Fixler R, Shimoni Y, Hassin D, Admon D, Raz S, Yarom R, Hasin Y
Department of Cardiology, Hadassah-Hebrew University Hospital, Jerusalem, Israel.
J Mol Cell Cardiol. 1994 Mar;26(3):351-60. doi: 10.1006/jmcc.1994.1044.
cytotoxic lymphocytes are important in the pathogenesis of several disease states, yet, the pathophysiology of lymphocyte-myocyte interaction is not well known.
We have developed a model for the in vitro evaluation of autoimmune cytotoxic myocardial damage. Cardiac myocytes were repeatedly injected to adult autologous rats. Following 3 months, histological evidence of myocarditis was seen in 20% of the hearts. Cultured myocytes obtained from newborn rats were exposed to lymphocytes isolated from the immunized animals. Cytotoxic activity was measured using crystal violet staining test. The percentage of killing was increased as the ratio of lymphocytes/myocytes was increased. Verapamil did not block this cytotoxic effect. No killing was seen when myocytes were exposed to non-sensitized lymphocytes. Physiological changes induced in myocytes by cytotoxic lymphocytes were studied. Cell wall motion was measured by an optical method and action potentials with intracellular microelectrodes. Physiological changes observed in myocytes following exposure to cytotoxic lymphocytes included: Impaired relaxation with prolonged contractions, oscillations and prolongation of the plateau of the action potential. Cellular contraction was prolonged up to 4 s before total arrest of spontaneous activity. Verapamil but not tetrodotoxin restored action potentials and contractions to normal. Supernatant collected from cultures of myocytes and lymphocytes had the same effect on myocytes contractility as observed following exposure of myocytes to cytotoxic lymphocytes.
This supports our hypothesis that these physiological alterations observed in myocytes are mediated by a soluble factor secreted by cytotoxic lymphocytes.
细胞毒性淋巴细胞在多种疾病状态的发病机制中起重要作用，然而，淋巴细胞与心肌细胞相互作用的病理生理学尚不清楚。
我们建立了一种体外评估自身免疫性细胞毒性心肌损伤的模型。将成年自体大鼠反复注射心肌细胞。3个月后，20%的心脏出现心肌炎的组织学证据。将新生大鼠获得的培养心肌细胞暴露于从免疫动物分离的淋巴细胞中。使用结晶紫染色试验测量细胞毒性活性。随着淋巴细胞/心肌细胞比例的增加，杀伤百分比增加。维拉帕米不阻断这种细胞毒性作用。当心肌细胞暴露于未致敏的淋巴细胞时未观察到杀伤现象。研究了细胞毒性淋巴细胞在心肌细胞中诱导的生理变化。通过光学方法测量细胞壁运动，并使用细胞内微电极记录动作电位。暴露于细胞毒性淋巴细胞后在心肌细胞中观察到的生理变化包括：舒张受损，收缩延长，动作电位平台期出现振荡和延长。在自发活动完全停止前，细胞收缩延长至4秒。维拉帕米而非河豚毒素使动作电位和收缩恢复正常。从心肌细胞和淋巴细胞培养物中收集的上清液对心肌细胞收缩性的影响与心肌细胞暴露于细胞毒性淋巴细胞后观察到的相同。
这支持了我们的假设，即心肌细胞中观察到的这些生理改变是由细胞毒性淋巴细胞分泌的可溶性因子介导的。
