Blockade of transforming growth factor β upregulates T-box transcription factor T-bet, and increases T helper cell type 1 cytokine and matrix metalloproteinase-3 …

A Di Sabatino, KM Pickard, D Rampton, L Kruidenier… - Gut, 2008 - gut.bmj.com
A Di Sabatino, KM Pickard, D Rampton, L Kruidenier, L Rovedatti, NAB Leakey, GR Corazza…
Gut, 2008gut.bmj.com
Background and Aims: The role of transforming growth factor β (TGFβ) in inhibiting T cell
function in the normal gut has been studied in animal models. However, the impact of TGFβ
inhibition on T cells in the normal human gut remains poorly understood. The effect of TGFβ
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 γ (IFNγ) production, T cell apoptosis and matrix metalloproteinase …
Background and Aims
The role of transforming growth factor β (TGFβ) in inhibiting T cell function in the normal gut has been studied in animal models. However, the impact of TGFβ inhibition on T cells in the normal human gut remains poorly understood. The effect of TGFβ 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 γ (IFNγ) production, T cell apoptosis and matrix metalloproteinase (MMP)-3 production has therefore been tested.
Methods
TGFβ transcripts were determined by quantitative reverse transcription-PCR in laser-captured gut epithelium and lamina propria. Biopsies and LPMCs were cultured with anti-TGFβ neutralising antibody. After 24 h culture, T-bet was determined by immunoblotting, and T cell apoptosis was assessed by flow cytometry. IFNγ, tumour necrosis factor α (TNFα), 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.
Results
A higher number of TGFβ 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-TGFβ antibody than in those cultured with control antibody. TGFβ blockade downregulated T cell apoptosis, and induced a significant increase in IFNγ, TNFα, 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-TGFβ antibody.
Conclusions
The findings support a crucial role for TGFβ in dampening T cell-mediated tissue-damaging responses in the human gut.
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