Ортореовирустар туқымы және олардың қасиеттері

Genus of viruses

Orthoreovirus is a genus of viruses, in the family Reoviridae, in the subfamily Spinareovirinae. Vertebrates serve as natural hosts. There are ten species in this genus. Diseases associated with this genus include mild upper respiratory tract disease, gastroenteritis, and biliary atresia. Mammalian orthoreovirus 3 (strain dearing T3D) induces cell death preferentially in transformed cells and therefore displays inherent oncolytic properties.

The name "orthoreovirus" comes from the Greek word ortho, meaning "straight" and the reovirus, which comes from taking the letters: R, E, and O from "respiratory enteric orphan virus". The Orthoreovirus was named an orphan virus because it was not known to be associated with any known disease. It was discovered in the early 1950s when it was isolated from the respiratory as well as gastrointestinal tracts of both sick and healthy individuals

Transmission of the virus is either through the fecal–oral route or through respiratory droplets. The virus is transmitted horizontally and only known to cause disease in vertebrates. Different levels of virulence may be observed depending on the strain of orthoreovirus. Species that are known to become infected with the virus include: humans, birds, cattle, monkeys, sheep, swine, baboons, and bats

Mammalian orthoreovirus does not really cause a significant disease in humans. Even though the virus is fairly common, the infection produced is either asymptomatic or causes a mild disease which is self limiting in the gastrointestinal tract and respiratory region for children and infants. Symptoms are similar to what a person might have when they have the common cold, such as a low grade fever and pharyngitis. However, in other animals such as baboons and reptiles, other known orthoreoviruses fusogenic strains can cause more serious illness. In baboons it can cause neurological illness while in reptiles it can be the cause of pneumonia. In birds this virus may even cause death.

Members of the Orthoreovirus genus have been known to cause apoptosis in host cells, and have thus been studied fairly extensively for this very purpose. Mammalian orthoreoviruses induce apoptosis via the activation of several death receptors—TNFR, TRAIL, and Fas—while avian orthoreovirus has been found to use the up regulation of p53 to induce apoptosis. The inhibition of the innate immune response has also been seen in mammalian and avian orthoreoviruses. Other strains of the orthoreoviruses have not been studied as frequently as mammalian and avian strains resulting in a lack of understanding in the pathophysiology of those strains, though it can be assumed they act in similar ways.

One of the most relevant uses for the mammalian orthoreoviruses are the manipulation of their oncolytic properties for their use in cancer treatments. This particular use of reoviruses was discovered in 1995 by Dr Patrick Lee who discovered these viruses could kill those cells that contained an over activated Ras pathway, often a hallmark of cancerous cells. These viruses are particularly ideal for these sort of therapies because they are self limiting while simultaneously harnessing the ability to induce apoptosis in tumor cells exclusively. One of the more widely used strains for these anti cancer clinical trials is the serotype 3 dearing strain, Resolysin, used in phase I III trials. A variety of cancers have been treated with this therapy, either alone or in tandem with others, including multiple myeloma, ovarian epithelial, and pancreatic cancers.

To be able to perform a proper diagnosis of this pathogen is it important to take samples from the suspected infected individuals such as a stool, throat, or nasopharyngeal sample. There are various tests that can be done on these samples to see if a person is infected. Viral antigen can be detected by performing an assay. A serological assay can also be performed on the sample to look for virus specific antibodies present in the sample, thus showing that the person is trying to combat the virus. The virus can be isolated in culture through the use of mouse L fibroblasts, green monkey kidney cells, as well as HeLa cells.