Inflammation 4 Flashcards
What is another word for removal of the agent (the 3rd R)?
Phagocytosis
What are the three steps to phagocytosis?
Recognition and attachment of the particle
Engulfment
Killing or degradation of ingested material
What are the two major phagocytes?
Neutrophils and macrophages
What happens to neutrophils during phagocytosis?
Once they degranulate and release enzymes, they’re dead
When do we see macrophages?
Mostly during chronic inflammation, but we still see in acute
What are the three phagocytic receptors?
Mannose receptors, scavenger receptors, and opsonin receptors
What do mannose receptors do?
They bind bacterial cell wall sugars, they don’t recognize host cell wall
What are scavenger receptors associated with?
Damage associated
What do opsonin receptors do?
Think of buttering bread, they make the molecule tasty for macrophages
What are the major opsonins?
C3b and IgG antibodies
Where are our major opsonins (C3b and IgG)?
Floating in the plasma and they have receptors that will automatically bind to microbes
What happens during engulfment?
Pseudopods surround particles bound to receptors —> pinches off to form a phagosome —> fusion with lysosome to form phagolysosome
What is an example of a bacteria that will inhibit phagolysosome fusion via their cell wall components? Why does it do this?
Mycobacterium
Allows it to persist to chronic inflammation
What is Chediak-Higashi Syndrome?
Inherited disorder of lysosomes. This includes impaired phagolysosome fusion.
It’s a mutation in the lyst gene, uncommon in vet species, but it does occur
What are the two methods of killing ingested material?
oxygen-dependent and oxygen-independent
