1.
Scanning electron microscope
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A scanning electron microscope is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography. The electron beam is scanned in a raster scan pattern. SEM can achieve better than 1 nanometer. Specimens can be observed in vacuum, in low vacuum, in wet conditions. The most common SEM mode is detection of electrons emitted by atoms excited by the electron beam. The number of electrons that can be detected depends, among other things. By scanning the sample and collecting the electrons that are emitted using a special detector. An account of the history of SEM has been presented by McMullan. Ardenne applied the principle not only to achieve magnification but also to purposefully eliminate the chromatic aberration otherwise inherent in the electron microscope. He further discussed the various modes, possibilities and theory of SEM. The types of produced by an SEM include secondary electrons, reflected or back-scattered electrons, photons of characteristic X-rays and light, absorbed current. Secondary electron detectors are standard equipment in all SEMs, but it is rare that a machine would have detectors for all other possible signals. The signals result from interactions of the beam with atoms at various depths within the sample. In the most common or standard detection mode, ie secondary electron imaging or SEI, consequently, SEM can produce very high-resolution images of a sample surface, revealing details less than 1 nm in size. Back-scattered electrons are beam electrons that are reflected from the sample by elastic scattering and they emerge from deeper locations within the specimen and consequently the resolution of BSE images is generally poorer than SE images. BSE images can provide information about the distribution of different elements in the sample, characteristic X-rays are emitted when the electron beam removes an inner shell electron from the sample, causing a higher-energy electron to fill the shell and release energy. These characteristic X-rays are used to identify the composition and measure the abundance of elements in the sample, due to the very narrow electron beam, SEM micrographs have a large depth of field yielding a characteristic three-dimensional appearance useful for understanding the surface structure of a sample
2.
White blood cell
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White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system, all white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells and platelets. Types of white cells can be classified in standard ways. Two pairs of broadest categories classify them either by structure or by cell division lineage and these broadest categories can be further divided into the five main types, neutrophils, eosinophils, basophils, lymphocytes, and monocytes. These types are distinguished by their physical and functional characteristics, further subtypes can be classified, for example, among lymphocytes, there are B cells, T cells, and NK cells. The number of leukocytes in the blood is often an indicator of disease, the normal white cell count is usually between 4 × 109/L and 11 × 109/L. In the US this is expressed as 4,000 to 11,000 white blood cells per microliter of blood. They make up approximately 1% of the blood volume in a healthy adult. However, this 1% of the blood makes a difference to health. An increase in the number of leukocytes over the limits is called leukocytosis. It is normal when it is part of immune responses. It is occasionally abnormal, when it is neoplastic or autoimmune in origin, a decrease below the lower limit is called leukopenia. The name white blood cell derives from the appearance of a blood sample after centrifugation. White cells are found in the buff, a thin, typically white layer of nucleated cells between the red blood cells and the blood plasma. The scientific term leukocyte directly reflects its description and it is derived from the Greek roots leuk- meaning white and cyt- meaning cell. The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, all white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways, two pairs of broadest categories classify them either by structure or by cell lineage
3.
Antibody
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An antibody, also known as an immunoglobulin, is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as bacteria and viruses. The antibody recognizes a molecule of the harmful agent, called an antigen. Each tip of the Y of an antibody contains a paratope that is specific for one particular epitope on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or a cell for attack by other parts of the immune system. Depending on the antigen, the binding may impede the process causing the disease or may activate macrophages to destroy the foreign substance. The ability of an antibody to communicate with the components of the immune system is mediated via its Fc region. The production of antibodies is the function of the humoral immune system. Antibodies are secreted by B cells of the immune system. In most cases, interaction of the B cell with a T helper cell is necessary to produce full activation of the B cell and, therefore, soluble antibodies are released into the blood and tissue fluids, as well as many secretions to continue to survey for invading microorganisms. Antibodies are glycoproteins belonging to the immunoglobulin superfamily and they constitute most of the gamma globulin fraction of the blood proteins. They are typically made of basic structural units—each with two heavy chains and two small light chains. There are several different types of heavy chains that define the five different types of crystallisable fragments that may be attached to the antigen-binding fragments. The five different types of Fc regions allow antibodies to be grouped into five isotypes, each Fc region of a particular antibody isotype is able to bind to its specific Fc Receptor, thus allowing the antigen-antibody complex to mediate different roles depending on which FcR it binds. The ability of an antibody to bind to its corresponding FcR is further modulated by the structure of the present at conserved sites within its Fc region. The ability of antibodies to bind to FcRs helps to direct the immune response for each different type of foreign object they encounter. For example, IgE is responsible for an allergic response consisting of mast cell degranulation, igEs Fab paratope binds to allergic antigen, for example house dust mite particles, while its Fc region binds to Fc receptor ε. The allergen-IgE-FcRε interaction mediates allergic signal transduction to induce conditions such as asthma and this region is known as the hypervariable region. Each of these variants can bind to a different antigen and this enormous diversity of antibody paratopes on the antigen-binding fragments allows the immune system to recognize an equally wide variety of antigens
4.
Red blood cell
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RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section
5.
Optical microscope
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The optical microscope, often referred to as light microscope, is a type of microscope which uses visible light and a system of lenses to magnify images of small samples. Optical microscopes are the oldest design of microscope and were invented in their present compound form in the 17th century. Basic optical microscopes can be simple, although there are many complex designs which aim to improve resolution. The image from a microscope can be captured by normal light-sensitive cameras to generate a micrograph. Originally images were captured by photographic film but modern developments in CMOS, purely digital microscopes are now available which use a CCD camera to examine a sample, showing the resulting image directly on a computer screen without the need for eyepieces. Alternatives to optical microscopy which do not use visible light include scanning electron microscopy, there are two basic types of optical microscopes, simple microscopes and compound microscopes. A simple microscope is one which uses a lens for magnification. A compound microscope uses several lenses to enhance the magnification of an object, the vast majority of modern research microscopes are compound microscopes while some cheaper commercial digital microscopes are simple single lens microscopes. Compound microscopes can be divided into a variety of other types of microscopes which differ in their optical configurations, cost. A simple microscope uses a lens or set of lenses to enlarge an object through angular magnification alone, the use of a single convex lens or groups of lenses are still found in simple magnification devices such as the magnifying glass, loupes, and eyepieces for telescopes and microscopes. A compound microscope uses a close to the object being viewed to collect light which focuses a real image of the object inside the microscope. That image is magnified by a second lens or group of lenses that gives the viewer an enlarged inverted virtual image of the object. The use of a compound objective/eyepiece combination allows for higher magnification. Common compound microscopes often feature exchangeable objective lenses, allowing the user to quickly adjust the magnification, a compound microscope also enables more advanced illumination setups, such as phase contrast. There are many variants of the optical microscope design for specialized purposes. Comparison microscope, which has two light paths allowing direct comparison of two samples via one image in each eye. Inverted microscope, for studying samples from below, useful for cell cultures in liquid, student microscope, designed for low cost, durability, and ease of use. Polarizing microscope, similar to the petrographic microscope, phase contrast microscope, which applies the phase contrast illumination method
6.
Bacteria
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Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods, Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only half of the bacterial phyla have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology, There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are approximately 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants, Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of bodies and bacteria are responsible for the putrefaction stage in this process. In March 2013, data reported by researchers in October 2012, was published and it was suggested that bacteria thrive in the Mariana Trench, which with a depth of up to 11 kilometres is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, You can find microbes everywhere—theyre extremely adaptable to conditions, the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial particularly in the gut flora. However several species of bacteria are pathogenic and cause diseases, including cholera, syphilis, anthrax, leprosy. The most common fatal diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year. In developed countries, antibiotics are used to treat infections and are also used in farming, making antibiotic resistance a growing problem. Once regarded as constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and these evolutionary domains are called Bacteria and Archaea. The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, for about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. In 2008, fossils of macroorganisms were discovered and named as the Francevillian biota, however, gene sequences can be used to reconstruct the bacterial phylogeny, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea, here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea
7.
Lymphopoiesis
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Lymphopoiesis is the generation of lymphocytes, one of the five types of white blood cell. It is more known as lymphoid hematopoiesis. Pathosis in lymphopoiesis leads to any of various disorders, such as the lymphomas. Lymphocytes are considered to be of the lineage as opposed to other lineages of blood cells such as the myeloid lineage. It is rare now for lymphopoiesis to refer to the creation of lymphatic tissues, and it gives insight into the nature of redundancy and overlap in the immune system and hints how to use this to advantage. The partial loss of or loss of function of any white blood cell type is a health matter. Were this system to fail, the body would be largely undefended from infection, examples of such cells are CFUs such as CFU-T. In mice, transplantation of a single cell can reconstitute a sub-lethally irradiated host with all these lineages of cells. This has been known for more than 40 years, lymphopoiesis continues throughout life and so progenitor cells and their parent stem cells must always be present. It is often not effective in preventing infections in the newborn, however early in gestation the developing embryo has begun its own lymphopoiesis from the fetal liver. Lymphopoiesis also arises from the yolk sac and this is in contrast to the adult where all lymphocytes originate in the bone marrow. There are four types of lymphocytes, many sub-types. All are generated by normal or abnormal lymphopoiesis except for certain artificial strains created in the laboratory by development from existing strains and this is hardly a simple topic. Lymphopoiesis can be viewed in a sense as a recursive process of cell division and also as a process of differentiation. Given that lymphocytes arise from specific types of limited stem cells - which we can call P cells - such cells can divide in several ways and these are general principles of limited stem cells. Considering the P as the cell, but not a true stem cell. Or the mother cell P may divide unequally into two new daughter cells both of which differ from other and also from the mother. Any daughter cell will usually have new specialized abilities and if it is able to divide it will form a new sub-lineage, the difference of a daughter cell from the mother may be great, but it could also be much less, even subtle
8.
Vertebrate
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Vertebrates /ˈvɜːrtᵻbrᵻts/ comprise all species of animals within the subphylum Vertebrata /-ɑː/. Vertebrates represent the majority of the phylum Chordata, with currently about 66,000 species described. Vertebrates include the fish and the jawed vertebrates, which include the cartilaginous fish. A bony fish known as the lobe-finned fishes is included with tetrapods, which are further divided into amphibians, reptiles, mammals. Extant vertebrates range in size from the frog species Paedophryne amauensis, at as little as 7.7 mm, to the blue whale, vertebrates make up less than five percent of all described animal species, the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do not have proper vertebrae due to their loss in evolution, though their closest living relatives, hagfish do, however, possess a cranium. For this reason, the vertebrate subphylum is sometimes referred to as Craniata when discussing morphology, molecular analysis since 1992 has suggested that hagfish are most closely related to lampreys, and so also are vertebrates in a monophyletic sense. Others consider them a group of vertebrates in the common taxon of craniata. The word origin of vertebrate derives from the Latin word vertebratus, the Proto-Indo-European language origins are still unclear. Vertebrate is derived from the vertebra, which refers to any of the bones or segments of the spinal column. All vertebrates are built along the basic body plan, a stiff rod running through the length of the animal, with a hollow tube of nervous tissue above it. In all vertebrates, the mouth is found at, or right below, the remaining part of the body continuing after the anus forms a tail with vertebrae and spinal cord, but no gut. However, a few vertebrates have secondarily lost this anatomy, retaining the notochord into adulthood, such as the sturgeon, jawed vertebrates are typified by paired appendages, but this trait is not required in order for an animal to be a vertebrate. All basal vertebrates breathe with gills, the gills are carried right behind the head, bordering the posterior margins of a series of openings from the pharynx to the exterior. Each gill is supported by a cartilagenous or bony gill arch, the bony fish have three pairs of arches, cartilaginous fish have five to seven pairs, while the primitive jawless fish have seven. The vertebrate ancestor no doubt had more arches than this, as some of their relatives have more than 50 pairs of gills. In amphibians and some primitive fishes, the larvae bear external gills. These are reduced in adulthood, their function taken over by the gills proper in fishes, some amphibians retain the external larval gills in adulthood, the complex internal gill system as seen in fish apparently being irrevocably lost very early in the evolution of tetrapods
9.
Immunity (medical)
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Immunity is the capability of multicellular organisms to resist harmful microorganisms from entering it. Immunity involves both specific and nonspecific components, the nonspecific components act as barriers or eliminators of a wide range of pathogens irrespective of their antigenic make-up. Other components of the immune system adapt themselves to each new disease encountered and are able to generate pathogen-specific immunity, an immune system may contain innate and adaptive components. The innate system in mammalians for example is composed of bone marrow cells that are programmed to recognise foreign substances. The adaptive system is composed of more advanced lymphatic cells that are programmed to recognise self substances, the reaction to foreign substances is etymologically described as inflammation, meaning to set on fire. The non-reaction to self substances is described as immunity, meaning to exempt or as immunotolerance, disease can arise when what is foreign cannot be eliminated or what is self is not spared. Innate immunity, also called native immunity, exists by virtue of an organisms constitution and it is divided into two types, Non-Specific innate immunity, a degree of resistance to all infections in general. Specific innate immunity, a resistance to a kind of microorganism only. As a result some races, specific individuals or breeds in agriculture do not suffer from certain infectious diseases, passive immunity is acquired through transfer of antibodies or activated T-cells from an immune host, it is short lived—usually lasting only a few months. The diagram below summarizes these divisions of immunity, humoral immunity is called active when the organism generates its own antibodies, and passive when antibodies are transferred between individuals or species. Similarly, cell mediated immunity is active when the organisms’ own T-cells are stimulated, the concept of immunity has intrigued mankind for thousands of years. Between the time of Hippocrates and the 19th century, when the foundations of the methods were laid. If someone were exposed to the miasma in a swamp, in evening air, or breathing air in a sickroom or hospital ward, the modern word immunity derives from the Latin immunis, meaning exemption from military service, tax payments or other public services. For no one was attacked a second time, or not with a fatal result. The term immunes, is found in the epic poem Pharsalia written around 60 B. C. by the poet Marcus Annaeus Lucanus to describe a North African tribes resistance to snake venom. In the treatise, Al Razi describes the presentation of smallpox. The first scientist who developed full theory of immunity was Ilya Mechnikov after he revealed phagocytosis in 1882, the birth of active immunotherapy may have begun with Mithridates VI of Pontus. To induce active immunity for snake venom, he recommended using a similar to modern toxoid serum therapy
10.
Stem cell
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Stem cells are undifferentiated biological cells that can differentiate into specialized cells and can divide to produce more stem cells. They are found in multicellular organisms, in mammals, there are two broad types of stem cells, embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues. In adult organisms, stem cells and progenitor cells act as a system for the body. There are three known accessible sources of adult stem cells in humans, Bone marrow, which requires extraction by harvesting. Adipose tissue, which requires extraction by liposuction, Stem cells can also be taken from umbilical cord blood just after birth. Of all stem cell types, autologous harvesting involves the least risk, by definition, autologous cells are obtained from ones own body, just as one may bank his or her own blood for elective surgical procedures. Adult stem cells are used in various medical therapies. Stem cells can now be artificially grown and transformed into specialized cell types with characteristics consistent with cells of tissues such as muscles or nerves. Embryonic cell lines and autologous stem cells generated through somatic cell nuclear transfer or dedifferentiation have also been proposed as promising candidates for future therapies. Research into stem cells grew out of findings by Ernest A. McCulloch, till at the University of Toronto in the 1960s. The classical definition of a cell requires that it possess two properties, Self-renewal, the ability to go through numerous cycles of cell division while maintaining the undifferentiated state. Potency, the capacity to differentiate into specialized cell types, apart from this it is said that stem cell function is regulated in a feed back mechanism. Stochastic differentiation, when one cell develops into two differentiated daughter cells, another stem cell undergoes mitosis and produces two stem cells identical to the original. Potency specifies the differentiation potential of the stem cell, totipotent stem cells can differentiate into embryonic and extraembryonic cell types. Such cells can construct a complete, viable organism and these cells are produced from the fusion of an egg and sperm cell. Cells produced by the first few divisions of the egg are also totipotent. Pluripotent stem cells are the descendants of totipotent cells and can differentiate into all cells. Multipotent stem cells can differentiate into a number of cell types, oligopotent stem cells can differentiate into only a few cell types, such as lymphoid or myeloid stem cells
11.
Natural killer cell
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Natural killer cells or NK cells are a type of cytotoxic lymphocyte critical to the innate immune system. The role NK cells play is analogous to that of cytotoxic T cells in the adaptive immune response. NK cells provide rapid responses to viral-infected cells, acting at around 3 days after infection, typically, immune cells detect major histocompatibility complex presented on infected cell surfaces, triggering cytokine release, causing lysis or apoptosis. NK cells are unique, however, as they have the ability to recognize stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named natural killers because of the notion that they do not require activation to kill cells that are missing self markers of MHC class 1. This role is important because harmful cells that are missing MHC I markers cannot be detected and destroyed by other immune cells. NK cells are defined as large granular lymphocytes and constitute the third kind of cells differentiated from the common lymphoid progenitor-generating B and T lymphocytes. NK cells are known to differentiate and mature in the marrow, lymph nodes, spleen, tonsils, and thymus. The NKp46 cell surface marker constitutes, at the moment, another NK cell marker of preference being expressed in humans, several strains of mice and in three common monkey species. The role of NK cells in both the innate and adaptive immune responses is becoming important in research using NK cell activity. NK cell receptors can also be differentiated based on function, NK Cells are not a subset of the T lymphocyte family. Natural cytotoxicity receptors directly induce apoptosis after binding to Fas ligand that directly indicate infection of a cell, the MHC-dependent receptors use an alternate pathway to induce apoptosis in infected cells. Natural killer cell activation is determined by the balance of inhibitory, for example, if the inhibitory receptor signaling is more prominent, then NK cell activity will be inhibited, similarly, if the activating signal is dominant, then NK cell activation will result. NCR, upon stimulation, mediate NK killing and release of IFNγ, cD94, NKG2, a C-type lectin family receptor, is conserved in both rodents and primates and identifies nonclassical MHC I molecules such as HLA-E. Though indirect, this is a way to survey the levels of classical HLA molecules, cD16 plays a role in antibody-dependent cell-mediated cytotoxicity, in particular, they bind IgG. Some KIRs are specific for certain HLA subtypes, most KIRs are inhibitory and dominant. Regular cells express MHC class 1, so are recognised by KIR receptors, ILT or LIR — are recently discovered members of the Ig receptor family. Ly49 have both activating and inhibitory isoforms and they are highly polymorphic on the population level, though they are structurally unrelated to KIRs, they are the functional homologues of KIRs in mice, including the expression pattern
12.
Interferon
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Interferons are a group of signaling proteins made and released by host cells in response to the presence of several pathogens, such as viruses, bacteria, parasites, and also tumor cells. In a typical scenario, a cell will release interferons causing nearby cells to heighten their anti-viral defenses. IFNs belong to the class of proteins known as cytokines, molecules used for communication between cells to trigger the protective defenses of the immune system that help eradicate pathogens. Interferons are named for their ability to interfere with viral replication by protecting cells from virus infections, certain symptoms of infections, such as fever, muscle pain and flu-like symptoms, are also caused by the production of IFNs and other cytokines. More than twenty distinct IFN genes and proteins have been identified in animals and they are typically divided among three classes, Type I IFN, Type II IFN, and Type III IFN. IFNs belonging to all three classes are important for fighting infections and for the regulation of the immune system. Based on the type of receptor through which they signal, human interferons have been classified into three major types, Interferon type I, All type I IFNs bind to a specific cell surface receptor complex known as the IFN-α/β receptor that consists of IFNAR1 and IFNAR2 chains. The type I interferons present in humans are IFN-α, IFN-β, IFN-ε, IFN-κ, in general, type I interferons are produced when the body recognizes a virus has invaded it. They are produced by fibroblasts and monocytes, however, the production of type I IFN-α is prohibited by another cytokine known as Interleukin-10. Once released, type I interferons will activate molecules which prevent the virus from producing and replicating its RNA and DNA, overall, IFN-α can be used to treat hepatitis B and C infections, while IFN-β can be used to treat multiple sclerosis. Interferon type II, This is also known as immune interferon and is activated by Interleukin-12, furthermore, type II interferons are released by T helper cells, type 1 specifically. However, they block the proliferation of T helper cells type two, the previous results in an inhibition of Th2 immune response and a further induction of Th1 immune response, which leads to the development of debilitating diseases such as multiple sclerosis. IFN type II binds to IFNGR, which consists of IFNGR1, Interferon type III, Signal through a receptor complex consisting of IL10R2 and IFNLR1. Although discovered more recently than type I and type II IFNs, in general, type I and II interferons are responsible for regulating and activating the immune response. All interferons share several common effects, they are antiviral agents, administration of Type I IFN has been shown experimentally to inhibit tumor growth in animals, but the beneficial action in human tumors has not been widely documented. A virus-infected cell releases viral particles that can infect nearby cells, however, the infected cell can prepare neighboring cells against a potential infection by the virus by releasing interferons. In response to interferon, cells produce large amounts of a known as protein kinase R. Another cellular enzyme, RNAse L—also induced by interferon action—destroys RNA within the cells to reduce protein synthesis of both viral and host genes
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