表达CD95L的HepG_2细胞自分泌和旁分泌的细胞毒效应

目的阐明乙型肝炎时肝细胞可表达细胞毒效应分子ＣＤ９５Ｌ的效应机制。方法ＨｅｐＧ２细胞诱导表达ＣＤ９５Ｌ，与ＨｅｎＧ２．２．１５细胞共培养；或以其培养上清液加于另一份未经诱导的ＨｅＰＧｚ细胞中，以流式细胞仪检测后者的凋亡率；以单个ＨｅｐＧ２细胞培养试验自体凋亡。结果表达ＣＤ９５Ｌ的ＨｅｐＧ２细胞致表达ＣＤ９５的ＨｅｐＧ２．２．１５细胞的凋亡率为：２４小时时１６．５％，４８小时时４３．０％；培养上清液引起的凋亡率：２４小时时３８．７％，４８小时时７３．３％，单个ＨｅｐＧ２细胞经诱导的自杀率２４小时为４３．８％，均高于各自的对照。结论ＨｅｐＧｅ细胞以ＣＤ９５Ｌ的膜性或可溶性分子、经旁分泌或自分泌发生“自杀”或“同胞相杀”。

Cytototic effect of HepG_2 cell expressing CD95L in an autocrine and paracrine way

Objective The clearance of HBV-infected hepatocyte is mainly mediated by the CTLexpressing CD95L. We have found that the hepatocytes also express CD95L in hepatitis B, a moleculewith cytotoxic effect. This Study was to elucidate its effect mechanism. Methods The HepG2 cell wasinduced to express CD95L and coincubated with HepG2.2.15 cell. The supernate from the inducd HepG2cell culture was added to another untreated HepG2 fraction. The apoptosis rates were examined with flowcytometry. The apoptosis of individual HepG2 cell incubation was also examined. Results The HepG2 cellexpressing CD95L was able to kill the HepG2.2.15 cell with CD95 expression, apoptotic rates were 16.5%at 24h and 43.0% at 48h incubation. The supernate induced apoptosis rates of 38.7% and 73.3%, and thesuicide rater of individual HapG2 cell incubation were 43.8% at 24h. All these data were higher than thosein controls. The apoptosis could be blocked with addition of anti-CD95L monoclonal antibody. ConclusionThe HepG2 cell expressing CD95L mediated cytotoxic effect by an autocrine and paracrine mechanism.