Lecture 11: Innate cells Flashcards
What are the 3rd class of phagocytes
Neutrophils
What are essential for fighting infections
Neutrophils
How long do neutrophils live
1-2 days
Where do neutrophils live
Live in the blood
What kind of phagocytes are neutrophils
Voracious phagocytes
What are voracious phagocytes
Phagocytes equipped with an antimicrobial arsenal
What are the four mechanisms neutrophils do
- phagocytosis
- degranulation
- oxidative burst
- NETs
What is phagocytosis
Eat the infecting pathogen
What is Degranulation
Dump cytotoxic granular contents on the target
What is oxidative burst
Generation of reactive oxygen species and reactive nitrogen species that can be used to make hydrogen peroxide and hydrochloric acid
What are NETs
Neutrophils extracellular traps
What are the three types of granules
- azurophilic (primary)
- specific (secondary)
- gelatinase (tertiary)
What two things can granules do
Can either fuse with the phagosome or can be released into the extracellular environment
What are neutrophils extracellular traps
Neutrophils kill themselves and release DNA into long strands coated in microbes trapping and killing bacteria
What do eosinophils do
Kill antibody coated parasites
Where are eosinophils recruited
Sites of parasitic infection
How do eosinophils kill pathogens
Degranulation and release cytotoxic proteins
What do basophils do
Promotion of allergic response and enlargement of anti parasitic immunity
What do basophils look like
Heavily granulated
Are basophils phagocytes
No, instead release large amounts of pharmacologically active compounds from granules
What do mast cells do
Release of granules containing histamine and active agents
What activates mast cells
IgE, bacterial products, parasites
What is the main role of mast cells
Role in fighting infection and their ability to cause allergies
Where do mast cells differentiate
In the tissue
Where are mast cells located
Host-environment surfaces, skin lung gut
Do mast cells have granules
Yes very granular
What do natural killer cells do?
Release granules that kill some virus infected cells
What are NK cells
Large granular lymphocytes
Are NK cells identical or different
Identical
How are NK cells regulated
Balance between activating and inhibiting receptors
What specific targets can NK cells recognize
Can recognize targets labelled with antibody
What is the endothelium
Single cell layer that forms continuous lining to contain blood
What three main things does the epithelium do
- play critical role in homeostasis
- barrier, regulated movement of fluids and macromolecules
- responsive to any mediators
What are platelets
Tiny blood cells with no nucleus that help blood clot
Where are platelets derived from
Bone marrow
