Buy Wholesale and maintain an Active status for 2 months and we will refund your $39 Distributor Fee![]()
08-SEPTEMBER-2008 09:13:22 - Cytokine This article may require cleanup to meet 's quality standards. Please improve this article if you can. June 2007 Cytokines are a category of signalling proteins and glycoproteins that, like hormones and neurotransmitters, are used extensively in cellular communication. While hormones are secreted from specific organs to the blood, and neurotransmitters are related to neural activity, the cytokines are a more diverse class of compounds in terms of origin and purpose. They are produced by a wide variety of hematopoietic and non-hematopoietic cell types and can have autocrine, paracrine and endocrine effects, sometimes strongly dependent on the presence of other chemicals. The cytokine family consists mainly of smaller, water-soluble proteins and glycoproteins with a mass between 8 and 30 kDa. Cytokines are critical to the development and functioning of both the innate and adaptive immune response. They are often secreted by immune cells that have encountered a pathogen, thereby activating and recruiting further immune cells to increase the system's response to the pathogen. Cytokines are also involved in several developmental processes during embryogenesis. Contents 1 Effects 2 Nomenclature 3 Classification 3.1 Structural 3.2 Functional 4 Cytokine receptors 5 Cysteine-knot cytokines 6 References 7 See also 8 External links Effects Each cytokine binds to a specific cell-surface receptor. Subsequent cascades of intracellular signalling then alter cell functions. This may include the upregulation and/or downregulation of several genes and their transcription factors, resulting in the production of other cytokines, an increase in the number of surface receptors for other molecules, or the suppression of their own effect by feedback inhibition. The effect of a particular cytokine on a given cell depends on the cytokine, its extracellular abundance, the presence and abundance of the complementary receptor on the cell surface, and downstream signals activated by receptor binding; these last two factors can vary by cell type. Cytokines are characterized by considerable redundancy, in that many cytokines appear to share similar functions. Generalisation of functions is not possible with cytokines. Nonetheless, their actions may be grouped as: autocrine, if the cytokine acts on the cell that secretes it. paracrine, if the target is restricted to the immediate vicinity of a cytokine's secretion. endocrine, if the cytokine diffuses to distant regions of the body carried by blood or plasma. It seems to be a paradox that cytokines binding to antibodies have a stronger immune effect than the cytokine alone. This may lead to lower therapeutic doses. Overstimulation of cytokines can trigger a dangerous syndrome known as a cytokine storm; this may have been the cause of severe adverse events during a clinical trial of TGN1412. Nomenclature Cytokines have been classed as lymphokines, interleukins, and chemokines, based on their presumed function, cell of secretion, or target of action. Because cytokines are characterised by considerable redundancy and pleiotropism, such distinctions, allowing for exceptions, are obsolete. The term interleukin was initially used by researchers for those cytokines whose presumed targets are principally leukocytes. It is now used largely for designation of newer cytokine molecules discovered every day and bears little relation to their presumed function. The vast majority of these are produced by T-helper cells. The term chemokine refers to a specific class of cytokines that mediates chemoattraction chemotaxis between cells. IL-8 interleukin-8 is the only chemokine originally named an interleukin. Classification Structural Structural homology has been able to partially distinguish between cytokines that do not demonstrate a considerable degree of redundancy so that they can be classified into four types: The four α-helix bundle family - Member cytokines have three-dimensional structures with four bundles of α-helices. This family in turn is divided into three sub-families: the IL-2 subfamily the interferon IFN subfamily the IL-10 subfamily. The first of these three subfamilies is the largest. It contains several non-immunological cytokines including erythropoietin EPO and thrombopoietin THPO. Also, four α-helix bundle cytokines can be grouped into long-chain and short-chain cytokines. the IL-1 family, which primarily includes IL-1 and IL-18 the IL-17 family, which has yet to be completely characterized, though member cytokines have a specific effect in promoting proliferation of T-cells that cause cytotoxic effects Functional A classification that proves more useful in clinical and experimental practice divides immunological cytokines into those that enhance cytokine responses, type 1 IFN-γ, TGF-β etc., and type 2 IL-4, IL-10, IL-13, etc., which favor antibody responses. A key focus of interest has been that cytokines in one of these two sub-sets tend to inhibit the effects of those in the other. Dysregulation of this tendency is under intensive study for its possible role in the pathogenesis of autoimmune disorders. Cytokine receptors Main article: Cytokine receptor In recent years, the cytokine receptors have come to demand the attention of more investigators than cytokines themselves, partly because of their remarkable characteristics, and partly because a deficiency of cytokine receptors has now been directly linked to certain debilitating immunodeficiency states. In this regard, and also because the redundancy and pleiomorphism of cytokines are, in fact, a consequence of their homologous receptors, many authorities are now of the opinion that a classification of cytokine receptors would be more clinically and experimentally useful. A classification of cytokine receptors based on their three-dimensional structure has, therefore, been attempted. Such a classification, though seemingly cumbersome, provides several unique perspectives for attractive pharmacotherapeutic targets. Immunoglobulin Ig superfamily, which are ubiquitously present throughout several cells and tissues of the vertebrate body, and share structural homology with immunoglobulins antibodies, cell adhesion molecules, and even some cytokines. Examples: IL-1 receptor types. Haemopoietic Growth Factor type 1 family, whose members have certain conserved motifs in their extracellular amino-acid domain. The IL-2 receptor belongs to this chain, whose γ-chain common to several other cytokines deficiency is directly responsible for the x-linked form of Severe Combined Immunodeficiency X-SCID. Interferon type 2 family, whose members are receptors for IFN β and γ. Tumor necrosis factors TNF type 3 family, whose members share a cysteine-rich common extracellular binding domain, and includes several other non-cytokine ligands like CD40, CD27 and CD30, besides the ligands on which the family is named TNF. Seven transmembrane helix family, the ubiquitous receptor type of the animal kingdom. All G-protein coupled receptors for hormones and neurotransmitters belong to this family. Chemokine receptors, two of which act as binding proteins for HIV CXCR4 and CCR5, also belong to this family. Cysteine-knot cytokines Members of the transforming growth factor beta superfamily belong to this group, including TGF-β1, TGF-β2 and TGF-β3. Please help improve this section by expanding it. Further information might be found on the talk page or at requests for expansion. February 2007 References Gallin J, Snyderman R eds. Inflammation: Basic Principles and Clinical Correlates. 3rd ion, Philadelphia, Lippincott William and Wilkins, 1999. Janeway CA et al. eds. Immunobiology. The immune system in Health and Disease, 4th ion, New York, Garland, 1999. Roitt I et al. eds. Immunology. 5th ion, London, Mosby, 2002. Science Vol. 311 No. 5769, pp. 1875 - 1876, 31 March 2006 DOI: 10.1126/science.1126030 See also Adipokines Apoptosis Chemokines Cytokine secretion assay Cytokine storm ELISA assays ELISPOT assays Interleukins Interferon Granulocyte-colony stimulating factor Signal transduction Tumor necrosis factors External links Cytokine Tutorial Cell Interactions: Cytokines Reperfusion Injury in Stroke. Cytokines Online Pathfinder Encyclopaedia Cytokines and inflammation, science and practical journal v d e Cell signaling Key concepts Ligand - Signal transduction - Apoptosis - Second messenger system Ca2+ signaling, Lipid signaling Processes Paracrine - Autocrine - Juxtacrine - Neurotransmitters - Endocrine Neuroendocrine Types of proteins Receptor Transmembrane, Intracellular - Transcription factor General, Preinitiation complex, TFIID, TFIIH - Adaptor protein receptor ligands hormones, neurotransmitters, cytokines, growth factors v d e Immune system / Immunology Systems Adaptive immune system vs. Innate immune system · Humoral immune system vs. Cellular immune system · Complement system Anaphylatoxins · Intrinsic immune system Antibodies and antigens Antibody Monoclonal antibodies, Polyclonal antibodies, Autoantibody · Allotype · Isotype · Idiotype · Antigen Superantigen · Polyclonal B cell response Immune cells/White blood cells Lymphoid: T cell · B cell · NK cell Myeloid: Mast cell · Basophil · Eosinophil · Macrophage Phagocytes: Neutrophil · Macrophage/Reticuloendothelial system Professional APCs: Dendritic cell · Macrophage · B cell Immunity vs. tolerance Immunity · Autoimmunity · Allergy · Tolerance Central · Immunodeficiency Immunogenetics Somatic hypermutation · VDJ recombination · Immunoglobulin class switching · MHC/HLA Substances Cytokines · Opsonin · Cytolysin Other Inflammation · Epitope Linear epitope and Conformational epitope · Hapten · Cross-reactivity · Diagnostic immunology · Immune complex v d e Cell signaling: cytokines Hematopoietic Stem cell factor - Colony-stimulating factor By cell Monokine - Lymphokine Lymphotoxin, Transfer factor By function Interleukin - Chemokine - Interferon - Tumor necrosis factor Other Autocrine motility factor - Hepatocyte growth factor - Osteopontin - TGF beta v d e Cytokines: chemokines CCL CCL1 - CCL2 - CCL3 - CCL4 - CCL5 - CCL6 - CCL7 - CCL8 - CCL9 - CCL10 - CCL11 - CCL12 - CCL13 - CCL14 - CCL15 - CCL16 - CCL17 - CCL18 - CCL19 - CCL20 - CCL21 - CCL22 - CCL23 - CCL24 - CCL25 - CCL26 - CCL27 - CCL28 CXCL CXCL1 - CXCL2 - CXCL3 - CXCL4 - CXCL5 - CXCL6 - CXCL7 - CXCL8 - CXCL9 - CXCL10 - CXCL11 - CXCL12 - CXCL13 - CXCL14 - CXCL15 - CXCL16 - CXCL17 CX3CL CX3CL1 XCL XCL1 - XCL2 v d e Cytokines: interleukins IL-1 superfamily IL-1 IL-1Ra - IL-18 - IL-33 IL-6 like/gp130 utilizing IL-6 - IL-11 - IL-27 - IL-30 - IL-31 +non IL Oncostatin M, Leukemia inhibitory factor, Ciliary neurotrophic factor, Cardiotrophin 1 IL-10 family IL-10 - IL-19 - IL-20 - IL-22 - IL-24 - IL-26 Interferon type III IL-28 - IL-29 Common γ-chain family IL-2/IL-15 - IL-3 - IL-4 - IL-7 - IL-9 - IL-13 - IL-21 IL-12 family IL-12 - IL-23 - IL-27 - IL-35 Other IL-5 - IL-8 - IL-14 - IL-16 - IL-17/IL-25 A - IL-32 Retrieved from http://en..org/wiki/Cytokine Categories: Cell signaling | Signal transduction | CytokinesHidden categories: Cleanup from June 2007 | All pages needing cleanup | Articles to be expanded since February 2007 | All articles to be expanded Views Article Discussion this page History Personal tools Log in / create account Navigation Main page Contents Featured content Current events Random article Search Go Search Interaction Community portal Recent changes Contact Donate to Help Toolbox What links here Related changes Upload file Special pages Printable version Permanent link Cite this page Languages Türkçe العربية Deutsch Español Français 한êµì–´ Italiano עברית Nederlands 日本語 Polski Português РуÑ?Ñ?кий Simple English SlovenÅ¡Ä?ina Suomi Svenska Tiếng Việt Türkçe 䏿–‡ This page was last modified on 9 August 2008, at 21:50
39 Reasons to Drink Acai Juice Every Day
What is MonaVie - Watch the 8-minute video
Discovering MonaVie Video
The Power of You Video
Effects of MonaVie Active on Antioxidant Capacity in Humans
Log into your Wholesale MonaVie Account
So many of us do not eat a balanced diet, get enough sleep, have too much stress, or are impacted with toxins and pollutants. Drinking 2 ounces of MonaVie twice a day will help your body detoxify as well as build your immune system. Its the smartest thing you can do for yourself, so start today. Buying MonaVie through our company guarantees you support 7 days a week and, if you would like to share MonaVie with your family and friends we will guide you from start to finish.
1. Click on Enroll Now (30 - 55% off retail price)
2. Pay $39 for your Wholesale ID number.
3. NO minimum order required.
4. MonaVie is delivered to your door in 3 to 5 days.