BPI作为内毒素自然抑制物的作用研究

目的　确认杀菌性 /通透性增加蛋白 (bactericidal/permeabilityincreasingprotein ,BPI)作为机体的自然防御武器在人中性粒细胞中的存在状态。　方法　检测猪源BPI与内毒素(lipopolysaccharide ,LPS)的结合能力及其对LPS诱导的肝库普弗细胞分泌TNFα的抑制作用 ,并采用流式细胞仪测定LPS刺激后PMNL中BPI的表达情况。　结果　猪源BPI与内毒素结合能力随着BPI浓度的增加而增加 ,其抑制LPS诱导肝库普弗细胞分泌TNFα的作用呈剂量效应依赖关系。在LPS刺激 30min内 ,BPI在PMNL表面的表达即明显增加 ,但并未立即释放入血。　结论　BPI具有强大的中和内毒素能力 ,在G-杆菌感染情况下补充外源BPI可能是有益的

study on bactericidal/permeability increasing protein ( BPI ) as a natural inhibitor of endotoxin

OBJECTIVE: To investigate the existential status of BPI as a natural defensive factor in human polymorphonuclear leukocytes (PMNL). METHODS: The abilities of porcine BPI to combine endotoxin (lipopolysaccharide, LPS) and inhibit the release of TNFalpha from hepatic Kupffer's cells were examined. And the expression of BPI in PMNL after stimulation by LPS was determined by flow cytometry. RESULTS: The ability of porcine BPI to combine LPS was increased along with the increment of BPI concentration. The effects of the BPI on the inhibition of the release of TNFalpha from hepatic Kupffer's cells were dose-dependant. The expression of BPI in PMNL was enhanced obviously within 30 mins of LPS stimulation. But there was no immediate release of BPI into blood. CONCLUSION: BPI possessed potential power of neutralizing LPS. It might be beneficial to supplement exogenous BPI in case of Gram negative bacterial infection.