what is the mechanism for which our bodies develop antibodies to substances we produce for ourselves?



This question stems from my understanding of how MRNA vaccines work, in particular COVID ones (please tell me if I got anything wrong): the mRNA goes in the cells and tells them to produce the spike protein, in this case. Once the cell has released it, the immune system recognises the protein as an antigen, and fights it producing antibodies.

My question is why it’s considered an antigen, since it was produced by the body?

In: Biology

Its like caling 911. Its an indicator of danger. We have a lots of proteins and other chemical stuffs that the only purpose is for signaling a problem. Its like a bait. How it occour in a celular level is more complicated of course. I would have to rewiew physiology to make a good awnser.
But its pretty much like real life. You dont only have coops and criminals. You have a whole system of ppl who awnser the telefone, guards, cameras, etc

Most of the time the cells who really attack and destroy virus or bacteria only come after a whole process of signaling..