期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1991
卷号：88
期号：19
页码：8681-8685
DOI：10.1073/pnas.88.19.8681
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：DL-1,2-Dioctanoylglycerol (1,2-DiC8) added to human peripheral resting T lymphocytes was rapidly metabolized to produce octanoic acid and further to small molecules, probably by the action of diacylglycerol lipase and/or nonspecific esterase. Only a small portion was converted to the corresponding phosphatidic acid or was isomerized to 1,3-DiC8 before being metabolized. The uptake of 1,2-DiC8 by the cell was apparently fast, and the rate of disappearance of 1,2-DiC8 was dependent on the cell densities; at a higher density of T lymphocytes 1,2-DiC8 was removed quickly, whereas at a lower cell density 1,2-DiC8 remained for a longer period of time. With a fixed amount of 1,2-DiC8 added, the extent of interleukin 2 receptor alpha-subunit (IL-2R alpha) expression was inversely related to the cell density and proportional to the duration of exposure of the cells to 1,2-DiC8. Repeated doses of 1,2-DiC8 potentiated IL-2R alpha expression. In contrast, a single dose of phorbol 12-myristate 13-acetate caused T-lymphocyte activation to similar extents irrespective of the cell density, probably because the phorbol ester was not metabolized and remained in membranes. The available evidence supports a proposal made in a previous paper and indicates that the sustained activation of protein kinase C for at least the first 3-4 hr is essential for the activation of resting T lymphocytes.
