Premium
Thrombin and trypsin‐induced Ca 2+ mobilization in human T cell lines through interaction with different protease‐activated receptors
Author(s) -
Mari Bernard,
Guerin Sandrine,
Far Dariush Far Ahi,
Breitmayer JeanPhilippe,
Belhacene Nathalie,
Peyron JeanFrancois,
Rossi Bernard,
Auberger Patrick
Publication year - 1996
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.10.2.8641564
Subject(s) - jurkat cells , thrombin receptor , thrombin , trypsin , protease activated receptor 2 , receptor , protease activated receptor , cell culture , microbiology and biotechnology , agonist , biology , biochemistry , chemistry , enzyme , enzyme linked receptor , immunology , t cell , platelet , immune system , genetics
This study was conducted to determine whether serine proteinases may induce [Ca 2+ ] i mobilization in different hematopoietic cell lines and to analyze their mechanisms of action. We show that in addition to thrombin and thrombin receptor agonist peptide (TRP, SFLLRN), trypsin induced [Ca 2+ ] i mobilization in a highly thrombin‐sensitive Jurkat T cell clone. Thromhin, TRP, and trypsin were found to induce [Ca 2+ ] i release in three different Jurkat T cell clones differing in the level of T cell receptor expression. Similar results were obtained with a prolhymocytic leukemic cell line, HPB.ALL, although these cells were much more responsive to trypsin than to thrombin and TRP. Other cell types such as THP1, a myelomonocytic cell line, or CEM, a CD4 + positive leukemic cell line, were unresponsive lo thromhin, TRP, and trypsin. The effect of trypsin was mimicked by SLIGRL, a peptide corresponding lo the cleaved amino‐terminal sequence of the recently characterized murine trypsin‐activated receptor (PAK2), At suboptimal concentrations, the effects of SFLLRN and SLIGRL were additive, whereas saturating doses of peptides did not further increase (Ca 2+ ] i mobilization in Jurkat T cells, indicating that both peptides were able to mobilize the same pool of calcium. Northern blot analysis of mRNAs from different leukemic cell lines indicated a remarkable correlation between PAR2 expression in different cell lines and SLIGRL or trypsin re‐sponses in the same cells. The expression of the “trypsin receptor” was also confirmed by polymerase chain reaction analysis. Moreover, a 24 h treatment of Jurkat cells by an anti‐CD3 monoclonal antibody, a condition known to down‐regulate thrombin receptor expression, induced loss of thrombin and TRP responses but only partially affected trypsin stimulation of [Ca 2+ ] i release. Finally, after a first stimulation with either thrombin or trypsin, Jurkat cells were still able to respond to trypsin or thrombin, respectively, demonstrating that thrombin and trypsin essentially activated their own receptors. Our data provided evidence that 1) the human T leukemic cell line Jurkat and other T cell lines express at least two different functional protease‐activated receptors, the thrombin receptor and a highly sensitive trypsin receptor, likely the human counterpart of the murine PAR2, and 2) at variance with the commonly accepted model, trypsin exerts most of its effect in T leukemic cell lines by thrombin receptor‐independent mechanisms.—Mari, B., Guerin, S., Far, D. F., Breitmayer, J.‐P., Belhacene, N., Peyron, J.‐F., Rossi, B., Auberger, P. Thrombin and trypsin‐induced Ca 2+ mobilization in human T cell lines through interaction with different protease‐activated receptors. FASEB J. 10, 309‐316 ( 1996)