Science: The new influenza gene

Brett Jagger and Paul Digard from the University of Edinburgh discovered a new flu gene that hides the 12 genes we know of in the past. This new gene, called PA-X, affects how the viral host reacts to the virus. Curiously, it seems to reduce the severity of the infection.

Science: The new influenza gene

I can write down the entire genome of the flu virus that exists in about one hundred birds, which is only 14,000 bases compared to the human gene, which contains more than 3 billion bases. However, this tiny genetic material is enough to kill thousands of people. Although sequencing is done again and again, we still have a lot of unknowns about it.

A study published in Science magazine is an excellent illustration of the depth of our ignorance. Brett Jagger and Paul Digard from the University of Edinburgh discovered a new flu gene that hides the 12 genes we know of in the past.

This new gene, called PA-X, affects how the viral host reacts to the virus. Curiously, it seems to reduce the severity of the infection. Virologist Ron Fouchier said: "This is indeed an exciting discovery in the flu field." Dendard's old colleague, flu researcher Wendy Barclay from Imperial College London, said: "How can we miss it? It highlights these genomes. How dense is it."

What is the influenza A virus? What are the characteristics, manifestations, complications, and prevention methods of influenza A?

What is the influenza A virus? What are the characteristics, manifestations, complications, and prevention methods of influenza A?

What is the influenza A virus? What are the characteristics, manifestations, complications, and prevention methods of influenza A?

Influenza A virus
Influenza A virus is a common influenza virus, and influenza A virus is the most susceptible to mutation. The subtype of influenza A virus is called "bird flu". Bird Flu is a kind of bird flu virus. Acute infectious diseases, virus gene mutations can infect humans, the symptoms after infection are mainly high fever, cough, runny, myalgia, etc., most of them are accompanied by severe pneumonia, severe heart, kidney and other organ failure leading to death The mortality rate is very high. The disease can be transmitted through digestive tract, respiratory tract, skin damage and conjunctiva. People and vehicles are important factors in the spread of this disease.
Influenza A is highly pathogenic to humans and has caused worldwide pandemics. Among the influenza A viruses, the avian influenza virus subtypes that have been found to directly infect humans are: H1N1, H5N1, H7N1, H7N2, H7N3, H7N7, H7N9, H9N2 and H10N8. Among them, H1, H5 and H7 subtypes are highly pathogenic, and H1N1, H5N1 and H7N9 are particularly worthy of attention.

Virus profile
Influenza A virus is a common influenza virus. It is mainly susceptible to mutating while the main subtype is called some bird flu, so it is also an acute infectious disease in daily life, and after infection. The main symptoms are some high fever, some cough, some pneumonia and some small dysfunction, so it is necessary to treat and prevent it in time.

What is a influenza virus? What are the routes of transmission, diagnostic methods, and preventive measures for influenza viruses?

What is a influenza  virus? What are the routes of transmission, diagnostic methods, and preventive measures for influenza viruses?

What is a influenza  virus? What are the routes of transmission, diagnostic methods, and preventive measures for influenza viruses?

Introduction to influenza virus
Influenza virus is a representative species of Orthomyxoviridae, abbreviated as influenza virus, including human influenza virus and animal influenza virus. Human influenza virus is divided into three types: A, B, and C. It is influenza. The pathogen of (flu). Among them, the antigenicity of influenza A virus is prone to mutation, causing a worldwide pandemic many times. For example, in the 1918-1919 pandemic, at least 20 million to 40 million people worldwide died of influenza; influenza B virus is also more pathogenic to humans, but people have not found that influenza B virus has caused worldwide A pandemic; influenza C virus causes only insignificant or mild upper respiratory tract infections in humans and rarely causes epidemics. Influenza A virus was successfully isolated in 1933, influenza B virus was acquired in 1940, and influenza C virus was not successfully separated until 1949.

Influenza classification

According to the target of influenza virus infection, the virus can be divided into human influenza virus, swine influenza virus, equine influenza virus and avian influenza virus. The human influenza virus can be divided into three categories according to the antigenicity of its nuclear protein:
Influenza A virus, also known as influenza A virus
Influenza B virus, also known as influenza B virus
Influenza C virus, also known as influenza C virus
Influenza viruses that infect other animals such as birds and pigs have the same antigenicity as the human influenza A virus, but since the classification of influenza A, B and C viruses is only for human influenza viruses, it is usually not An influenza virus other than a human host such as avian influenza virus is referred to as an influenza A virus.
Based on the antigenicity of nuclear proteins, influenza viruses are also classified into different subtypes based on the antigenicity of hemagglutinin HA and neuraminidase NA.

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.

What is the cause of the flu? The genomic product of the flu virus

Abstract: Influenza virus belongs to the Orthomyxoviridae family. It is an enveloped RNA virus with a spherical shape of 80-100 nm in diameter or a filament of thousands of nanometers.

What is the cause of the flu? The genomic product of the flu virus

Cause of influenza

The influenza virus belongs to the Orthomyxoviridae family and is an enveloped RNA virus. Its appearance is spherical with a diameter of 80-100 nm or a filament of thousands of nanometers. The virus consists of the envelope and the nucleocapsid .

The components of the envelope include membrane proteins (M1, M2), bilayer lipid membranes, and glycoprotein protrusions. The glycoprotein neurites contain both hemagglutinin (HA) and neuraminidase (NA), both of which are antigenic and subtype specific. The nucleocapsid is a thin spiral filament, spirally symmetric, 9 to 15 nm in diameter, including nuclear protein (NP), three polymerase proteins (PB-1, PB-2, PA) and viral RNA; the viral genome is single-stranded Negative strand RNA.

Classification and nomenclature of influenza virus According to the different antigenicity of viral nuclear protein (NP) and membrane protein (MP), the influenza virus is divided into three types: A, B, and C; according to the difference of HA and NA antigens, the same type of virus is divided into two types. Several subtypes. Subtype division is based on genetic analysis and agar diffusion double diffusion. The principles of influenza virus nomenclature published by the World Health Organization in 1980 are as follows: type/host/separation site/segregation date/viral strain number (hemagglutinin subtype and neuraminidase subtype). For example, A/equine/Singapore/3/52 (H7/N3), meaning: influenza A virus/host is horse/separated in Singapore/time is March 1952/subtype is H7N3. Up to now, there have been 15 subtypes of hemagglutinin (H1~15), and 9 subtypes (N1~9) of neuraminidase. The main ones related to humans are A1 (H1N1), A. 2 (H2N2), A3 (H3N2) and Type B.

Do you get the flu? The answer may be in your genome

From the end of last year to March and April this year, the flu pandemic around the world, and even many people have died. Have you ever worried that you will be infected with this terrible virus? According to Genomic Medicine, there is now a way to predict if you are susceptible to the flu.

Do you get the flu? The answer may be in your genome

In this study, researchers at Stanford University School of Medicine found a sign in human blood that predicts whether or not they will be infected with the flu virus. Specifically, the researchers found that people infected with influenza had lower levels of natural killer cells (NK cells) in their immune cells. If the levels of these cells in the blood are above a certain threshold, people will not get the flu.

NK cells are cytotoxic lymphocytes that are essential for the innate immune system and function similarly to cytotoxic T cells in adaptive immune responses in vertebrates. NK cells provide a rapid response to virus-infected cells, function about 3 days after infection, and respond to tumor formation. Typically, immune cells detect the major histocompatibility complex (MHC) present on the surface of infected cells, triggering the release of cytokines, causing lysis or apoptosis. However, NK cells are unique in that they are able to recognize stress cells without antibodies and MHC, allowing for a faster immune response.

For the first time in history, the influenza virus gene can finally be detected directly in its original RNA form.

The latest technology allows the flu virus to be sequenced for the first time in the form of its original RNA. The genetic code of the influenza virus, like other viruses, is stored in RNA, so if you want to measure its gene sequence, it can only be obtained by sequencing the reverse-transcribed DNA under the previous limited technology. However, this new invention uses nanopore sequencing technology to directly read out its RNA sequence as it passes through a tiny molecular pump.

For the first time in history, the influenza virus gene can finally be detected directly in its original RNA form.

“This is the first time in history that we can look at the original form of the gene,” says microbiologist John Barnes of the Center for Disease Control and Prevention (CDC) in Atlanta. Barnes led the study and published a pre-release of the paper on BioRxiv on April 12. He said: "This will bring a lot of possibilities for subsequent research."

Barnes and his team are most interested in studying the genes of viruses. Other studies involve RNA in various tissues and organs, as well as RNA in humans. Researchers have long wanted to elucidate their role in cellular function by measuring molecular modifications on RNA, but it has been difficult to conduct such experiments.

“The biggest breakthrough this invention will bring is the ability to discover RNA modifications that are transformative,” said Ewan Birney, co-director of the European Bioinformatics Institute (EMBL-EBI).