11.2 Innate Immunity Flashcards
Broadly, what can be found inside the granules of neutrophils?
- Enzymes
- Antimicrobial peptides
What is granulopoiesis?
Production of granulocytes
Name one cytokine that drives granulopoiesis
Granulocyte-colony simulating factor (G-CSF)
List and described the three functions of neutrophils
- Phagocytosis: (ingestion, release of granules to destroy phagosome contents)
- Degranulation: (release of granule contents into external environment)
- Netosis: (expulsion of nuclear material to form neutrophil extracellular traps (NETs)
How do NK cells kill?
- Apoptosis
- Victim cell forms into blebs, which can be removed by neutrophils or macrophages
Are dendritic cells capable of endocytosis, phagocytosis, or both?
Both; think about it: it needs to bring the sample into the cell, and break it down for presentation
With regards to surface receptors, under what circumstances would an NK cell/not kill a cell?
It would only kill if the activating receptor is activated, and the inhibitory receptor is not. All other circumstances, no killing of the cell
Describe degranulation of NK cells; what is released?
- Release perforins, which create channels for…
- Granzymes, which cause apoptosis
Describe the collectrin family of proteins?
- Contain six recognition domains which bind to microbe surface carbohydrates
- Contain a collagen-like region, which is recognised by phagocytes
What are some examples of opsonins from the collectin family?
- Surfactant protein
- Mannose binding lectin
Describe the pentraxin family of opsonins
- FIVE polypeptides
- Bind to bacteria-specific structures
Give an examples of a pentraxin opsonin
C Reactive Protein
Which type of PRRs detect DAMPs?
Scavenger receptors
Which CD surface protein means “don’t eat me”!
CD47
Which protein flips from inside to outside the cell during apoptosis, and is detected by macrophage PRRs?
Phosphatidyl serine
