Distinct fibroblast subsets drive inflammation and damage in arthritis
- Nature. 2019 Jun;570(7760):246-251. doi: 10.1038/s41586-019-1263-7.
- 1. Rheumatology Research Group, Institute for Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK.
- 2. Versus Arthritis Centre of Excellence in the Pathogenesis of Rheumatoid Arthritis, College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK.
- 3. The Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK.
- 4. Musculoskeletal Medicine, University of Muenster, Muenster, Germany.
- 5. Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany.
- 6. Department of Medicine, Division of Rheumatology, Northwestern University, Feinberg School of Medicine Chicago, Evanston, IL, USA.
- 7. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
- 8. Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- 9. University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- 10. MRC and Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK.
- 11. Rheumatology Research Group, Institute for Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK. [email protected].
- 12. Versus Arthritis Centre of Excellence in the Pathogenesis of Rheumatoid Arthritis, College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK. [email protected].
- 13. The Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK. [email protected].
- 14. MRC and Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), College of Medical and Dental Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK. [email protected].
The identification of lymphocyte subsets with non-overlapping effector functions has been pivotal to the development of targeted therapies in immune-mediated inflammatory diseases (IMIDs)1,2. However, it remains unclear whether fibroblast subclasses with non-overlapping functions also exist and are responsible for the wide variety of tissue-driven processes observed in IMIDs, such as inflammation and damage3-5. Here we identify and describe the biology of distinct subsets of fibroblasts responsible for mediating either inflammation or tissue damage in Arthritis. We show that deletion of fibroblast activation protein-α (FAPα)+ fibroblasts suppressed both inflammation and bone erosions in mouse models of resolving and persistent Arthritis. Single-cell transcriptional analysis identified two distinct fibroblast subsets within the FAPα+ population: FAPα+THY1+ immune effector fibroblasts located in the synovial sub-lining, and FAPα+THY1- destructive fibroblasts restricted to the synovial lining layer. When adoptively transferred into the joint, FAPα+THY1- fibroblasts selectively mediate bone and cartilage damage with little effect on inflammation, whereas transfer of FAPα+ THY1+ fibroblasts resulted in a more severe and persistent inflammatory Arthritis, with minimal effect on bone and cartilage. Our findings describing anatomically discrete, functionally distinct fibroblast subsets with non-overlapping functions have important implications for cell-based therapies aimed at modulating inflammation and tissue damage.