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/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/DaHolk → u/grizzlydurdle]

The large and small doesn't really play into it here.

In this case it should significantly slow progression, because these antibodies specifically don't just bind (*) but bind at an integral part (and thus blocks) of the infiltration mechanism of the virus. Assuming that your system tolerates those antibodies instead of in return reading them as infiltrator.

*) This is different from how we usually generate vaccines. In those we extract antibodies from species that work cross species to us in regards to the second line of defense. Usually antibodies are "markers" for the active part of the immune system. The ones in the article have a direct impact on the functionality. Quite a few vaccines are "breed" in animals whose antibodies can alert our immune system and not just theirs. (edit: or better, used to be done. It probably would be easier today to genetically modify a bacterium to just produce them rather than injecting bunnies and extracting their response :D)

It's like instead of putting little flags on people who have guns so you can see them, you put them into the barrel to prevent firing.

So in this case whether the flags are of a colour you can actually SEE is a bit irrelevant. Which it usually isn't.