The relationship between virus and immune system is like cat and mouse game

category:Health
 The relationship between virus and immune system is like cat and mouse game


Gao Fu is now the director of China Center for Disease Control and prevention. His main research direction is the mechanism of cross species transmission of pathogenic microorganisms and molecular immunology. He is mainly engaged in the molecular mechanism of T-cell recognition, invasion of envelope viruses such as influenza virus, cross species transmission of animal-borne pathogens such as avian influenza, etc.

Invisible enemy

Popular science China net:

Viruses are both familiar and unfamiliar to ordinary people. So what is virus, what is the relationship between human and virus?

Gao Fu:

Viruses are like invisible enemies. You dont know when it will come or leave. It can be said that it is come without trace, go without shadow.

At present, there are hundreds of viruses that infect human beings. If we count the unknown and exist, there are thousands of kinds of viruses, and our knowledge of viruses is too little. There are a lot of viruses in nature, and from time to time, some will jump out. Its like though SARS has come and gone, in fact, in 2015, mers, SARSs younger brother or younger sister, came to China again (I dont know whether its younger brother or younger sister because the gender of the virus cant be identified).

Viruses like SARS and mers are now clear. They are not coming and going, but coming and going. The so-called come and have a trace is that we have found that SARS and mers viruses are from bats. (aside: now it seems that bats carry many highly pathogenic viruses for humans and animals. Even the distant relatives of influenza virus were first carried by bats.) The original host of SARS was bats, and then jumping from bats to humans caused the immune system to respond.

What is the immune system? There are a group of cells in the human body that recognize abnormal cells, such as cancer cells, and kill them when they are found. Thats what we often call immune surveillance: see it, act, kill you. For example, the security guard on duty in the community will not block you in and out because he sees you every day and knows you very well, but he will certainly intervene when he sees a stranger. Our immune system is basically like this. Regardless of the familiar self, we must monitor and observe the unfamiliar non self. I often joke that peoples immune system is like aunt Chaoyang to maintain public order and prevent bad guys from invading.

Generally speaking, some viruses have reached a consensus with the immune system in the long-term symbiosis with human beings. For example, we often have long bubble around the mouth, which occurs when the immunity is low, and then self-healing after two days. This is herpes simplex virus, which has formed a mutual understanding relationship with the immune system. The immune system knows that it can not eliminate it, so it has to coexist peacefully.

However, when the SARS virus came, the human immune system had never seen it before, thinking how big the enemy was coming, so we called on the immune system, kill will go up. At this time, it is particularly easy to have a situation called cytokine storm: that is, the immune cell response is too fast and strong, so that it is not the virus itself that finally kills people, but the immune response caused by the virus, which is what we call maladjustment. The human bodys response to the virus represented by SARS is roughly the same. This kind of virus includes the Ebola I studied.

Figuratively speaking, the relationship between virus and immune system is like cat and mouse game. Herpes simplex virus (HSV), including influenza virus, can fight against it, but it cant be eliminated at the same time, forming a peaceful relationship with people, that is, Tom and Jerry in Disney cartoons. But the SARS virus is a wild mouse. The cat eats it and its gone.

Popular science China net:

Its the flu season. Is the flu Jerry or wild mouse?

Gao Fu:

At the beginning of October every year, seasonal influenza begins to occur frequently in Beijing, especially in October and November. Because its accompanied by human beings every year, we define influenza virus as the enemy that cant hide, just like the herpes virus we just said. But occasionally there will be a very big change and strong independence of the flu, that is, the great flu. Different from seasonal influenza, pandemic influenza may be a new type of virus formed by mixing gene fragments of wild migratory birds in other places and then re pairing them. The immune system has never been seen. The morbidity and mortality are very high.

SARS doesnt need to be feared even if it comes back

Popular science China net:

Just now you said that human beings have eliminated the SARS virus directly. But if one day, some SARS like viruses come back because their hosts are gone, how can we recognize them? There is also a media question: are we ready for SARS to return?

Gao Fu:

It is possible that SARS will come back.

Human beings are evolving and science is advancing. We have identified SARS as a coronavirus. The surface of the virus is observed under the electron microscope. It seems that there is a crown around it, so it gets its name. Human understanding of coronavirus is still very superficial. In the last century, we began to recognize the coronavirus. Up to now, there are only ten kinds of coronaviruses. According to reports, some of them have even infected only one patient. But now it seems that SARS or SARS like or SARS like viruses are very important and may infect human beings. After many years, there will be no resistance to SARS. SARS or SARS like virus will come back. So from the perspective of research, we need to do a good job in research, in vaccine storage and in drug storage, which is what scientists all over the world are trying to do.

At present, we have mastered the technical reserve and what kind of vaccine is needed to conquer SARS virus. This basic research has been very clear. I am very confident to tell you that if there is SARS, a vaccine will be produced soon. So why hasnt a vaccine been produced? Because SARS is now gone, who will fight the vaccine produced? We need to invest in the production of vaccines for other diseases that are more important than the prevention and control of SARS.

The existence of the virus is also the birth of the vaccine

Popular science China net:

Have humans learned to get along with viruses?

Gao Fu:

The ultimate goal of human beings is to eliminate the virus, but in the process of recognizing the virus and the immune system, some viruses may have unconsciously become the relationship between Tom and Jerry, such as the herpes virus just described. But can humans finally wipe it out? I believe that with the deepening of scientific research, we will find a way to eliminate them one day.

For example, smallpox is a famous virus that people kill. We seldom meet people with pockmarked faces now, because in 1980, smallpox virus was eliminated by vaccination. There are many species on the earth, such as Australias kangaroo and Africas dodo. But this is not intentional behavior of human beings. It is caused by the damage of human beings to the ecological environment of these species. Smallpox virus is the first purposeful and organized eradication of human beings on the earth, and it also opens up the subject of human immunology. Based on some immunotherapies, humans can turn some tumors into chronic diseases. This is what human beings summed up in the process of eradicating smallpox, that is, modern immunology. Modern immunology helps people protect their bodies better. Due to the emergence of smallpox vaccine and the extension of theory, more vaccines have been developed to prevent and control hepatitis (hepatitis A, hepatitis B) and poliomyelitis.

But for now, human cognition has entered the ceiling period, commonly known as brain card. A typical case is that all scientists and all disease control and prevention workers around the world have worked hard for nearly 40 years, and there is no AIDS vaccine. It cant be solved by relying on existing knowledge. Is it possible to solve it in the future? I think so. This is the periodic law of scientific development.

In the future, mankind may be invincible

Popular science China net:

Do viruses have to be bad?

Gao Fu:

In a strict sense, there is no difference between a virus and a bacterium. This also answers your question: not all viruses are bad, some viruses are good, so are bacteria. Some experts dont agree with the theory that pathogenic microorganism is microorganism, and the quality is relative. Some viruses are very beneficial to human beings. For example, some bacterial phages stationed in the gastrointestinal tract are viruses. Bacterial viruses are conducive to maintaining the bacterial balance in our intestines. Once the balance is broken, people will get sick. Now research has also found that gastrointestinal microbes are now associated with Alzheimers and many other diseases. For example, whether you get a vaccine or not has something to do with the state of your microbial flora that day.

Popular science China net:

If from the perspective of science fiction, is it possible for human beings to one day be invincible to all poisons and evolve into an individual that is difficult for viruses to invade?

Gao Fu:

In the long evolutionary process of the long struggle between humans and viruses, this is quite possible. Human beings are evolving, and viruses themselves are evolving, just like human beings have eliminated smallpox, but HIV and influenza viruses are more severe than smallpox, and we have not been able to eliminate them.

In theory, as long as human beings do disease prevention and control step by step, through long-term evolution and selection, human beings will become invulnerable. The biggest plague that mankind ever faced was the plague. Half of the people in Europe were killed by the plague. According to the analysis of scientists, these people who are left behind are just resistant to the plague, and some susceptible people have been eliminated by the plague. Therefore, long-term evolutionary selection can turn some people into individuals with resistance to various diseases.

Source: editor in charge of global network: Wu Yanli ufe63 nbjs6202