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Alternate Complement Pathway
The alternative pathway is a type of cascade reaction of the complement system and is a component of the innate immune system, a natural defense against infections. The alternative pathway is one of three complement pathways that opsonize and kill pathogens. The pathway is triggered when the C3b protein directly binds a microbe. It can also be triggered by foreign materials and damaged tissues. Signaling cascade This change in shape allows the binding of plasma protein Factor B, which allows Factor D to cleave Factor B into Ba and Bb. Bb remains bound to C3(H2O) to form C3(H2O)Bb. This complex is also known as a fluid-phase C3-convertase. This convertase, the alternative pathway C3-convertase, although only produced in small amounts, can cleave multiple C3 proteins into C3a and C3b. The complex is believed to be unstable until it binds properdin, a serum protein. The addition of properdin forms the complex C3bBbP, a stable compound which can bind an additional C3b to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complement Pathway
Complement may refer to: The arts * Complement (music), an interval that, when added to another, spans an octave ** Complement (music)#Aggregate complementation, Aggregate complementation, the separation of pitch-class collections into complementary sets * Complementary color, in the visual arts Biology and medicine *Complement system (immunology), a cascade of proteins in the blood that form part of innate immunity *Complementary DNA, DNA reverse transcribed from a mature mRNA template *Complementarity (molecular biology), a property whereby double stranded nucleic acids pair with each other *Complementation (genetics), a test to determine if independent recessive mutant phenotypes are caused by mutations in the same gene or in different genes Grammar and linguistics * Complement (linguistics), a word or phrase having a particular syntactic role ** Subject complement, a word or phrase adding to a clause's subject after a linking verb **Object complement, a word or phrase add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD55
Complement decay-accelerating factor, also known as CD55 or DAF, is a protein that, in humans, is encoded by the ''CD55'' gene. DAF regulates the complement system on the cell surface. It recognizes C4b and C3b fragments that are created during activation of C4 ( classical or lectin pathway) or C3 (alternative pathway). Interaction of DAF with cell-associated C4b of the classical and lectin pathways interferes with the conversion of C2 to C2b, thereby preventing formation of the C4b2a C3-convertase, and interaction of DAF with C3b of the alternative pathway interferes with the conversion of factor B to Bb by factor D, thereby preventing formation of the C3bBb C3 convertase of the alternative pathway. Thus, by limiting the amplification convertases of the complement cascade, DAF indirectly blocks the formation of the membrane attack complex. This glycoprotein is broadly distributed among hematopoietic and non-hematopoietic cells. It is a determinant for the Cromer blood group syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Complement Pathway
The classical complement pathway is one of three pathways which activate the complement system, which is part of the immune system. The classical complement pathway is initiated by antigen-antibody complexes with the antibody isotypes IgG and IgM. Following activation, a series of proteins are recruited to generate C3 convertase (C4b2b, historically referred C4b2a), which cleaves the C3 protein. The C3b component of the cleaved C3 binds to C3 convertase (C4b2b) to generate C5 convertase (C4b2b3b), which cleaves the C5 protein. The cleaved products attract phagocytes to the site of infection and tags target cells for elimination by phagocytosis. In addition, the C5 convertase initiates the terminal phase of the complement system, leading to the assembly of the membrane attack complex (MAC). The membrane attack complex creates a pore on the target cell's membrane, inducing cell lysis and death. The classical complement pathway can also be activated by apoptotic cells, nec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C3 Glomerulonephritis
Glomerulonephritis (GN) is a term used to refer to several kidney diseases (usually affecting both kidneys). Many of the diseases are characterised by inflammation either of the glomeruli or of the small blood vessels in the kidneys, hence the name, but not all diseases necessarily have an inflammatory component. As it is not strictly a single disease, its presentation depends on the specific disease entity: it may present with isolated hematuria and/or proteinuria (blood or protein in the urine); or as a nephrotic syndrome, a nephritic syndrome, acute kidney injury, or chronic kidney disease. They are categorized into several different pathological patterns, which are broadly grouped into non-proliferative or proliferative types. Diagnosing the pattern of GN is important because the outcome and treatment differ in different types. Primary causes are intrinsic to the kidney. Secondary causes are associated with certain infections (bacterial, viral or parasitic pathogens), drug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C3 Glomerulopathy
C3, C-3, C.3, C03, C.III or C-III may refer to: Life and biology * C3 carbon fixation in plants * C3-convertase, an enzyme * Complement component 3, a protein of the innate immune system * Apolipoprotein C3, a human very low density lipoprotein * ATC code C03 ''Diuretics'', a subgroup of the Anatomical Therapeutic Chemical Classification System * Castavinol C3, a natural phenolic compound found in red wines * Cytochrome-c3 hydrogenase, an enzyme * Haplogroup C-M217, called C3 in older publications * In human anatomy, C3 may refer to: ** Cervical vertebra 3, one of the cervical vertebrae of the vertebral column ** Cervical spinal nerve 3 * Clinical Cell Culture, a medical technology company * C03, Malignant neoplasm of gum ICD-10 code * C3 Collaborating for Health, a health-promotion NGO * C3: an EEG electrode site according to the 10-20 system Military * C3, Command, control, and communications, a military concept * C-3 (plastic explosive), a plastic explosive related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue (biology)
In biology, tissue is an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Tissues occupy a Biological organisation#Levels, biological organizational level between cell (biology), cells and a complete organ (biology), organ. Accordingly, organs are formed by the functional grouping together of multiple tissues. The English word "tissue" Morphological derivation, derives from the French word "", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is Studied Space Shuttle designs, studied in both plant anatomy and Plant physiology, physiology. The classical tools for studying tissues are the Microtome#Applications, paraffin block in which tissue is embedded and then sectioned, the staining, histological stain, and the Microscope, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Related Macular Degeneration
Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur. Macular degeneration typically occurs in older people, and is caused by damage to the macula of the retina. Genetic factors and smoking may play a role. The condition is diagnosed through a complete eye exam. Severity is divided into early, intermediate, and late types. The late type is additionally divided into "dry" and "wet" forms, with the dry form making up 90% of cases. The difference between the two forms is categorized by the change in the macula. Those with dry-f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atypical Hemolytic Uremic Syndrome
Atypical hemolytic uremic syndrome (aHUS), also known as complement-mediated hemolytic uremic syndrome (not to be confused with hemolytic–uremic syndrome), is an extremely rare, life-threatening, progressive disease that frequently has a genetic component. In most cases, it can be effectively controlled by interruption of the complement cascade. Particular monoclonal antibodies, discussed later in the article, have proven efficacy in many cases. aHUS is usually caused by chronic, uncontrolled activation of the complement system, a branch of the body's immune system that destroys and removes foreign particles. The disease affects both children and adults and is characterized by systemic thrombotic microangiopathy (TMA), the formation of blood clots in small blood vessels throughout the body, which can lead to stroke, heart attack, kidney failure, and death. The complement system activation may be due to mutations in the complement regulatory proteins (factor H, factor I, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CFHR5
Complement factor H-related protein 5 is a protein that in humans is encoded by the ''CFHR5'' gene. Function CFHR5 is structurally related to complement factor H which plays an important role in the regulation of a branch of the innate immune system called the alternative complement pathway. Like complement factor H, CFHR5 is able to bind to complement C3. Clinical significance A mutation in CHFR5 was found in patients with the disease CFHR5 nephropathy, which is a common cause of renal disease in Cyprus. The mutated form of the protein found in patients with this disease has impaired ability to bind to complement C3, suggesting that CFHR5 is important in protecting the kidneys from attack by the complement system The complement system, also known as complement cascade, is a part of the humoral, innate immune system and enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inf .... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Factor H
Factor H (FH) is a member of the regulators of complement activation family and is a complement control protein. It is a large (155 kilodaltons), soluble glycoprotein that circulates in human plasma (at typical concentrations of 200–300 micrograms per milliliter). Its principal function is to regulate the alternative pathway of the complement system, ensuring that the complement system is directed towards pathogens or other dangerous material and does not damage host tissue. Factor H regulates complement activation on self cells and surfaces by possessing both cofactor activity for Factor I–mediated C3b cleavage, and decay accelerating activity against the alternative pathway C3-convertase, C3bBb. Factor H exerts its protective action on self cells and self surfaces but not on the surfaces of bacteria or viruses. There are however, important exceptions, such as for example the bacterial pathogen, '' Neisseria meningitidis (also called the meningococcus).'' This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD46
CD46 complement regulatory protein also known as CD46 (cluster of differentiation 46) and Membrane Cofactor Protein is a protein which in humans is encoded by the ''CD46'' gene. CD46 is an inhibitory complement receptor. Gene This gene is found in a cluster on chromosome 1q32 with other genes encoding structural components of the complement system. At least fourteen different transcript variants encoding fourteen different isoforms have been found for this gene. Function The protein encoded by this gene is a type I membrane protein and is a regulatory part of the complement system. The encoded protein has cofactor activity for inactivation (through cleavage) of complement components C3b and C4b by serum factor I, which protects the host cell from damage by complement. The protein encoded by this gene may be involved in the fusion of the spermatozoa with the oocyte during fertilization. Clinical significance Measles infection The encoded protein can act as a recepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complement Factor I
Complement factor I, also known as C3b/C4b inactivator, is a protein that in humans is encoded by the ''CFI'' gene. Complement factor I (factor I) is a protein of the complement system, first isolated in 1966 in guinea pig serum, that regulates complement activation by cleaving cell-bound or fluid phase C3b and C4b. It is a soluble glycoprotein that circulates in human blood at an average concentration of 35 μg/mL. Synthesis The gene for Factor I in humans is located on chromosome 4. Factor I is synthesized mostly in the liver, but also in monocytes, fibroblasts, keratinocytes, and endothelial cells. When synthesized, it is a 66kDa polypeptide chain with N-linked glycans at 6 positions. Then, factor I is cleaved by furin to yield the mature factor I protein, which is a disulfide-linked dimer of heavy chain (residues 19-335, 51 kDalton) and light chain (residues 340-583, 37 kDalton). Only the mature protein is active. Structure Factor I is a glycoprotein heterodimer c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
