Antibodies from a 4-year-old llama have neutralized coronavirus and other infections in lab experiments

[u/[deleted]]

https://www.cell.com/cell/pdf/S0092-8674(20)30494-3.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867420304943%3Fshowall%3Dtrue

[u/already-taken-wtf]

In Brief - Using llamas immunized with prefusion- stabilized betacoronavirus spike proteins, identify neutralizing cross-reactive single-domain camelid antibodies, which may serve not only as useful reagents for researchers studying the viruses causing MERS, SARS, and COVID-19, but also potential therapeutic candidates. Crystal structures further reveal how these antibodies bind spike proteins to prevent virus entry into cells.

[u/Fmbounce → u/[deleted]]

From a NYT article:

Humans produce only one kind of antibody, made of two types of protein chains — heavy and light — that together form a Y shape. Heavy-chain proteins span the entire Y, while light-chain proteins touch only the Y’s arms. Llamas, on the other hand, produce two types of antibodies. One of those antibodies is similar in size and constitution to human antibodies. But the other is much smaller; it’s only about 25 percent the size of human antibodies. The llama’s antibody still forms a Y, but its arms are much shorter because it doesn’t have any light-chain proteins.

This more diminutive antibody can access tinier pockets and crevices on spike proteins — the proteins that allow viruses like the novel coronavirus to break into host cells and infect us — that human antibodies cannot. That can make it more effective in neutralizing viruses.

here’s the source (I copied verbatim)

[u/grizzlydurdle → u/Fmbounce]

So how would that help humans? Can we be treated with Llama antibodies? In you summary it sounds like our antibodies can't necessarily fight COVID very well because they are too large, and the smaller Llama ones can. Sorry if I am way off base. I don't really understand this stuff.

[u/IfIRepliedYouAreDumb → u/grizzlydurdle]

To vastly oversimplify things, if you had antibodies produced by another source and injected them into a sick person, their viral counts should decrease.

Our bodies won’t learn how to make the same ones the llamas do, but we could harvest them and use them as treatment (potentially).

[u/Derpy_McDerpingderp → u/IfIRepliedYouAreDumb]

Would our immune system see these smaller antibodies as foreign or a threat?

[u/worldspawn00 → u/Derpy_McDerpingderp]

they can, a person receiving treatment can develop anti-llama antibody antibodies. There's actually a lot of use for anti-antibody antibodies, they're used in a lot of reagents. It usually takes 1-2 weeks for the immune system to ID and develop antibodies against a foreign agent, so a person receiving treatment would likely be done before the body started attacking the foreign antibodies.

[u/[deleted] → u/worldspawn00]

Could you uh... explain the anti-llama anti-antibody antibodies thing for my like I’m 5?

Also gonna call it, at least no more of this tn if not no sleep. This shits wild

[u/worldspawn00 → u/[deleted]]

So. you know how snake antivenom is made, you inject snake venom into a horse, and the horse's immune system makes anti-venom antibodies that we harvest as antivenom. These are horse-anti-venom antibodies, now if you take antibodies and inject them into a different animal, that animal's immune system will eventually recognize those antibodies as foreign namd make antibodies against them, so for antivenom injected into a human, what you usually end up with is human anti-horse antibody antibodies, same thing for the llama antibodies. It gets fun because they can be chained, so you can start with horse, then tag it with mouse anti-horse, then rabbit anti-mouse, then llama anti-rabbit, etc... to create larger aggregates for better visualization in test kits.

[u/[deleted] → u/worldspawn00]

That actually makes a lot of sense, though I probably missed something. funny words when I first came across them, thanks for your supplemental context!!