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1167 points jbredeche | 1 comments | | HN request time: 0.201s | source
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MrZander ◴[] No.43998447[source]
> To accomplish that feat, the treatment is wrapped in fatty lipid molecules to protect it from degradation in the blood on its way to the liver, where the edit will be made. Inside the lipids are instructions that command the cells to produce an enzyme that edits the gene. They also carry a molecular GPS — CRISPR — which was altered to crawl along a person’s DNA until it finds the exact DNA letter that needs to be changed.

That is one of the most incredible things I have ever read.

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Balgair ◴[] No.43999018[source]
One other fun part of gene editing in vivo is that we don't actually use GACU (T in DNA). It turns out that if you use Pseudouridine (Ψ) instead of uridine (U) then the body's immune system doesn't nearly alarm as much, as it doesn't really see that mRNA as quite so dangerous. But, the RNA -> Protein equipment will just make protiens it without any problems.

Which, yeah, that's a miraculous discovery. And it was well worth the 2023 Nobel in Medicine.

Like, the whole system for gene editing in vivo that we've developed is just crazy little discovery after crazy little discovery. It's all sooooo freakin' cool.

https://en.wikipedia.org/wiki/Pseudouridine

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alecco ◴[] No.43999243[source]
> [...] then the body's immune system doesn't nearly alarm as much, as it doesn't really see that mRNA as quite so dangerous

Please tell me there are measures to prevent this going into the wild. Please tell me this won't be used in large-scale industrial farming.

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Balgair ◴[] No.43999790[source]
Yeah, it's not a drama.

The reason that the body doesn't alarm as much to Pseudouridine, is that it's not a 'natural' RNA base. Meaning that, for the most part, nature really never uses it and so we haven't evolved to look out for it. Nature uses Uridine and so immune systems have evolved to look out for random bits of RNA in the body that use it and then clean that all up.

It's like if you're looking to clean up legos in you house with a romba that only cleans up legos. And all of a sudden it finds a duplo. It's going to take a hot second to figure out what to do with the duplo. And in that time, you can sneak by and build a duplo fort. (Look, I know this analogy is bad, but it's the best I can come up with on the fly, sorry. If anyone else wnats to come up with a better one, please do!).

The Pseudouridine is used up and degraded very quickly inside the cell, minutes at the very very longest, more like microseconds. It's just part of a messenger (the 'm' in 'mRNA') to tell the cell to do things.

You might see mRNA gene editing in factory farms, but it would just be easier to do germline editing instead and skip spraying animals, plants, and fungi. Why waste the equipment, right?

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1. kulahan ◴[] No.44000699[source]
I thought the analogy was good. They’re meant to be simple and easy to understand, not perfect representations.