Exam 2: Dr. Pinchuk Antigen Processing and Presentation Flashcards
In what form does TCR antigen recognition occur?
Only in the form of peptide bound to an MHC molecule on the surface of APC
What are the 2 things that occur in TCR antigen recognition?
Antigen processing and antigen presentation
What is antigen processing?
Pathogen-derived proteins must be degrade into peptides by APCs
What is antigen presentation?
When peptides are assembled into peptide:MHC complexes for display on the APC surfaces
What are the steps to antigen processing and presentation?
Protein antigen is in the cell
Antigen processing occurs by breakdown of protein
Presentation of peptide by MHC molecule
What do the 2 classes of MHC present antigens to?
CD8 and CD4 T cells
What co-receptor is MHC class I associated with?
CD8
What co-receptor is MHC class II associated with?
CD4
What do MHC molecules bind?
A variety of peptides in different intracellular compartments
What does TCR specifically recognize?
Both peptide (foreign) and MHC (self) molecules
What are dendritic cells?
Universal antigen presenting cells
The best presenting cells
What are macrophages when they are in blood circulation?
Monocytes
Where are dendritic cells located in the lymph node?
T cell areas
How do dendritic cells do antigen uptake?
Macropinocytosis and phagocytosis by tissue dendritic cells
Viral infection
What is MHC expression like in dendritic cells?
Low on tissue DCs
High on DCs in lymphoid tissues
What is the co-stimulatory delivery of DCs?
Constitutive by mature, nonphagocytic lymphoid dendritic cells
What is the antigen presented to DCs?
Peptides
Viral antigens
Allergens
What is the location of DCs?
Ubiquitous throughout the body
What is the process of antigen uptake in macrophages?
Phagocytosis
What is MHC expression like for macrophages?
Inducible by bacteria and cytokines
What is the co-stimulatory delivery for macrophages like?
Inducible
What is the antigen presented to macrophages?
Articulate antigens
Intracellular and extracellular pathogens
What is the location of macrophages?
Lymphoid tissue
Connective tissue
Body cavities
What is the location of B cells in the lymph node?
Follicle