7 ms·

This is what antibodies do, right? How exactly does the body figure out how to configure the variable part of the antibody so that it binds? Does it just try c

This is what antibodies do, right? How exactly does the body figure out how to configure the variable part of the antibody so that it binds? Does it just try countless variations until it finds a match? Can we take an antibody from a healed person and reverse engineer the binding protein?

candiodari 7y ago
Yes and no. Antibodies bind against essentially anything on the virus surface, and (depending on the exact type of antibody) do that to multiple virus particles. This is often enough to prevent the membrane from successfully merging with a cell and therefore prevents or seriously reduces the infection rate (you don't have to get infection rate to zero, just low enough). Additionally these antibodies are collected and expelled by other parts of the immune system. But afaik the immune system does nothing to target active sites. This makes sense: specificity matters. For example disabling HIV is easy: just prevent CD4 binding. That will prevent the virus from attacking any human cell. Unfortunately, it has the same effect as AIDS, over time it cripples the immune system. You want to bind, not to the active sites, but to whatever is on the virus and isn't on anything else.
gmm1990 7y ago
Yeah probably an oversimplification but it just creates different combinations and the ones that attach to the pathogen (and don't attach to non-pathogenic things in the body) are reproduced. But the immune system is wild I would say comes close to the neurological system from a how does this exist perspective. https://en.wikipedia.org/wiki/Antibody#Immunoglobulin_diversity https://en.wikipedia.org/wiki/Antibody#Immunoglobulin_divers...
littlestymaar 7y ago
> How exactly does the body figure out how to configure the variable part of the antibody so that it binds? Does it just try countless variations until it finds a match? Not a biologist but IIRC, the body produces cells with a shuffled sequence of DNA. Then this specific cell produces one specific variant of antibodies, located on its surface. At this point the antibody is just a random sequence that matches with nothing. If one day a virus (or anything else) happen to match with the antibody located on the surface of the cell, the cell will then multiply and most of the new cells will specialize into antibody-producing cells (released in the body, not remaining on the surface of the cell) and a small amount will not. The one who aren't producing antibodies are kept in the body for a long time, and they are here to provide quick specific response next time you meet the pathogen again (that's where immunity comes from). So yeah, it's basically brute-force until a matching antibody is found.
deleted 7y ago
[deleted]

candiodari 7y ago

Yes and no. Antibodies bind against essentially anything on the virus surface, and (depending on the exact type of antibody) do that to multiple virus particles. This is often enough to prevent the membrane from successfully merging with a cell and therefore prevents or seriously reduces the infection rate (you don't have to get infection rate to zero, just low enough). Additionally these antibodies are collected and expelled by other parts of the immune system. But afaik the immune system does nothing to target active sites. This makes sense: specificity matters. For example disabling HIV is easy: just prevent CD4 binding. That will prevent the virus from attacking any human cell. Unfortunately, it has the same effect as AIDS, over time it cripples the immune system. You want to bind, not to the active sites, but to whatever is on the virus and isn't on anything else.

gmm1990 7y ago

Yeah probably an oversimplification but it just creates different combinations and the ones that attach to the pathogen (and don't attach to non-pathogenic things in the body) are reproduced. But the immune system is wild I would say comes close to the neurological system from a how does this exist perspective. https://en.wikipedia.org/wiki/Antibody#Immunoglobulin_diversity https://en.wikipedia.org/wiki/Antibody#Immunoglobulin_divers...

littlestymaar 7y ago

> How exactly does the body figure out how to configure the variable part of the antibody so that it binds? Does it just try countless variations until it finds a match? Not a biologist but IIRC, the body produces cells with a shuffled sequence of DNA. Then this specific cell produces one specific variant of antibodies, located on its surface. At this point the antibody is just a random sequence that matches with nothing. If one day a virus (or anything else) happen to match with the antibody located on the surface of the cell, the cell will then multiply and most of the new cells will specialize into antibody-producing cells (released in the body, not remaining on the surface of the cell) and a small amount will not. The one who aren't producing antibodies are kept in the body for a long time, and they are here to provide quick specific response next time you meet the pathogen again (that's where immunity comes from). So yeah, it's basically brute-force until a matching antibody is found.

deleted 7y ago

[deleted]