I’m an immunologist and this is what would happen if all the germs attacked you at exactly the same time

When I was younger, I watched “Batman” on my black and white television after school. In general, Batman would face the Joker, the Penguin, the Puzzler, Catwoman or any of his usual adversaries. However, on certain occasions, Batman should face them all at once.

What if, like Batman, the immune system had to face all its rivals at once?

I am an immunologist who teaches the fundamentals of immunology to university students . My research generally focuses on factors that regulate immune responses and prevent autoimmune diseases: conditions in which the immune system attacks its own body. As a scientist who studies how we develop immunity to pathogens like the virus that causes Covid-19, understanding how the immune system fights multiple threats at the same time is extremely important to me.

There’s no reason why you shouldn’t have strep throat at the same time as you have a cold. In fact, sometimes fighting an enemy can leave a hole in your defenses that another opportunistic pathogen can exploit.

The first point to consider is What does your immune system protect you from? . Possible villains include cancer cells and dangerous microorganisms (including bacteria, viruses, fungi, etc.) that cause infections. The immune system must also be careful do not damage healthy cells and beneficial microorganisms that live inside and outside of you.

You interact with thousands of microorganisms with every breath you take. Does the immune system handle them all? Something like that.

It takes a a huge amount of energy fight a battle once a rival gains a foothold in your blood or tissue, so your immune system works to prevent it from entering the body in the first place. The skin, snot saliva and the tears form a first line of defense fundamental. This is the reason why burned they lose too much skin They often die from massive infection: their defensive barriers are too compromised and pathogens flood.

The immune system largely prefers trap a microbe in snot and blow it out your nose, or give it time to wash it off the skin of your hands, rather than having to wage cellular warfare. Gather an army of immune cells Fighting pathogens takes a lot of energy and makes you feel terrible.

For example, the immune system increases your body temperature to make it an uncomfortable place for microorganisms to live and grow, but this fever can also make you want to lie down for days.

When Batman faced multiple adversaries, he would find a weakness shared by all adversaries and target it to thwart their plans. The immune system uses exactly the same strategy.

Some microbes are considered pathogens largely because they are in the wrong place (e.g. inside the body rather than on the skin) and cause damage. Pathogens have specific parts on their surface called Pathogen-associated molecular patterns or PAMPs (for its acronym in English).

Very important, your body does not produce PAMPS . This means that if your immune system encounters a PAMP, it will know it shouldn’t be there and launch an attack. Since the same PAMP is present in many different pathogens, a strategy to combat one PAMP can defeat many pathogens.

There are molecules in cells throughout the body that can recognize PAMPs and destroy whatever they are on. It’s as if your immune system has set up explosive traps that can only attack your enemies.

Many of these traps are toll type receivers . This family of molecules is found on the surface and inside many of your cells. Once microbes come into contact with these traps, they trigger an alarm that warns other cells of potential danger. In technical terms, this alarm is called inflammation .

While Batman should come up with a new strategy to fight the Joker, Penguin and Catwoman, your immune system came up with a plan a long time ago.

When the virus causing Covid-19 appeared in 2019, It was something people’s immune systems had probably never seen before. . However, some people already had immune cells capable of attacking components of the virus. How is it possible?

The immune system produces many antigen-specific immune cells, or unique, recognizable parts of cancers and microorganisms you’ve never encountered before. This happens through a process in which parts of your DNA they recombine randomly to form unique receptors of immune cells. The DNA of each of these immune cells is different from the DNA of any other cell in the body. Researchers believe that each person can generate at least a billion different combinations immunological receptors, which is more than the number of pathogens that an average person would face it throughout their life in general.

Although the immune system produces many immune cells, most of them are not used because you are not exposed to the antigen they are supposed to recognize. However, when an immune cell recognizes an antigen, it makes many copies of himself . Since pathogens can also multiply quickly, clonal selection allows you to quickly build an army to fight them.

This strategy generally works well with one or two co-infections , like you have a cold and an eye infection at the same time. But what would happen if you were infected with a trillion pathogens at the same time? It would take an enormous amount of energy and time to build an adequate army against every microorganism at the same time. Unfortunately, the immune system would likely be overwhelmed by this challenge and you would likely die.

Fortunately, your immune system, like Batman, He usually discovers the best way to turn a battle against his rivals in his favor. scoring a victory in the final minutes of the episode.

* Joseph Larkin III associate professor of microbiology and cell sciences, University of Florida