Viruses have a bad reputation. They are responsible for the COVID-19 pandemic and a long list of diseases that have plagued humankind since time immemorial. However, viruses are intriguing subjects to study. “High-tech” talks about the most interesting discoveries and the facts associated with them.
Viruses were first discovered in 1892, but even 109 years later, scientists continue to make new discoveries about them. They are found everywhere on Earth and, according to scientists, there are 10 times more of them than bacteria. Antibiotics do not work on them; only a few antiviral and antiretroviral drugs and vaccines can eliminate or reduce the severity of viral diseases such as AIDS, COVID-19, measles and smallpox.
What else do we know about viruses?
An ancient virus lived in the human brain
The neurons of the brain of animals, including humans, contain genetic remnants of an ancient viral infection. Scientists believe it may be the key to thought processes. Biologists talked about this in two articles (one, two) for the journal Cell. About 350-400 million years ago, a retrovirus entered the mammalian organism, contact with which led to the formation of a gene called Arc.
It turned out that it is a genetic code left over from an ancient virus. It is necessary for synaptic plasticity – the ability of nerve cells to form and consolidate new nerve connections. A virus-like gene helps neurons to carry out higher mental functions.
Viruses literally fall from the sky
In one study, scientists found out why viruses that are genetically similar to each other can be found on different parts of the earth. The thing is that they are able to move along with the air currents. Viruses can catch on particles of soil or water and rise high into the atmosphere (free troposphere) and, ultimately, fall hundreds and thousands of kilometers from their original point.
The virus manipulates genes to defend itself
Almost everyone several times in their life becomes infected with the respiratory syncytial virus. In most cases, the body can easily overcome it and everything is done with a mild cold. But some people – most often young children who have had their first infection or older people who have weakened immune systems – develop pneumonia or bronchiolitis. These are serious lung infections that can lead to hospitalization and sometimes death.
Scientists have recently discovered how the virus undermines the body’s defenses. It turned out that the virus produces non-structural protein 1, or NS1, which penetrates into the nucleus and alters the activity of immune genes, sabotaging the immune response. The results of the study provide more information about how the virus is causing serious illness in vulnerable populations.
Rift Valley Fever is causing economically devastating outbreaks of haemorrhagic fever in livestock. The virus is transmitted by mosquitoes and usually infects people who work with dead or dying animals. As a result, hundreds of people fall ill and die every year.
There is no specific treatment for fever. And, although it is only common in Africa and the Arabian Peninsula, mosquitoes carrying the virus can be found all over the world.
Recently, a group of American scientists discovered that the virus responsible for fever invades cells using a special protein. It is usually involved in the absorption of low density lipoproteins (LDL, carriers of “bad cholesterol”) from the blood. The discovery could lead to treatments that prevent or lessen Rift Valley Fever by interfering with the virus’s ability to enter cells.
Alzheimer’s disease and viruses
The theory that viruses may play a role in Alzheimer’s disease gained more support after the publication of a study by American scientists in the journal Neuron. Specialists studied about a thousand brains of deceased people from several organ banks. Among them were people with and without Alzheimer’s disease. During the study, scientists analyzed genetic sequences taken from brain tissue.
It turned out that the brains of deceased people with Alzheimer’s disease contained higher levels of viruses than the brains of patients without it. In particular, the brain that suffered from dementia had twice as many of the two common strains of herpes viruses as the normal one.
The researchers noted that it is not entirely clear what role viruses may play in the development of the disease. They are capable of both causing the disease and simply accelerating its progression. However, it is possible that herpes viruses do not play a role at all in the disease and are found in the brain that has suffered from dementia for some other reason.
Much is unknown
It is believed that viruses are the “aborigines” of our planet. According to one version, they came to Earth at the time of its creation. All this time, namely 4.54 billion years, they have been developing. Much more about viruses is unknown to man and the main discoveries are yet to come.