胆红素对新生儿脐血单核细胞分泌趋化蛋白-1和白细胞介素-12的影响

目的探讨胆红素对新生儿脐血单核细胞（cord blood monocyte,CBMC）趋化蛋白-1（monocyte chemoattractantprotein-1,MCP-1）和白细胞介素-12（interleukin-12,IL-12）分泌的影响。方法选择10例健康足月新生儿作为研究对象,收集脐血,采用明胶/自体血浆贴壁法分离CBMC。经含有不同浓度胆红素的牛血清白蛋白溶液孵育1 h,再给予脂多糖（LPS）刺激培养细胞,收集上清液。采用酶联免疫吸附法检测MCP-1和IL-12的含量。结果 LPS可促进CBMC分泌MCP-1和IL-12,6 mg/dl浓度的胆红素单独即可抑制CBMC的MCP-1和IL-12的分泌。先经不同浓度（2.5、6、9、12.9和18 mg/dl）胆红素孵育,CBMC的MCP-1和IL-12的分泌受到不同程度的抑制,再接受LPS刺激,不能纠正胆红素的这种抑制作用。在相同浓度的胆红素作用下,CBMC分泌MCP-1的量随IL-12水平的增加而增多。结论胆红素可以通过抑制CBMC分泌MCP-1和IL-12,从而影响其免疫功能。

The Effect of Bilirubin on MCP-1 and IL-12 Production of the Cord Blood Monocyte

Objective To explore the effects of bilirubin on monocyte chemoattractant protein-1(MCP-1) and interleukin-12(IL-12) production of cord blood monocyte(CBMC).Methods 10 cases of healthy full-term newborn infants with normal Apgar score were selected randomly as subjects;Their monocytes in the umbilical cord blood were in vitro separated by the method of gelatin/plasma coated flasks.The CBMC were preincubated with unconjugated bilirubin dissolved in bovine albumin solution at various levels(0～18 mg/dl).After being preincubated,the CBMC were further cultured with LPS for inducing cellular activation,and then the supernatant were collected.The level of MCP-1 and IL-12 in the cultural supernatant was detected by the enzyme linked immunosorbent assay(ELISA).Results The LPS caused increase of the production of MCP-1 and IL-12,The bilirubin inhibited the CBMC to secrete MCP-1 and IL-12.By comparison,in the presence of LPS,their secretion of the 6 mg/dl group,9 mg/dl group,12.9 mg/dl group and 18 mg/dl group was significantly lower than those of the normal control group and LPS control group.At the same bilirubin concentration,the level of MCP-1 was positive correlation with the level of IL-12.Conclusions Bilirubin can inhibit the secretion of MCP-1 and IL12 of cord blood monocyte,the mechanism may be involved in immunotoxicity of bilirubin.