Di Sabatino A, Pickard K M, Rampton D, Kruidenier L, Rovedatti L, Leakey N A B, Corazza G R, Monteleone G, MacDonald T T
Centre for Infectious Disease, Institute of Cell and Molecular Science, Barts, London School of Medicine and Dentistry, Whitechapel, London E1 2AT, UK.
Gut. 2008 May;57(5):605-12. doi: 10.1136/gut.2007.130922. Epub 2008 Jan 4.
The role of transforming growth factor beta (TGFbeta) in inhibiting T cell function in the normal gut has been studied in animal models. However, the impact of TGFbeta inhibition on T cells in the normal human gut remains poorly understood. The effect of TGFbeta blockade in normal intestinal biopsies grown ex vivo and lamina propria mononuclear cells (LPMCs) on T-bet, a T-box transcription factor required for T helper cell type (Th)1 differentiation, interferon gamma (IFN gamma) production, T cell apoptosis and matrix metalloproteinase (MMP)-3 production has therefore been tested.
TGFbeta transcripts were determined by quantitative reverse transcription-PCR in laser-captured gut epithelium and lamina propria. Biopsies and LPMCs were cultured with anti-TGFbeta neutralising antibody. After 24 h culture, T-bet was determined by immunoblotting, and T cell apoptosis was assessed by flow cytometry. IFN gamma, tumour necrosis factor alpha (TNFalpha), interleukin (IL) 2, IL6, IL8, IL10, IL12p70 and IL17 were measured by ELISA. MMP-3 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were assessed by immunoblotting.
A higher number of TGFbeta transcripts was found in the lamina propria than in the epithelium in normal gut. T-bet expression was significantly higher in biopsies and LPMCs cultured with anti-TGFbeta antibody than in those cultured with control antibody. TGFbeta blockade downregulated T cell apoptosis, and induced a significant increase in IFN gamma, TNFalpha, IL2, IL6, IL8 and IL17 production. A higher expression of MMP-3, but not TIMP-1, was observed in the tissue and supernatant of biopsies treated with anti-TGFbeta antibody.
The findings support a crucial role for TGFbeta in dampening T cell-mediated tissue-damaging responses in the human gut.
在动物模型中已对转化生长因子β（TGFβ）在正常肠道中抑制T细胞功能的作用进行了研究。然而，TGFβ抑制对正常人体肠道中T细胞的影响仍知之甚少。因此，已测试了TGFβ阻断对体外培养的正常肠道活检组织和固有层单核细胞（LPMC）中T-bet（一种辅助性T细胞1型（Th1）分化所需的T盒转录因子）、γ干扰素（IFNγ）产生、T细胞凋亡和基质金属蛋白酶（MMP）-3产生的影响。
通过定量逆转录聚合酶链反应在激光捕获的肠道上皮和固有层中测定TGFβ转录本。活检组织和LPMC用抗TGFβ中和抗体培养。培养24小时后，通过免疫印迹法测定T-bet，并通过流式细胞术评估T细胞凋亡。通过酶联免疫吸附测定法测量IFNγ、肿瘤坏死因子α（TNFα）、白细胞介素（IL）2、IL6、IL8、IL10、IL12p70和IL17。通过免疫印迹法评估MMP-3和基质金属蛋白酶组织抑制剂（TIMP）-1。
在正常肠道中，固有层中的TGFβ转录本数量高于上皮中的数量。在用抗TGFβ抗体培养的活检组织和LPMC中，T-bet表达明显高于用对照抗体培养的组织和细胞。TGFβ阻断下调了T细胞凋亡，并导致IFNγ、TNFα、IL2、IL6、IL8和IL17产生显著增加。在用抗TGFβ抗体处理的活检组织的组织和上清液中观察到MMP-3表达较高，但未观察到TIMP-1表达升高。
这些发现支持TGFβ在抑制人体肠道中T细胞介导的组织损伤反应中起关键作用。
