'Unparalleled' snake antivenom made from man bitten 200 times
'Unparalleled' snake antivenom made from man bitten 200 times
cross-posted from: https://lemmy.ca/post/43303191
I feel like all the coverage of this leaves out a massive gaping logical hole.
Like anti-venom / anti-bodies are produced by injecting a horse with venom and then collecting the anti-bodies it produces as a result.
In this situation our man Tim is that horse, and he had to inject himself with 900 different venom injections to produce these broad anti-bodies.
Is the plan going forward, to give horses 900 different venom injections to try and recreate this? Is there a synthetic way of making a known anti-body that they're not mentioning? If there is, then why are we still injecting horses with so much snake venom?
The immune system is super complicated but essentially when an animal or person are exposed to some sort of substance white blood cells sample that compound and create an antibody that is tailored to bind and neutralize it. Different substances range in their ability to induce this response and it often takes repeat exposures to get the titre to high enough levels. So one way or another some sort of animal needs to be exposed to the venom whether it be horse, goat or mouse and we would harvest the antibody for use in emergency situations where we need to immediately reverse the effects of a snake bite.
Another way would be to do this in cell culture but I'm not quite sure how that works, I think thats easier to do when the proteins are directly coded for like insulin or something. You could probably harvest B cell clones that produce the antibody to the venom, make them immortal and harvest it that way but I'm less familiar with that sort of wok so I can't really comment further.
To produce ABs in cell culture you usually create a hybridoma cell line, by fusing the B-Cell to an immortal tumour cell line (as you postulated). This approach does however require you to identify the cells that produce the proper antibody.
It gets much easier if you know the exact sequence/structure. To learn this (or find a better one) it is also possible to generate libraries of antibody sequences with semi-random hypervariable regions (the part that binds the antibody) using for example phages that will display any protein on their surface area and then measuring the binding affinity! This is called - drum roll - phage display (very creative).
Alright, enough trivia for now.
Thanks for the explainer! My lab specializes in IHC so I'm generally familiar with ag-ab interactions but not so much with antibody development. Its fascinating!
Why the antibodies can't be analyzed and chemically synthesized in lab? I'm a total noob in immunology but haven't we got quite good at synthesizing organic stuff with say custom bacteria?
To my knowledge its easy to do this with proteins that are directly coded for in our genes. For example there is a gene for insulin so we can clip it, transfect it into a cell culture and get those cells to crank out a bunch of insulin that we can extract, purify and make into a usable, stable product. The problem with antibodies is that we need to be exposed to an antigen capable of stimulating the development of the corresponding antibody. There is a very complicated set of receptors that capture the antigen, internalize and process it to present it to cells that will modify a whole bunch stuff (Thats the limit of my personal knowledge) to generate an antibody capable of neutralizing that substance. In short you still need a living being with some sort of immune system capable of processing that compound and generating an antibody to it, its unbelievably complicated. The good news is once that cell starts cranking out antibody it starts to clone itself so we can extract it, make a hybridoma (fuze the antibody-producing cell from a live animal with immortal cancer cells to create an immortal hybrid that cranks out the desired antibody) then we can continue with the process in cell culture as per usual. Its just cheaper and easier to use live animals with high titre to that antibody. Source: I've taken a couple immunology courses and my lab specializes in immunohistochemistry so I'm quite familiar with antigen/antibody interactions but not so much with antibody production.
So once the cell under immune response makes the antibody, the antibody is a big complex organic molecule right? Have there been any success with synthesizing it in vitro with some crazy ass chemical synthesis? Or cloning such with engineered cells? You said it's possible with immortal cancer cells. After all cells do not generate antibody out of thin air, the cloning 'algorithm' should be somewhere coded.
I don't think you can do that with a single population of cells. Theres a group of cells that sample antigens and process them for presentation then a separate group of cells that the first group will present the antigen to. Once presented there are a set of standardized regions related to the class of antibody then a set of "hypervariable" regions. You would need an organoid/organ system to accomplish this in vitro or ex vivo. Most of the time it will be a macrophage or something that for example ingests a live bacteria (or venom), it will register this as foreign, process the particle and travel to a lymph node where all the immunology takes place (B cells). I don't think theres a simple way to recreate this in the lab its completely different from synthesizing chemicals since each antibody is fine-tuned to its antigen. You might even get different antibodies generated for the same compound depending on how everything went down and which region was presented (eg monoclonal vs poloclonal products).
Wow this is fascinating. I'll read about it more :)
