不同浓度胆红素对新生儿脐血单核细胞分泌白介素1β和白介素8的影响

摘要

Objective To explore the effect of different concentrations of bilirubin on the secretion of interleukin1β (IL-1β) and interleukin-8 (IL-8) in cord blood monocytes (CBMC).Methods Ten healthy full-term newborns were chosen as subjects, their cord blood were collected under the sterile condition.The CBMC were isolated by the method of gelatin/plasma coated flasks.The purity of the monocytes was analyzed by a direct immunofluorescence method using flow cytometry.The cytoactivity was analyzed by 0.4％ trypan blue dye exclusion.The CBMC were preincubated with unconjugated bilirubin dissolved in bovine albumin solution at various concentrations (0 μmol/L,42.8 μmol/L, 102.6 μ mol/L, 153.9 μmol/L, 220.6 μ mol/L and 307.8 μmol/L).Bilirubin-treated CBMC were further cultured with LPS for inducing cellular activation for 24 hours, the supernatants were collected.The levels of IL-1β and IL-8 in the cultural supernatant were detected by the enzyme linked immunosorbent assay (ELISA).Results Compared with the normal control group, the levels of IL-1β and IL-8 increased significantly in LPS control group.The levels of IL- 1β and IL-8 decreased remarkably, with the concentration of bilirubin exceeding 102.6 μmol/L (6 mg/dl).The levels of IL-1β and IL-8 decreased with the concentration of bilirubin going up, and were negatively correlated with the bilirubin concentration.Conclusions The bilirubin inhibits the production of IL-1β and IL-8 in CBMC.The inhibitory effect is more obvious with the increase of bilirubin concentration.%目的 探讨不同浓度胆红素对脐血单核细胞(CBMC)分泌白介素1β(IL-1β)、白介素8(IL-8)的影响.方法 取10份健康足月新生儿脐血,采用纤维连接蛋白结合法分离得到CBMC,将其加入含胆红素0、42.8、102.6、153.9、220.6和307.8 μmol/L的牛血清白蛋白溶液中孵育1 h,再加入脂多糖(LPS)刺激24 h.:集上清液,采用ELISA法检测上清液中IL-1β、IL-8的水平.结果 与空白对照组相比,LPS对照组IL-1β、IL-8水平显著升高;当胆红素浓度≥ 102.6 μmol/L时,CBMC分泌IL-1β、IL-8水平明显降低.随着胆红素浓度的升高,CBMC分泌IL-1β、IL-8水平降低明显.相关性分析显示,CBMC分泌IL-1β、IL-8水平与胆红素浓度呈负相关.结论 胆红素对单核细胞分泌IL-1β和IL-8有不同程度的抑制作用,随着胆红素浓度的升高,这种抑制作用更为明显.