Innate Immunity Cont. Flashcards
(56 cards)
What can perform phagocytosis?
neutrophils, dendritic cells, macrophages
What is phagocytisis?
the uptake and degradation of extracellular material
Steps of phagocytosis
=
How is phagocytosis initiated?
2 ways
- PAMP recognition by a PRR
- opsonins
Do all PRRs initiate phagocytosis?
no
How do opsonins initiate phagocytosis?
- bind to microbes and mark them for phagocytosis
- bind to receptor on phagocytic cell which then initiates phagocytosis
What is microbe degradation?
when the phagosome fuses with the lysosome, the contents of lysosome act to kill and degrade the pathogen
What ways does microbial degradation occur?
- antimicrobial proteins
- low pH
- enzymes
- molecules that mediate oxidative attack
What antimicrobial proteins do microbial degradation?
lysozyme and defensins
How does low pH do microbial degradation?
kills pathogen, activates enzymes
What enzymes do microbe degradation?
proteases
What does proteases do?
degrade protein
What molecules mediate oxidative attack?
- reactive oxygen species (ROS)
- reactive nitrogen species
What is an example of a reactive oxygen species?
hydrogen peroxide (H2O2)
What is an example of reactive nitrogen species?
nitric oxide (NO)
Steps of NETs
-
What does NETs stand for?
neutrophil extracellular traps
What do NETs do?
trap pathogens
How do NETs trap pathogens?
contain antimicrobial proteins from cytoplasmic granules that kill the trapped pathogens
What is the process using NETs called?
NETosis
What happens to the neutrophil as a result of NETosis?
neutrophil dies
What does inflammation result from?
cellular response and tissue damage due to pathogens getting through the physical barriers of innate immune system
What are characteristics of the inflammatory response?
- pain
- redness
- heat
- swelling
- loss of function
What causes heat and reddness?
reflect an increase in vascular diameter which increases blood flow to area
