Antigen processing and presentation Flashcards
Understand which cells present antigen.
Dendritic/B cells/macrophage
What is a professional APC?
ability to present antigen in the context of MHC II
What are unique characteristics of professional APCs?
present antigen in the context of MHC II
What makes a dendritic cell unique among the professional APCs?
only APC that can activate T cells
What are the differences between an immature and mature dendritic cell.
Immature- low surface MHCII, increased endocytosis, low cytokine secretions
Mature- increased surface MHCII, decreased endocytosis, increased cytokine secretions
How does the B present antigen to a T cell and get help from the same T cell?
B cell presents antigen in the context of MHC II; T cell recognizes it and sends a signal to B cell, B cell then sends a second signal to the T cell to activate it
Understand processing of exogenous antigens
uptake (pahgocytosis); degradation (phagolysosome); complex formation of MHC II; presentation on MHC II on APC
Understand processing of endogenous antigens
uptake (intracellular proteins, viruses, intracellular bacteria); degradation by ubiquitin and proteosome; complex formation of MHC I (loaded in the ER); presentation of MHC I on nucleated cells
What kinds of cells process which antigen?
APC- exogenous; macrophages/neutrophils- endogenous
Where is the protein antigen processed with exogenous antigen? Endogenous antigen?
exogenous- phagolysosome
endogenous- within cytoplasm
Understand the proteins and organelles involved in antigen processing.
exogenous- phagosome fusing with lysosome; MHC class I and II; golgi apparatus endogenous- proteosomes, golgi and ER
On what cells is MHC I found?
nucleated cells
What kind of antigen does MHC I present?
endogenous; viral/intracellular organisms
What cell type does MHC I present to?
CD8 cytotoxic cells
What is the outcome of successful presentation via MHC I?
destruction of the cell via apoptosis
