Laboratorio de Hígado, Páncreas y Motilidad (HIPAM), Departamento de Medicina Experimental, Facultad de Medicina-Universidad Nacional Autónoma de México (UNAM), Hospital General de México, México Distrito Federal, México.
Neurogastroenterol Motil. 2013 Nov;25(11):872-e699. doi: 10.1111/nmo.12204. Epub 2013 Aug 12.
Immune activation, increased Toll-like Receptors (TLR) expression, and gut epithelial diffusion of bacterial molecules have been reported in irritable bowel syndrome (IBS). Thus, we sought to relate these factors by analyzing gut homing (integrin α4β7), intestinal recruiting (CCR5) and activation (CD28) phenotypes, and the cytokines and chemokines concentration in peripheral blood T-lymphocytes stimulated with TLR-ligands.
Twenty-one IBS-Rome II (1 PI-IBS) patients and 19 controls were studied. Isolated peripheral blood mononuclear cells were cultured with and without Escherichia coli lipopolysaccharide (LPS), Staphylococcus aureus peptidoglycan (PGN), and unmethylated cytosine-phosphate-guanine motifs (CpG). Phenotypes were investigated by flow cytometry and supernatant cytokines and chemokines were also measured.
After LPS, CCR5 expression in CD4⁺ α4β7⁺ cells remained unchanged in IBS, but decreased in controls (p = 0.002), to lower levels than in IBS (Mean fluorescence intensity [MFI]: 1590 ± 126.9 vs 2417 ± 88.4, p < 0.001). There were less CD8(+) α4β7⁺ CCR5⁺ cells (85.7 ± 1.5 vs 90.8 ± 0.9%, p = 0.006) after LPS and CD3⁺ α4β7⁺ CCR5⁺ (40.0 ± 1.7 vs 51.2 ± 4.3%, p = 0.006) after PGN in controls. Also, after LPS, CD28 decreased in CD4⁺ α4β7⁺ CCR5⁺ in IBS (MFI: 2337 ± 47.2 vs 1779 ± 179.2, p < 0.001), but not in controls. Cytokines and chemokines were similar, except for lower IL8/CXCL8 in the unstimulated condition in IBS (4.18, 95% CI: 3.94-4.42 vs 3.77, 3.59-3.95; p = 0.006).
CONCLUSIONS & INFERENCES: Pathogen-associated molecular patterns stimulation of peripheral blood T cells expressing gut homing marker in IBS compared with controls resulted in an unsuccessful down-regulation of the co-expression of intestinal recruiting/residence phenotype and a state of activation. These findings support an interaction between an innate immune predisposition and microbial triggers, which may unleash or exacerbate IBS.
免疫激活、Toll 样受体 (TLR) 表达增加以及肠道上皮细胞扩散细菌分子在肠易激综合征 (IBS) 中均有报道。因此，我们试图通过分析肠道归巢（整合素α4β7）、肠道募集（CCR5）和激活（CD28）表型以及 TLR 配体刺激外周血 T 淋巴细胞产生的细胞因子和趋化因子浓度来相关这些因素。
研究了 21 名 IBS-Rome II（1 PI-IBS）患者和 19 名对照者。分离外周血单核细胞，并用和不用大肠杆菌脂多糖（LPS）、金黄色葡萄球菌肽聚糖（PGN）和未甲基化胞嘧啶-磷酸-鸟嘌呤基序（CpG）进行培养。通过流式细胞术检测表型，并测量上清液细胞因子和趋化因子。
在 LPS 刺激后，IBS 患者 CD4⁺α4β7⁺细胞中的 CCR5 表达保持不变，但对照组的 CCR5 表达下降（p = 0.002），降至低于 IBS 组的水平（平均荧光强度 [MFI]：1590 ± 126.9 对 2417 ± 88.4，p < 0.001）。在 LPS 刺激后，对照组中 CD8(+)α4β7⁺CCR5⁺细胞（85.7 ± 1.5 对 90.8 ± 0.9%，p = 0.006）和 CD3⁺α4β7⁺CCR5⁺细胞（40.0 ± 1.7 对 51.2 ± 4.3%，p = 0.006）减少。此外，在 LPS 刺激后，IBS 患者 CD4⁺α4β7⁺CCR5⁺细胞中的 CD28 减少（MFI：2337 ± 47.2 对 1779 ± 179.2，p < 0.001），而对照组则没有。细胞因子和趋化因子相似，除了 IBS 患者未刺激状态下的 IL8/CXCL8 较低（4.18，95%CI：3.94-4.42 对 3.77，3.59-3.95；p = 0.006）。
与对照组相比，IBS 患者外周血表达肠道归巢标志物的 T 细胞对病原体相关分子模式的刺激导致肠道募集/居留表型的共表达下调和激活状态失败。这些发现支持先天免疫易感性和微生物触发之间的相互作用，这可能引发或加重 IBS。
