Viewing a single comment thread. View all comments

Xambia t1_iuhtjma wrote

Reply to comment by tinybabymoose in How do white blood cells know in which direction there is a bacteria? by Enocli

Once the neutrophils make it to the bacteria they follow chemoattractants released from the bacteria (and behave as you see in the video) usually in response to oligopeptides released from the bacteria which have a formyl functional group attached to the N-terminus of the peptide (ex: fMLP)

Edit: I should add that these oligopeptides bind to protein receptors (GPCRs) on the surface of the neutrophil and the location of these activated receptors on its surface let the neutrophil "know" where to go.

186

_AlreadyTaken_ t1_iui3lim wrote

Some microorganisms, like malaria, are very good at hiding themselves and the immune system is blind to them.

50

kippypapa t1_iuiq68j wrote

So why did these cells evolve this way? How did cells like this start out?

4

Xambia t1_iuizjkj wrote

Are you asking "Why/how did white blood cells evolve chemotaxis?" or "Why/how did bacteria evolve to release chemoattractants?"

10

CTH2004 t1_iujchrp wrote

well, I dunno bout him, but I'm curious about both!

and, basicly they "smell" bacteria, right?

6

Limmert t1_iujwe7i wrote

They don’t «smell» it like we think of the word «smell». It’s more like: pieces (chemoattractants) fall of the bacteria and attaches to receptor on phagocyte (because high consentration of a substance = higher chance of said substance to «collide» with the receptor on the phagocyte).

And when a «piece» binds to the receptor it causes an intracellular signal in said phagocyte -> phagocyte shoots out lamellipodium (which basically is a grappler that binds to the ecm in the direction of the receptor binding, and contracts pulling the phagocyte in that direction) -> repeat until catching your target.

I don’t know if that made any sense? Or if it was an answer to your question? The evolution is rather uncertain i believe.

Edit: Fagocyte -> phagocyte

8

CindyTheHooker t1_iujxurs wrote

Did you mean ‘Phagocyte’ instead of ‘Fagocyte’? Fagocyte gave me an interesting definition…

5