CD14抑制肽的体外生物活性

Biological activity of CD14 inhibitory peptide in vitro

目的研究CD14抑制肽(CD14inhibitory peptide,CD14-IP)与CD14的结合活性及对内毒素(LPS)和脂多糖结合蛋白(LBP)诱导的人单核巨噬细胞株U937表达肿瘤坏死因子-α(TNF-α)的影响。方法采用酶联免疫吸附(ELISA)法进行CD14-IP与CD14的结合实验。U937细胞用佛波脂(PMA)诱导成熟后分为五组:正常对照组、LPS组(100ng/mLLPS+100ng/mLrhLBP)、高剂量多肽组、中剂量多肽组及低剂量多肽组,后三组分别给予10μg/mL、1.0μg/mL和0.1μg/mL的CD14-IP。用ELISA测定培养细胞上清TNF-α的含量,用RT-PCR测定U937细胞TNF-αmRNA的表达水平。结果CD14-IP有较强的与CD14结合的能力;CD14-IP组TNF-α和TNF-αmRNA水平均较LPS组低,较正常组高。结论CD14-IP能与CD14结合,并能降低培养细胞TNF-α和TNF-αmRNA的表达,具有抑制CD14生物活性的作用。

Objective To investigate the binding efficacy of CD14 inhibitory peptide （ CD14 - IP） binding CD14 and the effect of CD14 - IP on TNF -α expression in U937 cells induced by LPS. Methods The binding test of CDI4 - IP binding to CD14 was carried out by ELISA. Then, U937 cells were stimulated by Phorbol myristate acetate （ PMA ） and divided into five groups： control group, LPS group （ 100 ng/mL LPS plus 100 ng/mL rhLBP） , high dose inhibitory peptide group, middle dose inhibitory peptide group and low dose inhibitory peptide group （ 10 μg/mL, 1.0 μg/mL , and 0.1 μg/mL , respectively） . The concentration of TNF-α released from cells was detected by ELISA. The mRNA of TNF-α in U937 cells was determined by RT - PCR. Results CD14 - IP has a high binding efficacy with CD14. The the concentration of TNF -α and level of TNF-α mRNA in inhibitory peptide group were significantly lower than that in LPS group, and were significantly higher than that in control group. Conclusion CD14 - IP has a high binding efficacy with CD14, and can reduce the level of TNF -α and TNF-α mRNA in U937 cells induced by LPS. It can inhibit biological activity of CD14.