TY - JOUR
T1 - Leukotriene C4 production from human eosinophils in vitro. Role of eosinophil chemotactic factors on eosinophil activation
AU - Tamura, N.
AU - Agrawal, D. K.
AU - Townley, R. G.
PY - 1988/1/1
Y1 - 1988/1/1
N2 - We studied the role of naturally occurring eosinophil chemotactic factors on leukotriene (LT)C4 production from highly purified (87.1 ± 2.4%) normodense eosinophils. Platelet activating factor (PAF) directly induced LTC4 production from eosinophils in a dose (10-9 to 10-5 M) and a time-dependent manner. PAF (10-5 M) induced 0.74 ± 0.08 ng of LTC4 production/106 eosinophils. However, lyso-PAF, eosinophil chemotactic factor of anaphylaxis, and LTB4 failed to induce LTC4 production within the tested range. Furthermore, the pre-incubation of eosinophils with 5 μg/ml of cytochalasin B did not alter the chemotactic factor-induced LTC4 production. When eosinophils were stimulated by the submaximal concentration (1 μg/ml) of calcium ionophore A23187, the pre-incubation of eosinophils with 10-6 M or 10-5 M of PAF, or 10-5 M of eosinophil chemotactic factor of anaphylaxis significantly enhanced LTC4 production up to 163.9 ± 17.5% (p <0.05), 279.2 ± 32.9% (p <0.01) and 165.2 ± 21.2% (p <0.05) of the control, respectively. However, the pre-incubation with lyso-PAF or LTB4 failed to enhance A23187-induced LTC4 production. The preincubation of eosinophils with phosphatidyl serine also failed to enhance A23187-induced LTC4 production. However, the direct stimulation of protein kinase C by PMA enhanced the submaximal concentration of A23187-induced LTC4 production from eosinophils up to 179.5 ± 20.9% (p <0.05) of the control. Our findings indicate that PAF and ECF-A work not only as chemotactic factors but also induce a functionally active state of eosinophils probably through their post-receptor mechanisms, and contribute to the inflammatory processes.
AB - We studied the role of naturally occurring eosinophil chemotactic factors on leukotriene (LT)C4 production from highly purified (87.1 ± 2.4%) normodense eosinophils. Platelet activating factor (PAF) directly induced LTC4 production from eosinophils in a dose (10-9 to 10-5 M) and a time-dependent manner. PAF (10-5 M) induced 0.74 ± 0.08 ng of LTC4 production/106 eosinophils. However, lyso-PAF, eosinophil chemotactic factor of anaphylaxis, and LTB4 failed to induce LTC4 production within the tested range. Furthermore, the pre-incubation of eosinophils with 5 μg/ml of cytochalasin B did not alter the chemotactic factor-induced LTC4 production. When eosinophils were stimulated by the submaximal concentration (1 μg/ml) of calcium ionophore A23187, the pre-incubation of eosinophils with 10-6 M or 10-5 M of PAF, or 10-5 M of eosinophil chemotactic factor of anaphylaxis significantly enhanced LTC4 production up to 163.9 ± 17.5% (p <0.05), 279.2 ± 32.9% (p <0.01) and 165.2 ± 21.2% (p <0.05) of the control, respectively. However, the pre-incubation with lyso-PAF or LTB4 failed to enhance A23187-induced LTC4 production. The preincubation of eosinophils with phosphatidyl serine also failed to enhance A23187-induced LTC4 production. However, the direct stimulation of protein kinase C by PMA enhanced the submaximal concentration of A23187-induced LTC4 production from eosinophils up to 179.5 ± 20.9% (p <0.05) of the control. Our findings indicate that PAF and ECF-A work not only as chemotactic factors but also induce a functionally active state of eosinophils probably through their post-receptor mechanisms, and contribute to the inflammatory processes.
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M3 - Article
C2 - 2848892
AN - SCOPUS:0024165190
VL - 141
SP - 4291
EP - 4297
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 12
ER -