horizon wrote:Audax67 wrote:horizon wrote:From the Guardian this morning:
https://www.theguardian.com/world/2020/ ... us-vaccine
Do read it - it explains that the human body (lung cells) have a perfect receptor (the ACE-2 receptor) ready to meet and greet the virus. A perfect fit in fact. So would anyone like to hazard a guess as to why the human body (yes, your body) is set up in this way? Fifth column perhaps?
You're putting the cart before the horse: the ACE-2 receptor is part of the body's blood-pressure control system. Angiotensin - the A in ACE - causes blood vessels to contract, not just in humans but in practically every animal that has a circulatory system. Many coronaviruses have evolved to target ACE receptors: since they're so common, it's no surprise.
You must admit though that the relationship between the human body and the virus is quite interesting. We don't seem to have evolved to shut the virus out, indeed we seem quite friendly to it - a sort of old friend popping in who knows already where to hang his coat and where the biscuit tin is.
It's certainly interesting, but it's no different from the way that viruses have always worked. Animal cells provide gateways in the cell walls so that substances necessary for the life of the cell can get through. There are "keys" that open the gateways, e.g. insulin opens the way for glucose to get in, and in people with diabetes the gateway no longer opens easily so the sugar stays out and gums things up.
Viruses exploit available gateways simply by matching the keys. They manage to do so by simple evolution: several million viruses will fizzle and die for one that gets in, but that one will take over the mechanisms of the nucleus to produce multiple copies of itself, which will then burst out through the cell wall, killing the cell on the way, and infect other cells. And so it goes...