The Tsinghua team revealed: Why are these people more favored by mosquitoes?

Itching and swollen bags, in the summer memory of many people, mosquitoes are a kind of annoying existence. In addition, mosquitoes have brought people a variety of terrible mosquito media infectious diseases. In 2018, among the eight types of infectious diseases that the World Health Organization needed to pay attention to, the viral infectious diseases of Zika fever and Rift Valley fever viral infectious diseases were included.

What kind of people are the most attractive mosquitoes in the vast sea of ​​people?

The reporter learned from Tsinghua University that in a study just published in "Cell", Professor Cheng Gong's team of the school's medical school revealed the cunning of mosquito media virus: mosquito does not bite the host randomly, the human smell is to regulate mosquito behavior to regulate mosquito behavior The key factor.

"The olfactory nervous system of mosquitoes can perceive a characteristic odor molecule that is derived from the infected person. Those who are infected with high efficiency are positioned. Then they bite and eat blood with virus, which causes the virus to spread between the" host-mosquito ". "Cheng Gong said that the main source of human smell is the skin microorganism. By regulating the skin microorganisms and reshaping the smell of the infected person, it can affect the sense of smell of mosquito. The relevant evaluation believes that this discovery provides a new strategy for blocking the rapid spread of mosquito media viruses in nature.

Why are these people more favored by mosquitoes

Related data show that there are hundreds of mosquito media viruses in nature, which can be carried and spread to humans and animal hosts by mosquitoes, causing severe diseases such as viral encephalitis, meningitis and hemorrhage fever. In the past 20 years, the new hair and re -possession media virus represented by Dengca virus, Zika virus, Kidon Kenya virus, and Sinilla virus are popular around the world. Thousands of people died.

But unfortunately, so far, most of the mosquito mosquito media virus has no effective vaccine and targeted therapeutic drugs. The scientific community urgently needs to study the basic principles of the popular spread of mosquito media virus in nature, and develop new prevention and control strategies to block the prevention and control strategies blocked The large -scale transmission of viruses in the world.

"Mosquito media virus spreads between the host and the mosquito. In the virus transmission cycle, mosquito needs to find, position and bite the infected people or animals to eat blood with virus. The ability. If mosquito bite non -infected people, it will not effectively obtain virus infection, and the transmission cycle of the virus will be interrupted. "Cheng Gong said.

How does mosquitoes pay attention to virus infected people? Why do these people look more "delicious" in mosquitoes? For a long time, scientists have been committed to unveiling this mystery and finding simple and effective methods to curb the rapid spread of viruses.

In this study of Cheng Gong's team, the researchers established two classic set of behavioral device (the three cage smell measurement device, the arms smell measurement device), and found that mice infected with dengue virus and Zika virus infection were obviously more attractive. Egyptian mosquito and white -textured mosquito. Subsequently, the researchers analyzed the body temperature, carbon dioxide release and volatile smell of virus infection, and found that the change of the host smell was a decisive factor that caused the infection to attract mosquitoes. Further research results show that after mosquito media infection, a large number of volatile small molecules, phenyl, phenylthone can effectively activate the olfactory nervous system of mosquitoes and enhance the behavior trend of mosquito infected mice.

San cage smell measurement device (provided by the research team)

Researchers further collected the smell of dengue fever and healthy volunteers, and found that the smell of dengue fever patients showed stronger attractiveness to Egyptian mosquitoes. In addition, in the smell of dengue fever patients, the content of phenyl is also significantly higher than that of healthy volunteers. Researchers apply different concentrations of phenylthone to the human arm to verify mosquito behavior, and find that the content increased in the body's smell can significantly attract mosquito.

The above test shows that dengue fever patients have greatly improved their attractiveness to mosquito because of the release of a large amount of benzene ketone to change their own smell, attract mosquito bites, and accelerate the spread of virus.

The research team is evaluating the behavior of mosquitoes through the olfactory measurement device. From left to right as the first author of the paper, Dr. Zhang Hong, assistant researcher of Zhu Yibin, and Professor Cheng Gong. (Photo confession of the research team)

How to attract the "fragrance" of mosquito

Since phenylone is the "culprit" that attracts mosquito bites, how does this kind of "fragrance" that attracts mosquitoes produces?

Researchers have found that the phenosterone released by the human body or animal is mainly derived from the skin symbiotic microorganisms of the body surface. It is a typical bacterial metabolic product. After removing the skin symbiotic microorganisms, infection mice will lose a stronger attractive effect on mosquitoes.

Further studies have shown that the abundance of bacteria in the dengue virus and Zika virus infection can increase significantly, and the abundance of bacteria in the skin surface has increased significantly, and Skin Bacillus has the ability to metabolize a large amount of benzoneone.

At this point, the researchers revealed the cause of the mosquito media infection that attracted mosquito bites: virus infection increased the proportion of specific bacteria in human skin, significantly increased the ability of the infected person's release, thereby significantly increased the mosquito to the infected host of the infected host Behavioral trends.

Subsequently, the researchers conducted transcription group sequencing analysis of the skin tissue of virus infected mice and non -infectious mice. The results showed that DengDir virus and Zika virus infection could inhibit the expression of specific immunomas such as resistantin -like molecules or resistance in the host's skin, which caused excessive proliferation of skin sporebacteria that was originally suppressed, resulting in the release of the infected host's benzide release release The quantity increases.

Subsequently, the researchers fed a vitamin A derivatives infected with mice in the dengue virus and Zika virus infection, which is a widely used dermatological treatment drug. The results show that the above operations can effectively restore the expression of specific immunomasous molecules in the infection of the skin. By inhibiting the proliferation of Bacillus in the infection of the infection, the infection of the infected host release phenyl. Therefore, after being infected with alcoholic acid acid, mosquitoes cannot locate and discover the infected host through the host of the host, thereby blocking the transmission cycle of the virus. By replenishing vitamin A drugs, reshape the release of phenylthone infected with microorganisms infected with individual skin, reducing the recycling of mosquito media virus transmission (research team drawing)

How to block the rapid spread of mosquito media virus

According to the above discovery, researchers have proposed a new idea of ​​mosquito media virus prevention: it can regulate the smell of human body and block the rapid spread of mosquito media virus.

Due to the influx of mosquito media virus infectious diseases, the proportion of infected people in the crowd was only one tenth or even lower, so the research team speculated that the mosquito was unable to pass the smell of phenylone after oral vitamin A drugs in the infected person. To distinguish between infected people and non-infected people, this can greatly reduce the chance of mosquito-eating infection and infection, so that mosquito media viruses cannot efficiently establish the transmission cycle of "host-mosquito" in nature.

Based on this, the research team proposes a new strategy to prevent and treat mosquito media infectious diseases: in the epidemic areas of mosquito media virus infectious diseases such as dengue fever and Zika fever, vitamin A or related drugs can be widely supplemented to infected people, and infection infection can be reshaped to infection and infection. The volatile smell of the skin's microorganisms greatly reduces the cycle efficiency of the mosquito media virus, and effectively prevent mosquito to carry and spread the virus. Based on the above findings, vitamin A or related drugs can be supplemented with specific infected people, and the large -scale spread of mosquito media virus infectious diseases can be avoided.

It is reported that at present, the Cheng Gong team has completed the study of the skin changes in the skin of the infected and non -infected people in Malaysia, and it is about to conduct clinical trials of different vitamin acid. It is expected to promote its research results in the future.

Source: Guangming Daily

Edit: Wang Jing

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