3DI2 , 3DI3
34-413: (Redirected from IL7 ) IL-7 or IL 7 can refer to: Interleukin 7 Illinois's 7th congressional district Illinois Route 7 [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change
68-422: A "characteristic tight pavement-like appearance". But this is not always the case, such as when the cells are derived from a tumor. In these cases, it is often necessary to use certain biochemical markers to make a positive identification. The intermediate filament proteins in the cytokeratin group are almost exclusively found in epithelial cells, so they are often used for this purpose. Cancers originating from
102-474: A cell and the extracellular matrix , or they build up the paracellular barrier of epithelia and control the paracellular transport . Cell junctions are the contact points between plasma membrane and tissue cells. There are mainly 5 different types of cell junctions: tight junctions , adherens junctions , desmosomes , hemidesmosomes , and gap junctions . Tight junctions are a pair of trans-membrane protein fused on outer plasma membrane. Adherens junctions are
136-440: A connexion). Epithelial tissues are derived from all of the embryological germ layers : However, pathologists do not consider endothelium and mesothelium (both derived from mesoderm) to be true epithelium. This is because such tissues present very different pathology. For that reason, pathologists label cancers in endothelium and mesothelium sarcomas , whereas true epithelial cancers are called carcinomas . Additionally,
170-500: A plaque (protein layer on the inside plasma membrane) which attaches both cells' microfilaments. Desmosomes attach to the microfilaments of cytoskeleton made up of keratin protein. Hemidesmosomes resemble desmosomes on a section. They are made up of the integrin (a transmembrane protein) instead of cadherin. They attach the epithelial cell to the basement membrane. Gap junctions connect the cytoplasm of two cells and are made up of proteins called connexins (six of which come together to make
204-468: A pre-pro-B cell growth-stimulating factor. This cytokine is found to be a cofactor for V(D)J rearrangement of the T cell receptor beta (TCRß) during early T cell development. This cytokine can be produced locally by intestinal epithelial and epithelial goblet cells , and may serve as a regulatory factor for intestinal mucosal lymphocytes. Knockout studies in mice suggested that this cytokine plays an essential role in lymphoid cell survival. IL-7 binds to
238-438: A sheet of polarised cells forming a tube or tubule with cilia projecting into the lumen ." Primary cilia on epithelial cells provide chemosensation, thermoception , and mechanosensation of the extracellular environment by playing "a sensory role mediating specific signalling cues, including soluble factors in the external cell environment, a secretory role in which a soluble protein is released to have an effect downstream of
272-574: Is a protein that in humans is encoded by the IL7 gene . IL-7 is a hematopoietic growth factor secreted by stromal cells in the bone marrow and thymus . It is also produced by keratinocytes , dendritic cells , hepatocytes , neurons , and epithelial cells , but is not produced by normal lymphocytes . A study also demonstrated how the autocrine production of the IL-7 cytokine mediated by T-cell acute lymphoblastic leukemia (T-ALL) can be involved in
306-427: Is stimulated by IL-3 ). It also stimulates proliferation of all cells in the lymphoid lineage ( B cells , T cells and NK cells ). It is important for proliferation during certain stages of B-cell maturation, T and NK cell survival, development and homeostasis . IL-7 is a cytokine important for B and T cell development. This cytokine and the hepatocyte growth factor ( HGF ) form a heterodimer that functions as
340-450: Is supplied by nerves. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or compound , either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to
374-435: Is the epidermis , the outermost layer of the skin . Epithelial ( mesothelial ) tissues line the outer surfaces of many internal organs , the corresponding inner surfaces of body cavities , and the inner surfaces of blood vessels . Epithelial tissue is one of the four basic types of animal tissue , along with connective tissue , muscle tissue and nervous tissue . These tissues also lack blood or lymph supply. The tissue
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#1732872305788408-443: Is the type of epithelium that forms the glands from the infolding of epithelium and subsequent growth in the underlying connective tissue. They may be specialized columnar or cuboidal tissues consisting of goblet cells , which secrete mucus . There are two major classifications of glands: endocrine glands and exocrine glands : Some epithelial cells are ciliated , especially in respiratory epithelium , and they commonly exist as
442-817: The IL-7 receptor , a heterodimer consisting of Interleukin-7 receptor alpha and common gamma chain receptor . Binding results in a cascade of signals important for T-cell development within the thymus and survival within the periphery. Knockout mice which genetically lack IL-7 receptor exhibit thymic atrophy , arrest of T-cell development at the double positive stage, and severe lymphopenia . Administration of IL-7 to mice results in an increase in recent thymic emigrants, increases in B and T cells, and increased recovery of T cells after cyclophosphamide administration or after bone marrow transplantation. IL-7 promotes hematological malignancies (acute lymphoblastic leukemia, T cell lymphoma). Elevated levels of IL-7 have also been detected in
476-488: The epigenome of these cells, which enables a rapid response to immunological challenges. The slide shows at (1) an epithelial cell infected by Chlamydia pneumoniae ; their inclusion bodies shown at (3); an uninfected cell shown at (2) and (4) showing the difference between an infected cell nucleus and an uninfected cell nucleus. Epithelium grown in culture can be identified by examining its morphological characteristics. Epithelial cells tend to cluster together, and have
510-512: The blood and lymphatic vessels are of a specialised form of epithelium called endothelium . Epithelium lines both the outside ( skin ) and the inside cavities and lumina of bodies. The outermost layer of human skin is composed of dead stratified squamous , keratinized epithelial cells. Tissues that line the inside of the mouth, the esophagus , the vagina , and part of the rectum are composed of nonkeratinized stratified squamous epithelium. Other surfaces that separate body cavities from
544-537: The blood vessels in the underlying tissue. The basement membrane acts as a selectively permeable membrane that determines which substances will be able to enter the epithelium. The basal lamina is made up of laminin (glycoproteins) secreted by epithelial cells. The reticular lamina beneath the basal lamina is made up of collagen proteins secreted by connective tissue . Cell junctions are especially abundant in epithelial tissues. They consist of protein complexes and provide contact between neighbouring cells, between
578-412: The cell shapes. However, when taller simple columnar epithelial cells are viewed in cross section showing several nuclei appearing at different heights, they can be confused with stratified epithelia. This kind of epithelium is therefore described as pseudostratified columnar epithelium . Transitional epithelium has cells that can change from squamous to cuboidal, depending on the amount of tension on
612-575: The cells, the stretch that they experience rapidly activates cell division. Alternatively, when too many cells accumulate, crowding triggers their death by activation epithelial cell extrusion . Here, cells fated for elimination are seamlessly squeezed out by contracting a band of actin and myosin around and below the cell, preventing any gaps from forming that could disrupt their barriers. Failure to do so can result in aggressive tumors and their invasion by aberrant basal cell extrusion. Epithelial tissues have as their primary functions: Glandular tissue
646-470: The epithelium are classified as carcinomas . In contrast, sarcomas develop in connective tissue . When epithelial cells or tissues are damaged from cystic fibrosis , sweat glands are also damaged, causing a frosty coating of the skin. The word epithelium uses the Greek roots ἐπί ( epi ), "on" or "upon", and θηλή ( thēlē ), "nipple". Epithelium is so called because the name was originally used to describe
680-488: The epithelium. Stratified or compound epithelium differs from simple epithelium in that it is multilayered. It is therefore found where body linings have to withstand mechanical or chemical insult such that layers can be abraded and lost without exposing subepithelial layers. Cells flatten as the layers become more apical, though in their most basal layers, the cells can be squamous, cuboidal, or columnar. Stratified epithelia (of columnar, cuboidal, or squamous type) can have
714-452: The filaments that support these mesoderm-derived tissues are very distinct. Outside of the field of pathology, it is generally accepted that the epithelium arises from all three germ layers. Epithelia turn over at some of the fastest rates in the body. For epithelial layers to maintain constant cell numbers essential to their functions, the number of cells that divide must match those that die. They do this mechanically. If there are too few of
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#1732872305788748-447: The fluid flow, and mediation of fluid flow if the cilia are motile . Epithelial cells express many genes that encode immune mediators and proteins involved in cell-cell communication with hematopoietic immune cells. The resulting immune functions of these non-hematopoietic, structural cells contribute to the mammalian immune system ("structural immunity"). Relevant aspects of the epithelial cell response to infections are encoded in
782-446: The following specializations: Epithelial tissue cells can adopt shapes of varying complexity from polyhedral to scutoidal to punakoidal. They are tightly packed and form a continuous sheet with almost no intercellular spaces. All epithelia is usually separated from underlying tissues by an extracellular fibrous basement membrane. The lining of the mouth, lung alveoli and kidney tubules are all made of epithelial tissue. The lining of
816-558: The homeostasis of both CD8+ and CD4+ T cells with a commensurate decrease in the percentage of CD4+CD25+Foxp3+ T regulatory cells. No objective cancer regression was observed, however a dose limiting toxicity (DLT) was not reached in this study due to the development of neutralizing antibodies against the recombinant cytokine . Associated with antiretroviral therapy, IL-7 administration decreased local and systemic inflammations in patients that had incomplete T-cell reconstitution. These results suggest that IL-7 therapy can possibly improve
850-415: The inner lining of blood vessels and the heart , and is known as vascular endothelium, and lining lymphatic vessels as lymphatic endothelium. Another type, mesothelium , forms the walls of the pericardium , pleurae , and peritoneum . In arthropods, the integument , or external "skin", consists of a single layer of epithelial ectoderm from which arises the cuticle , an outer covering of chitin ,
884-763: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IL-7&oldid=1108839220 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Interleukin 7 3574 16196 ENSG00000104432 ENSMUSG00000040329 P13232 P10168 NM_000880 NM_001199886 NM_001199887 NM_001199888 NM_008371 NM_001313888 NM_001313889 NM_001313890 NP_000871 NP_001186815 NP_001186816 NP_001186817 NP_001300817 NP_001300818 NP_001300819 NP_032397 Interleukin 7 ( IL-7 )
918-504: The number of their layers and by the shape and function of the cells. The basic cell types are squamous, cuboidal, and columnar, classed by their shape. By layer, epithelium is classed as either simple epithelium, only one cell thick (unilayered), or stratified epithelium having two or more cells in thickness, or multi-layered – as stratified squamous epithelium , stratified cuboidal epithelium , and stratified columnar epithelium , and both types of layering can be made up of any of
952-414: The oncogenic development of T-ALL and offer novel insights into T-ALL spreading. The three-dimensional structure of IL-7 in complex with the ectodomain of IL-7 receptor has been determined using X-ray diffraction . IL-7 stimulates the differentiation of multipotent (pluripotent) hematopoietic stem cells into lymphoid progenitor cells (as opposed to myeloid progenitor cells where differentiation
986-431: The outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. Other epithelial cells line the insides of the lungs , the gastrointestinal tract , the reproductive and urinary tracts, and make up the exocrine and endocrine glands . The outer surface of the cornea is covered with fast-growing, easily regenerated epithelial cells. A specialised form of epithelium, endothelium , forms
1020-442: The placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epithelial cells. Functions of epithelial cells include diffusion , filtration, secretion , selective absorption , germination , and transcellular transport . Compound epithelium has protective functions. Epithelial layers contain no blood vessels ( avascular ), so they must receive nourishment via diffusion of substances from
1054-456: The plasma of HIV-infected patients . IL-7 as an immunotherapy agent has been examined in many pre-clinical animal studies and more recently in human clinical trials for various malignancies and during HIV infection . Recombinant IL-7 has been safely administered to patients in several phase I and II clinical trials . A human study of IL-7 in patients with cancer demonstrated that administration of this cytokine can transiently disrupt
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1088-501: The quality of life of those patients. IL-7 could also be beneficial in improving immune recovery after allogenic stem cell transplant. This article incorporates text from the United States National Library of Medicine , which is in the public domain . Epithelial cells Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix . An example
1122-408: The rigidity of which varies as per its chemical composition. The basal surface of epithelial tissue rests on a basement membrane and the free/apical surface faces body fluid or outside. The basement membrane acts as a scaffolding on which epithelium can grow and regenerate after injuries. Epithelial tissue has a nerve supply , but no blood supply and must be nourished by substances diffusing from
1156-486: The underlying connective tissue, through the basement membrane . Cell junctions are especially abundant in epithelial tissues. Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where absorption and filtration occur. The thinness of the epithelial barrier facilitates these processes. In general, epithelial tissues are classified by
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