Influenza genome can improve predictions for the next flu outbreak

This paper is a paper analysis of the paper "Nucleotide resolution mapping of influenza A virus nucleoprotein-RNA interactions reveals RNA features required for replication". The paper was published in the journal Nature Communications in January 2018 and was authored by the Washington University School of Medicine in St. Louis.

Influenza genome can improve predictions for the next flu outbreak

Influenza strains from different species (birds, humans or pigs) can produce a new influenza virus when genetically combined, when the new virus spreads faster in the population and the flu symptoms it causes are more than a single When the virus strain is more serious, an influenza pandemic will occur. Therefore, the public health monitoring department will pay special attention to the places where people are in close contact with animals to get the first signs of a new influenza pandemic. Some researchers believe that influenza strains from different species need to have some similar genomic properties in order to recombine and produce new strains. This study validates this hypothesis.

Influenza viruses infect cells and replicate a large number of genes and viral proteins in the cells, which then recombine into new viruses. The genome of the influenza virus can be divided into 8 small pieces of RNA, a DNA-like molecule. When a cell is simultaneously infected with two or more influenza viruses, genetic fragments from different strains are mixed. The result is often the creation of a new strain of influenza virus (whose genetic information comes from multiple parental strains).

Research methods and results

This study used photoactivated ribonucleoside enhanced cross-linking and immunoprecipitation (PAR-CLIP) to assess the interaction of influenza A virus nucleoprotein (NP) with viral RNA (vRNA) in infected human cells. Native state.

The results indicate that the influenza A virus nucleoprotein NP has no apparent sequence specificity when it binds a short fragment of RNA (12 nucleotides) to an inconsistent fragment. In addition, NP binding is reduced at specific locations within the viral genome, including those previously thought to be required for viral genomic segment packaging. In these low-NP binding regions, researchers used synonymous mutations to alter the specific structure of RNA, and found that structural changes affect the assembly of viral proteins and cause attenuation of the virus, while the same induced mutations are not similar in the NP-bound region. The effect appears.

This study found that certain parts of the viral RNA genome were folded into specific 3D shapes like origami, and these shapes were necessary for virus reproduction. When they induce a genomic mutation to change the shape, the virus does not multiply well.

in conclusion

This study demonstrates that sequence conservation of low NP binding regions is essential for the production of new strains. The results of this research allow us to focus on certain specific strains of influenza, and to narrow our monitoring targets to make monitoring more efficient, so that there is a better chance to determine the next flu before the virus spreads. Pandemic.