The study of the role of 2 kinds of TNF receptors regulating the TNF-induced apoptosis in eosinophils.

Apoptosis is important for the resolution of chronic eosinophilic inflammation observed in bronchial asthma.Using a human myeloblastic leukemia cell line，EoL-1，we investigated the effect of interferon-gamma(IFN-γ)on Fas-and tumor becrosis factor-α(TNF)-induced apoptosis.Both THN and anti-Fas monoclonal antibody(CH-11)induced apoptosis of EoL-1cells.Pretreatment with IFN-γenhanced the CH-11-induced apoptosis with up-regulation of Fas.However，the treatment markedly inhibited the TNF-induced apoptosis.In flow cytometric analysis，EoL-1expressed two types of tumor necrosis factor receptors(TNFR1，2)and the expression of TNFR2 but not of TNFR1was up-regulated significantly after the IFN-Γtreatment.The TNF-induced apoptosis was mimicked by a TNFR1stimulating antibody(htr-9)，and was reversed by a TNFR1blocking antibody(H398)。Although the TNFR1-mediated cytotoxic signal was not affected by IFN-γpretreatment，blocking TNFR2 by a specific antagonistic antibody(utr-1…More)canceled the inhibitory effect of IFN-Γ。In conclusion，TNF-induced apoptosis was mediated preferentially by TNFR1，and the anti-apoptotic effect of IFN-γresult from up-regulated TNFR2 in EoL-1cell line.Further，we investigated the signal transduction pathway from TNFR2 in IFN-γtreated EoL-1cells.We revealed that the stimulation through TNFR2 activated the NF-kappaB by western blot analysis.Recently，we reported that the effect of Rho/ROCK signaling on cell functions.Rho/Rock signaling inhibited the myosin phosphatase and kept the phosphoryrated myosin high.ROCK inhibitor(Y-27632)relaxed the muskarinic bronchiai smooth muscle contraction。Myosin is known to regulates the morphological change and migration of cells.So，we investigated the effect of ROCK inhibitor(Y-27632)on migration of eosinophols and found that Y-27632 inhibitted the migration of eosinophils without inhibitting the Ca I D1++i D1 influx or production of active oxygen。These findings were preparing for paper。Less：Less

Apoptosis is important for the resolution of chronic eosinophilic inflammation observed in bronchial asthma. Using a human myeloblastic leukemia cell line, EoL-1, we investigated the effect of interferon-gamma (IFN-γ) on Fas- and tumor becrosis factor-α (TNF)-induced apoptosis. Both THN and anti-Fas monoclonal antibody (CH-11) induced apoptosis of EoL-1 cells. Pretreatment with IFN-γ enhanced the CH-11-induced apoptosis with up-regulation of Fas. However, the treatment markedly inhibited the TNF-induced apoptosis. In flow cytometric analysis, EoL-1 expressed two types of tumor necrosis factor receptors (TNFR1, 2) and the expression of TNFR2 but not of TNFR1 was up-regulated significantly after the IFN-Γ treatment. The TNF-induced apoptosis was mimicked by a TNFR1 stimulating antibody (htr-9), and was reversed by a TNFR1 blocking antibody (H398). Although the TNFR1-mediated cytotoxic signal was not affected by IFN-γ pretreatment, blocking TNFR2 by a specific antagonistic antibody (utr-1 … More ) canceled the inhibitory effect of IFN-Γ. In conclusion, TNF-induced apoptosis was mediated preferentially by TNFR1, and the anti-apoptotic effect of IFN-γ result from up-regulated TNFR2 in EoL-1 cell line. Further, we investigated the signal transduction pathway from TNFR2 in IFN-γ treated EoL-1 cells. We revealed that the stimulation through TNFR2 activated the NF-kappaB by western blot analysis.Recently, we reported that the effect of Rho/ROCK signaling on cell functions. Rho/Rock signaling inhibited the myosin phosphatase and kept the phosphoryrated myosin high. ROCK inhibitor (Y-27632) relaxed the muskarinic bronchiai smooth muscle contraction. Myosin is known to regulates the morphological change and migration of cells. So, we investigated the effect of ROCK inhibitor (Y-27632) on migration of eosinophols and found that Y-27632 inhibitted the migration of eosinophils without inhibitting the CaィイD1++ィエD1 influx or production of active oxygen. These findings were preparing for paper. Less