This is a short teaser of the book I’m currently writing about immune cells. Didi is a dendritic cell, Max a macrophage and the guardians are enterocytes (cells in your intestine) which form the barrier between the inside of your body and the outside.
I live inside your intestine, deep down inside of you.
Can you see me or feel me?
Unfortunately, I don’t think you can. I’m so small and hidden that you don’t notice me.
I’m not alone down here, we are many. Many, many cells.
We are immune cells, a close family of cells working together to help you stay healthy- everyday of your life.
Our world is invisible to the naked eye and you can only get a glimpse of what we look like when you use a magnifying glass. And even if you’d look at us with a very powerful magnifying glass, you probably wouldn’t understand how we live.
To find out, you have to be here with us.
But it’s quite a journey to get to us.
First, you travel through your mouth, slide down your tongue- I know it’s a bit slippery but trust me, you won’t get hurt when you slide down. Now you travel through a tube -your esophagus- and then through your stomach. Slip through it and you’ll be at the beginning of your small intestine.
Come a bit closer to the bumpy wall.
You are still too big though. You need to shrink. Make yourself really small.
There you go.
Can you see the details of the wall? It looks different now, right?
The wall is made up of tiny little finger-like structures. Like a carpet, when you take a closer look it is made of thousands and thousands of threads.
Look closer, zoom in. Now you see that there are even more threads, tiny little strands.
This is the hair of all of our guardians’ heads. There are millions of guardians standing so close to each other, shoulder to shoulder, that from the outside you can’t distinguish the individuals. All you see is a sea of hair.
Come a bit closer and tell the guardians that you know me. Only then, they will let you in.
You should know that our guardians are very careful with whom and what they let inside. But you are invited.
Nice to meet you, I am Didi. I am part of a large family of immune cells.
Today is a quiet day. But it wasn’t always like that. We have had turbulent times. When you were just born, everything was new to us. We had to learn so much.
Oh, I still remember our first visitors.
Right after you were born, the guardians noted something odd.
Something was sticking to their hair. They could feel a vibration.
We all held our breath, realizing that we were not alone anymore.
“Who is it out there?” I whispered.
“I don’t really know, but they are talking to us. They are asking if they can stay here.” one of the guardians answered.
As long as I could remember nobody ever lived outside of our walls. Now we seemed to have neighbors. Was this going to change how we live? I wasn’t sure what to make of it.
Suddenly, more and more of them were arriving.
To get a better look outside, one guardian started to stretch a little.
“Hey, I can see one. It’s a bacterium.” he exclaimed, “Wow! This is what they look like.”
Apparently, the guardians had seen little pieces of them before. But never a whole, real, live bacterium.
“Be careful not to let any in.” I reminded him, deeply concerned.
I vividly remembered the stories about them. Some called them gruesome invaders and cold-blooded killers.
As if he had read my thoughts, the guardian said “Oh, but this is a really cute one. Look at it.”
At that very moment, a tiny, ball-sized furry bacterium squeezed right through the guardians. Its multiple eyes bounced around its whole body. Most of the neighboring guardians now looked curiously down at it.
I blinked. Did I now see two of them? It was multiplying right in front of me. At one point, there were so many of them that they formed a big cluster. Their multiple eyes seemed to meet each other’s eyes while they bounced around and giggled.
I grabbed the guardian to pull him a bit closer to me, “Shouldn’t we… be doing something?”
I stuttered, “There are too many here. They have to stay outside.” I inhaled deeply and almost yelled at him now “They can’t be INSIDE!”
But he didn’t seem to be impressed, let alone worried.
At that very moment, my brother appeared out of nowhere. He approached the cluster, wrapped his whole body around one single bacterium and swallowed it whole.
We were stunned.
“Max!” I was so relieved to see him.
“Hmm?” he asked, turning to me with a mouth full of bacterium. Then, a split second later he turned back around and caught another one which was right in front of him. Completely oblivious about him, the bacteria still giggled.
A second later, the whole cluster was gone.
He ate them all.
One furry bacterium at a time.
Illustrations by Evelien Jagtman