Basic Concepts - 1B Flashcards
What are macrophages sensors of?
The health of tissues
What type of generalised receptors can macrophages recognise material (soluble and particulate)?
Opsonisation and non-opsonic receptors
Is direct recognition opsonic or non-opsonic?
Non-opsonic
Is indirect recognition opsonic or non-opsonic?
Opsonic
- antibody-Fc receptor
-complement-complement receptor
What are CD200L and SIRP?
Inhibitory receptors
What does SIRP engage?
CD47 and particles that contain CD47 are not phagocytosed for example
What receptor is high affinity for IgG1?
CD64 - highly expressed on macrophages
What do CD64 receptors do very effectively?
Internalise anything opsonised
Are Fc receptors activating or inhibitory?
They can be activating and inhibitory
What is the process of Endocytosis turning acidic?
In endosome, mature into late from early and become more acidic
Then fuse with lysosomes and there will be complete degradation of material
What is a phaogosme combined with a lysosomes called?
Phagolysosomes
Why doesn’t a dendritic cell want to degrade everything?
Wants peptides to be able to deliver to T cells?
What are the microbicidal products of phagocytes?
- acidification
- toxic oxygen derived products
- toxic nitrogen oxides
- antimicrobial peptides
- enzymes
- competitors
What is the microbicidal activity used to make phagosomes as inhospitable as possible?
Toxic species damage bacterial proteins and DNA
Iron pump to remove iron fro phagosome
Antimicrobial peptides
What type of oxidase is responsible for production of radical species?
NADPH oxidase
What is autophagy?
A physiological process involved in the disposal of cytosolic material , relevant in clearance of intracellular pathogens
When do cells undergo autophagy?
In response to infection or nutrient starvation