Hello and welcome to a Fun Fact From Flora ,

Today we are going to have a quick look at what I think is a really badass aspect of your immune system that you probably don’t know about (sorry to all the humans who actually study this (@MJ) — I"m probably going to butcher it).

Now your body is able to recognise and respond to a virtually limitless number of different infectious agents. How on earth does it do that? How does it actually recognise the things that come into your body that shouldn’t be there ?

I imagine it’s not something you think about very often (if ever) because instinctively it feels like it should be easy — if it doesn’t look like something I"ve made then you should kill it. But in order to kill it, it has to be recognised first.

Then in the 1950s a classy bloke called Sir Macfarlane Burnet (oof to be called such a wonderful name) came up with a model, called the clonal selection theory of antibody formation , that explained this wonderful phenomenenomenenon.

Basically what happens if you have some lovely stem cells called hematopoietic stem cells that produce immature lymphocytes , which are a type of white blood cell.

The hematopoietic stem cell makes these by rearranging its genes and differentiating so that it produces lots of different immature lymphocytes. The reason that they are different is because they all have different receptors on their surfaces, known as antigen receptors, that can respond to different molecules.

Any of the cells that have antigen receptors that respond to your own tissues are immediately destroyed. The last thing that you want is immune cells that are trying to attack your own body.

The rest of them mature and become inactive lymphocytes.

The bit that I find totally mad though is that most of these will NEVER ENCOUNTER A MATCHING ANTIGEN .

EVER.

Your body produces so many immune cells that can respond to such a massive variety of compounds that most of them will never be needed.

ISN"T THAT MAD.

But what is so awesome is that as soon as there is an antigen or a pathogen that enters your body — you almost certainly have an immune cell that’s waiting to be activated. This is why you feel ill for a while before your immune system kicks in. There are so few of each of those inactive lymphocytes that it takes your body a little while to make enough of them to allow you to actually get rid of the infection.

Pretty cool though, eh?

Hope you enjoyed.

Love as always,

Flora

Here’s the GIF