A few corrections: First, MHC class I is expressed on all nucleated cells, not when the cell is infected. When the cell is infected, it actually decreases the MHC class I molecules it expresses. Second, MHC class I typically presents intracellular antigens, i.e., viruses. MHC class II does the extracellular (bacteria)
All nucleated cells can express MHC I but can only express it on the cell membrane for recognition by Tcells (CD8) only when it is affected by endogenous foreign material.
Awesome work, the visualizations are very nice and it helped me a lot in understanding the processing. Thanks a lot! Let me just add some corrections: 1.: Not only the infected cells express MHC-I proteins, but every nucleated cells. In case of virally infected cells or some tumour cells, actually, the level of MHC-I on the cell surface can be characteristically low, which will help the NK cell to recognize them and activate citotoxic processes. It is, also, the structure of antigene-bond MHC-I proteins that will be different so that it helps the CD8+ cells to recognize them, just as you explained on the video. 2.: You called the vesicle leaving the Golgi "endosome", which is incorrect. Only the endocytic vesicles that perform transport from the membrane to the lysosome are called endosomes. The vesicle carrying the MHC-I protein to the cell surface is simply a transport vesicle. Also, other people have left remarks before (bacterial infection, ubiquitinization), so I wouldn't repeat those. Apart from these small mistakes it is a really great video, thanks for making it again! Keep up the good work, you gained +1 follower!
He also said cd8 cells interact with mhc1 plus the pathogen. That's wrong. Cd4 cells react to bacteria. Cd8 will respond to mhc1 only if it's virus or tumor associated.
@@manjushreeinamdar1242 not correct..immuology is very convoluted,,,mch 1 is involved in some bacteria.......MHC class I helps mediate cellular immunity, a primary means to address intracellular pathogens, such as viruses and some bacteria, including bacterial L forms, bacterial genus Mycoplasma, and bacterial genus Rickettsia.
.immuology is very convoluted,,,mch 1 is involved in some bacteria.......MHC class I helps mediate cellular immunity, a primary means to address intracellular pathogens, such as viruses and some bacteria, including bacterial L forms, bacterial genus Mycoplasma, and bacterial genus Rickettsia.
I am an RMT medical student and I these videos are very well done and the visual helps me retain and visualize for my self what is occurring. This is great keep them up you know your stuff and you are truly helping me to fully understand.
Thank you very much for drawing everything out and uploading them! I got the human physiology exam tomorrow and I found your artworks are very useful!!! Im looking forward to more of your artworks.
This video was super helpful, I just want to note that MHC I is not CD8+ restricted because also NK cells can recognize them, But the CD8+ cell or the CTL is MHC I restricted
I was studying for about 3 hours presentation and didn't understand it at all. I watched your video and got it in 10 minutes. Thank you, you do awesome job!
what do you do armando? Are you a graduate student, teacher, ... ? Love your videos and they helped me during my basic science years of med school. Wish I could remember half of it though :)
Amazing! I am taking an intro to Immunology course at my university, and I had a homework of this and I have not had lecture yet about this, and your video really helped me! Nice drawings btw Thank you very much!!
Thank you very much Armando, the video was very good and your explanation was very clear which helped me understand the process rather easily. Keep up the videos and many thanks
My major is Genetics but i need to know some basic immunology and your videoes helped me a few times while i was completely frustrated. thanks a lot from Iran❤🇮🇷
Sir your videos are very very useful..I always watch your videos to understand those things which I didn't understand in my class. Your drawing and explanation is too good..I wish I could have a teacher like you.
Your videos are great. However, it is important that you make the difference between the peptides that are presented by MHC-I and MHC-II, because the class 1 would not normally present bacterial peptides; it only presents peptides that do not come from the outside.
Lee HJ Just as extracellular bacteria, the intracellular bacteria are internalized into endosomes (phagosomes) which then fuse with lysosome to form phagolysosome. Both types of bacteria will be presented with MHC II. However, certain intracellular bacteria such as Listeria, escape from the endosome before it fuses with lysosome and end up in the cytoplasm. They are ones that may then be processed for presentation with MHC I. Otherwise, only viral proteins - by virtue of the fact that viruses produce their proteins in the cytosol - are processed and presented with MHC I. The video should be changed to represent viral infection.
I'm a student from Korea.Your lecture showing process in pictorial way helps me a lot Really helps me god damn a lot.Shit i'd tried to understand by written text only and it took my 1 hour with giving nothingAfter I've watched it i thought 'Damn shit. why i wasted my single fucking hour' You have saved my test thanks. i will subscribe
Besttt Video sir. I watched it in 2019 for MSc Exam and again today For CSIR bcoz no any videos could Explain better than this. Thanks a lot sir for making these videos. 😊😊😊
small mistake; TCR is specific for BOTH the epitope (antigen) and the MHC. The peptide:MHC (pMHC) complex is the critical "antigenic determinant" that the TCR groove is specific for.
Great video, a little confused on the part where you mentioned cytokines. I thought cytokines were only triggered by helper T cells and that Cytotoxic cells release granules that contain proteins such as perforin (helps deliver content of granules into target cell) and granzyme (activates apoptosis)
Wow this is really informational. Can you make one of these specifically describing how the MHC tagged cell and T Cell interact in the case of the covid2019 coronavirus?
Hi! your videos are wonderful but I have a question: could you publish the final image of this video? Simply to have an overview of this process to print it and study please?
this is a very good video, with gerat explanations. i have only one question. doesn't the MHC I molecule present only endogenous antigens? because i think the bacterial proteins are exogenous proteins... i am a little confused.
The MHC I does not bind to a specific antigen, it can bind to several different proteins. A single binding site in the MHC I (or II) can bind peptides with high affinity while retaining the ability to bind to a wide variety of different peptides. This is shown by the crystal structures of peptide:MHC complexes
There's a question stuck in my head If MHC 1 binds intracellular pathogens and present it to LT8 How will the LT4 ever meet the pathogen ? Since it's intracellular and presented by MHC 1 ( which is not known by LT4 )
Great illustration of the process. One thing seems a little misleading - author says the MHC1 binding site fits a "specific antigen". I believe in reality it fits a broad range of antigen, and a cell has around 6 versions of MHC1 so that all the ranges cover any endogenous peptide that might be in the cytosol. Otherwise, it would seem highly unlikely that a Tc Cell with a very specific binding site would discover a compatible MHC1 complex with an equally specific binding site. And also a cell would need millions and millions of different MHC1 molecules to be sure of binding any protein.
Nice vid, however i just want to point out that MHC I is present in all cells, ant not only present in case of cell infection , as a matter of fact. MHC I presents peptides from the cell itself . Its like a quality control . If the cell its not infected then it will present only self peptides . If a virus has merged peptides to the cells DNA then , naturally it will present peptides which CD8 T cells will detect as an alien peptide and proceed to kill the cell. If it is not recognized as strage the T cell will be inhibited and not kill the uninfeccted cell.
MHC -1 is also the reason the initial onset of cancer can be spotted by the body correct? When it presents incorrect antigen havering the immune system recognize it and have the killer T cell break it down.
Well MHC can be the reason for a fails transfusion or the inability to accept tissue, but blood transfusion is more affected by blood type. Organ transplant and other tissue transplant is more commonly running in to reflection from MHC. Which depending what country, Provence or state your in they may check MHC comparability. But medical protocols vary, but your right checking it every time would insure compatibility and prevent a lot of problems.
A few corrections:
First, MHC class I is expressed on all nucleated cells, not when the cell is infected. When the cell is infected, it actually decreases the MHC class I molecules it expresses.
Second, MHC class I typically presents intracellular antigens, i.e., viruses. MHC class II does the extracellular (bacteria)
This is a good overview. Thanks :)
All nucleated cells can express MHC I but can only express it on the cell membrane for recognition by Tcells (CD8) only when it is affected by endogenous foreign material.
Awesome work, the visualizations are very nice and it helped me a lot in understanding the processing. Thanks a lot!
Let me just add some corrections:
1.: Not only the infected cells express MHC-I proteins, but every nucleated cells. In case of virally infected cells or some tumour cells, actually, the level of MHC-I on the cell surface can be characteristically low, which will help the NK cell to recognize them and activate citotoxic processes. It is, also, the structure of antigene-bond MHC-I proteins that will be different so that it helps the CD8+ cells to recognize them, just as you explained on the video.
2.: You called the vesicle leaving the Golgi "endosome", which is incorrect. Only the endocytic vesicles that perform transport from the membrane to the lysosome are called endosomes. The vesicle carrying the MHC-I protein to the cell surface is simply a transport vesicle.
Also, other people have left remarks before (bacterial infection, ubiquitinization), so I wouldn't repeat those.
Apart from these small mistakes it is a really great video, thanks for making it again! Keep up the good work, you gained +1 follower!
Can you teach me plxx
He also said cd8 cells interact with mhc1 plus the pathogen.
That's wrong.
Cd4 cells react to bacteria.
Cd8 will respond to mhc1 only if it's virus or tumor associated.
@@manjushreeinamdar1242 not correct..immuology is very convoluted,,,mch 1 is involved in some bacteria.......MHC class I helps mediate cellular immunity, a primary means to address intracellular pathogens, such as viruses and some bacteria, including bacterial L forms, bacterial genus Mycoplasma, and bacterial genus Rickettsia.
.immuology is very convoluted,,,mch 1 is involved in some bacteria.......MHC class I helps mediate cellular immunity, a primary means to address intracellular pathogens, such as viruses and some bacteria, including bacterial L forms, bacterial genus Mycoplasma, and bacterial genus Rickettsia.
i was stuck on this for 2 days, subscribed right away, amazing work
I am an RMT medical student and I these videos are very well done and the visual helps me retain and visualize for my self what is occurring. This is great keep them up you know your stuff and you are truly helping me to fully understand.
Thank you very much for drawing everything out and uploading them! I got the human physiology exam tomorrow and I found your artworks are very useful!!! Im looking forward to more of your artworks.
This video was super helpful,
I just want to note that MHC I is not CD8+ restricted because also NK cells can recognize them,
But the CD8+ cell or the CTL is MHC I restricted
I was studying for about 3 hours presentation and didn't understand it at all. I watched your video and got it in 10 minutes. Thank you, you do awesome job!
amazing video ! The lesson seems to me so hard but now everything is clear ! :D thank you
what do you do armando? Are you a graduate student, teacher, ... ? Love your videos and they helped me during my basic science years of med school. Wish I could remember half of it though :)
First of all I want to tell you that your videos are truly amazing, and I've passed over 10 classes from them !!!
You are amazing, Armando! Thanks once again for helping me understand this!
Amazing! I am taking an intro to Immunology course at my university, and I had a homework of this and I have not had lecture yet about this, and your video really helped me! Nice drawings btw
Thank you very much!!
Very nice. . You've simplified a very complicated lesson in 9 min!!!..
You are really talented..
Thanks. .
This video is informative, well-explained and the illustrations are kick-ass. Kudos!
You are awesome...love all your videos...helping me with my immunology exam preparation....a quick way of learning..thank you, appreciate it soo much
Great visualization and explanation. Extremely helpful in elucidating antigen processing, presentation and recognition. Thank you!
Thank You so much man! Took me two hours to finish watching this video due to pausing and drawing and taking notes, but very much worth it!
It's really understandable. Thank you so much for creating such a perfect video with clear voice.
Thank you very much Armando, the video was very good and your explanation was very clear which helped me understand the process rather easily.
Keep up the videos and many thanks
Beautifully explained, you have a gift.
Thank you so much for your video and this amazing crystal clear explanation and the dynamic representation is on point .
Great work and wonderful presantation!
it had been very difficult for me to understand all these stuffs.... but technology and you made it easier... thank you so much...
My major is Genetics but i need to know some basic immunology and your videoes helped me a few times while i was completely frustrated. thanks a lot from Iran❤🇮🇷
MHC class I is expressed all the time, not only whn a cell is infected!
Is it always "present" or always "expressed"?
Except Erythrocytes
Expect in red blood cells
@@couchpotato5778Always present and expressed on all nucleated Cells
@@JC---- Thanks! I do not even remember watching this video 2 years ago xD. Thank you so much.
many many thanks for giving a clear conception- just like it was so clear as like as crystal, super exquisite
unbelivable.....................great .....there is no words to praise you..thank you
AMAZING work! Thank you!
Sir your videos are very very useful..I always watch your videos to understand those things which I didn't understand in my class.
Your drawing and explanation is too good..I wish I could have a teacher like you.
This is amazing! , i totally love it, thank u soooo much 💖
Your videos are great. However, it is important that you make the difference between the peptides that are presented by MHC-I and MHC-II, because the class 1 would not normally present bacterial peptides; it only presents peptides that do not come from the outside.
it's rare, but MHC I will present bacterial peptide if that bacteria is intracellular bacteria.
But like you said, it's rare.
Lee HJ
Just as extracellular bacteria, the intracellular bacteria are internalized into endosomes (phagosomes) which then fuse with lysosome to form phagolysosome. Both types of bacteria will be presented with MHC II. However, certain intracellular bacteria such as Listeria, escape from the endosome before it fuses with lysosome and end up in the cytoplasm. They are ones that may then be processed for presentation with MHC I. Otherwise, only viral proteins - by virtue of the fact that viruses produce their proteins in the cytosol - are processed and presented with MHC I. The video should be changed to represent viral infection.
MHC Class I can present peptide from the outside via Cross-Presentation
I'm a student from Korea.Your lecture showing process in pictorial way helps me a lot Really helps me god damn a lot.Shit i'd tried to understand by written text only and it took my 1 hour with giving nothingAfter I've watched it i thought 'Damn shit. why i wasted my single fucking hour' You have saved my test thanks. i will subscribe
You graduated now?😂
You graduated?
Which one is the video where you talk about hypersensibility reactions I, II,III, IV?
Thank YOu!!!
Thanks so much for such a great video,really strengthen my understanding.
Besttt Video sir. I watched it in 2019 for MSc Exam and again today For CSIR bcoz no any videos could Explain better than this. Thanks a lot sir for making these videos. 😊😊😊
Thank you for doing this Armando, so useful and beautiful!!!:D
small mistake; TCR is specific for BOTH the epitope (antigen) and the MHC. The peptide:MHC (pMHC) complex is the critical "antigenic determinant" that the TCR groove is specific for.
Thank you for your efforts❤️❤️
It was amazing man ,thank you dude!
I'm addicted to ur videos
You are simply amazing! Thank you!
Excellent, sir. You are truly a great teacher 👍👍
Great video, a little confused on the part where you mentioned cytokines. I thought cytokines were only triggered by helper T cells and that Cytotoxic cells release granules that contain proteins such as perforin (helps deliver content of granules into target cell) and granzyme (activates apoptosis)
Wow this is really informational.
Can you make one of these specifically describing how the MHC tagged cell and T Cell interact in the case of the covid2019 coronavirus?
Awesome Video!
Was very very helpful....gr8 explanation 👍🏻
explained in so simple way! thank you.
Thank you for this presentation
Beautiful mechanism
Tú eres lo mejor. Gracias !! 👌👌💪
Great work
I love with ur videos :)
Thanx so much
From iraq ♥
That's a very clear explanation thank you so much💜💜
Thank You Armando. made it easier to understand
Is there any way I can get the pictures? Thank you.
thank you so much for your lesson, sir! i cleared all question about the theory after watching your video.
Hi! your videos are wonderful but I have a question: could you publish the final image of this video? Simply to have an overview of this process to print it and study please?
this was awesome. thank you very much!
awesome video! thanks
perfectly explained
thank you!
Thanks sir. It's clear my all dauts
can you also make some videos on biotechnology....please
Thank you for all the existing videos they're very useful.....
what is mhc 1 involved in? only self-orientated issues such as tumors and bad protein? or what about infection by virus and bacteria and fungus,ect?
Simply awesome 😎
Awesome video
an amazing channel
this is a very good video, with gerat explanations. i have only one question. doesn't the MHC I molecule present only endogenous antigens? because i think the bacterial proteins are exogenous proteins... i am a little confused.
Great work!
Great video!!! keep it up!!
love this, Thank you
Thank you so much. It helped a lot.
It helped me a lot ....U r good at explaining sir
Thanks sir,it is very helpful,great job
you should do a video on antigen processing of nuclear and ER proteins in MHC I
You forgot that the pathogen derived proteins must be tagged with ubiquitin first, before going into the proteasome.
LYSINE Molecule present in protein is attached to ubiquitin to make a ubiquitin protein complex
Thanks so much! this is really helpful!! keep doing it!!
This saved my day
Great explanation...thank you
You are awesome❤❤❤
Oooh..,, thats amazing..finally got it...thx
i would really like a video about ige dependent immune reactions
The MHC I does not bind to a specific antigen, it can bind to several different proteins. A single binding site in the MHC I (or II) can bind peptides with high affinity while retaining the ability to bind to a wide variety of different peptides. This is shown by the crystal structures of peptide:MHC complexes
There's a question stuck in my head
If MHC 1 binds intracellular pathogens and present it to LT8
How will the LT4 ever meet the pathogen ? Since it's intracellular and presented by MHC 1 ( which is not known by LT4 )
Thanks you are awsome❤️❤️
Great illustration of the process. One thing seems a little misleading - author says the MHC1 binding site fits a "specific antigen". I believe in reality it fits a broad range of antigen, and a cell has around 6 versions of MHC1 so that all the ranges cover any endogenous peptide that might be in the cytosol. Otherwise, it would seem highly unlikely that a Tc Cell with a very specific binding site would discover a compatible MHC1 complex with an equally specific binding site. And also a cell would need millions and millions of different MHC1 molecules to be sure of binding any protein.
Thank you so much 💚💚
thank you
Thank you, It was fantastic
you are amazing ! thank you !
thanks a lot . so clear and simple
Nice vid, however i just want to point out that MHC I is present in all cells, ant not only present in case of cell infection , as a matter of fact. MHC I presents peptides from the cell itself . Its like a quality control . If the cell its not infected then it will present only self peptides . If a virus has merged peptides to the cells DNA then , naturally it will present peptides which CD8 T cells will detect as an alien peptide and proceed to kill the cell. If it is not recognized as strage the T cell will be inhibited and not kill the uninfeccted cell.
MHC -1 is also the reason the initial onset of cancer can be spotted by the body correct? When it presents incorrect antigen havering the immune system recognize it and have the killer T cell break it down.
Please could someone clarify how the antigen is presented on the cell surface but the MHC I if its engulfed by the endosome?
great explanation, but isn't perforin and granzyme released in a T-cytotoxic cell and cytokine is released for the T-helper cells?
I believe they are also released in natural killer cells.
+3lle007 He probably meant cytotoxins (ie. the perforins/granzymes you mentioned) instead of cytokines.
I have my immunology final in about 40 minutes and you're saving my life.
lol you passed?
@@aeolismons4236 yes😂 it was 3 years ago.
@@catija good job mate, how was it tho? did u just prepare through these videos or used it to revise?
Love the Catholic bracelet! Not many Catholic scientists out there... thanks for the encouragement!
Hey could you post the pdf for these videos(MHC 1 and MHC 2 processing...They are really helpful)
Have a good day 😊
OUTSTANDING!!!
Brilliant!
Why in Blood transfusion is not needing to chek HLA compatability , while WBC is nucleated cell is not attaked by immune sys. ????
Well MHC can be the reason for a fails transfusion or the inability to accept tissue, but blood transfusion is more affected by blood type. Organ transplant and other tissue transplant is more commonly running in to reflection from MHC. Which depending what country, Provence or state your in they may check MHC comparability. But medical protocols vary, but your right checking it every time would insure compatibility and prevent a lot of problems.
It's very nice and interesting .. thank you very much ..