BIO 515: Phagocytes

What is reaching phagocytosis?

actin-driven membrane extensions surround and engulf particle (ex. dectin-1)

What is sinking phagocytosis?

target particles drawn directly into the phagocyte (ex. complement receptors)

What is triggered phagocytosis?

actin-driven membrane ruffles and micropinocytosis, receptor triggered, but not receptor mediated, engulfs what’s around the particle as well

What are the steps of phagocytosis?

early endosome → multivesicular body → late endosome → lysosome → phagolysosome - pH decreases throughout process

What are the microbicidal mechanisms employed by phagocytes?

acidification of phagosome, reactive O/N species, antimicrobial proteins, enzymes, competitors

What is margination and diapedesis?

margination: tethering and eventual adhesion fo the neutrophil to the blood vessel wall

diapedesis: escape of the neutrophil between endothelial cells

What percent of immune cells do phagocytes make up?

~50% of immune cells and 80% by mass