Täger M, Ittenson A, Franke A, Frey A, Gassen H G, Ansorge S
Institute of Experimental Internal Medicine, Otto-von-Guericke University of Magdeburg, Germany.
Ann Hematol. 1995 May;70(5):237-42. doi: 10.1007/BF01784042.
The expression of the ectoenzyme gamma-glutamyl transpeptidase (EC2.3.2.2., gamma GT) was investigated by flow cytometry on populations of peripheral blood mononuclear cells (PBMC) from healthy subjects and patients suffering from several types of leukemia before and under chemotherapy. In unstimulated PBMC, 28% of these cells were found to be gamma GT positive. The highest expression was measured on monocytes (CD14/gamma GT+ cells: 60%). Within the subsets of T lymphocytes (CD3/gamma GT+ cells: 18%) we saw no clear differences between CD4+ and CD8+ cells. B lymphocytes, NK cells, and activated cells showed low expressions (up to 10%). Treatment of PBMC with mitogens, alpha-IFN, IL-2, and GM-CSF did not affect the enzyme expression on normal mononuclear cells (MNC). However, a rapid increase of gamma GT+ cells was found in the presence of glutathione (GSH) and n-acetyl cysteine (nAC), particularly on monocytes, B cells, and NK cells. Comparing 40 healthy subjects and untreated patients suffering from leukemias, a significantly higher expression of gamma GT+ cells in the total MNC populations (B-CLL: 57%, CML: 62% gamma GT+ cells) was observed in B-chronic lymphocytic leukemia (B-CLL) and chronic myelogenous leukemia (CML), whereas other leukemias did not show clear differences. Most interestingly, the gamma GT expression was diminished in all populations of CML cells after 5 h of incubation in the presence of 10 units/ml IFN-alpha. These data suggest a possible protective role of gamma GT in MNC and a regulatory function of this enzyme in the development of CML.
通过流式细胞术，对健康受试者以及患有几种白血病的患者在化疗前和化疗期间外周血单个核细胞（PBMC）群体中的胞外酶γ-谷氨酰转肽酶（EC2.3.2.2.，γGT）表达进行了研究。在未受刺激的PBMC中，发现28%的细胞γGT呈阳性。单核细胞上的表达最高（CD14/γGT+细胞：60%）。在T淋巴细胞亚群中（CD3/γGT+细胞：18%），我们未发现CD4+和CD8+细胞之间有明显差异。B淋巴细胞、NK细胞和活化细胞表达较低（高达10%）。用丝裂原、α-干扰素、白细胞介素-2和粒细胞巨噬细胞集落刺激因子处理PBMC，对正常单个核细胞（MNC）的酶表达没有影响。然而，在存在谷胱甘肽（GSH）和N-乙酰半胱氨酸（nAC）的情况下，γGT+细胞迅速增加，特别是在单核细胞、B细胞和NK细胞上。比较40名健康受试者和未治疗的白血病患者，在B-慢性淋巴细胞白血病（B-CLL）和慢性粒细胞白血病（CML）中，总MNC群体中γGT+细胞的表达明显更高（B-CLL：57%，CML：62%γGT+细胞），而其他白血病没有明显差异。最有趣的是，在10单位/ml干扰素-α存在的情况下孵育5小时后，CML细胞的所有群体中γGT表达均降低。这些数据表明γGT在MNC中可能具有保护作用，并且该酶在CML的发展中具有调节功能。
