I’ve heard about antibodies, but how does your immune system physically attack or destroy a virus? Or in the case of someone with something like MS, how does your immune system physically attack your nervous system?
In: 3
White blood cells are the answer here! They are part of your immune system and go through your bloodstream and your organs/tissue and basically act as the bouncer in your body. They fight the illness/injury in the body (and I say they bc there are a few different types that do different things, but that is the gist of their function). For folks with autoimmune conditions they basically attack everything – good and bad. So they attack good and healthy tissue too and cause inflammation and pain and disfunction, even though they are trying to help. I think that’s the most I’ve got!
I think antibodies are mostly effective against bacteria, and they operate inside the bloodstream. Viruses tend to infect cells, so there are other cells dedicated to killing those infected cells. But they actually are a variant to those producing antibodies (they are also specific to each threat)
I feel like you’re asking for a bit more advanced answer so here: viruses are a bit different than bacteria because they mostly stay hidden from the immune system by living inside your cells. Luckily the cells in your body have devised a system to detect hidden viruses. Basically, every cell in your body is constantly chopping up a small portion of the proteins inside and attaching the short chopped up pieces to other proteins called the “major histocompatability complex” or MHC. The MHC molecules move to the surface of the cell and leaves these chopped up pieces of proteins extended, sticking out of the cell. Here’s where the immune system comes in. There is a type of immune cell, a specialized T cell, called a cytotoxic T cell. These special cells float around throughout your body and test all the pieces of protein sticking out from cells on MHC molecules. This is getting hard to do ELI5 so I’ll just say there’s basically a system that trains these cells while they’re developing so that they will ignore pieces of protein from anything normally made in your body, but when they detect something abnormal – a piece of a viral or intracellular bacteria protein – they kill the cell which prevents the pathogen from replicating.
There’s lots of ways to do it. First you need recognition:
– Many different white cells have receptors that can recognize when something is covered in complement proteins or antibodies.
– Also many cells have receptors capable of recognizing molecules common to particular classes of pathogens, like LPS in gram-negative bacterial membranes, or molecules associated with damage to other cells of the own body, like DNA (which belongs strictly inside your cells’ nuclei).
– Particular cells of the *adaptive* immune system — T and B cells — can generate their very own unique receptor that can recognize one very specific molecular pattern.
Once you’ve got recognition, there are then a couple of ways to attack a virus, cell or larger thing:
– Eat & digest it
– Dump harmful molecules on it
– Bog it down with antibodies
– Let complement poke it full of holes
– If inside an infected host cell, trigger that cell’s self-destruction to force it out in the open and *then* do any of these other things
Hope that’s broadly informative.
In the specific case of MS, people have B cells that have somehow become sensitized to myelin. Myelin is a molecule that forms a sheath around nerves, which hugely improves their ability to quickly transmit electrical signals (and you depend very much on that working correctly). These B cells produce antibodies, which will end up binding to myelin wherever they find it, and once they’re bound, any other passing white cell with antibody receptors will think “well, this has antibodies stuck to it, so it’s gotta be bad”, and attacks the myelin sheath. That’s mostly T cells going the *dump harmful molecules* route.
White blood cells are the answer here! They are part of your immune system and go through your bloodstream and your organs/tissue and basically act as the bouncer in your body. They fight the illness/injury in the body (and I say they bc there are a few different types that do different things, but that is the gist of their function). For folks with autoimmune conditions they basically attack everything – good and bad. So they attack good and healthy tissue too and cause inflammation and pain and disfunction, even though they are trying to help. I think that’s the most I’ve got!
I think antibodies are mostly effective against bacteria, and they operate inside the bloodstream. Viruses tend to infect cells, so there are other cells dedicated to killing those infected cells. But they actually are a variant to those producing antibodies (they are also specific to each threat)
I feel like you’re asking for a bit more advanced answer so here: viruses are a bit different than bacteria because they mostly stay hidden from the immune system by living inside your cells. Luckily the cells in your body have devised a system to detect hidden viruses. Basically, every cell in your body is constantly chopping up a small portion of the proteins inside and attaching the short chopped up pieces to other proteins called the “major histocompatability complex” or MHC. The MHC molecules move to the surface of the cell and leaves these chopped up pieces of proteins extended, sticking out of the cell. Here’s where the immune system comes in. There is a type of immune cell, a specialized T cell, called a cytotoxic T cell. These special cells float around throughout your body and test all the pieces of protein sticking out from cells on MHC molecules. This is getting hard to do ELI5 so I’ll just say there’s basically a system that trains these cells while they’re developing so that they will ignore pieces of protein from anything normally made in your body, but when they detect something abnormal – a piece of a viral or intracellular bacteria protein – they kill the cell which prevents the pathogen from replicating.
There’s lots of ways to do it. First you need recognition:
– Many different white cells have receptors that can recognize when something is covered in complement proteins or antibodies.
– Also many cells have receptors capable of recognizing molecules common to particular classes of pathogens, like LPS in gram-negative bacterial membranes, or molecules associated with damage to other cells of the own body, like DNA (which belongs strictly inside your cells’ nuclei).
– Particular cells of the *adaptive* immune system — T and B cells — can generate their very own unique receptor that can recognize one very specific molecular pattern.
Once you’ve got recognition, there are then a couple of ways to attack a virus, cell or larger thing:
– Eat & digest it
– Dump harmful molecules on it
– Bog it down with antibodies
– Let complement poke it full of holes
– If inside an infected host cell, trigger that cell’s self-destruction to force it out in the open and *then* do any of these other things
Hope that’s broadly informative.
In the specific case of MS, people have B cells that have somehow become sensitized to myelin. Myelin is a molecule that forms a sheath around nerves, which hugely improves their ability to quickly transmit electrical signals (and you depend very much on that working correctly). These B cells produce antibodies, which will end up binding to myelin wherever they find it, and once they’re bound, any other passing white cell with antibody receptors will think “well, this has antibodies stuck to it, so it’s gotta be bad”, and attacks the myelin sheath. That’s mostly T cells going the *dump harmful molecules* route.
There’s a bunch of different white blood cells, all do different things. Phagocytes surround and digest the cells like single-celled organisms do. Lymphocytes puncture try to puncture the cell walls of pathogens and insert enzymes, they also can recognize infected human cells and do the same to prevent viruses replicating. And an entire swarm of other cells to help find and identify pathogens.
Autoimmune diseases are diseases where your WBCs target healthy parts of your body instead of infected parts.
There’s a bunch of different white blood cells, all do different things. Phagocytes surround and digest the cells like single-celled organisms do. Lymphocytes puncture try to puncture the cell walls of pathogens and insert enzymes, they also can recognize infected human cells and do the same to prevent viruses replicating. And an entire swarm of other cells to help find and identify pathogens.
Autoimmune diseases are diseases where your WBCs target healthy parts of your body instead of infected parts.
Latest Answers