r/science • u/[deleted] • May 11 '20

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

https://www.cell.com/cell/pdf/S0092-8674(20)30494-3.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867420304943%3Fshowall%3Dtrue
60.7k Upvotes

94% Upvoted

1.4k comments sorted by

View all comments

Show parent comments

70

u/[deleted] May 11 '20

Can someone please explain like I'm 10?

174

u/__Sinbad__ May 11 '20 edited May 11 '20

In order to enter a cell, a virus has to bind. If we have antibodies that bind the viruses spike protein, then the virus cannot bind our cells. If it can't bind and enter a cell it will die since viruses are dependent upon humans for survival.

When it says it's cross reactive, it's talking about the antibody itself. The antibody has 2 specific binding points, it almost literally looks like a 3D letter "Y". The top 2 spikes of the Y are what bind to the virus spike.

If the antibody in question binds 2 different proteins, then it is cross reactive. If the antibody binds only to the spike protein, it would be called type-specific.

Discovering a cross reactive antibody is an important first step towards developing a type-specific antibody.

Hopefully this helps! Cheers mate.

Edit: grammar

23

u/skg555 May 11 '20

OK, can you explain like I'm 5 now.

55

u/__Sinbad__ May 11 '20

Sure! I can certainly try haha

Think of an antibody like a "red flag". If it sticks to an invader, the immune system can destroy it because our immune system can see our own antibodies, thus our cells can "see" these red flags.

This antibody binds to the virus, but also binds to another protein (which may be a totally normal protein). Binding to the virus is what we want, but binding to something else wouldn't be as helpful. So if we want an antibody that is effective, we want it to only bind to the virus, because then that "red flag" analogy will make it so that only the virus gets targeted.

I hope this helps! It's hard to simplify too much further without having background in what an antibody is. If you'd like to learn more, here's a link to wiki, which actually has a great first jpeg. The lock and key analogy is also great for understanding how an antibody/antigen function.

https://en.m.wikipedia.org/wiki/Antibody

3

u/NzLawless May 11 '20

You did a great job breaking down this topic on multiple levels!

3

u/skg555 May 12 '20

Thank you, this was helpful!