Effect of chymase inhibitors on tryptase release from human colon mast cells / 中国免疫学杂志

ABSTRACT

Objective:To investigate the ability of chymase inhibitors on tryptase release from human colon mast cells.Methods:Human mast cells were dispersed from colon tissue with collagenase and hyaluronidase,and were challenged with stimulus for 15 min at 37℃.Tryptase assay performed following previous procedures.In brief,a 96-well microtitre plate was coated with antiserum to human tryptase.The tryptase levels in the samples were detected with a monoclonal antibody specific to tryptase and the reaction was visualized by addition of OPD.Results:At 15 min and 35 min following incubation,anti-IgE and calcium ionophore were able to provoke significant tryptase release from human colon mast cells.Chymase inhibitors ZIGPFM,TPCK and ?1-antitrypsin had no stimulatory effect on colon mast cells at both 15 min and 35 min incubation periods.All the chymase inhibitors were able to inhibit anti-IgE induced tryptase release in a concentration dependent manner with a maximum of 37%,40% and 36.6% inhibition being achieved with 1 ?mol/mL of ZIGPFM,80 ?mol/mL of TPCK,30 ?mol/mL of ?1-antitrypsin,respectively.Preincubation of inhibitors of ZIGPFM and TPCK with cells for 20 min at 37℃ before challenging with anti-IgE was able to slightly enhance their inhibitory actions.Amastatin,a specific inhibitor of aminopeptidase,had no effect on anti-IgE induced tryptase release.All the chymase inhibitors were able to inhibit calcium ionophore induced tryptase release,the maximum inhibition were 23%-35.3%.And the extent of inhibition by ZIGPFM was increased when colon mast cells were preincubated for 20 min before calcium ionophore being added.However,the same treament failed to improve the action of TPCK.Conclusion:We found for the first time that inhibitors of chymase were able to inhibit anti-IgE and calcium ionophore induced tryptase release from human colon mast cells,which may indicated a potential of a novel therapy for the treatment of inflammatory bowel disease or other mast cell related diseases.