DOP076 Translational and preclinical study validating anterior gradient 2 as a novel epithelial therapeutic target in Inflammatory Bowel Disease (IBD) involved in inflammation, fibrosis, and intestinal barrier integrity
Authors: Tretón X , Beq S , Lhomond S , Calloch J , Pineau R , Cazals-Hatem D , Bassal F , Meuwis M A , Vieujean S , Delom F , Louis E , Chevet E , Ogier-Denis E 
Published: January 2025

Abstract

Background
Anterior Gradient 2 (AGR2) is an endoplasmic reticulum (ER) resident protein involved in protein folding, predominantly expressed in mucin-secreting epithelial cells. Under stress, AGR2 is secreted into the extracellular milieu (eAGR2), where it disrupts epithelial integrity, attracts monocytes, and activates fibroblasts. We explored the relationship between AGR2 tissue expression in IBD patients and the efficacy of a neutralizing anti-eAGR2 antibody (TH-009) in murine models of colonic inflammation and fibrosis

Methods
AGR2 expression was analyzed by immunohistochemistry on ileal and colonic biopsies from IBD patients and controls. In mice, the efficacy of TH-009 was evaluated in models of colitis (3% DSS) and digestive fibrosis (3 cycles of 1.5% DSS)

Results
132 ileal and colonic endoscopic biopsies from 66 patients with Crohn’s disease (CD), 50 patients with ulcerative colitis (UC), and 16 controls, and 96 surgical samples from 11 CD patients, 24 UC patients, and 11 controls were included. AGR2 expression correlated with mucosal inflammation (R² = 0.416, p&lt;0.0001) and tissue damage (R² = 0.329, p&lt;0.0001). All patients with mucosal inflammation showed AGR2 overexpression, while 38% of histologically healed patients had high AGR2, with a relapse rate at 18 months three times higher than those whose AGR2 levels were comparable to controls.In a murine acute colitis model (3% DSS), intravenous (IV) treatment with TH-009 at doses of 5 and 20 µg showed an improvement in weight (p&lt;0.005 and p=0.0001, respectively), in the global colitis DAI score (p=0.002 and p=0.001), and in the histological colitis score (p=0.04 for 5 µg) compared to controls. Intraperitoneal and subcutaneous administration were also effective. There was a significant reduction in tissue infiltration by macrophages (p&lt;0.01) and T lymphocytes (p&lt;0.001), in myeloperoxidase activity, and in the tissue and serum expression of pro-inflammatory cytokines TNFα and IL-6. TH-009-treated mice restored intestinal permeability, measured by FITC-Dextran blood passage, to levels comparable to unexposed DSS mice, unlike DSS-only exposed mice (p&lt;0.01). In a fibrosis model (3 cycles of 1.5% DSS), preventive and curative treatment with TH-009 reduced digestive fibrosis by 49% (p&lt;0.0001), and reduced submucosal fibrosis thickness by 59% (p&lt;0.0001). There was a significant decrease in the colonic expression of fibrosis-related genes (Collagen A1, αSMA, fibrinogen, and TGFβ).

Conclusion
AGR2 is a novel therapeutic target in IBD, correlating with inflammation and complications. Its expression is not affected by major therapies and is overexpressed in 40% of patients with deep histological healing. TH-009 improves inflammation, reverses fibrosis, and restores epithelial barrier functions.

References
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2.Control of anterior GRadient 2 (AGR2) dimerization links endoplasmic reticulum proteostasis to inflammation. Maurel M, Obacz J, Avril T, et al. EMBO Mol Med. 2019 Jun;11(6):e10120.
3.Potential Role of Epithelial Endoplasmic Reticulum Stress and Anterior Gradient Protein 2 Homologue in Crohn's Disease Fibrosis. Vieujean S, Hu S, Bequet E, et al. J Crohns Colitis. 2021 Oct 7;15(10):1737-1750.