I: Adaptive Immune Responce Flashcards
Describe features of antigen presenting cells.
- Strategically located at mucous membranes (e.g. SALT, GALT, BALT) and in lympoid organs
- Able to capture pathogens (Via phagocytosis/macropinocytosis)
- Diverse PRRs
Describe the role of MHC molecules in relation to
microbe presentation.
Many peptides presented by the same MHC molecule to activate the humoral immunity (antibodies/complement/phagocytosis) or activate cell-dependant immunity (Cyotoxic T lympocytes/antibodies/macrophages)
Describe the endogenous processing and presentation of microbial antigens to T lymphocytes.
- Virus is in the cytoplasm of the cell
- Taken up into proteasome and degraded
- Antigenic peptide released and process by ER (entering via TAP1 and TAP2 channel)
- Presented on cell surface
What is the importance of Helper T cells (TH) in
determining the appropriate immune response
against intracellular vs extra-cellular microbes?
In order to activate cytotoxic T cells, CD4+ (TH) must also be activated.
NOTE: This is why HIV/AIDS suffers cannot use cytotoxic cells to kill viruses as CD4+ cells have been killed off.
Where are class 2 MHC molecules found?
Found on dendritic cells,
macrophages, B cells.
What are the the names of the 3 types of class 2 MHC complexes?
HLA-DR
HLA-DQ
HLR-DP
Do MHC class 1 present peptides from intracellular or extracellular microbes?
intracellular
Do MHC class 2 present peptides from intracellular or extracellular microbes?
Extracellular
Do MHC class 2 present peptides from intracellular or extracellular microbes?
Extracellular
Are MHC class 1 recognised by CD8+ T cells or CD4+ T cells?
CD8+
Are MHC class 2 recognised by CD8+ T cells or CD4+ T cells?
CD4+
Describe the exogenous processing and presentation of microbial antigens to T lymphocytes.
- ## Endogenous antigen enters cell in a vacuole (i.e. bacteria)
Describe the exogenous processing and presentation of microbial antigens to T lymphocytes.
- Endogenous antigen enters cell in a vacuole (i.e. bacteria)
- Proteins degraded by acid-dependent proteases
- Presented on cell surface?
Name 2 clinical problems with MHC molecules.
- Major causes for organ transplant rejection
2. HLA association with autoimmune disease
What do cyotoxic T cells release that kill targeted infected cells?
- Perforins
- Granzymes
