The critters seem to be little affected by the viruses. And we can learn from that.
Researchers argue this in the journal Cell Metabolism . In their paper, they argue, among other things, for more research into treatments that aim to make our immune system look a bit more like that of bats.
Resistant to viruses
We know that many potentially deadly viruses can also affect bats. For example, bats are carriers of the Ebola virus, but also of rabies (rabies) and various coronaviruses, including possibly SARS-CoV-2. And unlike us humans, the bats don’t seem to be bothered by these viruses.
But bats are not only exceptionally resistant to viruses. They also live remarkably long; many species can easily live to be 30 to 40 years old. And that’s much older than most other land-dwelling mammals of a similar size.
Scientists have now re-examined both properties of bats – their longevity and the fact that they are exceptionally resistant to viruses. Although a lot of research has been done on both properties separately, it is the first time that researchers have combined them in one study. And it leads to an intriguing conclusion. Namely that both the longevity and the fact that bats are exceptionally resistant to viruses can be traced back to their immune system. Or more precisely, to their ability to control inflammation.
“With COVID-19, inflammation (which causes the immune system to shut down invaders and repair any damage to the body, ed.) Is getting out of hand,” says researcher Vera Gorbunova. “And sometimes it can be those inflammatory reactions – not even the virus itself – that are fatal to the patient. This is how the human immune system works: as soon as we become infected, our bodies sound the alarm bells and we develop fever and inflammation. Its purpose is to kill the virus and fight the infection, but it can also be a devastating response if our bodies react too strongly to the threat. ” Bats don’t happen to that. Because they have developed specific mechanisms that prevent the multiplication of viruses and damp the immune response to those viruses somewhat.
It not only explains why bats are not bothered by virus infections, but also why they live so long. Because, the researchers argue, inflammation is not only a hallmark of disease, but also of aging and age-related conditions. And because the bats seem to have better control over their inflammatory responses, they may age more slowly and thus live relatively long. “We realized that there may be a strong link between the fact that bats are so resistant to infectious diseases and their longevity. And we also realized that bats can provide handles for treatments that we can use to fight disease among humans, ”said Gorbunova.
In short, our immune system should actually be a bit more like that of bats. But yes, how do you get our immune system there? The fact that bats are so resistant to viruses and so exceptionally long-lived is the result of a long evolutionary history and specific challenges that bats faced in that history. For example, the fact that bats – the only mammals – can fly probably plays a role. “Bats travel long distances and are exposed to different viruses, which they then bring back to the large groups where they live very close together and where the viruses can spread easily,” Gorbunova tells Scientias.nl. As a result, their immune systems are engaged in an ongoing arms race with pathogens. A new pathogen presents itself, the immune system invents something, the pathogen evolves in response, after which the immune system has to get back to work, and so on. “Dealing with all these viruses may shape the immune system and longevity.”
So the bats owe their unique immune system to an evolutionary process that has been going on for thousands of years. We do not do that in a few months. And while nowadays – just like bats – we are used to travel huge distances and live densely packed in big cities, all of us humans are quite recent developments and we have the advanced mechanisms that bats have to quickly to deal with viruses, not yet obtained through evolution. “One consequence of this is that our bodies may be more affected by inflammation,” said Gorbunova.
But maybe, just maybe, we can help evolution. By closely studying the immune system of bats, we may find new treatments. We know, for example, that bats have inhibited or even completely eliminated certain genes that play a role in inflammatory reactions. Medicines with which we can suppress these genes in humans may also be developed. Gorbunova and colleagues now want to investigate this further. “First of all, we need to find out whether it is possible to safely inhibit these genes and what the possible side effects are,” Gorbunova tells Scientias.nl . “Then we have to find out to what extent we have to slow them down.”
The approach proposed by Gorbunova can pay off in the fight against viruses, such as SARS-CoV-2. But the possibilities go beyond that. Most age-related diseases (arthritis, atherosclerosis, Alzheimer’s, etc.) are driven by inflammation. If we learn how to safely control inflammation, we may be able to slow down or even prevent these diseases. ”
Reason enough to take a closer look at the bat and its wonderful immune system. “People have two options if they want to prevent inflammation, live longer and avoid the deadly effects of diseases like COVID-19. One option is to ensure that you are not exposed to viruses at all, but that is not practical. The second is to regulate our immune system the way bats do. ” Follow-up research should give shape to that idea. And ultimately lead to people growing old healthier and living longer.