Struggling with the science: science evolves

Image by Willfried Wende from Pixabay

As I discussed in the previous blog, I had chosen several scientific facts for my science story.

But what is a scientific fact? And does that actually exist?

After all, science is evolving and insights can change, based on new studies.

Well, the good thing here, is that I wrote a very ‘basic’ piece about immunology. Chains of events that have been described and known for many, many years.

Of course, also on such basic knowledge, recent studies can shed new light. But here I chose basic mechanisms on how cells deal with invaders. And from a lot of options (a lot of different mechanisms that happen) I chose just one. The ‘classical’ one.

To give you an example, in my story the immune cells needed to kick out a fungus, candida albicans (a white thin monster).

I described a scene where this fungus attacks the immune cells in the intestine and the epithelial cells. Epithelial cells form a wall, separating the outside world from the inside- your body.

So, I asked myself, what is known about how cells fight off a fungal infection?

In scientific literature, ‘classical pathways’ are described and not so classical ones. After thoroughly checking the scientific literature again I distilled key elements from the most common pathways.

I was looking for features of how immune cells fight off a fungus that set it apart from say fighting a bacterium or a virus.

I asked myself what is so important, that it had to be incorporated into the story? And what could I leave out.

I often work with post-it notes where I would write down scientific facts for each of my sub-stories. My post-it for candida albicans infection looked like this:

That’s a lot of immunology jargon, yes.

To explain all this scientific jargon is beyond the scope of this blog, but it shows how difficult it was for me to fit this into a story. For me these summarized the basic scientific events that take place during and after infection.

From this I decided that the fungus needed to grab the epithelial cells. It needed to almost strangulate them. There needed to be some sense of urgency that the epithelial cells were attacked. In my story, the epithelial cells are called ‘the guardians’ (in my next blog I’ll tell you why).

I left out all the scientific detail on how cells recognize the fungus and chose to focus on the so- called complement system.

The complement system is a complex cascade of events that is triggered when things go wrong.

It helps immune cells to fight off, for example a fungus.

Think about it as pushing the first domino tile that starts the domino effect: the inevitable falling row of dominos.

This first event for the complement system is a protein that can cut another protein (an enzyme). Once the other protein (the next domino tile) is cut, more and more cleavage of proteins is initiated.

And so, the system rolls on and on. Until all the tiles have fallen.

For the complement cascade, the end of it all can be the formation of a ring of proteins. This ring can stick to, say a fungus. And by doing so it pokes holes into it. Think about it as a metal ring with spikes underneath it. These spikes pierce into the fungus.

As you can imagine, no fungus likes that. Now it’s hurt and will even start to shrink. It will lose its inner fluid and will slowly collapse.

This system is an ancient trick of the immune system which is well documented and described to its tiniest detail.

To include this as a basic immunology mechanism in the story is thus a safe bet. In the future we might learn more things about the complement cascades, but it will likely not change dramatically.

However, there are other scientific parts where the evidence is not so clear. New insights could change ‘the science’ quite dramatically.

One example is the idea that the fetus, the unborn child, in the womb is in a sterile environment.

What does this mean?

This means that the womb is so deep inside the mother’s body and so well protected that no microorganism (therefore called sterile) will make it there.

This ‘fact’ has been well established throughout the years. Well of course there are exceptions, as some microbes can make it there- such as certain viruses.

But for the most part we know this place is sterile because no microbes have been found there and immune cells in the placenta are naïve- meaning that they have not met any microorganism yet.

Scientist can profile immune cells on the basis of the structures (receptors) they show, to know if they have met bacteria, viruses, or fungi or not.

But in recent years there has been a lot of debate in the scientific community about the fact that the womb is sterile.

Several studies have shown that microbes can be detected there and maybe even some immune cells here and there look like they have seen an invader before.

The matter is not fully settled yet.

But it looks like -at least for detecting microorganisms in the womb- that the results were very likely caused by measuring contamination.

If you’re interested in this subject check out this article from my favorite science writer Ed Yong in the Atlantic.

So, what does this whole debate mean for my story?

Well, first of all, my story starts with the birth of the child.

Right after birth, or hours later, microorganisms, such as a ton of bacteria, will find their way onto the skin, into the gut and into the lungs. And onto a lot of other places where we have contact to the outside world.

So, for me, this debate is not essential. It doesn’t matter too much for the story, if the womb is indeed sterile or not.

But would I ever set my story inside the fetus’s body, inside the womb of the mother- that would be a different thing.

Until this scientific debate is not fully resolved, I will probably not set my story in such as place then.

In my next blog I’ll tell you more about the immune cells who are featured in my story.

Maybe you know about immune cells already? About white blood cells?

Do you also know which types exist? And what they do?

Spoiler alert: there are so many different immune cell types that I cherry-picked a handful to include them into my story.

But which ones and why? And how can I define their personalities based on science?