also occurs as a single molecule but also polymerizes, primarily as a dimer and also associates with a separate protein when secreted. IgM occurs in the serum as a pentamer, with monomers linked by disulfide bonds and the inclusion of an additional polypeptide component, the J-chain. IgD and IgE occur primarily as membrane-bound monomers on -cells, or basophils and mast cells, respectively. 

Immunoglobulins can also be receptors. For example, molecules of IgE bound to basophils and the related mast cells of tissues serve as receptors for allergens. Binding of an allergen to the IgE molecules stimulates the release of granules containing histamine and other substances (Chapter 31). 

Histamine Release. Histamine release is mainly caused by cross-linking of immunoglobulin E on the mast cell surface by antigens. Basophil degranulation is caused mainly by histamine-releasing factors produced by inflammatory cells, such as neutrophils, platelets, and eosinophils. After its release, histamine diffuses rapidly into the blood stream and surrounding tissues. 

Strengthens the immune system enhances lactoferrin tolerance against viruses, bacteria, and fungi regulates keratinization, hematopoiesis, production of neutrophils, erythrocytes, basophils, eosinophils, and lymphocytes, as well as influence on immunoglobulin, TNF-a, TGF- 5, INF-y,... 

Koppelman, S J., Wensing, M., Ertmann, M., Knulst, A.C., and Knol, E.F. 2004. Relevance of Ara hi, Ara h 2, and Ara h 3 in peanut-allergic patients, as determined by immunoglobulin E Western blotting, basophil-histamine release and intracutaneous testing Ara h 2 is the most important peanut allergen. Clin Exp Allergy 34 583-590. 

Type I, or immediate immune, response involves the body s production of immunoglobulin E (IgE) antibodies in lymphatic tissue that bind to the surface of mast cells and basophils and prime them for action. The antibodies are produced in B lymphocytes during the period of sensitization. Sensitization occurs as the result of exposure to appropriate antigens through the respiratory tract, dermally, or by exposure via the gastrointestinal tract. Subsequent cross-linking of the antibodies... 

Examples of antibodies Many Abs to toxins, bacteria, viruses especially late in Ab response. Many Abs to infectious agents, especially early in Ab response antipolysaccharide Ab cold agglutinins. Important as secretory antibody on mucous membranes. No proved Ab activity main immunoglobulin on surface of (8 lymphocytes in newborn. Binds to mast and basophil cells raised in allergic and parasitic infections. 

In a type 1 or humoral hypersensitivity response, the allergen activates the B lymphocyte. Immunoglobulin E (IgE) is produced and binds to the surface of mast cells and basophils, causing them to become sensitized (Figure 13-1). 

With each blink the antigen-coated contact lens mechanically traumatizes the tarsal conjunctiva. This process causes the release of mediators, such as neutrophil chemotactic factor and eosinophil chemotactic factor, which attract inflammatory cells (e.g., neutrophils, eosinophils, mast cells, and basophils). The immunologic sequence of events results in an increase in tear immunoglobulins IgE and IgG and C3 anaphylatoxin. The tear immunoglobulins and C3 anaphylatoxin then interact with the inflammatory cells produced from the mechanical trauma. This interaction causes the release of vasoactive amines, resulting in subsequent clinical manifestations. Papillae formation is related to structural changes in the conjunctival epithelium and stroma associated with increased eosinophils and inflammatory cells. 

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