Iβm looking at a flow cyt question which has TLR4 as x axis and CD14 as the y axis. Iβm trying to see what cells would be present in the top right quadrant. I know monocytes express TLR4 on surface but could I also say macrophages could be present in the quadrant as they are a division of monocytes?
https://www.nature.com/articles/s41467-021-27426-x
Abstract
Lactic acidosis, the extracellular accumulation of lactate and protons, is a consequence of increased glycolysis triggered by insufficient oxygen supply to tissues. Macrophages are able to differentiate from monocytes under such acidotic conditions, and remain active in order to resolve the underlying injury. Here we show that, in lactic acidosis, human monocytes differentiating into macrophages are characterized by depolarized mitochondria, transient reduction of mitochondrial mass due to mitophagy, and a significant decrease in nutrient absorption. These metabolic changes, resembling pseudostarvation, result from the low extracellular pH rather than from the lactosis component, and render these cells dependent on autophagy for survival. Meanwhile, acetoacetate, a natural metabolite produced by the liver, is utilized by monocytes/macrophages as an alternative fuel to mitigate lactic acidosis-induced pseudostarvation, as evidenced by retained mitochondrial integrity and function, retained nutrient uptake, and survival without the need of autophagy. Our results thus show that acetoacetate may increase tissue tolerance to sustained lactic acidosis.
Authors:
- ClΓ©ment Adam
- LΓ©a Paolini
- NaΓ―g Gueguen
- Guillaume Mabilleau
- Laurence Preisser
- Simon Blanchard
- Pascale Pignon
- Florence Manero
- Morgane Le Mao
- Alain Morel
- Pascal Reynier
- CΓ©line Beauvillain
- Yves Delneste
- [Vincent Proca
This is probably a dumb question but I've had it for a while and haven't come across the answer yet.
When the B cell is the APC, its very easy for the Th cell to activate it since they are directly in contact . The B cell receives both of the signals needed to activate which I think I understand them to be first binding of the Ig molecule followed be eventual presentation of MHC class II for the TCR to bind to and create its second signal via B7/CD28 interaction (which now that I say this I'm not sure if that interaction is just for T cell second signal or not. Is the B cell second signal from MCH directly? or do both have second signal from B7/CD28? maybe I'm more confused than I thought).
Anyway for my question, lets say the Th cell gets its antigen presented via dendritic cell. The Th cell will become activated and it will release cytokines, but how does this T cell then activate the right B cell to release the right antibodies? I wouldn't have thought that cytokines alone would be enough to activate B cells which I thought needed 2 signals? and nowhere have I seen that cytokines can ever be either of those. I can see it allowing B cells to learn what area they are needed which then would allow the B cell to become the APC after it also functions as a phagocyte, but then that makes the dendritic cell-T cell interaction seem pointless.
As stupid as this sounds, can the Th cell move the antigen off of the dendritic cell onto its TCR to then carry it to the B cell MCH class II? it doesn't sound right to me but I don't see how else that specific T cell will be able to activate a B cell to ensure the proper antibody is produced.
Edit: clarified what my question is
https://preview.redd.it/pbbb9psixqe81.png?width=5500&format=png&auto=webp&s=7f4746028cfccb9451f3931aef860d2848d06c38
Character Basics
Full Name: Macrophage
Race/Ethnic Group: Bio Android containing Majin, Frieza race, and unknown other DNA
Character Nature: Dragon Ball Universe TTRPG character concept
-------------------
Character Details
Gender: male, we think
Size: Small (3 ft)
Age: somewhere in mid to late 20s
Facial Features: has a bunny nose and mouth like a cat. Eyes are Red with black sclera
Distinguishing Marks: indentations/holes in the skin on arms and chest
Body Type: somewhat muscular
Color Scheme: Pink, very pink
Gear: Wearing some kind of GI, most likely white or other light colour, with no distinguishing symbol to denote any allegiance to a specific school or master
Action/Pose: defensive stance of some sort, or reading a book
-------------------
Character persona
Alignment: Neutral
Personality: Will not fight when he can try to reason with people. if someone's life is on the line, whoever he will fight with the fury of a thousand suns. He prefers smarts over strength, but is by no means weak
So for some context, I'm reading Immune by Philipp Dettmer. What's confusing me is simply I guess the vast job that Macrophages do. Why do some move around while others remain still? Why do Neutrophils do similar yet different jobs? I'm not done reading but some of the simplifications that Philip made aren't quite articulate
