Expression of and functional responses to protease-activated receptors on human eosinophils

Journal of Leukocyte Biology

Colin R. A. Hewitt¹  Clare A. McNulty²  Andrew J. Wardlaw²  Rebecca J. Thomas²  Sarah J. Bolton² 

[1]Department of Microbiology and Immunology, School of Biological Sciences, Maurice Shock Medical Science Building, Leicester University, United Kingdom Department of Microbiology and Immunology, School of Biological Sciences, Maurice Shock Medical Science Building, Leicester University, United Kingdom Department of Microbiology and Immunology, School of Biological Sciences, Maurice Shock Medical Science Building, Leicester University, United Kingdom

[2]Division of Respiratory Medicine, Leicester Warwick Medical School, and Division of Respiratory Medicine, Leicester Warwick Medical School, and Division of Respiratory Medicine, Leicester Warwick Medical School, and

关键词: trypsin;    thrombin;    activation;   

DOI  :  10.1189/jlb.0702351

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

Eosinophil recruitment to airway tissue is a key feature of asthma, and release of a wide variety of toxic mediators from eosinophils leads to the tissue damage that is a hallmark of asthma pathology. Factors that control the release of these toxic mediators are targets for potential therapeutic intervention. Protease-activated receptors (PARs) are a novel class of receptors that are activated by cleavage of the N terminus of the receptor by proteases such as thrombin or trypsin-like enzymes. To date, PAR1–4 have been identified, and there are several studies that have demonstrated the expression of PARs in airway tissue, particularly the respiratory epithelium. We have investigated whether eosinophils express PARs and if activation of these receptors will then trigger a functional response. Using a combination of reverse transcriptase-polymerase chain reaction, Western blotting, and flow cytometry analysis, we have demonstrated that eosinophils express PAR1 and PAR2. FACS analysis showed that PAR1 could be clearly detected on the surface of the cells, whereas PAR2 appeared to be primarily intracellular. Trypsin and the PAR2 agonist peptide were seen in trigger shape change, release of cysteinyl leukotrienes, and most obviously, generation of reactive oxygen species. In contrast, thrombin had no effect on eosinophil function. The PAR1 agonist peptide did have a minor effect on eosinophil function, but this was most likely down to its ability to activate PAR1 and PAR2. These results demonstrate that PAR2 is the major PAR receptor that is capable of modulating eosinophil function.

【 授权许可】

Unknown