Immunity Flashcards
Where do APCs go?
Lymph nodes
Describe how a B lymphocyte becomes an APC
Naive B cell binds an Ag via its BCR —> processes the Ag via receptor mediated endocytosis —> puts Ag in cell membrane/MHC2 —> this makes it an APC
Can a B cell that is now an APC able to continue replicating and making more MHC2?
No, it needs a stimulus
Needs macrophages, T cells, and ILs to make this happen
How does a T helper cell get activated (3 steps from the outside, and 1 from self after activated)
And what is this called?
- Macrophage presents MHC2 to naive helper T cell —> T helper cell has a TCR for a specific Ag and a CD4 that fits the MHC2 on the macrophage
- T helpers have a CD28 receptor that connects to macrophages B7 protein
- Macrophage release IL1 to bind T helper
***once activated by above the Thelper releases IL2 that acts on itself in autocrine signaling
This is called co stimulation (from self and outside source?)
After a t helper cell is activated, what does it produce and how does this lead to B lymphocyte proliferation?
Activated t helper releases IL4 & IL5 (unsure if IL2 release triggers this)
- but only if it also receives IL4
- this turns it into a Th2 cell —> makes more IL4 & IL5 —> induces other T cells to become Th2
Once t helper cells start releasing IL4 & IL5 and become Th2, how do those interleukins affect B cells
IL4 - signals B cells to start clonal expansion
IL5 - signals differentiation (creates B memory cells or plasma cells*)
*then plasma cells make Ig
What is the immunity name for B cell and T cell proliferation and antibody making?
Humeral immunity
What MHC do all uncleared cells express?
MHC 1
Describe cell mediated immunity
Cytotoxic T cells (ctcs) check MHC-1 on all cells (looking for self Ag) —> if it does not find self Ag or finds a virus/cancer infected cell —> CTC releases perforins (perforates cell membrane?) —> granzymes are then made in CTC and released into target cell (via perforins?) —> granzymes tell target cell DNA to make BAX —> BAX acts on BCL2 in mitochondria and pulls it out —> then cytochrome c and caspases are released and kill the cell (apoptosis)
IL 4 induces which T cell?
naive Th2 cells
Th1 cells are induced by what IL?
IL-12
What type of lymphocyte are NK cells and what 3 cells will it kill?
NKCs are large a granular lymphocytes
Try kill:
- Cells that don’t express MHC1
- Cells that express MICA (mhc lacking a B2 unit?)
- If it recognizes the IgG on it—> then goes through perforin granzyme BAX BCL2 cytochrome c and caspase process = cell death
Mast cell released h, L, & P cause what to be expressed that help with wbc margination
P & E selectins
V, P, & I-CAMs
What ILs trigger plasma cells to produce antibodies?
IL 5 & 6
Draw me the activation of NK cells and then which cells they go kill and how they do it (process)
We drew these together, I just can’t put pictures in notecards via my phone
