alternative complement pathway

補体第二経路、補体副経路、第二補体経路、副補体経路

WordNet

1. make complete or perfect; supply what is wanting or form the complement to; "I need some pepper to complement the sweet touch in the soup"
2. a complete number or quantity; "a full complement"
3. one of a series of enzymes in the blood serum that are part of the immune response
4. something added to complete or embellish or make perfect; "a fine wine is a perfect complement to the dinner"; "wild rice was served as an accompaniment to the main dish" (同)accompaniment
5. number needed to make up a whole force; "a full complement of workers" (同)full complement
6. a word or phrase used to complete a grammatical construction
7. either of two parts that mutually complete each other
8. pertaining to unconventional choices; "an alternative life style"
9. necessitating a choice between mutually exclusive possibilities; "alternative possibilities were neutrality or war"
10. a trodden path (同)footpath

PrepTutorEJDIC

1. (あるものを完全にするため)(…を)補う物(事)《+『of』+『名』》 / 補語(文法で文の成分の一つ) / (必要な)全数,全量;(船の)定員 / …を補足する,補う
2. (二つのうち)『どちらかを選ぶべき』,二者択一の / 代わりの / 反体制的な,現在の社会と違った価値体系を持った / 二つのものの一つを選ぶこと,二者択一 / (二者のうち)選ぶべき一方 / 代わりのもの;他にとりうる方法
3. 道,小道(path)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/07/02 20:34:39」(JST)

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[Wiki en表示]

The classical and alternative complement pathways.

Alternative pathway. (Some labels are in Polish.)

The alternative pathway of the complement system is an innate component of the immune system's 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.

Cascade

It is initiated by the spontaneous hydrolysis of C3, which is abundant in the blood plasma. "Tickover" occurs through the spontaneous cleavage of the thioester bond in C3 to form C3b(H₂O).

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 C3b(H₂O) to form C3b(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 alternative pathway C5-convertase.

The C5-convertase of the alternative pathway consists of (C3b)₂BbP (sometimes referred to as C3b₂Bb). After the creation of C5 convertase (either as (C3b)₂BbP or C4b2b3b from the classical pathway), the complement system follows the same path regardless of the means of activation (alternative, classical, or lectin). C5-convertase cleaves C5 into C5a and C5b. C5b binds sequentially to C6, C7, C8 and then to multiple molecules of C9 to form membrane attack complex.

Regulation

Since C3b is free and abundant in the plasma, it can bind to either a host cell or a pathogen surface. To prevent complement activation from proceeding on the host cell, there are several different kinds of regulatory proteins that disrupt the complement activation process:

• Complement Receptor 1 (CR1 or CD35) and DAF (decay accelerating factor also known as CD55) compete with Factor B in binding with C3b on the cell surface and can even remove Bb from an already formed C3bBb complex
• The formation of a C3 convertase can also be prevented when a plasma protease called complement factor I cleaves C3b into its inactive form, iC3b. Factor I requires a C3b-binding protein cofactor such as complement factor H, CR1, or Membrane Cofactor of Proteolysis (MCP or CD46)
• Complement Factor H can inhibit the formation of the C3 convertase by competing with factor B for binding to C3b; accelerate the decay of the C3 convertase; and act as a cofactor for Factor I-mediated cleavage of C3b. Complement factor H preferentially binds to vertebrate cells (because of affinity for sialic acid residues), allowing preferential protection of host (as opposed to bacterial) cells from complement-mediated damage.
• CFHR5 (Complement Factor H-Related protein 5) is able to bind to act as a cofactor for factor I, has decay accelerating activity and is able to bind preferentially to C3b at host surfaces.

Role in Disease

Dysregulation of the complement system has been implicated in several diseases and pathologies. Age Related Macular Degeneration (AMD) is now believed to be caused, at least in part, by complement mediated attack on ocular tissues. Alternative Pathway activation might also play a significant role in kidney pathology associated with Lupus

See also

• Classical complement pathway
• Lectin pathway

References

Further reading

• Immunobiology. Janeway, et al. 5th 3ed. ISBN 0-8153-4101-6. (5th ed. text online at [1].)
• BioCarta's diagram of the alternative pathway, [2]

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 補体系の概要および臨床的評価 overview and clinical assessment of the complement system
• 2. 補体経路 complement pathways
• 3. C3糸球体腎症：デンスデポジット病およびC3糸球体腎炎 c3 glomerulopathies dense deposit disease and c3 glomerulonephritis
• 4. 補体系の遺伝性疾患 inherited disorders of the complement system
• 5. 補体系の後天性欠損 acquired deficiencies of the complement system

English Journal

• The role of complement in C3 glomerulopathy.

• Zipfel PF1, Skerka C2, Chen Q2, Wiech T3, Goodship T4, Johnson S4, Fremeaux-Bacchi V5, Nester C6, Córdoba SR7, Noris M8, Pickering M9, Smith R6.
• Molecular immunology.Mol Immunol.2015 Sep;67(1):21-30. doi: 10.1016/j.molimm.2015.03.012. Epub 2015 Apr 28.
• C3 glomerulopathy describes a spectrum of disorders with glomerular pathology associated with C3 cleavage product deposition and with defective complement action and regulation (Fakhouri et al., 2010; Sethi et al., 2012b). Kidney biopsies from these patients show glomerular accumulation or depositio
• PMID 25929733

• MBL-associated serine proteases (MASPs) and infectious diseases.

• Beltrame MH1, Boldt AB2, Catarino SJ1, Mendes HC1, Boschmann SE1, Goeldner I1, Messias-Reason I3.
• Molecular immunology.Mol Immunol.2015 Sep;67(1):85-100. doi: 10.1016/j.molimm.2015.03.245. Epub 2015 Apr 8.
• The lectin pathway of the complement system has a pivotal role in the defense against infectious organisms. After binding of mannan-binding lectin (MBL), ficolins or collectin 11 to carbohydrates or acetylated residues on pathogen surfaces, dimers of MBL-associated serine proteases 1 and 2 (MASP-1 a
• PMID 25862418

• Age-related macular degeneration and the role of the complement system.

• McHarg S1, Clark SJ1, Day AJ2, Bishop PN3.
• Molecular immunology.Mol Immunol.2015 Sep;67(1):43-50. doi: 10.1016/j.molimm.2015.02.032. Epub 2015 Mar 21.
• Age-related macular degeneration (AMD) is a leading cause of visual impairment. It is characterised by damage to a tissue complex composed of the retinal pigment epithelium, Bruch's membrane and choriocapillaris. In early AMD extracellular debris including drusen accumulates in Bruch's membrane and
• PMID 25804937

Japanese Journal

• 溶血性尿毒症症候群(Hemolytic Uremic Syndrome:HUS)(<特集>血小板減少症とアフェレシス)

• 芦田 明,玉井 浩
• 日本アフェレシス学会雑誌 31(1), 20-26, 2012-02-29
• … Recently, it has been clarified that Stx activates a complement in human serum through an alternative pathway by binding to the cell-binding domains of complement factor H and inhibiting its regulatory function. … In addition, newer treatments for typical HUS are currently being examined, including Shiga toxin-neutralizing antibodies, multibranched Stx receptor analogs, and therapies targetting the terminal complement cascade. …
• NAID 110009327449

• Activation of the alternative complement pathway by mannose-binding lectin via a C2-bypass pathway

• Tateishi Koichiro,Matsushita Misao
• Microbiology and immunology 55(11), 817-821, 2011-11-20
• NAID 10031121537

• Protective effect of FUT-175 on pulmonary function of xenografts in a guinea pig-to-rat lung perfusion model

• Ryu Chusei,Tagawa Tsutomu,Nagayasu Takeshi
• Acta Medica Nagasakiensia 56(2), 43-48, 2011-08-00
• … in addition to its stable potent serine protease inhibitory activity, it exerts far stronger anti-complement activity than other protease inhibitors. … The following parameters were serially measured in these three groups: complement activity causing 50% hemolysis (CH50 units) in the perfusion blood either before or during perfusion, pulmonary arterial pressure, dynamic pulmonary compliance, and airway resistance. …
• NAID 110008767591

Related Pictures

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★リンクテーブル★

リンク元	「補体第二経路」「副補体経路」「補体副経路」「第二補体経路」
関連記事	「alternative」「complement」「pathway」「alternatives」

「補体第二経路」

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英

alternative complement pathway

関

副補体経路、第二補体経路、補体副経路

-第二経路

「副補体経路」

　　[★]

英

alternative complement pathway

関

第二補体経路、補体副経路、補体第二経路

「補体副経路」

　　[★]

英

alternative complement pathway

関

副補体経路、第二補体経路、補体第二経路

「第二補体経路」

　　[★]

英

alternative complement pathway

関

副補体経路、補体副経路、補体第二経路

「alternative」

　　[★]

• adj.

• 代替の、二者択一の、別の、オルタナティブな、アルタナティブな

• n.

• 代替物

関

alternatively、alternatives、otherwise、substitution、surrogate

　 　 　

「complement」

　　[★]

• n.

• 補って完全にする物、補完物。(免疫)補体
• (必要な)全数、善良

• vt.

• 補って完全にする。補完する。～の補足となる。

　 　 　 　 　 　 　 　

「pathway」

　　[★]

• 経路、パスウェイ

関

route

　 　

「alternatives」

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代替物

関

alternative