Extracellular matrix proteins attenuate activation and degranulation of stimulated eosinophils.

摘要: Cellular adhesion plays an important role in the recruitment and activation of eosinophils. Here, we investigated whether extracellular matrix (ECM) proteins modify effector functions activated human We coated 96-well plates with laminin or fibronectin blocked nonspecific protein-binding sites serum albumin (HSA). When eosinophils were stimulated platelet-activating factor (PAF) incubated these ECM-coated wells, adhered using both beta 1- 2-integrins. Degranulation adherent to laminin- fibronectin-coated wells was reduced about 50% compared cells uncoated, HSA-blocked wells. Furthermore, inhibitory effects concentration-dependent secretagogue-specific, that is, degranulation induced by C5a IL-5 inhibited while secretory IgA PMA not inhibited. Plasma fibronectin, type I collagen IV also PAF- C5a-induced eosinophil degranulation, whereas fibrinogen did not. By microscopy, PAF-stimulated eosinophils, adhering uncoated appeared elongated many pseudopods. In contrast, laminin-coated oval few when production a second messenger, inositol phosphate, markedly reduced. These findings suggest ECM protein, such as attenuate influence their morphology after stimulation physiologic secretagogues. Thus, may regulate they traverse between peripheral blood targets.