Single cell analysis of self-reactive rogue b-cell clones in autoimmune disease — ASN Events
  1. Schedule
  2. Workshop 10: Autoimmunity
  3. Single cell analysis of self-reactive rogue b-cell clones in autoimmune disease

Single cell analysis of self-reactive rogue b-cell clones in autoimmune disease (#115)

Joanne H Reed 1 , Manu Singh 1 , Jing J Wang 2 , Katherine J.L Jackson 1 , David Koppstein 3 , Simone Rizzetto 3 , Auda Eltahla 3 , Alex Colella 2 , Tim Chataway 2 , Matt Field 4 , Fabio Luciani 3 , Tom P Gordon 2 , Chris C Goodnow 1
  1. Garvan Institute, Darlinghurst, NSW, Australia
  2. Flinders University, Bedford Park, SA, Australia
  3. Kirby Institute, UNSW Sydney, Randwick, NSW, Australia
  4. Australian Institute of Tropical Health & Medicine, James Cook University, Townsville, QLD, Australia

The development and persistence of B-cells that recognise self-antigens and produce autoantibodies is central to the pathogenesis of autoimmune disease. Yet our capacity to target these “rogue” B-cells for therapeutic intervention has been hampered by an inability to distinguish them from B-cells that contribute to host defense. The aim of this study was to identify and interrogate rogue B-cells, expressing the same B-cell receptors (BCR) as secreted autoantibody in patients with Sjogren’s syndrome.

Massively parallel sequencing of peripheral blood BCR was combined with mass spectrometry sequencing of secreted (serum) autoantibodies to identify rogue B-cells. Using the unique BCR sequence as a barcode, single cell RNAseq and targeted genomic DNA sequencing was used to evaluate the transcriptomic and genomic profiles of rogue clones compared to polyclonal, developmentally matched B-cells from the same patient.

Circulating rogue B-cell clones and their matched serum autoantibodies were identified in 3 patients with Sjogren’s syndrome. Longitudinal evaluation of one patient revealed a clonal memory B-cell population that persisted for 6 years and expressed the same IgM cryoglobulin rheumatoid factor as the serum autoantibody. These rogue B-cells expressed an aberrant gene expression profile distinct from developmentally matched polyclonal B-cells from the same patient with increased expression of genes involved in BCR activation, antigen presentation and nucleic acid sensing. The rogue B-cells also contained a somatic mutation in klhl6, which plays a role in BCR signalling. Intriguingly, the same mutation has been reported in multiple cases of lymphoma.

The analysis of rogue clones in patients with autoimmune disease reveals novel mechanisms for how rogue B-cells break immune tolerance, proliferate and persist. Moreover, profiling the differences between rogue B-cells and their developmentally matched counterparts, from the same patient, reveals therapeutic targets, which could be used to eliminate self-reactive rogue B-cells while preserving the B-cells that protect from infection.

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