Antigen processing and presenting Flashcards
Where is MHC 2 found
Only on APC cells
What are the three professional APC
Dendritic cell
B Cell
Macrophage
What are some characteristics of dendritic cells
Best APC
only one that can stimulate naive cell
Regulate both innate and acquired immune systems
Can take up many different antigens
Where do dendritic cells come from
bone marrow
What makes an immature DC into a mature DC
antigen
What is proteolysis
protein degradation
What is phagolysosome
digestive enzymes in the lysosome
Where are antigens presented
MHC-peptide complex on cell surface
How do we uptake endogenous antigen
Sample of intracellular proteins
Viruses, intracellular bacteria
How does degradation of endogenous antigens happen
Ubiquitin-chaperone protein, brings protein to the proteosome
Proteosome- group of enzymes that digest proteins
What is the complex formation of endogenous antigens
MHC class 1
What is the presentation of endogenous antigens
MHC class 1 on all nucleated cells
What are processed and presented on MHC class 1
all intraceytoplasmic proteins
What recognizes foregin MHC 1
CD8 cytotoxic T cells
What do NK cells recognize on cell and what happens
Lack of MHC 1, if there is none it is killed by NK
What causes the uptake of exogenous antigen
Phagocytosis, endocytosis, BCR-mediated
What does MHC 2 present on
only on antigen presenting cells
What does MHC class 2 cells do
presents a sampling of the proteins outside of the cell
What recognizeses MHC class 2 cells
CD4 helper T cells
What does MHC class 2 activate
acquired immune system
Is MHC 2 stable without an antigen
No
What recognizes MHC class 1
CD8
Is MHC stable without antigen
no
Endogenous vs Exogenous
Endogenous: All nuc. cells, intracellular antigen, virus, proteozome, Ag loading on ER, MHC 1, CD8 T-cell
Exogenous: Only on APC, extracellular antigen, bacteria, fungus protozoa, phagolysosome, Ag loading in phagolysosome, MHC 2, CD4 T-cell
What is the “rule of 8”
MHC 1 goes with CD8 T-cell
MHC 2 goes with CD4 T-cell
1x8=8
2x4=8
What do CD4 T cells do if they make IL-2, IFN-gamma
If they do this they are Th1
They just help, don’t do any of the work
What does a Th1 response do
Stimulate cell mediated killing
CD8 cytotoxic T cell does the killing
What does CD4 T cells that make IL-4, IL-5 do
Th2
Stimulate humoral response (B-cells)
What do effector cells do
Surveying for infected cells and killing or producing antibody
Characteristics of CD8 T cells (cytotoxic effector cells)
Intracellular antigens
Recognize MHC 1
What causes the exogenous degredation
phagolysosome
What is the complex formation of exogenous antigen
MHC 2
Loaded in phagolysosome
How is exogenous antigen presented
MHC 2 only on APC
How do APC’s function by
Internalizing antigen
Digesting antigen
Display peptide Ag bound to MHC 2
