title: Effect of the house dust mite allergen Der p 1 on tryptase release from human mast cells.
abstract: This study aimed to investigate the effects of the house dust mite allergen Der p 1 on the secretion of tryptase from the human mast cell line HMC-1. Flow cytometry was used to determine the expression levels of protease-activated receptor-2 (PAR2) on the surface of HMC-1 cells. HMC-1 cells were treated with Der p 1, SLIGRL-NH2 (PAR2 agonist), LRGILS-NH2 (control peptide for PAR2), or Der p 1 + FSLLRY (PAR2 antagonist), and the tryptase levels were measured using enzyme-linked immunosorbent assay. The biological functions of PAR2 were determined using the calcium green indicator, and intracellular calcium fluorescence intensity in the different groups (Der p 1, SLIGRL-NH2, LRGILS- NH2, Der p 1 + FSLLRY, tryptase, tryptase + FSLLRY, or cell culture medium) was detected by laser scanning confocal microscopy. The mast cells expressed PAR2 receptor on their surfaces. Der p 1 alone induced a significant release of intracellular calcium and tryptase in HMC-1 cells compared with the SLIGRL- NH2 treatment group and the control group. The combination of Der p 1 and FSLLRY partly inhibited intracellular calcium and tryptase release in HMC-1 cells compared with the Der p 1 treatment group. Moreover, tryptase induced a significant release of intracellular calcium in the HMC-1 cells. Der p 1 induced HMC-1 cell degranulation and the release of tryptase by activating the PAR2 receptor on the cell surfaces. Tryptase activated the PAR2 receptor and induced intracellular calcium release from the HMC-1 cells in a positive feedback loop.
authors.affiliation: Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: D Q
authors.initials: DQ
authors.lastname: Wang
authors.affiliation: Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Shen
authors.affiliation: Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: J H
authors.initials: JH
authors.lastname: Xu
authors.affiliation: Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: H
authors.initials: H
authors.lastname: Tang
mesh_terms: D039741:Antigens, Dermatophagoides / Q000276:immunology / Q000494:pharmacology*; D060829:Arthropod Proteins / Q000276:immunology / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000276:immunology / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D008407:Mast Cells / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D009842:Oligopeptides / Q000494:pharmacology; D044464:Receptor, PAR-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000276:immunology; D015398:Signal Transduction; D053802:Tryptases / Q000378:metabolism*
chemical_list: D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D009842:Oligopeptides; D044464:Receptor, PAR-2; C497499:leucyl-arginyl-glycyl-isoleucyl-leucyl-serinamide; C112356:seryl-leucyl-isoleucyl-glycyl--arginyl-leucinamide; D053802:Tryptases; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1; D002118:Calcium