Thursday, September 12, 2013
Proteinase and nonproteinase allergen-induced inflammation. Proteinase allergens cleave fibrinogen into
fibrinogen cleavage products [a]. Nonproteinase allergens activate
endogenous proteinases, such as thrombin
[b], to cleave fibrinogen into cleavage products. Fibrinogen cleavage
products act as ligands for toll-like receptor 4 (TLR4) expressed on
cells including macrophages and airway epithelial cells [c]. Activated
TLR4 stimulates recruitment of innate immune cells and airway inflammation [d].