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Interleukin 15-like
Interleukin 15-like (IL-15L) is an interleukin, a type of cytokine signaling in the immune system. It is a secreted protein of approximately 120 amino acids and related to IL-2 and IL-15. Intact ''IL-15L'' genes are found in bony fish, cartilaginous fish, reptiles, and many mammals. However, in humans and mice only an ''IL-15L'' pseudogene is found. The location of the ''IL-15L'' gene in the genome is conserved from sharks to mammals and on a different chromosome than ''IL-2'' and ''IL-15''. Bony fish (trout) IL-15L specifically stimulates the expression of type 2 immunity cytokines IL-4/13A and IL-4/13B (homologs of IL-4 and IL-13.), probably by stimulating ILC2 cells; this is quite different from the functions found for IL-2 and IL-15, including in fish. For mammalian IL-15L, a function has not been found yet. In both fish and mammals, IL-15L seems to be quite dependent for its stability on “heterodimer” formation with IL-15Rα, and functions for fish IL-15L could onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin
Interleukins (ILs) are a group of cytokines (secreted proteins and signal molecules) that are expressed and secreted by white blood cells (leukocytes) as well as some other body cells. The human genome encodes more than 50 interleukins and related proteins. The function of the immune system primarily depends on interleukins, and rare deficiencies of a number of them have been described, all featuring autoimmune diseases or immune deficiency. The majority of interleukins are synthesized by CD4 helper T-lymphocyte, as well as through monocytes, macrophages, and endothelial cells. They promote the development and differentiation of T and B lymphocytes, and hematopoietic cells. Interleukin receptors on astrocytes in the hippocampus are also known to be involved in the development of spatial memories in mice. History and name The name "interleukin" was chosen in 1979, to replace the various different names used by different research groups to designate interleukin 1 (lymphocyte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, but generally not hormones or growth factors (despite some overlap in the terminology). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against virus infections. Other basic immune mechanisms evolved in ancient plants and animals and remain in their modern descendants. These mechanisms include phagocytosis, antimicrobial pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 2
Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells. IL-2 receptor IL-2 is a member of a cytokine family, each member of which has a four alpha helix bundle; the family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through the IL-2 receptor, a complex consisting of three chains, termed alpha (CD25), beta (CD122) and gamma ( CD132). The gamma chain is shared by all family members. The IL-2 receptor (IL-2R) α subunit binds IL-2 with low affinity (Kd~ 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 15
Interleukin-15 (IL-15) is a cytokine with structural similarity to Interleukin-2 (IL-2). Like IL-2, IL-15 binds to and signals through a complex composed of IL-2/IL-15 receptor beta chain (CD122) and the common gamma chain (gamma-C, CD132). IL-15 is secreted by mononuclear phagocytes (and some other cells) following infection by virus(es). This cytokine induces the proliferation of natural killer cells, i.e. cells of the innate immune system whose principal role is to kill virally infected cells. Expression IL-15 was discovered in 1994 by two different laboratories, and characterized as T cell growth factor. Together with Interleukin-2 (IL-2), Interleukin-4 ( IL-4), Interleukin-7 ( IL-7), Interleukin-9 ( IL-9), granulocyte colony-stimulating factor (G-CSF), and granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-15 belongs to the four α-helix bundle family of cytokines. IL-15 is constitutively expressed by a large number of cell types and tissues, including mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudogene
Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Most arise as superfluous copies of functional genes, either directly by DNA duplication or indirectly by Reverse transcriptase, reverse transcription of an mRNA transcript. Pseudogenes are usually identified when genome sequence analysis finds gene-like sequences that lack regulatory sequences needed for Transcription (biology), transcription or Translation (biology), translation, or whose coding sequences are obviously defective due to Frameshift mutation, frameshifts or premature stop codons. Most non-bacterial genomes contain many pseudogenes, often as many as functional genes. This is not surprising, since various biological processes are expected to accidentally create pseudogenes, and there are no specialized mechanisms to remove them from genomes. Eventually pseudogenes may be deleted from their genomes by chance DNA replication or DNA repair errors, or they may accumulate so many mutational cha ... [...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 repair. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 13
Interleukin 13 (IL-13) is a protein that in humans is encoded by the ''IL13'' gene. IL-13 was first cloned in 1993 and is located on chromosome 5q31 with a length of 1.4kb. It has a mass of 13 kDa and folds into 4 alpha helical bundles. The secondary structural features of IL-13 are similar to that of Interleukin 4 (IL-4); however it only has 25% sequence identity to IL-4 and is capable of IL-4 independent signaling. IL-13 is a cytokine secreted by T helper type 2 (Th2) cells, CD4 cells, natural killer T cell, mast cells, basophils, eosinophils and nuocytes. Interleukin-13 is a central regulator in IgE synthesis, goblet cell hyperplasia, mucus hypersecretion, airway hyperresponsiveness, fibrosis and chitinase up-regulation. It is a mediator of allergic inflammation and different diseases including asthma. Functions IL-13 has effects on immune cells that are similar to those of the closely related cytokine IL-4. However, IL-13 is suspected to be the central mediator of the physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ILC2
ILC2 cells, or type 2 innate lymphoid cells are a type of innate lymphoid cell. Not to be confused with the ILC. They are derived from common lymphoid progenitor and belong to the lymphoid lineage. These cells lack antigen specific B or T cell receptor because of the lack of recombination activating gene. ILC2s produce type 2 cytokines (e.g. IL-4, IL-5, IL-9, IL-13) and are involved in responses to helminths, allergens, some viruses, such as influenza virus and cancer. The cell type was first described in 2001 as non-B/non-T cells, which produced IL-5 and IL-13 in response to IL-25 and expressed MHC class II and CD11c. In 2006, a similar cell population was identified in a case of helminthic infection. The name "ILC2" was not proposed until 2013. They were previously identified in literature as natural helper cells, nuocytes, or innate helper 2 cells. It is believed that ILC2s are rather old cell type with ancestor populations emerging in lamprey and bony fish. Parasitic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 15 Receptor, Alpha Subunit
Interleukin 15 receptor, alpha subunit is a subunit of the interleukin 15 receptor that in humans is encoded by the ''IL15RA'' gene. Structure The IL-15 receptor is composed of three subunits: IL-15R alpha, CD122, and CD132. Two of these subunits, CD122 and CD132, are shared with the receptor for IL-2, but IL-2 receptor has an additional subunit (CD25). The shared subunits contain the cytoplasmic motifs required for signal transduction, and this forms the basis of many overlapping biological activities of IL15 and IL2, although ''in vivo'' the two cytokines have separate biological effects. This may be due to effects of the respective alpha chains, which are unique to each receptor, the kinetics and affinity of cytokine-cytokine receptor binding, or due to the availability and concentration of each cytokine. Function IL-15Ralpha specifically binds IL15 with very high affinity, and is capable of binding IL-15 independently of other subunits. It is suggested that this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymic Stromal Lymphopoietin
Thymic stromal lymphopoietin (TSLP) is a protein belonging to the cytokine family. It is known to play an important role in the maturation of T cell populations through activation of antigen-presenting cells. TSLP is produced mainly by non-hematopoietic cells such as fibroblasts, epithelial cells and different types of stromal or stromal-like cells. Gene ontology TSLP production has been observed in various species, including humans and mice. In humans TSLP is encoded by the ''TSLP'' gene. Alternative splicing of this gene results in two transcript variants. Function It mainly impacts myeloid cells and induces the release of T cell-attracting chemokines from monocytes and enhances the maturation of myeloid (CD11c+) dendritic cells. TSLP has also been shown to activate the maturation of a specific subset of dendritic cells located within the epidermis, called Langerhans cells. Within the thymus TSLP activation of both myeloid and plasmacytoid (CD123+) dendritic cells res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 25
Interleukin-25 (IL-25) – also known as interleukin-17E (IL-17E) – is a protein that in humans is encoded by the ''IL25'' gene on chromosome 14. IL-25 was discovered in 2001 and is made up of 177 amino acids. IL-25 and IL-17 family IL-25 is a cytokine that belongs to the IL-17 cytokine family together with IL-17A (named also IL-17), IL-17B, IL-17C, IL-17D and IL-17F. This is why IL-25 has the alternative name IL-17E. All members have homologous amino acid sequence segments and spatially conserved cysteines. It is the IL-25 that differs from other members in its function and structure. IL-25 has a heterodimeric receptor. The receptor is composed of two subunits IL-17RA and IL-17RB. The IL-17RA subunit is also common for IL-17A and IL-17F. And Il-17RB is also common for IL-17B. Both subunit receptors are essential for IL-25 functions. IL-25 does not bind directly to IL-17RA, but this subunit is necessary for its functions - as well as IL-17RB which directly bind IL-25. Func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
