Massey G V, McCrady C W, Dunn N L, Russell E C, Carchman R A
Department of Pediatrics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0001.
Leukemia. 1989 Aug;3(8):602-10.
Signals from many receptor-ligand interactions are mediated by enhancement of phospholipid hydrolysis which generates metabolic intermediates stimulating protein kinase C (PKC) and elevating cellular calcium. Pharmacologic agents such as phorbol 12, 13-dibutyrate (PDBu) and ionomycin selectively stimulate PKC and elevate intracellular calcium to directly stimulate downstream mechanisms critical to cell growth and function. This study examines the effects of PDBu, ionomycin, and rIL-2 on childhood ALL blasts of early B lineage with respect to various aspects of cell activation, including DNA synthesis, induction of non-MHC restricted tumoricidal activity, and changes in morphology and phenotype. Five childhood ALL samples were tested. A marked heterogeneity was seen among the ALL samples with respect to in vitro growth following manipulation with PDBu, ionomycin, and/or rIL-2, whereas normal peripheral blood lymphocytes (PBL) were consistently stimulated to grow with the combination of PDBu and ionomycin. Growth responsiveness did not appear to correlate with morphologic or phenotypic classification of the leukemia samples. Four of the five leukemia samples developed substantial non-MHC restricted cytotoxicity to K562 (natural killer cell (NK) sensitive) and Daudi (NK resistant) targets in response to rIL-2. This functional cytotoxic response correlated with morphologic changes in the cells and the appearance of granules. Phenotypic analyses of the ALL samples at the time of their peak cytotoxic function were consistent with the fresh ALL phenotype and showed no major change in cell populations. Three of the five ALL samples also retained rIL-2 induced cytotoxic capabilities when exposed simultaneously to the combination of PDBu and ionomycin, whereas rIL-2 induced tumoricidal activity in normal PBL and bone marrow cultures was inhibited by these reagents. These data show that morphologically and phenotypically similar ALL blasts have heterogeneous proliferative responses to the PKC and calcium modulators PDBu and ionomycin, as well as to rIL-2. Cytotoxic responses are also different from those of normal PBL and bone marrow cells with respect to kinetics and responsiveness to inducing agents. Thus current morphologic and phenotypic classifications of ALL may not adequately reflect the heterogeneity of this disorder as described here.
许多受体 - 配体相互作用的信号是通过增强磷脂水解来介导的，磷脂水解会产生代谢中间体，刺激蛋白激酶C（PKC）并升高细胞内钙水平。诸如佛波醇12,13 - 二丁酸酯（PDBu）和离子霉素等药理剂选择性地刺激PKC并升高细胞内钙，以直接刺激对细胞生长和功能至关重要的下游机制。本研究考察了PDBu、离子霉素和重组人白细胞介素 - 2（rIL - 2）对早期B系儿童急性淋巴细胞白血病（ALL）原始细胞在细胞活化各个方面的影响，包括DNA合成、非主要组织相容性复合体（MHC）限制的杀肿瘤活性诱导以及形态和表型的变化。对五个儿童ALL样本进行了检测。在用PDBu、离子霉素和/或rIL - 2处理后，ALL样本在体外生长方面表现出明显的异质性，而正常外周血淋巴细胞（PBL）在PDBu和离子霉素联合作用下持续受到刺激而生长。生长反应性似乎与白血病样本的形态或表型分类无关。五个白血病样本中的四个在对rIL - 2的反应中，对K562（自然杀伤细胞（NK）敏感）和Daudi（NK抗性）靶标产生了大量非MHC限制的细胞毒性。这种功能性细胞毒性反应与细胞形态变化和颗粒的出现相关。在ALL样本细胞毒性功能达到峰值时进行的表型分析与新鲜ALL表型一致，并且细胞群体没有出现重大变化。五个ALL样本中的三个在同时暴露于PDBu和离子霉素组合时，也保留了rIL - 2诱导的细胞毒性能力，而rIL - 2在正常PBL和骨髓培养物中诱导的杀肿瘤活性则被这些试剂抑制。这些数据表明，形态学和表型相似的ALL原始细胞对PKC和钙调节剂PDBu和离子霉素以及rIL - 2具有异质性增殖反应。在动力学和对诱导剂的反应性方面，细胞毒性反应也与正常PBL和骨髓细胞不同。因此，目前ALL的形态学和表型分类可能无法充分反映本文所述的这种疾病的异质性。
