When I wrote the macrophage blind method in the last issue, many people in the background expressed dissatisfaction, why did they put a handsome white blood ball for no more than three seconds, but did not put the gentle and cute giant breast phage big sister.
#那为什么不扪心自问我为啥要给你们看我老婆 #
Image source | 《Working Cell》
But on second thought, it would be nice to have a few more lovers who fell under my wife's pomegranate skirt, after all, the people who have done this in the past are two meters high...
No kidding, macrophages are dancing a gorgeous dance when they play a role in innate immunity.
Look, how elegant, flowing, and enthusiastic this flaming fiery red skirt is, and it seems to be stained with the blood of the enemy.
Since the author himself is more excited, put another accelerated version.
Students with better eyes may have noticed that between the skirts as thin as cicada wings, there seem to be some poking and poking.
Take a high-contrast look.
These thorns are the key to how the skirt can be so flowing.
It can be seen that on the surface of macrophages, two spines are first extended to prop up the cell membrane, and then the two spines rotate and cross to retract into the cell.
Taking care of students who are addicted to meitu and have no time to think, we put some steps to decompose. Look at the white box, this is a separate "skirt".
You can clearly see the whole process~
Where did the retracted "skirt" go?
Scientists found that after the thorns were withdrawn, a similar hollow structure appeared at the roots of the two thorns.
Look at this detail map. Different proteins are labeled, and the cavity structure is more pronounced.
The formation of this structure is very interesting. Scientists broke down the whole process and found that things look like this.
First, two spines protrude out of the cell and support a piece of membrane tissue; then the roots of the two spines come closer together to form a V-shape, at which point the membrane tissue in the middle begins to sink; then the two spines undergo a rotation, closing the depression, forming a hollow structure.
Students who don't quite understand it look at this diagram.
In this process, the propped up cell membrane becomes the beautiful "skirt" we see.
The retracted membrane forms an intracellular vesicle, or cellular bubble.
The whole process is inseparable from a protein called Rab13, it does not matter who it is, look at the picture, no it can not.
On the right are Rab13 knockout macrophages
In fact, this is one of the processes of macrophage phagocytosis, "macropinosytosis". With macrocytosis, macrophages can non-specifically ingest some extracellular substances, including soluble molecules, nutrients, and antigens. The size of the bubble also varies greatly, from 0.2-5 microns.
This is arguably at the heart of macrophage function, to name a few simple examples.
When stimulated by the pathogen, macrophages activate macrocytosis, which can absorb the antigen into the body, and then after a series of processing processes, the antigen is loaded onto the main histocompatibility complex (MHC) molecule, so that the enemy message can be transmitted to the T cell, which in turn activates the downstream immune response, such as promoting T cell proliferation.
This scene is the antigen presentation
However, some pathogens are also very witty, and even learned to use giant drinks. For example, pathogens such as the rampant Ebola virus, Salmonella typhi and Listeria can actively activate giant drinking through different mechanisms, lie down and so on to be absorbed, and effortlessly expand the scope of infection.
After all, if you really enter the cell, you have to go through a set of lysosomal baptism, and you can survive it can be said to be super small and strong.
Image source | National University of Singapore
In fact, the giant drinking process is not the first time scientists have studied it, but previous findings have generally observed that the surface of macrophages forms a cup-like structure like the above figure, or a C-shaped fold.
This may be a difference brought about by technology. The lattice light sheet microscope (LLSM) used in this study can be continuously imaged at intervals of seconds, otherwise it would not have been found that the surface of macrophages is so dynamic. Typical cup-shaped or C-shaped folds can last about 30 minutes, while the "skirt" phenomenon found in this study averaged only 176 seconds during the whole process.
The C-fold looks like this
Including the tissue-resident macrophages introduced last time, macrophages are a series of functionally continuous cell populations (hence the long-haired, short-haired, large-breasted sisters).
What we often call M1/M2 macrophages are two types of functionally more extreme. The former promotes inflammation and sterilization, while the latter is anti-inflammatory. The traitor in our midst, tumor-related macrophages, which are mainly M2 phenotypes, actually promote tumor growth (two or five!). ）。
But...... Cuteness is justice! My wife is justice! Forward sharing points in the look at it to show you a little more of my wife!
Editor God nagging
Today's article is from the Journal of Cell Biology.
Let's take a look at the picture below.
Comrade BioTalker stared at it for a while and told me that it looked a lot like a rural fishing net... It is said that the author of the paper and the reviews distributed by the magazine use the metaphor of the tent pole...
What a middle-aged man who has no dreams about the bottom of a girl's skirt!
Resources:
[1] Condon N D, Heddleston J M, Chew T L, et al. Macropinosome formation by tent pole ruffling in macrophages[J]. J Cell Biol, 2018, 217(11): 3873-3885.
[2]http://jcb.rupress.org/content/217/11/3774
[3]https://en.wikipedia.org/wiki/Macrophage#Types
[4]https://www.mechanobio.info/what-is-the-plasma-membrane/what-is-membrane-trafficking/what-is-macropinocytosis/
[5]https://www.mechanobio.info/what-is-the-plasma-membrane/what-is-membrane-trafficking/what-is-phagocytosis/
This article is written by | Daisy Rain
Don't you like the author's kitten?