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Researchers discover how mosquitoes avoid succumbing to viruses they transmit
The mediators that balance the interactions between mosquito and virus are virus-derived short-interfering RNAs (viRNAs), which are generated by the mosquito's immune response to infection. "If the mosquito is not able to cut up the virus genome into viRNAs, an otherwise invisible infection becomes fatal-- for both the mosquito and the virus. In other words, to complete the circle and be transmitted back to a vertebrate host, the virus must submit, to some extent, to the mosquito's antiviral response," said Kevin M. Myles, assistant professor of entomology at Virginia Tech.
The researchers used the arthropod-borne virus Sindbis -- a model virus for a wide variety of mosquito-transmitted viruses, such as chikungunya and eastern equine encephalitis, both of which cause serious diseases in humans. They infected a mosquito called Aedes aegypti, an important vector of yellow fever and dengue. In response, the mosquito immune system generated viRNAs, which make up 10 percent or more of total cellular small RNAs. "The proportion of the small RNAs that are viRNAs was surprising," the article states.
The researchers then altered the Sindbis genome so that it would carry a protein known to suppress the ability of a cell to cut up virus genomes into viRNAs. "We can't yet knock-out the mosquito's immune response, so we had to alter the virus," Adelman said.
"We would still have mosquitoes biting us, but they would not be transmitting viruses," said Adelman.
Full story: http://www.physorg.com/news147374555.html
The mediators that balance the interactions between mosquito and virus are virus-derived short-interfering RNAs (viRNAs), which are generated by the mosquito's immune response to infection. "If the mosquito is not able to cut up the virus genome into viRNAs, an otherwise invisible infection becomes fatal-- for both the mosquito and the virus. In other words, to complete the circle and be transmitted back to a vertebrate host, the virus must submit, to some extent, to the mosquito's antiviral response," said Kevin M. Myles, assistant professor of entomology at Virginia Tech.
The researchers used the arthropod-borne virus Sindbis -- a model virus for a wide variety of mosquito-transmitted viruses, such as chikungunya and eastern equine encephalitis, both of which cause serious diseases in humans. They infected a mosquito called Aedes aegypti, an important vector of yellow fever and dengue. In response, the mosquito immune system generated viRNAs, which make up 10 percent or more of total cellular small RNAs. "The proportion of the small RNAs that are viRNAs was surprising," the article states.
The researchers then altered the Sindbis genome so that it would carry a protein known to suppress the ability of a cell to cut up virus genomes into viRNAs. "We can't yet knock-out the mosquito's immune response, so we had to alter the virus," Adelman said.
"We would still have mosquitoes biting us, but they would not be transmitting viruses," said Adelman.
Full story: http://www.physorg.com/news147374555.html