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
What are the immune functions of IgG?
Fc-dependent phagocytosis
Complement activation
Neonatal Immunity
Toxin/virus neutralization
What are the immune functions of IgE?
Immunity against helminths
Mast cell degranulation
(allergies)
What are the immune functions of IgA?
Mucosal Immunity
What are the immune functions of IgM?
Complement activation
