A Finnish researcher found a virus in the brain of a dead man, which may revolutionize our understanding of the human body


Senior Member
I thought I post this article as it is somewhat related to Bhupesh Prusty's study on tissue specific signature of HHV-6 infection in ME/CFS

Link to the article which is in Finnish

I Google translated it and fixed some errors:

Lari Pyöriä and Maria Perdomo's research shows that numerous viruses acquired in childhood hide in our bodies and form a whole world of their own. Viruses can affect health in unpredictable ways - harmful or beneficial.

When medical researcher Lari Pyöriä, 31, who is doing a doctoral thesis on viral diseases, looked at the virus analysis done on a piece of brain tissue in the Haartman Institute's research room in January 2019, a real surprise lay ahead.

Pyöria had graduated as a doctor from the Faculty of Medicine of the University of Helsinki a year earlier. When he was studying, the professors had always said that the brain was very sterile. So, in his professors opinion, there shouldn't have been many microbes such as bacteria and viruses hiding in them.

But now there were viruses in it.

HHV-6B viruses were found in the brain tissue of a man who died in an accident at the age of 67, which causes fever, chicken pox, in small children.

And there was another cause of childhood diseases: parvovirus B 19, which causes an infection with mild symptoms, parvopox.

TT virus was also found in the tissue. It was a mystery.

"It has been known that the TT virus appears in the body of most people very soon after birth. But it has not been linked to any disease," says Pyöriä.

Virologists Maria Perdomo (left) and Lari Pyöriä examine virus samples at the Haartman Institute in Meilahti.

Pyöria and his dissertation supervisor, Colombian-born doctor Maria Perdomo, have recently completed a significant study at the Virology Department of the University of Helsinki's Faculty of Medicine.

The research has not yet been made public, but it was published in March in the prestigious scientific journal Nucleic Acids Research.

"This is the world's first study that extensively maps the hiding places of various viruses in our body. It reveals that even a healthy person's body contains a huge collection of viruses, or virome," says Perdomo.

It may be that this overall picture will revolutionize our understanding of viruses in the same way that the conception of bacteria has changed in recent years.

New research data highlights, for example, the great importance of intestinal bacteria as health maintainers and inhibitors of inflammatory diseases.

Viruses, on the other hand, are used to being seen as bad guys. This is part of the truth, but not the whole picture.

In their study, Pyöria and Perdomo looked at tissue samples from 31 recently deceased people.

The effort was specifically to find out the composition of the virome of an "ordinary" person, so the samples obtained from autopsies were chosen from people who had died in accidents or had, for example, a sudden heart attack.

Pyöria and Perdomo believe that viruses remaining in the body can influence the onset or progression of chronic diseases.

In addition to the brain, samples were taken from the colon, liver, lungs, heart, kidneys, skin, blood and hair. The genetic material of the viruses was analyzed from the samples using new generation gene amplification and sequencing methods. The research focused on human DNA viruses.

Based on their inheritance, viruses are divided into DNA and RNA viruses. For example, coronaviruses are RNA viruses and herpes viruses are DNA viruses.

Up until now, the perception of viruses has largely been that they can be found in the blood of a sick person and also in the digestive system of healthy people and on the outer surfaces of the body, such as the skin.

"However, based on our research, this picture is far too narrow. Viruses can be found all over the body, even in the hair, even in people who are considered to be basically healthy," says Perdomo.

He says that a total of 17 different virus species were identified in the tissue samples. They were mainly viruses of the herpes, parvo, papilloma, polyoma and anello genera.

In the study, viruses were found, for example, in the liver. Pink dots illustrate viral proteins in the liver.

In the classic series Il était une fois... la vie , which is familiar to many, viruses are described as yellow miscreants that sneak into the body like stealth, hide and laugh as they run around. Then the person gets sick.

In the end, white blood cells and antibodies arrive as heroes and sweep the viruses out of the body and the person gets better.

However, Perdomo and Pyöriä's research shows that many viruses are real master hiders, more than previously known. They come and never go.

"Almost all of us get viral infections as children. These viruses are like guests who come to the village for a few days but decide to stay in the corner for the rest of their lives," explains Perdomo.

"Many viruses, such as the influenza A and B viruses that cause influenza, do not remain in our bodies, but are thrown away by our immune system."

Perdomo clarifies that it is a complex mechanism: our immune system would quickly kill the viruses, if the viruses were not very cunning. Such cunning viruses are, for example, the herpes viruses mentioned at the beginning of the article.

Viruses can also live in a symbiotic relationship with our body to settle in our body. The problem is that we don't have anywhere near comprehensive research information on what these hidden viruses can cause."

However, Pyöria and Perdomo believe that viruses that remain in the body can affect the onset or progression of chronic diseases such as cancer and autoimmune diseases.

It is already known that, for example, the varicella zoster virus that causes chickenpox can be activated in the body years after contracting chickenpox and cause shingles.

Reactivations of herpes viruses, on the other hand, cause a lot of problems for people whose immune defenses do not work normally - for example, organ transplant patients.

The connection between enteroviruses and type 1 diabetes has been studied a lot. The Epstein-Barr virus, which causes painful sore throat, mononucleosis, or "whooping cough", seems to be essential in the development of MS, especially if the virus is acquired only in adulthood.

If the Il était une fois... la vie series were made now, perhaps viruses would not be portrayed as black and white as raging evildoers. Viruses can also live in a symbiotic relationship with our body, but according to Perdomo and Pyöriä, not nearly enough is known about the subject.

For example, the TT virus described at the beginning of the article was found in almost all samples, but the virus in question has not been linked to any disease.

"Similarly, for example, herpes virus 7 was found in almost all the persons we examined. Why has this virus been with us for millions of years, when for many it does not seem to cause any visible symptoms or illness?” Perdomo wonders.

It is already known that viruses inherited by humans in ancient times help, for example, in getting pregnant: the genes obtained from them create proteins that help form the placenta and produce hormones that help the pregnant body to accept the "intruder" growing inside.

It has been shown in mouse experiments that certain viruses can protect mice from bacterial infections. There is also evidence that the herpes virus latent in the body, cytomegalovirus, can protect against influenza.

"However, viruses are typically studied individually and as part of a specific disease. Our research points the way to the fact that viruses should be studied as a whole and try to find out, for example, whether viruses cooperate in the body with each other or with other microbes," says Pyöriä.

Perdomo nods.

"Viruses probably have many other beneficial effects, such as the training and regulation of the immune defense. The interaction between the body, viruses and other microbes certainly has a significant impact on our health," he says.


Senior Member
Some of the hidden viruses might be phages, which spring into action during a bacterial infection, and their presence is due to evolutionary benefits for the host. Some might have no significant effect in healthy people, and evolution didn't develop mechanisms to clear them out. Activation during other medical disorders is something that needs to be studied.