并且GG通过Toll样受体4（TLR4）和Toll样受体2（TLR2）调节结肠炎中辅助性T细胞17（Th17）/调节性T细胞（Treg）平衡。

and GG regulate the Th17/Treg balance in colitis via TLR4 and TLR2.

作者信息

Jia Lu, Wu Ruiqing, Han Nannan, Fu Jingfei, Luo Zhenhua, Guo Lijia, Su Yingying, Du Juan, Liu Yi

机构信息

Laboratory of Tissue Regeneration and Immunology and Department of Periodontics Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction School of Stomatology Capital Medical University Beijing China.

Beijing Tiantan Hospital Capital Medical University Beijing China.

出版信息

Clin Transl Immunology. 2020 Nov 24;9(11):e1213. doi: 10.1002/cti2.1213. eCollection 2020.

OBJECTIVES

CD4 T cells are the key to many immune-inflammatory diseases mediated by microbial disorders, especially inflammatory bowel disease (IBD). The purpose of this study was to explore how pathogenic and probiotic bacteria directly affect the T helper (Th)17 and T regulatory (Treg) cell balance among CD4 T cells to regulate inflammation.

METHODS

(Pg; ATCC 33277) and GG (LGG; CICC 6141) were selected as representative pathogenic and probiotic bacteria, respectively. Bacterial extracts were obtained via ultrasonication and ultracentrifugation. Flow cytometry, RT-qPCR, ELISAs, immunofluorescence and a Quantibody cytokine array were used. The dextran sodium sulphate (DSS)-induced colitis model was selected for verification.

RESULTS

The Pg ultrasonicate induced the apoptosis of CD4 T cells and upregulated the expression of the Th17-associated transcription factor RoRγt and the production of the proinflammatory cytokines IL-17 and IL-6, but downregulated the expression of the essential Treg transcription factor Foxp3 and the production of the anti-inflammatory factors TGF-β and IL-10 via the TLR4 pathway. However, LGG extract maintained Th17/Treg homeostasis by decreasing the IL-17 Th17 proportion and increasing the CD25 Foxp3 Treg proportion via the TLR2 pathway. Pg-stimulated CD4 T cells aggravated DSS-induced colitis by increasing the Th17/Treg ratio in the colon and lamina propria lymphocytes (LPLs), and Pg + LGG-stimulated CD4 T cells relieved colitis by decreasing the Th17/Treg ratio via the JAK-STAT signalling pathway.

CONCLUSIONS

Our findings suggest that pathogenic Pg and probiotic LGG can directly regulate the Th17/Treg balance via different TLRs.

目的

CD4 T细胞是许多由微生物紊乱介导的免疫炎症性疾病的关键因素，尤其是炎症性肠病（IBD）。本研究的目的是探讨致病菌和益生菌如何直接影响CD4 T细胞中辅助性T细胞（Th）17和调节性T细胞（Treg）的平衡以调节炎症。

方法

分别选择牙龈卟啉单胞菌（Pg；美国典型培养物保藏中心33277）和鼠李糖乳杆菌GG（LGG；中国工业微生物菌种保藏管理中心6141）作为代表性的致病菌和益生菌。通过超声处理和超速离心获得细菌提取物。采用流式细胞术、逆转录定量聚合酶链反应（RT-qPCR）、酶联免疫吸附测定（ELISA）、免疫荧光和定量抗体细胞因子阵列技术。选择葡聚糖硫酸钠（DSS）诱导的结肠炎模型进行验证。

结果

Pg超声提取物通过Toll样受体4（TLR4）途径诱导CD4 T细胞凋亡，上调Th17相关转录因子维甲酸相关孤儿受体γt（RoRγt）的表达以及促炎细胞因子白细胞介素（IL）-17和IL-6的产生，但下调关键Treg转录因子叉头框蛋白3（Foxp3）的表达以及抗炎因子转化生长因子（TGF）-β和IL-10的产生。然而，LGG提取物通过TLR2途径降低IL-17⁺ Th17比例并增加CD25⁺ Foxp3⁺ Treg比例，从而维持Th17/Treg细胞稳态。Pg刺激的CD4 T细胞通过增加结肠和固有层淋巴细胞（LPL）中的Th17/Treg比率加重DSS诱导的结肠炎，而Pg + LGG刺激的CD4 T细胞通过JAK-信号转导和转录激活因子（STAT）信号通路降低Th17/Treg比率来缓解结肠炎。