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!
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
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!!
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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
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.
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.
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. 😊😊😊
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 :)
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?
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.
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.
