Adaptive immunity Flashcards
Characteristics of adaptive immunity
Takes a longer time period to be activated
Specific
Highly specialised
Functions of adaptive immune system
Recognises non-self antigens
Generates specific response
Immunological memory
What are the three main cells in the adaptive immune system?
B cells
T cells
NK cell
What are cytokines?
Cell signalling molecules
Function of interleukins
Target leukocytes
Function of interferons
Antiviral response
Function of chemokines
Mediate chemotaxis
What are the 4 different ways in which cytokines can act?
Individually - autocrine
Individually - paracrine
Individually - endocrine
Together
What is an autocrine chemical?
Acts on cell releasing chemical
What is a paracrine chemical?
Targets nearby cell
What is an endocrine chemical?
Released into blood stream to target distant cells
Which cytokines activate t-cells?
IL-12
IL-2
IFN-gamma
TNF- alpha
Which cytokines stimulate antibody production?
IL-4
IL-5
IL-13
Which cytokines are anti-inflammatory?
IL-10
TGF-beta
Where are T cells produced?
Bone marrow
Where do T-cells mature?
Thymus
Where are T-cells activated?
Lymph node
What are CD4 cells?
Helper cells
What are CD8 cells?
Cytotoxic cells
Which three cells can activate helper T cells and why?
Dendritic cells, macrophages and B cells
They all have MCH II
How are T-helper cell activated?
- CD4 t-cells activated by antigen presentation
- Antigen presented to helper T cell by MHC II molecule on dendritic cell in lymph node
- Second signal - co-stimulation
- Third signal - cytokines released
- All 3 signals = activated CD4 T-cell that specifically targets this pathogen
- CD4 cell proliferates and clonally expands
What will MHC II bind to always?
CD4 helper cells
What is produced when a helper T cell is exposed to IL-12?
TH1
What is produced when a helper T cell is exposed to IL-4?
TH2
What is produced when a helper T cell is exposed to IL-1 beta and IL-6?
TH17
What is produced when a helper T cell is exposed to IL-10 and TGF-beta?
T reg cells
What do TH1 cells do?
Fight intracellular pathogens by releasing IFN-gamma and IL-2
Cell-mediated response
What are the two outcomes when TH1 cells are exposed to IFN-gamma?
B - cell and the plasma cell
Macrophage - activated macrophage
What are the two outcomes when TH1 cells are exposed to IFN-gamma and IL-2?
NK cell - activated NK cell
CD8 cell - cytotoxic T cell
What do TH2 cells do?
Defend against extracellular bacteria and parasites
Humoral response
What is produced when Th2 cells are exposed to Il-4?
Plasma cells
What is produced when TH2 cells are exposed to IL-4 and Il-13?
Alternatively activated macrophage
What is produced when TH2 cells are exposed to Il-3 and IL-5?
Eosinophils
What is produced when TH2 cells are exposed to IL-3 and IL-9?
Basophils