receptors and cytokines Flashcards
(27 cards)
What is the main purpose of receptors in the immune system?
To understand how receptors are involved in signalling in the immune system
Receptors play a crucial role in enabling individual cells to sense changes in their environment.
What is a ligand?
A molecule that binds to a receptor
What happens when a ligand binds to a receptor?
Changes take place that transmit a signal
What are antigens?
Foreign molecules signalling non-self
What are cytokines?
Small molecules that communicate between immune cells
What is the specialized group of cytokines called?
Chemokines
What is a cellular signal?
An event which causes a cell to change its metabolic or proliferative state
How are signals usually generated in the immune system?
By the binding of a ligand to a receptor
What can change a cell’s responsiveness to a ligand?
Up- or down-regulating the expression of the receptor for that ligand
What type of bonds are involved in ligand-receptor binding?
Non-covalent bonds
What are the types of non-covalent bonds?
- Hydrogen bonds
- Ionic bonds
- Hydrophobic interactions
- Van der Waals interactions
What is the result of ligand binding to a receptor?
Induces a change in the receptor, setting off a cascade of intracellular events
What is the end result of receptor-ligand interaction?
Often a change in transcription in the target cell
True or False: More than one receptor may need to be activated to induce an effect.
True
What is the B cell receptor complex composed of?
- Antigen receptor
- Igα
- Igβ
- Co-receptors (CD21, CD32, CD19)
What initiates downstream signalling in the B cell receptor?
Binding results in phosphorylation
What is the T cell receptor associated with?
- CD3
- CD4
- MHC molecules
What do cytokines do when they bind to a target cell?
Change the expression of cell surface molecules
What term was first used to describe cytokines?
Interleukins
Give an example of an interleukin.
- Interleukin-1
- Interleukin-2
What does the term ‘chemokine’ refer to?
A subpopulation of cytokines that mobilize immune cells
What is a key characteristic of cytokines?
They are pleiotrophic
What does it mean that cytokines can have redundancy?
Several cytokines can have the same effect
What can soluble receptors do?
Bind the cytokine in solution
