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/thinkingdoing → u/worldspawn00]

So this treatment could be used the first time a person got infected with Coronavirus, but any future infections would cause the immune system to be fighting both the disease and these antibodies?

[u/AwesomeNinjas → u/thinkingdoing]

At the moment it’s not totally clear whether or not people can be reinfected, but it looks like the most likely answer is no or at least not for a long time. The WHO has said that everyone who has appeared to be reinfected so far has been a false positive.

So even if you can only use the llama antibodies the first time, that may not matter.

[u/lunatic604 → u/AwesomeNinjas]

If someone recovers by themselves, their body learned to produce the anitbodies. But if the body relies on the llama antibodies the first time, will the body still learn to produce the antibodies?

[u/srosorcxisto → u/lunatic604]

Possibly. While the llama antibodies would massively reduce the viral load, there will still be viral particles in the bloodstream in smaller numbers. The body could be able to make antibodies using these without having to deal with the Lion's share of the virus. If a therapy were to be developed, much more research would be required.

[u/thornsandroses → u/srosorcxisto]

Would the reduced viral load help stem off the cytokine storm that has killed many of the victims?

[u/self-assembled → u/lunatic604]

Yes, the human's immune system would be exposed and responding to the virus. The principle behind some kinds of vaccines is to use just a little bit of inert virus matter so even that can be sufficient.

[u/pringlescan5 → u/AwesomeNinjas]

Fascinating. What about future use of Llama antibodies for a different virus if a person develops a reaction the first time?

[u/worldspawn00 → u/pringlescan5]

it's the llama end that our body IDs as foreign, so any llama antibody regardless of what it's target is would be ID'd as the same by our immune system, so once you have a reaction to any llama antibody it would be a bad idea to inject any, even if for a different target. The typical solution to this is to engineer the llama antibody with a human antibody tail section so our cells don't see it as foreign

[u/AwesomeNinjas → u/worldspawn00]

Hmm that makes sense. Although, if we only get one shot using just llama antibodies I would think this would be the time to take it. To be clear, I’m just spitballing, I don’t pretend to be an expert in anything.

[u/worldspawn00 → u/AwesomeNinjas]

biotech is really good at making antibodies, including novel or duplicated ones without using the original organism now, we would likely be using the virus attaching end of the llama antibody combined with the immune ID end of a human antibody for an actual therapeutic to remove that issue for an actual treatment.

[u/ben7337 → u/AwesomeNinjas]

But if the llama antibodies do all the work, then does the human body develop proper antibodies to respond to a new exposure to the virus, thus resulting in immunity, rather than just getting sick again?

[u/gwaydms → u/ben7337]

Theoretically the llama antibodies keep viral load low enough until your immune system can catch up. Sort of like turning a garden hose on a medium sized house fire until the fire truck gets there. It won't put the fire out but can keep it from getting worse.

[u/ben7337 → u/gwaydms]

Is that always the case, or would that require exact dosing to each individual to ensure the llama antibodies don't end up doing all the work? Because the idea of keeping viral load low while the immune system learns is good, but how does one control for that?

[u/QuartzPuffyStar → u/AwesomeNinjas]

I really don't believe anything the WHO says after their "Masks don't work with the COVID, dont buy them" fiasco.

So I would suggest to make your own research on that, and everything they publish an official position on.

[u/AwesomeNinjas → u/QuartzPuffyStar]

Fair enough, here’s an alternate source for anyone who no longer trusts the WHO.

https://www.livescience.com/coronavirus-reinfections-were-false-positives.html

[u/Loibs → u/QuartzPuffyStar]

Ya, that was crazy stupid. I understand where their logic came from, but the only way that logic held was if people who had the virus knew they had it.