😂

Bro literally said underrated instead of overrated 💀💀💀

@@afreakingwaffle No no, he actually mean underrated, he find camera jokes funny af, so he had tell the other guy to shut up because those camera man jokes where making him laugh so badly that he wasn't able to focus on learn the content of the video.

LOL!

I know, right?

So good you could barely hear the narrator... lol

Hmm... Today I will regret going to the comment section

I thought the sound effects were horrible and distracting.

they are ASMR

...

T-cell: launching granule in 3...2....1..... [mission completed, you may return to the nearest lymph nodes]

You're immune system just wants to kill, that's its function and that's what it loves doing. It takes an awful lot of effort to stop it from breaking your body down cell by cell!

The “Revenge system” sounds cool.

lol true

lmao yeah

Check out The Body. It's on curiosity stream but you can probably find it in other places too.

i have a learning disability

Don't tell those t-cells about your cough, they may come after you.

i came from cells at work too. thanks japan.

bro literally just came from the anime

I’m here because of that show too!

Same here 🤣🤣🤣

same hereXD

Your inability to understand or comprehend the complexity of evolution is not evidence of its creation. I'm terribly sorry that your indoctrination outweighs your ability to think rationally.

@@MatMabee get back to me when you can perceive the entire electromagnetic spectrum.

1. Cells indeed try to undergo apoptosis when infected, but many viruses have specific mechanisms to turn off apoptosis of their target cells. There is even a separate "class" of viruses called oncogenic viruses, which drive the cells away from apoptosis and into proliferation, causing cancer. 2. It wasn't exactly stated in the video, but the animation in fact showed two different MHC molecules. - the first one (the one on the antigen-presenting cell) was MHC II, which the T-cells recognize as the molecule that teaches them to react to a specific virus fragment. - the second one was MHC I, which is expressed on all cells and basically serves as a show case for what kind of peptides the cell produces. If a virus peptide is recognized bound on MHC I, the T-cell knows that this is just a normal cell that is infected. Good questions :)

One more point that I forgot to mention concerning both your questions: The infected cells themselves do not recognize the virus. Well sometimes they do (there are few molecular hints, such as double-strand RNA, which is not typical for eukaryotes), but the way cells present the viral peptides on MHC I molecules is completely independent of recognition - they do this with every peptide they produce. MHC I is, as I said, a showcase of what kind of peptides is produced inside cells, not only viral ones. It is the duty of the T-cell to recognize that this one cell shows odd peptides that the immune system wasn't trained to tolerate as its own. +Mr Niceguy - 1. not precisely, but you touched important subject. Indeed, part of the cytotoxic mechanism of T-cells is to . activate death receptors on target cells, and some viruses produce proteins that block the downstream death pathway. But for cells to downregulate the death receptors themselves is more typical of cancer cells, another threat that the T-cells have to recognize. So that's why cancer often avoids recognition and destruction by immune system. 2. Good thinking, though the antigen-presenting cells are of various types. The one shown in the video is most likely a dendritic cell, which belongs to so-called "professional antigen-presenting cells", the main (nearly sole) work of which consists of gathering different, potentially interesting peptides from bacteria, viruses and environment. These cells present thousands of different peptides at once, but yeah, most of them get the chance of their lifetime when they meet a T-cell that is "interested" in one of their peptides and becomes activated. But no, they don't get destroyed :) There's many more types of antigen-presenting cells, some of which do this just as their side function - B-lymphocytes are a good example. As B-lymphocytes produce antibodies, it would be a poor design if the population of virus-recognizing T-cells killed of the population of the same-virus-recognizing B-cells :) All APCs use a distinct signal - MHC II - to present their antigens without danger of being destroyed. Amen :)

One problem is that cells don't have much capability to recognise many kinds infections within themselves. Viruses work by using back doors in to cells. If you've managed to get in, there's very little a normal cell can do about it. Another problem is mediating cell responses. Nearly all life recognises self and non-self through peptides, glycoproteins and other parts. They have no ability to directly observe items like we do. So imagine if cells simply detected alien parts and self-destructed. You'd have mass tissue death, collateral damage, pandemonium. This is why we need a specialised immune system, to compartmentalise these responses to certain cells that can independently verify problems and kill without the rest of the body overreacting. You'll notice that when non-immune tissue does have involvement in an immune response, such as inflammation, the side-effects, misfires and self-damaging issues are manifold.

Another interesting fact: some infections disable the cell's MHC protein, to prevent the cell from displaying viral peptides. But the immune system has a response for that: natural killer cells. Rather than targeting cells that display viral peptides, natural killer cells target cells which don't display normal peptides, which implies that their MHC system was shut down.

@@samuel.hricko Great answers... thanks

yes and yes

Snake venom is neutralized with antibodies. Antibodies are produced by B cells. The T cells shown here are specialized towards killing infected cells in your own body. It usually happens when they are infected by viruses or damaged by pathogens in other ways. It's important for the body to kill off it's own cells that have become infected, because they spread the disease. The cytotoxic T cells are the special task force that does this exact job.

It uses MHC1 for cytotoxic T ones, and MCH2 for helper T cells

It uses the mhc2 because it is the one responsible for showing foreign peptides on a cell (part of a virus for example) while it uses mh1 to show its own protein which it makes usually to identify itself

Cytotoxic T cells crawl with 'ameoboid' type movement as seen in this video kzfaq.info/get/bejne/pNqba7uk3byomWQ.html

It's not new.

The cells shrink as part of the apoptosis process en.wikipedia.org/wiki/Apoptosis

@@WEHImovies How weird. Its more like the cell has conective tissues inside that change their relative tension or break down.

You are correct - cells have internal structural elements that change and 'break apart' during apoptosis kzfaq.info/get/bejne/qrVdipue26jFZ2w.html

Yes

No. Kurzgesagt made a video or two about it; it's called the Complement system.

ofc not

good question

I've always wondered that

Because the antigen presenting cell is using *MHC II* which was not specified in the video. If the antigen was presented from the MHC I - which the rest of the cells have instead - that would trigger a response from the T cell.

@@regulate.artificer_g23.mdctlsk Hang on isn't the cd8 coreceptor only able to bind to MHC I?

@@adenosine2electricboogaloo647 and thus only allow it to kill MHC I cells?

That’s your white blood cell or immune cell that causes infection. Cytotoxic T Cells Only kills the infected cell so if the dead bury of the cell does not get cleaned up by your body it causes infection.

I think it's a different T cell that does that.

Are you an idiot?

Viruses are too small for cytotoxic t-cells to be effective

@@scrittle Dude, they just explained. They kill the cells inficted by the virus :'D

I think it's different with COVID. We are injected with the proteins that you find on the outside of the Coronavirus cell, which the immune cells target because it's a foreign body. The body then learns how to attack that protein in the future, so that it can pluck the proteins off of the cell wall and destroy each Coronavirus cell, when it's in the body. It means you feel much less unwell, if you do catch it because the body has that immunity and ability to destroy the virus much more easily.

@@Craigy2818 You will be injected the rna for your cells to produce that protein/antigen. After learning how the virus looks it still destroys the infected cells.(Coronavirus still being a virus) You feel much less unwell becouse your immunsystem reacts much quicker if everything went well.

Only if it can respond to the virus FIRST

they do use antibodies that target receptors on t-cells that cause t cells to stop dividing. Antibody used to target for example ctla-4 increases peoples survival chance from 4% to 20%.

Ted Hutnik Yes. If you keep boosting the Immune System and stay healthy

Ted Hutnik very strong possibility. Check out Dr. soon of NantKwest stock symbol: NK. He is very close, using no chemo or radiation.

If it is, then how come people are still getting cancer? T cells are found within all organisms including humans, mind you.

@@gelatinocyte6270 too much money to be made in "research". Cancer is supposed to be a virus.

omg you're right XD