Dokur Madhavi, Boyadjieva Nadka I, Sarkar Dipak K
Endocrinology Program, Center of Alcohol Studies, Rutgers, The State University of New Jersey, New Brunswick, USA.
Alcohol Clin Exp Res. 2003 Apr;27(4):670-6. doi: 10.1097/01.ALC.0000060528.53113.5C.
Chronic alcohol consumption can impair the immune system and predispose individuals to an increased risk of cancer and infection. Natural killer (NK) cells are the first line of defense against viral, bacterial, and fungal infections and play an important role in cellular resistance to malignancy and tumor metastasis. We have shown previously that ethanol administration suppresses NK cell cytolytic activity in male Fischer rats. This study analyzed the effects of ethanol on perforin, granzyme B, and the cytokine interferon (IFN)-gamma, factors that modulate NK cell cytolytic activity, to understand the molecular mechanism involved in ethanol's suppression of NK cell activity.
A group of male Fischer rats was fed an ethanol-containing diet (8.7% v/v), whereas a control group was pair-fed an isocaloric diet. At the end of 2 weeks, animals were decapitated, and spleen tissues were immediately removed and used for analysis of NK cell cytolytic activity, perforin, granzyme B, and IFN-gamma messenger RNA (mRNA) or protein levels. The mRNA levels of perforin, granzyme B, and IFN-gamma were evaluated by quantitative real-time polymerase chain reaction, and protein levels of these factors were analyzed by Western blot, enzyme-linked immunosorbent assay, or enzymatic activity assay.
Ethanol reduced the NK cell cytolytic activity and decreased the mRNA expression of perforin, granzyme B, and IFN-gamma in ethanol-fed animals when compared with pair-fed animals. Ethanol also significantly reduced the protein levels of perforin and IFN-gamma and the enzyme activity of granzyme B in alcohol-fed animals as compared with pair-fed animals.
These data suggest that chronic ethanol consumption may suppress NK cell cytolytic activity in male Fischer rats by decreasing the production, activity, or both of granzyme B, perforin, and IFN-gamma.
长期饮酒会损害免疫系统，使个体患癌症和感染的风险增加。自然杀伤（NK）细胞是抵御病毒、细菌和真菌感染的第一道防线，在细胞抵抗恶性肿瘤和肿瘤转移中发挥重要作用。我们之前已经表明，给雄性Fischer大鼠喂食乙醇会抑制其NK细胞的细胞溶解活性。本研究分析了乙醇对穿孔素、颗粒酶B和细胞因子干扰素（IFN）-γ的影响，这些因子可调节NK细胞的细胞溶解活性，以了解乙醇抑制NK细胞活性所涉及的分子机制。
一组雄性Fischer大鼠喂食含乙醇的饮食（8.7% v/v），而对照组则喂食等热量的配对饮食。在2周结束时，将动物断头，立即取出脾脏组织，用于分析NK细胞的细胞溶解活性、穿孔素、颗粒酶B以及IFN-γ信使核糖核酸（mRNA）或蛋白质水平。通过定量实时聚合酶链反应评估穿孔素、颗粒酶B和IFN-γ的mRNA水平，通过蛋白质印迹法、酶联免疫吸附测定法或酶活性测定法分析这些因子的蛋白质水平。
与配对喂食的动物相比，喂食乙醇的动物中，乙醇降低了NK细胞的细胞溶解活性，并降低了穿孔素、颗粒酶B和IFN-γ的mRNA表达。与配对喂食的动物相比，乙醇还显著降低了喂食乙醇动物中穿孔素和IFN-γ的蛋白质水平以及颗粒酶B的酶活性。
这些数据表明，长期饮酒可能通过降低颗粒酶B、穿孔素和IFN-γ的产生、活性或两者，来抑制雄性Fischer大鼠NK细胞的细胞溶解活性。
