Immune: A Journey Into the Mysterious System That Keeps You Alive

by Philipp Dettmer

When you look at yourself in the mirror, what you are really seeing is a very thin film of death covering your alive parts.

And now this has become a whole situation.

In a nutshell, cytokines are very small proteins that are used to convey information.

If there are too many cytokines the immune system can lose all constraint, become super enraged, and overreact massively—which leads to an appropriately named cytokine storm.

Inflammation rises massively and is no longer limited just to the place of infection. Immune cells flood the affected organs and can cause profound damage. Blood vessels all over the body get leaky and fluid rushes into the tissue and out of the vascular system. In the worst case, the blood pressure will fall to critical levels, and organs will not receive enough oxygen and begin to shut down, which can end deadly.

one of the biggest advantages microorganisms have over multicellular animals is the rapid pace at which they are able to change and adapt.

Basically the complement system is an army of over thirty different proteins (not cells!) that work together in an elegant dance to stop strangers from having a good time inside your body. All in all, about FIFTEEN QUINTILLION complement proteins are saturating every fluid of your body right now.

Helper T Cell.

CD4+

crab-like sniper rifles,

Well, first of all the activated B Cell moves to another area in the lymph node and begins cloning itself. One becomes two, two become four, four become eight, and so on. This cloning continues until there are roughly 20,000 identical clones, all with copies of the specific receptor that was able to connect to the original antigen, the first virgin B Cells picked up. These B Cell clones begin producing Antibodies that use the blood as a lift to the site of infection and can flood the battlefield and help out—although they are second-rate antibodies. They are OK at their job but not amazing, snipers that land more body shots than head shots.

Basically, a B Cell takes a complex antigen and turns it into many processed, simpler pieces that are then presented to the Helper T Cell.

Which will make it sad and after a while it will kill itself.

Another thing that makes IgG Antibodies special is that they are the only Antibodies that are able to pass from the blood of a mother into the blood of an unborn fetus via the placenta.

Passive immunity

So if you have a nasty cold, your snot is full of IgA giving viruses and bacteria a hard time.

When mothers are breastfeeding they provide their offspring with a large amount of IgA Antibodies through their breast milk. These antibodies then cover the gut of the newborn and protect its still-fragile intestinal tract from infections.

ALSO works through passive immunity. Cool!

So B Cells are not locked into making a certain class of Antibody—they always start with IgM but can switch the Antibody type if the Helper T Cell asks and encourages them to! Having a nasty cold or a gut infection and need a lot of antibodies in your snot or stool? Make IgA! Having a parasitic worm in your intestines? Make IgE! A lot of bacteria have infected a wound? Make IgG flavor one! There are a lot of virus-infected cells? Please, more IgG flavor three!

And IgA does not activate the complement system and does not trigger inflammation, which are both very important here. IgA is really good at something else though: with its four pincers that reach in opposite directions, it is an expert at grabbing two different bacteria and clumping them together.

Almost as crazy as the idea that the positions of stars when you were born have an influence on your character and personality traits.

Interferons will seldomly eradicate an infection by themselves, but they don’t have to. All they have to do is slow down the multiplication of new viruses by making cells in the vicinity much more resistant to the virus infection. And sometimes this response is enough to prevent the spread of a virus infection so efficiently that it goes nowhere and you’ll never even know anything happened at all.

the job of an MHC class I molecule is to present antigen.

do you know how crazy of an experience it is to be not paying much attention in class in favor of reading this book and then paying attention at the exact moment we start talking about MHC1

If the Helper T Cell is the careful planner that makes smart decisions and shines through its ability to organize, the Killer T Cell is a dude with a hammer that bashes heads in while laughing maniacally.

This process is extremely efficient and the virus count drops harshly as thousands of Killer T Cells move through the battlefield, checking every cell they meet for infection, in a process that is called “serial killing.” Yes, this really is what it is called, praise where praise is due, immunologists nailed this term.

Except, of course, if they are red blood cells. As we said before, they are the only cells in your body that don’t have MHC class I receptors, no display windows. This is what happens in malaria—the parasite plasmodium infects red blood cells and Natural Killer Cells cannot check these cells for windows and have to do something else to combat this infection.

because they have no nucleus

And lastly, let us mention the newest type of vaccine, the mRNA vaccines. The basic principle here is pretty genius, it is basically making our own cells produce antigens that the immune system can then pick up.

Well fun fact, it is not cool with that but actually really indignant about the sudden flood of horse or bunny protein. So while the antivenom will work fine the first time, the second time you might be immune to it because your body might make antibodies against the antibodies from a horse or bunny. This is one of the cases where the immune system just could not have expected that modern medicine would come up with creative solutions like pumping venom into a horse and then using its blood for ourselves.

Some people are allergic to latex and can wear neither latex gloves nor full-body latex suits (which is a real tragedy if they are into that).

histamine can cause the smooth muscles in your lung to contract and make breathing hard or even impossible.

Or put simply: Worms release a plethora of chemicals to downregulate and modulate your immune system to make it weaker.

Because of this fact, some scientists argue the lack of worms in humans in the developed world is weird for your immune system because it evolved assuming that you would suffer from parasitic worms on a regular basis.

GENUINELY REALLY INTERESTING

our immune system still operates under the assumption that worms are making it weaker and that it needs to be more aggressive as a counterbalance.

If this general idea is true it might explain a lot of diseases caused by too-aggressive immune systems in people without worms, mostly allergies and inflammatory disease. And not only that—the lack of worms leaves a whole bunch of our cells without the enemy they were made to fight on a regular basis. So the idea makes sense that without wormy stimulation, these weapons just found new targets.

It seems like you can draw a direct line from how developed and rich a society is to how much of its population suffers from some kind of allergy or autoimmune disorder.

And there is a huge difference between Amish and Hutterites: While the Amish practice a traditional style of farming, where single families have their own farms with dairy cows and horses that are used for field work and for transportation and in general avoid modern technology, the Hutterites live on large and industrialized communal farms, with industrial machines and vacuums and many amenities of the modern world. Consequently, researchers found a much higher rate of microbes and microbe poop in the houses of the Amish compared to the Hutterites. The rates of asthma and other allergic disorders are four times higher in Hutterites than in the Amish.

So it seems growing up in a less-urban environment offers some protection against allergic disorders.

Both C-sections and the lack of breastfeeding are correlated with a higher rate of immune disorders like allergies.

So what can you take away from this chapter? Wash your hands at least every time you use the restroom, clean your apartment but don’t try to sterilize it, and clean the tools you use to prepare food properly. But let your kids play in the forest.

What is generally troubling about these appeals to naturalism is the idea itself, that something natural is somehow better. Nature does not care about you or any individual at all. Your brain and body and immune system are built on the bones of billions of your would-be ancestors who were not fast enough to escape a lion, were killed by a mild infection, or were just a little worse at pulling the nutrients from their food. Nature gave us charming diseases like smallpox, cancer, rabies, and parasitic worms that feast on the eyes of your children. Nature is cruel and without any form of care for you. Our ancestors fought tooth and nail to build a different world for themselves, a world without all this suffering and pain and horror. And consequently we should celebrate and marvel at the enormous progress we’ve made as a species. While we obviously still have a long way to go and the modern world has a lot of downsides, the notion that “natural is better” is something only people who are not actually living in nature can say, and who have forgotten why our ancestors worked so hard to escape it.

Boosting the Immune System is a horrible idea that is used by people trying to make you buy useless stuff!

Over everything else, you want a balanced immune system. Homeostasis. Aggression and calmness.

At least for now, there are no scientifically proven ways to directly boost your immune system with any products that are easily available. And if there were, it would be very dangerous to use them without medical supervision.

The most important thing you need to do to have a healthy immune system is to eat a diet that provides you with all the vitamins and nutrients your body needs. The reason is, simply, your immune system constantly makes many billions of new cells.

You can’t physically fight your client if the deadline is close

All in all, the easiest way to get cancer is to be alive long enough. It is statistically impossible to not develop some cancer at some point in your life, even if it ends up not being the cause of your death.