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TNFSF4
OX40L is the ligand for OX40 (also known as CD134 or TNFRSF4) and is stably expressed on many antigen-presenting cells such as DC2s (a subtype of dendritic cells), macrophages, and activated B lymphocytes. The OX40 molecule, conversely, is present on the surface of activated T lymphocytes (mainly CD4+ T cells), but also on NK cells, NKT cells, and neutrophils. The ligation of OX40-OX40L is a source of survival signal for T cells and enables the development of memory T cells. Signaling through these two molecules also leads to polarization towards Th2 immune response even in an environment with low levels of IL-4 cytokine. OX40L is also present on the surface of many non-immune cells, for example, endothelial cells and smooth muscle cells. The surface expression of OX40L is induced by many pro-inflammatory mediators, such as TNF-α, e.g. produced by mast cells, IFN-γ and PGE2 (prostaglandin E2). OX40L has also been designated CD252 (cluster of differentiation 252). Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand (biochemistry)
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from Latin ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein. The binding typically results in a change of conformational isomerism (conformation) of the target protein. In DNA-ligand binding studies, the ligand can be a small molecule, ion, or protein which binds to the DNA double helix. The relationship between ligand and binding partner is a function of charge, hydrophobicity, and molecular structure. Binding occurs by intermolecular forces, such as ionic bonds, hydrogen bonds and Van der Waals forces. The association or docking is actually reversible through dissociation. Measurably irreversible covalent bonding between a ligand and target molecule is atypical in biological systems. In contrast to the definition o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 4
The interleukin 4 (IL4, IL-4) is a cytokine that induces differentiation of naive helper T cells ( Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4 in a positive feedback loop. IL-4 is produced primarily by mast cells, Th2 cells, eosinophils and basophils. It is closely related and has functions similar to IL-13. Function Interleukin 4 has many biological roles, including the stimulation of activated B cell and T cell proliferation, and the differentiation of B cells into plasma cells. It is a key regulator in humoral and adaptive immunity. IL-4 induces B cell class switching to IgE, and up-regulates MHC class II production. IL-4 decreases the production of Th1 cells, macrophages, IFNγ, and dendritic cells IL-12. Overproduction of IL-4 is associated with allergies. * Inflammation and wound repair Tissue macrophages play an important role in chronic inflammation and wound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Lupus Erythematosus
Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. Children up to 18 years old develop a more severe form of SLE termed childhood-onset systemic lupus erythematosus. The cause of SLE is not clear. It is thought to involve a combination of genetics and environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-nucleotide Polymorphism
In genetics and bioinformatics, a single-nucleotide polymorphism (SNP ; plural SNPs ) is a germline substitution of a single nucleotide at a specific position in the genome. Although certain definitions require the substitution to be present in a sufficiently large fraction of the population (e.g. 1% or more), many publications do not apply such a frequency threshold. For example, a Guanine, G nucleotide present at a specific location in a reference genome may be replaced by an Adenine, A in a minority of individuals. The two possible nucleotide variations of this SNP – G or A – are called alleles. SNPs can help explain differences in susceptibility to a wide range of diseases across a population. For example, a common SNP in the Factor H, CFH gene is associated with increased risk of age-related macular degeneration. Differences in the severity of an illness or response to treatments may also be manifestations of genetic variations caused by SNPs. For example, two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cluster Of Differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophenotyping of cells. In terms of physiology, CD molecules can act in numerous ways, often acting as receptors or ligands important to the cell. A signal cascade is usually initiated, altering the behavior of the cell (see cell signaling). Some CD proteins do not play a role in cell signaling, but have other functions, such as cell adhesion. CD for humans is numbered up to 371 (). Nomenclature The CD nomenclature was proposed and established in the 1st International Workshop and Conference on Human Leukocyte Differentiation Antigens (HLDA), held in Paris in 1982. This system was intended for the classification of the many monoclonal antibodies (mAbs) generated by different laboratories around the world against epitopes on the surface mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin E2
Prostaglandin E2 (PGE2), also known as dinoprostone, is a naturally occurring prostaglandin with oxytocic properties that is used as a medication. Dinoprostone is used in labor induction, bleeding after delivery, termination of pregnancy, and in newborn babies to keep the ductus arteriosus open. In babies it is used in those with congenital heart defects until surgery can be carried out. It is also used to manage gestational trophoblastic disease. It may be used within the vagina or by injection into a vein. PGE2 synthesis within the body begins with the activation of arachidonic acid (AA) by the enzyme phospholipase A2. Once activated, AA is oxygenated by cyclooxygenase (COX) enzymes to form prostaglandin endoperoxides. Specifically, prostaglandin G2 (PGG2) is modified by the peroxidase moiety of the COX enzyme to produce prostaglandin H2 (PGH2) which is then converted to PGE2. Common side effects of PGE2 include nausea, vomiting, diarrhea, fever, and excessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferon Gamma
Interferon gamma (IFNG or IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock as a product of human leukocytes stimulated with phytohemagglutinin, and by others as a product of antigen-stimulated lymphocytes. It was also shown to be produced in human lymphocytes. or tuberculin-sensitized mouse peritoneal lymphocytes challenged with Mantoux test (PPD); the resulting supernatants were shown to inhibit growth of vesicular stomatitis virus. Those reports also contained the basic observation underlying the now widely employed interferon gamma release assay used to test for tuberculosis. In humans, the IFNG protein is encoded by the ''IFNG'' gene. Through cell signaling, interferon gamma plays a role in regulating the immune response of its target cell. A key signaling pathway that is activated by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mast Cell
A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells were discovered by Friedrich von Recklinghausen and later rediscovered by Paul Ehrlich in 1877. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing, angiogenesis, immune tolerance, defense against pathogens, and vascular permeability in brain tumors. The mast cell is very similar in both appearance and function to the basophil, another type of white blood cell. Although mast cells were once thought to be tissue-resident basophils, it has been shown that the two cells develop from different hematopoietic lineages and thus cannot be the same cells. Structure Mast cells ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Necrosis Factor Alpha
Tumor necrosis factor (TNF), formerly known as TNF-α, is a chemical messenger produced by the immune system that induces inflammation. TNF is produced primarily by activated macrophages, and induces inflammation by binding to its receptors on other cells. It is a member of the tumor necrosis factor superfamily, a family of transmembrane proteins that are cytokines, chemical messengers of the immune system. Excessive production of TNF plays a critical role in several inflammatory diseases, and TNF-blocking drugs are often employed to treat these diseases. TNF is produced primarily by macrophages but is also produced in several other cell types, such as T cells, B cells, dendritic cells, and mast cells. It is produced rapidly in response to pathogens, cytokines, and environmental stressors. TNF is initially produced as a type II transmembrane protein (tmTNF), which is then cleaved by TNF alpha converting enzyme (TACE) into a soluble form (sTNF) and secreted from the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediator (coactivator)
Mediator is a multiprotein complex that functions as a Transcription (genetics), transcriptional coactivator (genetics), coactivator in all eukaryotes. It was discovered in 1990 in the lab of Roger D. Kornberg, recipient of the 2006 Nobel Prize in Chemistry. Mediator complexes interact with transcription factors and RNA polymerase II. The main function of mediator complexes is to transmit signals from the transcription factors to the polymerase. Mediator complexes are variable at the evolutionary, compositional and conformational levels. The first image shows only one "snapshot" of what a particular mediator complex might be composed of, but it certainly does not accurately depict the conformation of the complex ''in vivo''. During evolution, mediator has become more complex. The yeast ''Saccharomyces cerevisiae'' (a simple eukaryote) is thought to have up to 21 subunits in the core mediator (exclusive of the CDK module), while mammals have up to 26. Individual subunits can be ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pro-inflammatory Cytokine
An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include interleukin-1 (IL-1), IL-6, IL-12, and IL-18, tumor necrosis factor alpha (TNF-α), interferon gamma (IFNγ), and granulocyte-macrophage colony stimulating factor (GM-CSF) and play an important role in mediating the innate immune response. Inflammatory cytokines are predominantly produced by and involved in the upregulation of inflammatory reactions. Excessive chronic production of inflammatory cytokines contribute to inflammatory diseases, that have been linked to different diseases, such as atherosclerosis and cancer. Dysregulation has also been linked to depression and other neurological diseases. A balance between proinflammatory and anti-inflammatory cytokines is necessary to maintain health. Aging and exercise also play a role i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smooth Muscle Cells
Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal muscle, skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non-striated muscle tissue, striated, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It can be divided into two subgroups, ''single-unit'' and ''multi-unit'' smooth muscle. Within single-unit muscle, the whole bundle or sheet of #Smooth muscle cells, smooth muscle cells muscle contraction, contracts as a syncytium. Smooth muscle is found in the walls of hollow organs, including the stomach, intestines, urinary bladder, bladder and uterus. In the walls of blood vessels, and lymph vessels, (excluding blood and lymph capillaries) it is known as vascular smooth muscle. There is smooth muscle in the tracts of the respiratory, urinary, and reproductive Organ system, systems. In the eyes, the ciliary muscles, ir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
