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.
I’m currently writing a book for children (>10 years) on immunology. I have been thinking about doing this basically since I started my master’s and Immunology was one of the topics I chose to focus on.
For me Immunology was easy to learn because I envisioned the cells to be alive. How they would react to invaders, what they would do, where they would meet – was one big story for me. I drew large posters of the lymph nodes (where they indeed meet and chat about what they have seen) and envisioned these places as a sort of bar or house where they would get together, to stay up to date (and maybe have some fun as well).
For friends and family, who knew (very) little about immunology, or later even fellow PhD students studying something completely different, immunology was always perceived as very complex. Often this perceived complexity lead to the decision that it was not worth studying.
This is a real miss. So much has to do with your immune system. Think about all the infections you undergo in your lifetime; all the known immune diseases, such as Arthritis or Celiac Disease (two examples of autoimmune diseases). In recent years, it has become clear that the tons and tons of microbes living (primarily) in our intestines, greatly influence our immune system- so much even that certain neurological disorders could be linked to it.
Intrigued by the complexity and relevance of our immune system I began my PhD, focusing on an immune disorder in which your immune cells can’t handle the -normally totally harmless- ingredient of bread and pasta, namely gluten. If you’re immune cells fight gluten you often get celiac disease.
As you can imagine, here I studied mostly immune cells from the intestine. The place it all happens for celiac patients.
Years later now, I found myself working in the (still vague) field of science communication.
After all, during my PhD and post-doc time, I spend hours and hours (sometimes way too many hours) in the lab, running experiments after experiments. Back then I realized that I mostly enjoyed giving presentations, talking and (after some hesitancy) also writing about my research.
I guess I was also a bit too social for most of my colleagues. I still had hobbies while lots and lots where so engulfed by their research that it was hard for some to spend time without it.
The birth of my child eventually was the turning point for me to finally start writing a book about immune cells in a story format (the way I’ve always learned immunology myself).
Witnessing my child struggling with lots and lots of infections, made me realize that it’s really true what they always said during these lectures: young children have an immature immune system and are therefore vulnerable to infections.
The more I read about recent discoveries about the immune system in newborns and young babies, the more I was at awe for the incredible work our immune cells do, in particular during the first 2 years of life. Newborn babies deal with thousands of completely new species in form of microbes, the very moment they are born.
So, I asked myself: What would it be like, to be one of them in this particular moment in life? Do the immune cells really know what is about to happen? How are they prepared for this dramatic impactful event?
These are the questions that guide me when I’m writing the story of Didi: an immune cell (well to be precise a Dendritic Cell) in the intestine of a baby that was just about to be born.
(Illustrations by Evelien Jagtman)