The proteolytic effect of mast cell tryptase to eotaxin-1/CCL11•eotaxin-2/CCL24 and eotaxin-3/CCL26 produced by conjunctival fibroblasts

PurposeTo investigate the proteolytic effect of mast cell tryptase on eotaxin-1/CCL11, eotaxin-2/CCL24 and eotaxin-3/CCL26 produced by conjunctival fibroblasts.Study designExperimental.MethodsThe production of eotaxin-1, -2 and -3 by conjunctival fibroblasts stimulated both with and without IL-4/IL-13 or/and TGF-(1) was assessed by ELISA. The proteolytic activity of tryptase on eotaxins derived from conjunctival fibroblasts and recombinant eotaxins was also estimated by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR).ResultsConjunctival fibroblasts produced eotaxin-1 and -3, but not eotaxin-2. Stimulation with IL-4/IL-13 and TGF-(1) synergistically increased eotaxin-1 and -3 production. Tryptase reduced the immunoreactivity of eotaxin-1 and -3 but not of eotaxin-2, due to the proteolysis of these eotaxins but not the inhibition of their m-RNA expression.ConclusionMast cell tryptase may exercise proteolytic activity on eotaxin-1 and -3 produced by conjunctival fibroblasts, resulting in partial suppression of the ability of eotaxin-1 and -3 to accumulate eosinophils in the conjunctiva. Eotaxin-2 in the tears may be a suitable biomarker of severity of allergic conjunctival disease.