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You have antibodies that will bind to just about anything foreign, including viruses that your body has never seen before, M-type immunoglobulin (IgM). It's th
by tux3 5y ago
You have antibodies that will bind to just about anything foreign, including viruses that your body has never seen before, M-type immunoglobulin (IgM). It's the kind of antibodies that responds in the first phases of an infection.
The problem is that IgMs are not very specific. They bind to a lot of things, but they bind poorly. In the library of Alexandria analogy, it's like a book that happens to mention a subject you care about, but only in passing.
Vaccines (and infections) result in your immune system developing IgG. That's the hyper-specific books for the pathogen you care about.
So it's not that the book wasn't at the front. Your immune system has to write the book on the fly, during the fight, using chopped up pieces of pathogen gathered by antigen-presenting cells.
- mmastrac 5y agoIs there a good resource to learn more about this without a Biology degree? I always assumed the body generated matching snippets at random and the law of large numbers would result in a match eventually.
- majkinetor 5y agoAFAIK it does.
- webwielder2 5y agohttps://www.amazon.com/Immune-Kurzgesagt-gorgeously-illustrated-immune-ebook/dp/B08YR8FNCP https://www.amazon.com/Immune-Kurzgesagt-gorgeously-illustra...
- tux3 5y ago>Is there a good resource to learn more about this without a Biology degree? Immunology is complicated. Some people call it the second most complicated system, behind the human brain. Someone else has mentioned the Kurzgesagt resources, which are great. If you want something more formal, OME is also a great resource I think. https://onlinemeded.org/spa/immunology https://onlinemeded.org/spa/immunology >I always assumed the body generated matching snippets at random and the law of large numbers would result in a match eventually. Right. Antibodies have a Y shape, where the two tips of the Y are variable, and the base is fixed. The IgM are the completely random snippets that happen to match a wide variety of things. However, because it's chemistry, it's more subtle than match or no match. Think of it like a variable degree of stickiness. When a pathogen is found, your body is going to iteratively mutate new antibodies and select those that bind the best to the collected antigens, until you have something very specific (= sticks very readily). I'm simplifying a little bit, but that's the process for generating IgGs that I was talking about.
- pas 5y agoDo we know how exactly this happens? How fast this process "converges"? How big is the search space and how fast new candidates are generated?
- tux3 5y agoAbout 3e11 combinations are possible, about 10 billions different antibodies will be generated by a human body (numbers I just sourced from Wikipedia). The shuffling is done by recombination, which means joining segments of DNA in a random fashion (a similar recombination process is actually used for DNA repair, though with somewhat less randomness!) There's a lot more to say about all of this, but I don't know how much immunology I can usefully describe in a few HN comments =]
- mmastrac 5y agoThis is a very helpful start for me, thank you
- cipheredStones 5y ago(10 billion (1e9) / 3e11 ~= 3%, for those like me who don't have powers of 10 memorized.) Does that imply that there's a good chance someone's immune system will just fail to generate any appropriate antibodies against a novel intruder? Or does the "fuzzy matching" aspect mean that exploring a small percentage of the space mean you're very likely to get at least some degree of success?
- therec 5y agoI like the videos of the Amoeba Sisters. I’m not a biologist, but I feel they go really deep in the subjects while still being relatively easy to understand. Immune system: https://m.youtube.com/watch?v=fSEFXl2XQpc https://m.youtube.com/watch?v=fSEFXl2XQpc Vaccines: https://m.youtube.com/watch?v=uVUf_pt7Sh0 https://m.youtube.com/watch?v=uVUf_pt7Sh0
- brutuscat 5y agoThis book was written by makers of the Kurzgesagt's YouTube channel recently. https://www.amazon.com/-/es/gp/aw/d/0593241312/ref=tmm_hrd_swatch_0?ie=UTF8&qid=&sr= https://www.amazon.com/-/es/gp/aw/d/0593241312/ref=tmm_hrd_s... Pretty cool illustrations too.
- Griffinsauce 5y agoJust read this, it's amazing and also funny, fits the bill perfectly.
- sova 5y agoTangentially relevant is the way CRISPR works, and I would recommend the Nobel acceptance speeches by Jennifer Doudna and Charpentier.
- mmastrac 5y agoI found a speech by Jennifer Doudna here: https://www.youtube.com/watch?v=KSrSIErIxMQ https://www.youtube.com/watch?v=KSrSIErIxMQ Listening now, thanks!
- sova 5y agoGlad you found it. A very simple explanation I heard a while back (NPR?) was that the system is able to keep "mugshots" of intruders it has seen and then snip their DNA when there's a match with the mugshot.