Laboratoire de Bactéries Lactiques et Immunité des Muqueuses, Institut Pasteur de Lille - Institut de Biologie de Lille, Lille, France.
PLoS One. 2007 Mar 21;2(3):e313. doi: 10.1371/journal.pone.0000313.
Disruption of the intestinal homeostasis and tolerance towards the resident microbiota is a major mechanism involved in the development of inflammatory bowel disease. While some bacteria are inducers of disease, others, known as probiotics, are able to reduce inflammation. Because dendritic cells (DCs) play a central role in regulating immune responses and in inducing tolerance, we investigated their role in the anti-inflammatory potential of probiotic lactic acid bacteria.
METHODOLOGY/PRINCIPAL FINDINGS: Selected LAB strains, while efficiently taken up by DCs in vitro, induced a partial maturation of the cells. Transfer of probiotic-treated DCs conferred protection against 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Protection was associated with a reduction of inflammatory scores and colonic expression of pro-inflammatory genes, while a high local expression of the immunoregulatory enzyme indolamine 2, 3 dioxgenase (IDO) was observed. The preventive effect of probiotic-pulsed DCs required not only MyD88-, TLR2- and NOD2-dependent signaling but also the induction of CD4+ CD25+ regulatory cells in an IL-10-independent pathway.
CONCLUSIONS/SIGNIFICANCE: Altogether, these results suggest that selected probiotics can stimulate DC regulatory functions by targeting specific pattern-recognition receptors and pathways. The results not only emphasize the role of DCs in probiotic immune interactions, but indicate a possible role in immune-intervention therapy for IBD.
肠道内稳态的破坏和对常驻微生物群的耐受性是炎症性肠病发展的主要机制之一。虽然有些细菌是疾病的诱导物，但另一些被称为益生菌的细菌能够减轻炎症。由于树突状细胞（DCs）在调节免疫反应和诱导耐受方面发挥着核心作用，我们研究了它们在益生菌乳酸菌的抗炎潜力中的作用。
方法/主要发现：选择的 LAB 菌株在体外能有效被 DCs 摄取，诱导细胞部分成熟。将益生菌处理的 DCs 转移可赋予对 2,4,6-三硝基苯磺酸（TNBS）诱导的结肠炎的保护作用。保护作用与炎症评分和结肠中促炎基因的表达降低有关，而观察到免疫调节酶吲哚胺 2,3 二加氧酶（IDO）的高局部表达。益生菌脉冲 DCs 的预防作用不仅需要 MyD88、TLR2 和 NOD2 依赖性信号，还需要在 IL-10 非依赖性途径中诱导 CD4+CD25+调节细胞。
结论/意义：总而言之，这些结果表明，选定的益生菌可以通过靶向特定的模式识别受体和途径来刺激 DC 调节功能。这些结果不仅强调了 DCs 在益生菌免疫相互作用中的作用，而且表明其在 IBD 的免疫干预治疗中可能具有作用。
