The pandemic of the new coronavirus continues for two months. Everyone already considers himself an expert in this topic. Did you know that a virus cannot be killed? He does not live, so he can only be broken, destroyed. The virus is not a being, but rather a substance. But at the same time, viruses are able to communicate, cooperate and disguise themselves.
The social life of viruses
Scientists discovered this just three years ago. As often happens, by accident. The aim of the study was to test whether hay bacteria can alert each other to an attack by bacteriophages, a special class of viruses that selectively attack bacteria. After adding the bacteriophages to the hay bacilli tubes, the researchers recorded the signals in an unknown molecular language. But the "negotiations" on it were not at all bacteria, but viruses.
It turned out that after penetrating bacteria, viruses forced them to synthesize and send special peptides to neighboring cells. These short protein molecules signaled to the rest of the viruses about the next successful capture. When the number of signal peptides (and therefore captured cells) reached a critical level, all viruses, as if on command, stopped actively dividing and lurked. If it were not for this deceptive maneuver, the bacteria could organize a collective rebuff or completely die, depriving the viruses of the opportunity to parasitize on them further. The viruses have clearly decided to put their victims to sleep and give them time to recover. The peptide that helped them do this was named "arbitrium" ("decision").
Further research has shown that viruses are capable of making more complex decisions. They can sacrifice themselves during an attack on a cell's immune defenses to ensure the success of the second or third wave of the offensive. They are able to move in a coordinated manner from cell to cell in transport vesicles (vesicles), exchange gene material, help each other mask from immunity, cooperate with other strains to take advantage of their evolutionary advantages.
Chances are that even these amazing examples are just the tip of the iceberg, says Lan'in Zeng, a biophysicist at the University of Texas. A new science - sociovirology - should study the latent social life of viruses. We are not talking about the fact that viruses are conscious, says one of its creators, microbiologist Sam Diaz-Muñoz. But social connections, language of communication, collective decisions, coordination of actions, mutual assistance and planning are signs of intelligent life.
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Are viruses sane?
Can something that is not even a living organism have a mind or consciousness? There is a mathematical model that allows this possibility. It is an integrated information theory developed by the Italian neuroscientist Giulio Tononi. He considers consciousness as the ratio of the quantity and quality of information, which is determined by a special unit of measurement - φ (phi). The idea is that between completely unconscious matter (0 φ) and the conscious human brain (maximum φ) there is an ascending series of transition states. Any object capable of receiving, processing and generating information has a minimum level φ. Including those certainly inanimate, such as a thermometer or LED. Since they know how to convert temperature and light into data, it means that "information content" is the same fundamental property for them,as mass and charge for an elementary particle. In this sense, the virus is clearly superior to many inanimate objects, since it itself is a carrier of (genetic) information.
Consciousness is a higher level of information processing. Tononi calls this integration. Integrated information is something that qualitatively surpasses the simple sum of collected data: not a set of individual characteristics of an object such as yellow, round shape and warmth, but an image of a burning lamp made up of them.
It is generally accepted that only biological organisms are capable of such integration. To test whether inanimate objects can adapt and gain experience, Tononi, together with a team of neuroscientists, developed a computer model resembling an arcade game for a retro console. The subjects were 300 "animats" - 12-bit units with basic artificial intelligence, simulation of the senses and the locomotor apparatus. Each of them was given randomly generated instructions for working parts of the body and everyone was launched into a virtual maze. Time after time, the researchers selected and copied the animats that showed the best coordination. The next generation inherited the same code from the "parents". Its size did not change, but random digital "mutations" were introduced into it, which could strengthen, weaken, or supplement the connections between the "brain" and "limbs."As a result of this natural selection, after 60 thousand generations, the efficiency of passage of the labyrinth among animats increased from 6 to 95%.
Animats have one advantage over viruses: they can move independently. Viruses have to move from carrier to carrier in the passenger seats in saliva and other physiological secretions. But they have more chances to increase the level of φ. If only because viral generations are replaced faster. Once in a living cell, the virus forces it to churn out up to 10,000 of its genetic copies per hour. However, there is one more condition: to integrate information to the level of consciousness, a complex system is needed.
How complex is a virus? Let's look at the example of the new coronavirus SARS-CoV-2, the culprit of the current pandemic. In shape, it looks like a horned sea mine. Outside - a spherical lipid shell. These are fats and fat-like substances that must protect it from mechanical, physical and chemical damage; it is they that are destroyed by soap or sanitizer. On the envelope is the crown that gave it its name, that is, the spine-like processes of S-proteins, with the help of which the virus enters the cell. Under the envelope is an RNA molecule: a short chain with 29,903 nucleotides. (For comparison: there are more than three billion of them in our DNA.) Quite a simple construction. But a virus doesn't need to be complex. The main thing is to become a key component of a complex system.
Science blogger Philip Bouchard compares viruses to Somali pirates hijacking a huge tanker in a tiny boat. But in essence, the virus is closer to a lightweight computer program compressed by an archiver. The virus does not need the entire control algorithm for the captured cell. A short code is enough to make the entire cell operating system work for it. For this task, its code is ideally optimized in the process of evolution. It can be assumed that the virus "revives" inside the cell only as much as the system resources allow. In a simple system, he is able to share and control metabolic processes. In a complex (like our body) - it can use additional options, for example, to achieve a level of information processing that, according to Tononi's model, borders on intelligent life.
What do viruses want?
But why do viruses need it at all: sacrifice themselves, help each other, improve the communication process? What is their purpose if they are not living beings?
Oddly enough, the answer is directly related to us. By and large, a virus is a gene. The primary task of any gene is to copy itself as much as possible in order to spread in space and time. But in this sense, the virus is not much different from our genes, which are also concerned primarily with the preservation and replication of the information recorded in them. In fact, the similarities are even greater. We're a bit of a virus ourselves. By about 8%. There are so many viral genes in our genome. Where did they come from there?
There are viruses for which the introduction of a host cell into the DNA is a necessary part of the "life cycle". These are retroviruses, which include, for example, HIV. The genetic information in a retrovirus is encoded in an RNA molecule. Inside the cell, the virus starts the process of making a DNA copy of this molecule, and then inserts it into our genome, turning it into a conveyor for assembling its RNAs based on this template. But it so happens that the cell suppresses the synthesis of viral RNA. And the virus, embedded in its DNA, loses the ability to divide. In this case, the viral genome can become a genetic ballast that is passed on to new cells. The age of the oldest retroviruses, whose “fossil remains” have been preserved in our genome, is from 10 to 50 million years. Over the years of evolution, we have accumulated about 98 thousand retroviral elements that once infected our ancestors. Now they make up 30-50 families, which are subdivided into almost 200 groups and subgroups. According to the calculations of geneticists, the last retrovirus that managed to become part of our DNA infected the human population about 150 thousand years ago. Then our ancestors survived a pandemic.
What are relic viruses doing now? Some do not show themselves in any way. Or so it seems to us. Others work: protect the human embryo from infections; stimulate the synthesis of antibodies in response to the appearance of foreign molecules in the body. But in general, the mission of viruses is much more significant.
How viruses communicate with us
With the emergence of new scientific data on the influence of the microbiome on our health, we began to realize that bacteria are not only harmful, but also useful, and in many cases are vital. The next step, writes Joshua Lederberg in The History of Infections, should be to break the habit of demonizing viruses. They really often bring us sickness and death, but the purpose of their existence is not the destruction of life, but evolution.
As in the example with bacteriophages, the death of all cells of the host organism usually means defeat for the virus. Hyperaggressive strains that kill or immobilize their hosts too quickly lose their ability to spread freely and become dead-end branches of evolution. Instead, more “friendly” strains get a chance to multiply their genes. “As viruses evolve in a new environment, they usually stop causing serious complications. This is good for the host organism and for the virus itself,”says New York epidemiologist Jonathan Epstein.
The new coronavirus is so aggressive because it only recently broke the interspecies barrier. According to immunobiologist Akiko Iwasaki of Yale University, "When viruses first enter the human body, they don't understand what's going on." They are like first-generation animats in a virtual maze. But we are no better. When confronted with an unknown virus, our immune system can also get out of control and respond to the threat with a "cytokine storm" - an unnecessarily powerful inflammation that destroys the body's own tissues. (It is precisely this overreaction of immunity that causes many deaths during the 1918 Spanish flu pandemic.) adapt to them, and to them - to us.
We exert an evolutionary influence on each other not just as environmental factors. Our cells are directly involved in the assembly and modification of viral RNAs. And viruses are in direct contact with the genes of their carriers, introducing their genetic code into their cells. The virus is one of the ways our genes communicate with the world. Sometimes this dialogue gives unexpected results.
The emergence of the placenta - the structure that connects the fetus to the mother's body - has become a key moment in the evolution of mammals. It is difficult to imagine that the synticin protein required for its formation is encoded by a gene that is nothing more than a "domesticated" retrovirus. In ancient times, synticin was used by a virus to destroy the cells of living organisms.
The story of our life with viruses is drawn by an endless war or an arms race, writes anthropologist Charlotte Bivet. This epic is built according to one scheme: the origin of the infection, its spread through a global network of contacts and, as a result, its containment or eradication. All his plots are associated with death, suffering and fear. But there is another story.
For example, the story of how we got the neural gene Arc. It is necessary for synaptic plasticity - the ability of nerve cells to form and fix new nerve connections. A mouse in which this gene is disabled is not capable of learning and forming long-term memory: having found cheese in the maze, it will forget the way to it the very next day.
To study the origins of this gene, scientists have isolated the proteins it produces. It turned out that their molecules spontaneously assemble into structures that resemble HIV viral capsids: protein envelopes that protect the RNA of the virus. Then they are released from the neuron in the transport membrane vesicles, merge with another neuron and release their contents. Memories are transmitted like a viral infection.
350-400 million years ago, a retrovirus entered the mammalian organism, contact with which led to the formation of Arc. Now, this virus-like gene is helping our neurons to carry out higher mental functions. It may be that viruses do not gain consciousness through contact with our cells. But in the opposite direction, it works. At least it worked once.
Author: Sergey Pankov
