中文摘要：

目的：研究4-1BBL胞膜外区融合蛋白（ex4-1BBL）对人外周血淋巴细胞（PBL）体外活性的调节作用。方法：表达纯化人4-1BBL胞膜外区融合蛋白，台盼蓝计数观察其对淋巴细胞增殖的作用；CytoTox 96非放射性细胞毒试剂盒检测培养液的乳酸脱氢酶（LDH）水平，ELISA检测白介素-2（IL-2）水平。CytoTox 96检测其联合应用anti-CD3／anti-Pgp微型双功能抗体及PBL对靶细胞K562／A02细胞的杀伤作用。结果：4-1BBL胞膜外区融合蛋白能够促进淋巴细胞增殖，减少细胞死亡，促进IL-2分泌；联合应用ex4-1BBL的淋巴细胞组的杀伤效率优于对照组。结论：ex4-1BBL可能成为增强淋巴细胞活性的重要免疫佐剂。

英文摘要：

AIM： To investigate the role of the extracellular domain of human 4-1BBL （ex4-1BBL） in regulating the in vitro activities of peripheral blood lymphocytes （ PBL ）. METHODS： Viable cells were quantified with Trypan-blue exclusion assay. CytoTox 96 Nonradioactive Cytotoxicity Assay Kit was used for measuring LDH levels of supernatant. ELISA kit was used for measuring IL-2 level. In vitro cytotoxity of PBL combined with anti-CD3/anU-Pgp bispecific diabody plus ex4-1BBL was analyzed with CytoTox 96 nonradioactive method. RESULTS： Ex4-1 BBL can increase the proliferation of PBL, reduce cell death, promote IL-2 secretion, and the experimental group with ex4-1BBL showed obviously enhanced cytotoxic effect toward K562/A02 cells. CONCLUSION： Ex4-1BBL may be an important adjuvant for improving activities of PBL.