Acute Inflammation Flashcards
(73 cards)
Who expresses P selectins? Where are they stored? What stimulates their expression?
Platelets (alpha granules), endothelium (WP bodies), and monocytes; Histamine and thrombin
What do selectins bind to? What does this interaction result in?
Sialyl Lewis X-modified glycoproteins; Rolling
What stimulates the conversion of integrins on leukocytes to their high affinity state? What cleaves the L-selectins off the leukocytes?
Chemokines (IL-8) from WP bodies; ADAM17
What are the ligands for integrins? Where are they expressed? What induces their expression?
ICAM and VCAM; endothelial cells; TNF, IL-1, Substance P
What are the beta1 integrin(s)? What ligand does it bind to? Who expresses beta1 integrins?
VLA-4; VCAM-1; monocytes and T cells
What are the beta2 integrin(s)? What ligand does it bind to? Who expresses beta2 integrins?
LFA-1 and MAC-1; ICAM-1; All leukocytes
What is the other name for beta1 integrins?
CD49CD29
What is the other name for beta2 integrins?
CD11CD18
What do chemokines bind on endothelial cells?
Proteoglycans
Mediators involved in leukocyte activation
TNF, IL-1, IL-6 (cytokines), C5a, IL-8 (chemokines), PAF, PDGF (from platelet alpha granules)
Diapedesis ligands on endothelial cell and receptors on leukocytes
PECAM-1 (CD31) to itself
JAM A to JAM A or LFA-1
JAM C to JAM B or MAC-1
Most potent endogenous chemoattractants; what do they bind to on leukocytes? Result?
Cytokines (IL-8)
C5a
Leukotriene B4, also 5HETE and PGD2
G-protein-coupled receptors
Polymerization of actin at front and myosin at back
In leukocyte activation, what is the end result?
Increase in cytosolic Ca and activation of enzymes like Protein kinase C and phospholipase A2
What are the major opsonins? What recognizes opsonins?
IgG, C3b, MBL and collectins (C type lectins); phagocytes have high affinity receptors
What enzyme produces ROS in phagocytosis? What converts H2O2 to hypochlorite to kill microbes in neutrophils?
NADPH oxidase; myeloperoxidase from primary granule
What converts superoxide anion to peroxynitrite radical in macrophages? What does iNOS do?
NO; converts arginine to NO
Two types of granules in neutrophils; what do they contain?
Primary: MPO, proteases, lysozyme, defensins
Secondary: beta2 integrins and above
Most important antiprotease; primary purpose
Alpha 1 antitrypsin; inhibits neutrophil elastase
What initiates NET formation?
ROS activation of arginine deaminase to convert arginine to citrulline, causing chromatin decondensation
Part of adaptive immune response that is crucial for acute inflammation
Th17 cells and IL17!
What receptors do mast cells have? Who also expresses these?
FcepsilonRI for IgE, which cluster and crosslink; basophils
What do mast cells degranulate in response to? (4)
Physical injury, heat, cold
Crosslinking of IgE by antigens
Complement products (C3a and C5a)
Substance P
What do mast cells store in preformed granules
Histamine, tryptase, TNF-alpha, cytokines, GFs
What do mast cells synthesize?
PGD2, PAF, heparin, cytokines, C-C chemokines