Filoviridae
From Free net encyclopedia
| Filoviridae | |
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| Image:Marburg-emb.jpg Marburg virus particles, ~100,000x magnification Template:Taxobox begin placement virus Template:Taxobox group v entry | |
| Order: | Mononegavirales |
| Family: | Filoviridae |
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!Genera
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Marburgvirus
Ebolavirus
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Filoviruses are viruses belonging to the family Filoviridae, which is in the order Mononegavirales. These viruses are single stranded negative sense RNA viruses that target primates. There are two general viruses, the Ebola virus (Ebolavirus, with four species) [1] and the Marburg virus (Marburgvirus).
These viruses cause viral hemorrhagic fevers, characterized by massive bleeding from every orifice of the body. These diseases are shockingly lethal, with very high mortality rates and possibility of transfer. They are classified by the CDC as BSL4, or biosafety level 4. This means that they are among the most lethal and destructive viruses known to man.
The virions (viral particles) are characteristically shaped as long, cylindrical, filamentous particles which may be straight, curved, coiled, or found in a "6" or "U" shaped configuration. They are occasionally branched and the particles vary greatly in length but the diameter (about 80nm) is consistent.
They are produced by budding from an infected cell, and consist of the viral RNA strand and proteins encapsulated in a lipid membrane formed from the host cell's plasma membrane.
The inability of the immune system to clear these viruses may, at least in part, be due to the complex synthesis of a viral glycoprotein which forms heterotrimeric spikes within the virons plasma membrane. The gene encoding this contains a stop codon and as such two forms of the precursor can be produced via a frame shift during translation. These precursors then undergo proteolytic cleavage to form GP1 and GP2 which are also glycosylated before forming the expressed trimer. This results in a variety of epitopes which may result in a less focussed immune response that simply doesn't have the time to clear the infection before the organism succumbs. Another virally expressed protein recognised by the immune system is VP40 which is normally expressed on the membrane complexed to VP24. VP40 has been shown to resemble a human cell matrix protein antigenically and so it could cause an autoimmune response through molecular mimicry.
Template:Virus-stubde:Filoviridae fr:Filoviridae nl:Filovirussen pl:Filowirusy zh:纖維病毒科