Hemagglutinin (HA) is an antigenic glycoprotein, which is placed on the surface of the influenza viruses. It is responsible for binding the virus to the host cell, that is being infected. The name „hemagglutinin“ comes from the ability of protein to cause erythrocytes to agglutinate („clump together“). The process is like this: Hemagglutinin (HA) binds to the monosaccharide sialic acid which is present on the surface of its target host cells. The cell membrane then engulfs the virus through endocytosis and followed by formation of endosome. The cell then attempts to begin digesting the contents of the endosome by acidifying its interior and transforming it into a lysosome. When the pH decrease to 6.0, the HA molecule becomes partially unfold, and release a hydrophobic portion of peptide chain that was previously hidden. This so-called „fusion peptide“ acts like a molecular grapple hook for lock on the endosomal membrane. The rest of the HA molecule refolds into a new structure and pulls the endosomal membrane right up next to the viral membrane, causing the two to fuse together. When it happened, the viral RNA genome enters into the cell‘s cytoplasm.
BACKGROUND: Fibrinogen-related proteins with lectin activity are believed to be part of the tick innate immune system. Several fibrinogen-related proteins have been described and characterised mainly on the basis of their cDNA sequences while direct biochemical evidence is missing. One of them, the haemolymph lectin Dorin M from the tick Ornithodoros moubata was isolated and characterised in more depth. RESULTS: Several fibrinogen-related proteins were detected in the haemolymph of ixodid ticks Dermacentor marginatus, Rhipicephalus appendiculatus, R. pulchellus, and R. sanguineus. These proteins were recognised by sera directed against the tick lectin Dorin M and the haemagglutination activity of the ticks R. appendiculatus and D. marginatus. Cross-reactivity of the identified proteins with antibodies against the fibrinogen domain of the human ficolin was also shown. The carbohydrate-binding ability of tick haemolymph was confirmed by haemagglutination activity assays, and this activity was shown to be inhibited by neuraminic acid and sialylated glycoproteins as well as by N-acetylated hexosamines. The fibrinogen-related proteins were shown to be glycosylated and they were localised in salivary glands, midguts, and haemocytes of D. marginatus. Hemelipoglycoprotein was also recognised by sera directed against the fibrinogen-related proteins in all three Rhipicephalus species as well as in D. marginatus. However, this protein does not contain the fibrinogen domain and thus, the binding possibly results from the structure similarity between hemelipoglycoprotein and the fibrinogen domain. CONCLUSIONS: The presence of fibrinogen-related proteins was shown in the haemolymph of four tick species in high abundance. Reactivity of antibodies directed against ficolin or fibrinogen-related proteins with proteins which do not contain the fibrinogen domain points out the importance of sequence analysis of the identified proteins in further studies. Previously observed expression of fibrinogen-related proteins in haemocytes together with the results of this study suggest involvement of fibrinogen-related proteins in tick immunity processes. Thus, they have potential as targets for anti-tick vaccines and as antimicrobial proteins in pharmacology. Research on fibrinogen-related proteins could reveal further details of tick innate immunity processes.
- MeSH
- anatomické struktury zvířat chemie MeSH
- Dermacentor chemie MeSH
- fibrinogen imunologie MeSH
- glykoproteiny imunologie metabolismus MeSH
- hemaglutininy imunologie metabolismus MeSH
- hmyzí proteiny imunologie metabolismus MeSH
- lektiny imunologie metabolismus MeSH
- lidé MeSH
- metabolismus sacharidů MeSH
- Ornithodoros chemie MeSH
- protilátky imunologie MeSH
- Rhipicephalus chemie MeSH
- vazba proteinů MeSH
- zkřížené reakce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Jedním z faktorů, které zásadně ovlivňují prognózu pacientů po transplantaci srdce, je absence rejekce – odhojení štěpu. Pokud k rejekci dojde, může být zprostředkována imunokompetentními buňkami nebo protilátkami. Historicky lépe prozkoumanou i terapeuticky lépe zvládnutou je buněčná rejekce, která byla v popředí výzkumu a zájmu posledních 45 let. K výraznému oživení zájmu o protilátkami zprostředkovanou rejekci došlo poté, co byla prokázána kauzální souvislost s rozvojem dysfunkce až selháním štěpu v časném potransplantačním období a s koronární nemocí štěpu v pozdějším období. Tento přehledový článek si klade za cíl seznámit čtenáře se současnými možnostmi diagnostiky a léčby rejekce zprostředkované protilátkami.
A factor shown to heavily impact the prognosis of heart transplant recipients is absence of rejection, i.e., the failure of the body to accept a transplanted tissue. Historically, a better characterized and more readily treatable type is cellular rejection which has been at the forefront of research and interest over the past 45 years. There has been an appreciable renewal of interest in antibody-mediated rejection after graft dysfunction up to graft failure in the early post-transplant period had been shown to be causally related to transplant coronary artery disease at a later time. This review article aims at keeping the reader up to date about current options in diagnosing and treating antibody-mediated rejection.
- Klíčová slova
- Diagnostika, Léčba,
- MeSH
- financování organizované MeSH
- glukokortikoidy terapeutické užití MeSH
- hemaglutininy imunologie izolace a purifikace škodlivé účinky MeSH
- histokompatibilita - antigeny imunologie izolace a purifikace škodlivé účinky MeSH
- HLA-A antigeny imunologie izolace a purifikace škodlivé účinky MeSH
- imunokomplex imunologie izolace a purifikace MeSH
- intravenózní imunoglobuliny terapeutické užití MeSH
- kyseliny boronové terapeutické užití MeSH
- lidé MeSH
- monoklonální protilátky terapeutické užití MeSH
- průtoková cytometrie metody využití MeSH
- pyraziny terapeutické užití MeSH
- rejekce štěpu diagnóza etiologie komplikace MeSH
- sirolimus terapeutické užití MeSH
- splenektomie metody využití MeSH
- transplantace srdce imunologie škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Profesor Josef Pelnář uvádí kapitolu o chřipce v roce 1933 takto: Chřipka, jejíž jméno bereme tak často nadarmo, je nemoc, která až do našich dnů je tajemná svým původcem i svou silou, s níž dovede v ohromných pandemiích proletět celou zeměkouli s takovým počtem obětí, že se jí žádná jiná epidemická nemoc nevyrovná. Sklátí na lůžko mladé, staré, slabé i silné.
- MeSH
- chřipka lidská klasifikace komplikace přenos MeSH
- epidemický výskyt choroby prevence a kontrola statistika a číselné údaje MeSH
- genetický drift MeSH
- hemaglutininy imunologie MeSH
- lidé MeSH
- morbidita MeSH
- mortalita trendy MeSH
- mutace genetika MeSH
- ptačí chřipka u ptáků genetika prevence a kontrola přenos MeSH
- virové nestrukturální proteiny imunologie MeSH
- vitamin D imunologie metabolismus MeSH
- zoonózy mikrobiologie přenos MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
