Blood | Targeting EREG with Antibody Therapy for Skin Fibrosis Diseases

This study developed a high-affinity and specific anti-EREG neutralizing antibody and validated its anti-fibrotic effects in vitro and in vivo models. Using single-cell sequencing and spatial transcriptomics analysis, the EREG-TNC-TLR4 signaling axis was revealed as a mechanistic contributor to skin fibrosis, providing a novel therapeutic target for treating scleroderma and chronic graft-versus-host disease.

 

Literature Overview
The article titled 'Sclerotic GvHD and Scleroderma Share Dysregulated Gene Expression that is Ameliorated by EREG Therapeutic Antibody', published in the journal Blood, reviews and summarizes the role of EREG in skin fibrosis diseases and its potential as a therapeutic target. The study identified elevated EREG expression in the skin of patients with scleroderma, morphea, and sclerotic chronic graft-versus-host disease (SclGvHD) through single-cell RNA sequencing and spatial transcriptomics analysis. It was found that this protein promotes TNC (tenascin-C) expression, which acts as an endogenous ligand for TLR4, further activating pro-inflammatory genes such as CCL2 and IL6. By developing a neutralizing antibody targeting EREG, the research team validated its anti-fibrotic and anti-inflammatory effects in humanized mouse models and patient-derived skin explants. The paper also explores the expression patterns of EREG across different diseases and its connection with the TLR4 signaling pathway, providing a theoretical foundation for future therapeutic strategies.

Background Knowledge
Skin fibrosis is a central pathological feature of diseases such as systemic sclerosis (SSc) and chronic graft-versus-host disease (cGvHD), severely affecting patients' quality of life. Currently, treatment options for these diseases are limited and often ineffective. EREG (epiregulin) is an epidermal growth factor receptor (EGFR) ligand secreted by DC3 dendritic cells. It is elevated in the skin and lungs of SSc patients and correlates with disease severity. TNC (tenascin-C), a pro-inflammatory glycoprotein, induces the expression of CCL2 and IL6 via the TLR4 signaling pathway, thereby recruiting and activating immune cells and promoting fibrosis. Although previous studies have explored targeting TLR4 or EGFR pathways, therapeutic strategies specifically modulating the EREG-TNC-TLR4 axis have not yet been reported. This study presents the development of a highly specific anti-EREG neutralizing antibody and, through humanized mouse models and skin explant analysis from patients, systematically demonstrates its anti-fibrotic effects, providing a foundation for clinical translation.

 

 

Research Methods and Experiments
The research team developed the anti-EREG neutralizing antibody using Alloy mice, selected high-affinity clones, and analyzed binding kinetics via surface plasmon resonance (SPR). Subsequently, in a humanized EREG mouse model, skin fibrosis was induced via subcutaneous bleomycin injection, and the effects of anti-EREG antibody treatment on skin thickness, gene expression, and inflammatory markers were evaluated. Additionally, single-cell RNA sequencing (scRNA-Seq) and spatial transcriptomics were employed to compare skin cell types among healthy individuals, SSc patients, those with localized scleroderma (morphea), and SclGvHD patients, determining the expression patterns of EREG and TNC in fibrosis-associated cells. Finally, patient-derived skin explant experiments were conducted to assess the impact of anti-EREG antibody on the secretion of TNC, CCL2, TIMP1, and collagen proteins.

Key Conclusions and Perspectives

• The anti-EREG neutralizing antibody demonstrates high affinity and specificity, effectively inhibiting activation of both EGFR and TLR4 signaling pathways.
• In the bleomycin-induced skin fibrosis model in humanized mice, anti-EREG treatment significantly reduced skin thickness and the expression of fibrosis-associated genes such as COL1A1, COL3A1, and FN1.
• DC3 cells were found to be significantly enriched in the skin of patients with SSc, morphea, and SclGvHD, with elevated EREG expression, suggesting a shared pathogenic mechanism across these diseases.
• Anti-EREG treatment decreased TNC and CCL2 expression while increasing MMP1/2 and reducing TIMP1, promoting extracellular matrix (ECM) degradation and indicating potential in modulating matrix remodeling.
• In patient skin explants, anti-EREG treatment reduced TLR4 and EGFR-related biomarkers without affecting healthy skin, demonstrating specific targeting of fibrotic tissues.

Research Significance and Prospects
This study is the first to systematically identify the central role of EREG in skin fibrosis diseases and to develop a highly specific anti-EREG neutralizing antibody. The antibody showed robust anti-fibrotic effects in both humanized mouse models and patient-derived skin explants without notable toxicity, offering theoretical support for future clinical trials. Further research should evaluate its therapeutic efficacy in cGvHD patients and explore its applicability in other TLR4- or EGFR-associated diseases, such as cancer-related fibrosis or chronic inflammatory skin disorders.

 

 

Conclusion
This study systematically analyzed the role of EREG in skin fibrosis diseases and developed a highly effective and specific anti-EREG neutralizing antibody. Using humanized mouse models and patient-derived skin explants, the research team demonstrated the antibody’s ability to reduce TNC, CCL2, and TIMP1 expression, highlighting its potential in modulating the TLR4 and EGFR signaling pathways. These findings provide a new therapeutic target for the treatment of SSc, morphea, and SclGvHD, and support the clinical translation of anti-EREG antibody therapy. In the future, this antibody may serve as a novel therapeutic strategy for skin fibrosis and related inflammatory diseases, particularly in patients who are unresponsive or resistant to conventional immunosuppressive treatments.

 

Nathan M Newton, Kriti Agrawal, Anahi V Odell, Richard A Flavell, and Ian D Odell. Sclerotic GvHD and Scleroderma Share Dysregulated Gene Expression that is Ameliorated by EREG Therapeutic Antibody. Blood.