1
|
Cowan GJM, Miles K, Capitani L, Giguere SSB, Johnsson H, Goodyear C, McInnes IB, Breusch S, Gray D, Gray M. In Human Autoimmunity, a Substantial Component of the B Cell Repertoire Consists of Polyclonal, Barely Mutated IgG +ve B Cells. Front Immunol 2020; 11:395. [PMID: 32265907 PMCID: PMC7099054 DOI: 10.3389/fimmu.2020.00395] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 02/19/2020] [Indexed: 12/29/2022] Open
Abstract
B cells are critical for promoting autoimmunity and the success of B cell depletion therapy in rheumatoid arthritis (RA) confirms their importance in driving chronic inflammation. Whilst disease specific autoantibodies are useful diagnostically, our understanding of the pathogenic B cell repertoire remains unclear. Defining it would lead to novel insights and curative treatments. To address this, we have undertaken the largest study to date of over 150 RA patients, utilizing next generation sequencing (NGS) to analyze up to 200,000 BCR sequences per patient. The full-length antigen-binding variable region of the heavy chain (IgGHV) of the IgG B cell receptor (BCR) were sequenced. Surprisingly, RA patients do not express particular clonal expansions of B cells at diagnosis. Rather they express a polyclonal IgG repertoire with a significant increase in BCRs that have barely mutated away from the germline sequence. This pattern remains even after commencing disease modifying therapy. These hypomutated BCRs are expressed by TNF-alpha secreting IgG+veCD27-ve B cells, that are expanded in RA peripheral blood and enriched in the rheumatoid synovium. A similar B cell repertoire is expressed by patients with Sjögren's syndrome. A rate limiting step in the initiation of autoimmunity is the activation of B cells and this data reveals that a sizeable component of the human autoimmune B cell repertoire consists of polyclonal, hypomutated IgG+ve B cells, that may play a critical role in driving chronic inflammation.
Collapse
Affiliation(s)
- Graeme J M Cowan
- Ashworth Laboratories, School of Biological Sciences, Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, United Kingdom
| | - Katherine Miles
- MRC/University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - Lorenzo Capitani
- Ashworth Laboratories, School of Biological Sciences, Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, United Kingdom
| | - Sophie S B Giguere
- Ashworth Laboratories, School of Biological Sciences, Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, United Kingdom.,Harvard Medical School, Boston, MA, United States
| | - Hanna Johnsson
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Carl Goodyear
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Iain B McInnes
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Steffen Breusch
- Orthopaedic Unit, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - David Gray
- Ashworth Laboratories, School of Biological Sciences, Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, United Kingdom
| | - Mohini Gray
- MRC/University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, United Kingdom
| |
Collapse
|