乳酸菌对Caco-2细胞分泌APRIL和IL-10的影响

【目的】通过检测促炎细胞因子APRIL和抗炎细胞因子IL-10的分泌水平来观察屎肠球菌和乳酸乳球菌对肠上皮细胞先天性免疫应答的调节作用。【方法】Caco-2细胞分别和PBS（CT组，阴性对照组）、Escherichia coli K88（EC组，阳性对照组），Enterococcus faecium（EF组）或Lactococcus lactis（LL组）共孵育2 h，以及先分别和Enterococcus faecium或Lactococcus lactis共孵育1 h，再和Escherichia coli K88共孵育2 h（EF-EC组和LL-EC组）。试验结束时，用ELISA方法检测细胞培养上清中APRIL和IL-10的含量。【结果】结果表明，2株乳酸菌都促进正常状态下的肠上皮细胞分泌促炎细胞因子APRIL和抗炎细胞因子IL-10，抑制Escherichia coli K88对APRIL分泌的诱导作用，促进Escherichia coli K88感染的肠上皮细胞分泌IL-10。【结论】体外试验条件下，屎肠球菌和乳酸乳球菌能够诱导肠上皮细胞产生先天免疫应答，分泌APRIL和IL-10，抑制大肠杆菌K88引起的促炎反应，表现出抗炎作用。

Effects of Lactic Acid Bacteria on APRIL and IL-10 Secretion in Caco-2 Cells

【Objective】The study was designed to evaluate the immunological effects of probiotic strains Enterococcus faecium and Lactococcus lactis on production of pro-inflammatory cytokine of APRIL and anti-inflammatory cytokine interleukin-10 in intestinal epithelial cells.【Method】Human colon adenocarcinoma cell line,Caco-2 cells were incubated with PBS(Group CT,negative control),Escherichia coli K88(Group EC,positive control),and Enterococcus faecium(Group EF),and Lactococcus lactis(Group LL) for 2 h,respectively.Besides,Caco-2 cells were firstly treated with E.faecium and L.lactis for 1 h,respectively,and then followed by incubation with E.coli K88 for an additional 2 h(Group EF-EC and Group LL-EC).Culture supernatants were collected for analyzing the contents of APRIL and IL-10 by ELISA method.【Result】Results showed that E.faecium and L.lactis induced an increased release of APRIL and IL-10.Pre-culture of Caco-2 cells with E.faecium and L.lactis was capable of markedly up-regulating production of IL-10 while decreasing APRIL secretion following co-culture with E.coli K88.【Conclusion】These findings demonstrated that E.faecium and L.lactis could activate immunity of intestinal epithelial cells by inducing APRIL and IL-10 secretion.Moreover,these two strains of lactic acid bacteria also exhibited anti-inflammatory properties via modulating the immune response in Caco-2 cells when they were infected with E.coli K88.