乳凝集素通过ERK、p38 MAPK通路调节未成熟树突状细胞分泌IL-12和IL-10的研究

Effect of lactadherin on secretion of IL-12 and IL-10 by immature dendritic cells through ERK and p38 MAPK signaling pathway

目的探讨乳凝集素通过ERK、p38 MAPK信号通路对未成熟树突状细胞(iDCs)分泌白介素(IL)-12和IL-10的影响。方法脐带血中分离得到单核细胞,加入重组人粒细胞巨噬细胞集落刺激因子(50 ng/mL)和重组人白介素-4(10 ng/mL),同时按照不同组合加入乳凝集素(10μg/mL)和信号通路阻滞剂,诱导分化为iDCs。分组如下:①对照组;②乳凝集素组;③ERK通路阻滞组;④ERK通路阻滞剂+乳凝集素组;⑤p38MAPK通路阻滞组;⑥p38MAPK通路阻滞剂+乳凝集素组;⑦JNK通路阻滞组;⑧JNK通路阻滞剂+乳凝集素组。采用Western blotting检测ERK、JNK、p38MAPK蛋白磷酸化水平,ELISA法检测iDCs分泌IL-12和IL-10的变化。结果与对照组比较,乳凝集素组ERK蛋白磷酸化水平升高(P<0.05),p38 MAPK蛋白磷酸化水平降低(P<0.05),JNK蛋白磷酸化水平无明显差异(P>0.05),IL-12和IL-10的分泌量显著降低(P<0.05),IL-12/IL-10比值显著升高(P<0.05)。ERK通路阻滞组和ERK通路阻滞剂+乳凝集素组中ERK蛋白磷酸化水平几乎为零;ERK阻滞剂+乳凝集素组IL-12和IL-10的分泌量显著高于乳凝集素组(P<0.05),IL-12/IL-10比值显著低于乳凝集素组(P<0.05)。p38 MAPK通路阻滞组和p38 MAPK通路阻滞剂+乳凝集素组中p38 MAPK蛋白磷酸化水平几乎为零;p38 MAPK通路阻滞剂+乳凝集素组IL-12和IL-10的分泌量显著低于乳凝集素组(P<0.05),IL-12/IL-10比值显著高于乳凝集素组(P<0.05)。结论乳凝集素可能通过激活ERK通路的活化及抑制p38MAPK通路的活化调节iDCs分泌IL-10和IL-12。

Objective To investigate the effect of lactadherin on secretion of interleukin （IL）-12 and IL-10 by immature dendritic cells （iDCs） through ERK and p38 MAPK signaling pathway. Methods Cord blood monocytes were isolated from human umbilical cord blood and cultured in vitro in the presence of recombinant human granulocyte-macrophage colonystimulating factor （50 ng/mL） and recombinant human interleukin-4 （ 10 ng/mL） to obtain the iDCs. According to different interventions with lactadherin （ 10 ug/mL） and signaling pathway inhibitors, iDCs were divided into 8 groups： ①control group; （②laetadherin group;③ERK signaling pathway inhibitor group; ④ERK signaling pathway inhibitor ＋ laetadherin group;⑤p38 MAPK signaling pathway inhibitor group; ⑥p38 MAPK signaling pathway inhibitor ＋ lactadherin group; ⑦JNK signaling pathway inhibitor group; ⑧JNK signaling pathway inhibitor ＋ lactadherin group. The phosphorylation of ERK, JNK and p38MAPK protein was detected by Western blotting, and the levels of IL-12 and IL-10 in the culture media were determined by ELISA. Results Compared with control group, the phosphorylation of ERK protein was increased （P 〈0.05）, the phosphorylation of p38 MAPK protein was decreased （P 〈 0.05）, the levels of IL-12 and IL-10 were significantly decreased （P 〈 0.05）, and the ratio of IL-12/IL-10 was significantly increased in laetadherin group （P 〈 0.05）. There was almost no phosphorylation of ERK protein in ERK signaling pathway inhibitor group and ERK signaling pathway inhibitor ＋ lactadherin group, the levels of IL-12 and IL-10 in ERK signaling pathway inhibitor ＋ lactadherin group were significantly higher than those in lactadherin group （P 〈 0.05）, and the ratio of IL-12/IL-10 in ERK signaling pathwayinhibitor ＋ lactadherin group was significantly lower than that in lactadherin group （ P 〈 0.05）. There was almost no phosphorylation of p38 MAPK protein in p38 MAPK signaling pathway inhibitor group and p38 MAPK signaling pathway inhibitor ＋ lactadherin group, the levels of IL-12 and IL-10 in p38 MAPK signaling pathway inhibitor ＋ lactadherin group were signifieantly lower than those in lactadherin group （P 〈 0.05）, and the ratio of IL-12/IL-10 in p38 MAPK signaling pathway inhibitor ＋ lactadherin group was significantly higher than that in lactadherin group （ P 〈 0.05）. Conclusion Lactadherin regulates the secretion of IL-12 and IL-10 by iDCs through activation of ERK signaling pathway and inactivation of p38 MAPK signaling pathway.