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Properdin
Properdin is protein that in humans is encoded by the CFP (complement factor properdin) gene. Properdin is plasma glycoprotein that activates the complement system of the innate immune system. This protein binds to bacterial cell walls and dying human cells to stabilize the C3 and C5-convertase enzyme complexes to form an attack complex that lead to the lysis of the cell. Structure Properdin is a gamma globulin protein composed of multiple identical protein subunits with a separate ligand-binding site. Native properdin occurs in head-to-tail dimers, trimers and tetramers in the fixed ratio 22:52:28. Function It is known that it participates in some specific immune responses. It plays a part in tissue inflammation as well as the engulfing of pathogens by phagocytes. In addition it is known to help to neutralize some viruses. The properdin promotes the association of C3b with Factor B and provides a focal point for the assembly of C3bBb on a surface. It binds to preformed al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Properdin Deficiency
Properdin deficiency is a rare X-linked disease in which properdin, an important Complement system, complement factor responsible for the stabilization of the alternative C3 convertase, is deficient. There are three forms of properdin deficiencies: Type I, which is identified by the total absence of the properdin protein in the plasma, Type II, which is a low but detectable amount of the properdin protein in the plasma, and Type III, which is a rare case of normal levels of properdin protein, but a dysfunctional variant. One of the first studied cases of properdin deficiency was in 1980 bDavis and Forrestal These families had members with only partial deficiencies which resulted in a lowered consumption of the Complement component 3, C3 protein. Properdin deficiency was studied again shortly after in 1982 bSjoholmin which all of the subjects were deceased shortly after the study because of their disease. The largest study of properdin deficiency was in 1989 bFijenwhich included nine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Pillemer
Louis Pillemer (1908 – August 31, 1957) was an American immunologist, an early investigator of the alternative complement pathway (a system of defense not dependent upon antibodies). Biography Pillemer was born in Johannesburg, South Africa, in 1908, the son of Lithuanian parents. He was brought to the United States at the age of one year, and was naturalized in 1916. He attended public schools in Catlettsburg and Ashland, Kentucky, and began collegiate work at Ohio State University in Columbus, Ohio, later attending Marshall College at Huntington, West Virginia, and Duke University at Durham, North Carolina. At Duke he received a B.S. degree in 1932, and started studying medicine in the same school, he however quit the course in middle of his third year. Kentucky at the time encouraged those with medical knowledge to serve patients in areas not normally served by physicians, he passed the examination required and began to travel across the state on horseback, visiting and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meningococcal Disease
Meningococcal disease describes infections caused by the bacterium ''Neisseria meningitidis'' (also termed meningococcus). It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries. There are approximately 2,600 cases of bacterial meningitis per year in the United States, and on average 333,000 cases in developing countries. The case fatality rate ranges between 10 and 20 percent. The incidence of endemic meningococcal disease during the last 13 years ranges from 1 to 5 per 100,000 in developed countries, and from 10 to 25 per 100,000 in developing countries. During epidemics the incidence of meningococcal disease approaches 100 per 100,000. Meningococcal vaccines have sharply reduced the incidence of the disea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C5-convertase
C5 convertase is an enzyme belonging to a family of serine proteases that play key role in the innate immunity. It participates in the complement system ending with cell death. There are four different C5 convertases able to specifically convert the protein C5 to C5a and C5b fragments. Two of the convertases are physiological complement enzymes, associate to the cell-surface and mediate the classical pathway (C4b2b3b, or ''C4b2a3b'' depending on source) or the alternative pathway (C3bBbC3b) of complement system. Two fluid phase C5 convertases have been described: the classical pathway enzyme, C4b2boxy3b and the cobra venom factor-dependent C5 convertase, CVFBb. Structure Cell-bound C3 and C5 convertase differ in their C3b requirement. C3-convertase (C3bBb) need only one molecule of C3b to form, whereas two or more C3b are required for generation of C5 convertase (C3bBb). It means, when C3b is randomly distributed on the surface of a cell, only C3 convertase activity app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complement System
The complement system, also known as complement cascade, is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane. It is part of the innate immune system, which is not adaptable and does not change during an individual's lifetime. The complement system can, however, be recruited and brought into action by antibodies generated by the adaptive immune system. The complement system consists of a number of small proteins that are synthesized by the liver, and circulate in the blood as inactive precursors. When stimulated by one of several triggers, proteases in the system cleave specific proteins to release cytokines and initiate an amplifying cascade of further cleavages. The end result of this ''complement activation'' or ''complement fixation'' cascade is stimulation of phagocytes to clear foreign and damaged materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C3-convertase
C3 convertase (''C4bC2b'', formerly ''C4b2a'') belongs to family of serine proteases and is necessary in innate immunity as a part of the complement system which eventuate in opsonisation of particles, release of inflammatory peptides, C5 convertase formation and cell lysis. C3 convertase can be used to refer to the form produced in the alternative pathway (C3bBb) or the classical and lectin pathways (C4bC2b, formerly C4b2a). Once formed, both C3 convertases will catalyze the proteolytic cleavage of C3 into C3a and C3b (hence the name "C3-convertase"). The smaller fragment called C3a serves to increase vascular permeability and promote extravasation of phagocytes, while the larger C3b fragment can be used as an opsonin or bind to either type of C3 convertase to form the trimolecular C5 convertase to activate C5 for the membrane attack complex. Formation C3 convertase formation can occur in three different pathways: the classical, lectin, and alternative pathways. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Factor B
Complement factor B is a protein that in humans is encoded by the ''CFB'' gene. Function This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in the blood as a single chain polypeptide. Upon activation of the alternative pathway, it is cleaved by complement factor D yielding the noncatalytic chain Ba and the catalytic subunit Bb. The active subunit Bb is a serine protease that associates with C3b to form the alternative pathway C3 convertase. Bb is involved in the proliferation of preactivated B lymphocytes, while Ba inhibits their proliferation. This gene localizes to the major histocompatibility complex ( MHC class III) region on chromosome 6. This cluster includes several genes involved in regulation of the immune reaction. The polyadenylation site of this gene is 421 bp from the 5' end of the gene for complement component 2. References Further reading * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Western Reserve University
Case Western Reserve University (CWRU) is a private research university in Cleveland, Ohio. Case Western Reserve was established in 1967, when Western Reserve University, founded in 1826 and named for its location in the Connecticut Western Reserve, and Case Institute of Technology, founded in 1880 through the endowment of Leonard Case Jr., formally federated. Case Western Reserve University is a member of the Association of American Universities and is classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, in 2019 the university had research and development (R&D) expenditures of $439 million, ranking it 20th among private institutions and 58th in the nation. The university has eight schools that offer more than 100 undergraduate programs and about 160 graduate and professional options. Seventeen Nobel laureates have been affiliated with Case Western Reserve's faculty and alumni or one of its two predecessors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Droga Alternatywna
''Droga'' (Polish for 'road') was a monthly magazine dedicated to literary and social topics. It was published in Nazi-occupied Warsaw from December 1943 to April 1944. Its founders were Ewa Pohoska and Juliusz Garztecki. See also * List of magazines in Poland The following is a list of notable current and defunct magazines in Poland. In the country, there are also English-language magazines in addition to those published in Polish.1943 establishments in Poland 1944 disestablishments in Poland [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotactic Factors
Chemotaxis (from '' chemo-'' + ''taxis'') is the movement of an organism or entity in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and development (e.g., migration of neurons or lymphocytes) as well as in normal function and health (e.g., migration of leukocytes during injury or infection). In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. The aberrant chemotaxis of leukocytes and lymphocytes also contribute to inflammatory diseases such as atherosclerosis, asthma, and art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opsonins
Opsonins are extracellular proteins that, when bound to substances or cells, induce phagocytes to phagocytose the substances or cells with the opsonins bound. Thus, opsonins act as tags to label things in the body that should be phagocytosed (i.e. eaten) by phagocytes (cells that specialise in phagocytosis, i.e. cellular eating). Different types of things ("targets") can be tagged by opsonins for phagocytosis, including: pathogens (such as bacteria), cancer cells, aged cells, dead or dying cells (such as apoptotic cells), excess synapses, or protein aggregates (such as amyloid plaques). Opsonins help clear pathogens, as well as dead, dying and diseased cells. Opsonins were discovered and named "opsonins" in 1904 by Wright and Douglas, who found that incubating bacteria with blood plasma enabled phagocytes to phagocytose (and thereby destroy) the bacteria. They concluded that: “We have here conclusive proof that the blood fluids modify the bacteria in a manner which renders the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaphylatoxins
Anaphylatoxins, or complement peptides, are fragments ( C3a, C4a and C5a) that are produced as part of the activation of the complement system. Complement components C3, C4 and C5 are large glycoproteins that have important functions in the immune response and host defense. They have a wide variety of biological activities and are proteolytically activated by cleavage at a specific site, forming a- and b-fragments. A-fragments form distinct structural domains of approximately 76 amino acids, coded for by a single exon within the complement protein gene. The C3a, C4a and C5a components are referred to as anaphylatoxins: they cause smooth muscle contraction, vasodilation, histamine release from mast cells, and enhanced vascular permeability. They also mediate chemotaxis, inflammation, and generation of cytotoxic oxygen radicals. The proteins are highly hydrophilic, with a mainly alpha-helical structure held together by 3 disulfide bridges. Function Anaphylatoxins are able to tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
