Applying fibroblasts’ newly recognized role as immune sentinels

Discoveries made by our founders and other researchers in recent years show that fibroblasts, cells long known for their structural role in both health and disease, surprisingly also have a far-reaching influence on the primary players of the immune system, including T cells, B cells, dendritic cells and macrophages.

We’re developing new treatments that modulate these fibroblast-driven immune conversations, with the goal of increasing anti-cancer immune activity in the tumor microenvironment or diminishing the overactive immune response in inflammatory diseases.

Activated fibroblasts in disease

Through single-cell sequencing and other high-resolution technologies, our founders identified previously unknown activated fibroblast populations that share features of immune cells and actively influence immune effector cells in disease. Fibroblast-immune interactions are implicated as drivers of disease in multiple solid tumors, rheumatoid arthritis, scleroderma, inflammatory bowel disease, lupus and Sjogren’s syndrome.

In tumors, activated fibroblasts contribute to an immunosuppressive environment, interfering with response to checkpoint inhibitors. Specialist fibroblast populations also drive the creation of tertiary lymphoid structures which have been associated with improved outcomes in cancer patients.

In chronic inflammatory diseases, activated fibroblasts influence immune activity both directly and indirectly, in addition to playing a key role in structural remodeling and tissue integrity. Image of an inflamed joint, courtesy of Dr Jenny Marshall and Dr Triin Major.

Our approach

Advancing therapies to patients

Our approach signals a new era in immunotherapy. We’re urgently progressing a portfolio of sophisticated first-in-class antibody programs towards the clinic. We are also exploring important new targets in fibroblast-immune biology ourselves and in partnership with others.

Our activities are underpinned by highly specialist data analytics, complex tissue assays, human tissue focus and a deep understanding of antibody engineering.


In 2021 Mestag entered into a target discovery collaboration with Janssen Biotech, Inc. The collaboration leverages Mestag’s specialist fibroblast sub-population biology platform and state-of-the-art data analytics to identify novel therapeutic targets. We also partner extensively with academic institutions worldwide and with leading CROs.

For partnering discussions, please contact


Tertiary lymphoid structures and B cells determine clinically relevant T cell phenotypes in ovarian cancer
Kasikova et al. Nature Communications 2024
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The cancer-immunity cycle: Indication, genotype, and immunotype
Mellman et al. Immunity 2023
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High endothelial venules in cancer: Regulation, function, and therapeutic implication
Vella et al. Cancer Cell 2023
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Antibodies against endogenous retroviruses promote lung cancer immunotherapy
Ng et al. Nature 2023
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Cross-tissue, single-cell stromal atlas identifies shared pathological fibroblast phenotypes in four chronic inflammatory diseases
Korunsky et al. Med 2022
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Tertiary lymphoid structures generate and propagate anti-tumor antibody-producing plasma cells in renal cell cancer
Meylan et al. Immunity 2022
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Fibroblasts as immune regulators in infection, inflammation and cancer
Davidson et al. Nat Rev Immunol 2021
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Notch signalling drives synovial fibroblast identity and arthritis pathology
Wei et al. Nature 2021
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Mature tertiary lymphoid structures predict immune checkpoint inhibitor efficacy in solid tumors independently of PD-L1 expression
Vanhersecke et al. Nat Cancer 2021
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A framework for advancing our understanding of cancer-associated fibroblasts
Sahai et al. Nat Rev Cancer 2020
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Tertiary lymphoid structures improve immunotherapy and survival in melanoma
Cabrita et al. Nature 2020
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Cross-Species Single-Cell Analysis of Pancreatic Ductal Adenocarcinoma Reveals Antigen-Presenting Cancer-Associated Fibroblasts
Elyada et al Cancer Discovery 2019
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Distinct fibroblast subsets drive inflammation and damage in arthritis
Croft et al, Nature 2019
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