Mast cells Flashcards
Mast cells/Basophil response to TLR stimulation
cytokine/chemokine/lipid mediators released
NO degrandulation
Mast cell/basophil response to venoms, neuropeptides, C3a and C5a
degranulation
What causes degranulation?
neuropeptides, venom, C3a + C5a
What causes cytokine/chemokine/lipid mediator release?
TLR stimulation
Mast cell release of IL-8 causes
neutrophil recruitment
Neutrophil recruitment cascade
1) rolling - selectin-dependent
2) adhesion, crawling, transmigration - integrin dependent
IL-8 on the endothelial lining causes interactions with IL-8 receptors on neutrophils
IL-8–IL-8R causes conformational changes of neutrophil integrins
Neutrophils in a normal blood smear
3-5 lobes
mediate earliest phases of inflammatory reactions
how long do neutrophils last in the blood?
hours–days
how long do neutrophils last in tissues?
1-2 days, then die
Neutrophils
a) inflammatory mediators
b) cytoplasmic granules
c) main function
a) cytokines, prostaglandins, leukotrienes
b) defensins, lysozyme, peroxidase, degradative enzymes
c) phagocytosis
defensins
small, cysteine rich cationic proteins that act against enveloped and non-enveloped viruses
The dyes for neutrophiles
Specific granules: strain with a neutral dye (not basic methylene or eosin)
azurophilic granules: stain with a azure dye
Azurophilic granules
neutrosomal lysosomes that stain with azure dye
contain elastase, lysozyme myeloperoxidase cathepsin acid hydrolases
Specific granules
contain lactoferrin, lysozyme, secretory phospholipase A2
Neutrophil killing methods
phagocytosis, granule release, NET formation (self-death)
