中文摘要：

目的：观察高迁移率族蛋白B1（HMGB1）对健康人外周血T淋巴细胞增殖反应的影响,并对其机制进行初步探讨。方法：分离8例健康人外周血单个核细胞后接种于96孔培养板（2×10~6/ml）,以植物血凝素诱导细胞体外增殖后,采用不同剂量（0、1、10、100、1000 ng/ml）重组人HMGB1（rhHMGB1）刺激12～48 h。用噻唑蓝（MTT法检测T淋巴细胞增殖,观察HMGB1对T淋巴细胞增殖反应的影响。结果：12、24 h不同rhHMGB1剂量组间淋巴细胞增殖反应无明显差异;rhHMGB1刺激48h后不同剂量对淋巴细胞增殖影响差异有显著性（P =0.0453）,500、1000 ng/ml rhHMGB1组淋巴细胞增殖能力显著低于1、10 ng/ml组和对照组（P〈0.05～0.01）。结论：较高浓度HMGB1长时间刺激后体外T细胞增殖活力明显下降,HMGB1可能是诱导T细胞功能亚群从促炎免疫应答优势向抗炎优势转化的重要因素之一。

英文摘要：

Objective：To investigate the effect of high mobility group box-1 protein（HMGB1）on proliferative activity of human T Iymphocytes and its potential regulating mechanism.Methods：Peripheral blood mononuclear ceils（PBMC）were isolated by Ficoll-Hypaque from healthy adult volunteers and were suspended in RPMI 1640 with 10% FCS at 2×10^6 cells/ml.The cells were cultured with 20μg/ml of phytohemagglutin（PHA）in 5% CO2 at 37℃,and then recombinant human HMGB1（rhHMGB1,1-1 000 ng/ml）was added to cultures at 24, 48,60 and 72 hours.Cell viability was assessed by thiazolyl blue（MTT）assay after 72-hour incubation.The optical density was measured with a spectrophotometer at 560 nm.Results;Proliferative activity was not markedly affected by rhHMGB1 stimulation in low concentrations（less than 100 ng/ml）,while continued exposure of T lympbocytes to 500-1 000 ng/ml rhHMGB1 for 48 hours resulted in inhibition of lymphocytes proliferation（P= 0.0453）.Proliferative activities of T lymphoeytes in 500-1000 ng/ml rhHMGB1 were significantly decreased compared with those in 1,10 ng/ml rhHMGB1 and controls（P〈0.05 or P〈0.01）.Conclusion：These data suggest that continued exposure of T lymphoeytes to high dosage of rhHMGB1 result in decrease in MTT density. HMGB1 might suppress T-cell-mediated immune function as a Th2-polarizing stimulus.