Rabies is caused by a number of lyssaviruses including: rabies virus and Australian Bat Lyssavirus. [15]
The rabies virus. Is the type species of the, Lyssavirus genus in the family Rhabdoviridae order, Mononegavirales. Lyssaviruses have helical. Symmetry with a, length of about 180 nm and a cross-section of about 75 nm.[] These 16 viruses are enveloped and have a single - stranded RNA genome with negative sense. The genetic information is. Packed as a ribonucleoprotein complex in which RNA is tightly bound by the viral nucleoprotein. The RNA genome of the virus. Encodes five genes whose order is highly conserved: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein. (G),And the viral RNA polymerase (L). [17]
Once within a muscle or, nerve cell the virus undergoes replication. The trimeric. Spikes on the exterior of the membrane of the virus interact with a specific, cell receptor the most likely one being the. Acetylcholine, receptor acetyl.The cellular membrane pinches in a procession known as pinocytosis and allows entry of the virus into the cell by way. Of an endosome. The virus then uses the acidic environment which is, necessary of that, endosome and binds to its membrane. Simultaneously releasing its, five proteins and single strand RNA into the cytoplasm. [18]
.The L protein then transcribes five mRNA strands and a positive strand of RNA all from the original negative strand RNA. Using free nucleotides in the cytoplasm. These five mRNA strands are then translated into their corresponding proteins (P,, ,, L N G and M proteins) at free ribosomes in the cytoplasm. Some proteins require post-translative modifications, For example.The G protein travels through the rough, endoplasmic reticulum where it undergoes further folding and is, then transported. To the, Golgi apparatus where a sugar group is added to it (glycosylation). [18]
Where there are enough proteins the viral,, Polymerase will begin to synthesize new negative strands of RNA from the template of the positive strand RNA.These negative strands will then form complexes with, the N P L and, M proteins and then travel to the inner membrane. Of the cell where a, G protein has embedded itself in the membrane. The G protein then coils around the N-P-L-M complex. Of proteins taking some of the host cell membrane with it which will, form the new outer envelope of the virus, particle. The virus then buds from the cell. [18]
.
From the point of entry the virus, is neurotropic traveling quickly, along the neural pathways into the central nervous. System. The virus usually first infects muscle cells close to the site of infection where they, are able to replicate without. Being 'noticed' by the host 's immune system. Once enough virus has, been replicatedThey begin to bind to acetyl choline receptors (p75NR) at the neuromuscular junction. [] The 19 virus then travels through. The nerve cell axon via, retrograde transport as its P protein interacts with dyenin a protein, present in the cytoplasm. Of nerve cells. Once the virus reaches the cell body it travels rapidly to the Central Nervous System (CNS),Replicating in motor neurons and eventually reaching to the brain. [] After 2 the brain, is infected the virus travels. Centrifugally to the peripheral and autonomic, nervous systems eventually migrating to the salivary glands where it, is. Ready to be transmitted to the next host.
การแปล กรุณารอสักครู่..
