首页 | 本学科首页   官方微博 | 高级检索  
     


Differential effects of ouabain on human cell-mediated cytotoxicity. II. Stimulation of monocyte-mediated, spontaneous cytotoxicity against chicken red cell targets.
Authors:E C Lawrence  A V Muchmore  J M Decker  N J Dooley  R M Blaese
Affiliation:Cellular Immunology Section, Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20014 U.S.A.
Abstract:We have previously shown that ouabain inhibits mitogen-induced cellular cytotoxicity (MICC) and antibody-dependent cellular cytotoxicity (ADCC) against chicken red cell (CRC) targets. We now report that ouabain increases spontaneous killing of CRC targets in the absence of mitogen or antibody. Spontaneous cytotoxicity by fresh mononuclear leukocytes (MNL) was enhanced by ouabain in a dose-dependent fashion and was maximal at a ouabain concentration of 5 × 10?5M. Removal of phagocytic cells from the MNL effector cell population abrogated ouabain-induced spontaneous cytotoxicity, suggesting that the effector cell activated by ouabain was a monocyte. Ouabain-induced spontaneous cytotoxicity was relatively inefficient compared to MICC or ADCC and was only demonstrated consistently at effector:target cell ratios higher than those routinely employed for MICC and ADCC. Very low concentrations of ouabain (5 × 10?9M) also enhanced spontaneous cytotoxicity of MNL precultured for 7 days, when added at either Day 0 or Day 6 of preculture. The cell effecting spontaneous cytotoxicity after 7 days of culture has been previously shown to be a monocyte. Thus, ouabain has opposing effects on cell-mediated cytotoxic functions: it inhibits MICC and ADCC against CRC targets, but stimulates spontaneous, monocyte-mediated cytotoxicity against the same targets.
Keywords:Address reprint requests to Dr. E. Clinton Lawrence   Department of Internal Medicine   Pulmonary Section   Baylor College of Medicine and The Methodist Hospital   Texas Medical Center   Houston   Tex. 77030.
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号