amazing video, helped enormously. my class is doing online learning and so my teacher couldnt explain this easily, however this video is perfect. thank you!
I thought that through maturation process, the T lymphocyte (having both CD8 +CD4) would differentiate into t helper and t cytotoxic via downregualtion of genes. does this happen after the t cell has been presented with the antigen? or is it that a t cell randomly produced with the correct receptor which has the highest bidnign affinity to the antigen gets clonally selected via APC and then differentiated into a cytotoxic t cell if needed? thanks for the video, your response will be much appreicated
Hey, I was just reading through Class Notes whilst also watching your videos. What's the difference between a cell-meditated response & a cellular response?
question - if b cells can also become antigen presenting cells when they encounter the antigen and take it in by endocytosis, what makes them different from phagocytes/macrophages that also become APC cells?thanks so much for the videos!
cell-mediated involves MHC 2 where CD4 t helper cells bind onto the MHC2 complex of the APC such as the macrophage/dendritic cell. the MHC1 complex is only presented on those cells which are infected, which the Cytotoxic t cell binds onto and releases perforin destroying the cell by creating pores within the membrane which in turn reduces viral replication
Hi Miss, When the cytotoxic T cells release perforin to create pores in the cell surface membrane and substances are able to leak in and out of the cell, would you consider this as an example of apoptosis. Apoptosis is controlled and tightly cell regulated death so would you say that this could be considered an example since the death of the infected cells is tightly controlled by the immune system and the Cytotoxic cells? However, if the pathogen was to destroy the cell this would be an example of necrosis but I was interested to see what you thought?
Hello, As it is the body's response killing the cell, I would class it as apoptosis, not necrosis, as it isn't the pathogen directly causing the cell death.
vaccines are used to produce more antibodies essentially 1. vaccine contains antigen from pathogen 2. macrophage presents antigen on its surface and t cells simulate b cells 3. t cells with complementary receptor protein binds to the complementary antibody on its surface. 4. b cells secrete lots of antibodies 5. b cells divide to form clones secreting the same antibody to destroy the virus.
