{"doi":"10.1101/2025.08.10.669569","title":"B Cell Tolerance and BCR Signaling Dysregulation in NF155-Mediated Autoimmune Nodopathies","abstract":"Objective: Autoimmune nodopathies (AINs) are a group of rare, acquired autoimmune neuropathies with distinct clinical features and the presence of circulating autoantibodies - often of the immunoglobulin G4 (IgG4) subclass - targeting proteins at the node of Ranvier. Defects in B cell tolerance checkpoints have been implicated in several autoimmune diseases. Prior work identified defective B cell tolerance-reflected by a high frequency of self-reactive naïve B cells-in patients with MuSK-positive myasthenia gravis (MG), mediated by IgG4 autoantibodies. Here, we investigated whether tolerance defects exist in neurofascin-155-mediated AIN (NF155-AIN), similar to MuSK+ MG. Additionally, we analyzed B and T cell transcriptomics and interactions at the single-cell level to explore the underlying pathomechanism. Methods: Using a well-established assay, we assessed B cell tolerance fidelity by generating recombinant antibodies from new emigrant (NE) and mature naïve (MN) B cell populations- directly downstream of key tolerance checkpoints-from three NF155-AIN patients, and testing these antibodies for polyreactivity and autoreactivity, thereby determining the frequency of polyreactive and autoreactive B cells. The transcriptome of peripheral blood mononuclear cells (PBMC) was studied, with a special focus on naïve B cells and CD4+ T cells at the single-cell level, along with characterization of cell-cell interactions. Results: NF155-AIN patients have an elevated frequency of polyreactive B cells in the NE (37.4% compared to 9.7% in healthy controls (HCs), p = 0.03) and MN (31.5% compared to 10.5% in HCs, p = 0.03) compartments with increased B cell clones expressing autoreactive antibodies, consistent with a breach in early tolerance checkpoints. We observed abnormal B cell receptor (BCR) signaling characterized by low CD79B, CSK, BLNK, and BTK expression, which may contribute to a breach in B cell tolerance. We also observed evidence of impaired follicular helper T cells (Tfh) and regulatory T cells (Treg), which may limit the normal development and suppression of autoreactive B cells. Moreover, comparative gene expression analysis of B cells and CD4+ T cells from three patients with chronic inflammatory demyelinating polyneuropathy (CIDP) -a related autoimmune neuropathy- confirmed that these differences are largely specific to NF155-AIN, supporting a distinct pathophysiology in this subset. Conclusion: These findings demonstrated a breach in early B cell tolerance checkpoints, defective BCR signaling, and disrupted T cell-B cell interactions in NF155-AIN, all of which may contribute to the development of pathogenic autoreactivity. These immunologic abnormalities appear distinct from those seen in CIDP, supporting NF155-AIN as a unique immunopathologic entity.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":556644,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9566,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":105808,"name":"Abeer Obaid","orcid":"0000-0002-9846-1045","position":1,"is_corresponding":false},{"id":1456331,"name":"Z Wang","orcid":"0000-0002-1331-4207","position":2,"is_corresponding":false},{"id":1034881,"name":"Kristof Kovacs","orcid":"0000-0001-9576-641X","position":3,"is_corresponding":false},{"id":1055167,"name":"Sarah Ohashi","orcid":"0000-0002-5861-9012","position":4,"is_corresponding":false},{"id":1456332,"name":"F. Naz Cemre Kalayci","orcid":"0000-0002-5432-5252","position":5,"is_corresponding":false},{"id":84639,"name":"Daniel Joo","orcid":null,"position":6,"is_corresponding":false},{"id":888416,"name":"Gianvito Masi","orcid":"0000-0003-4754-2141","position":7,"is_corresponding":false},{"id":1456333,"name":"Carmina Coppola","orcid":"0009-0004-9772-7288","position":8,"is_corresponding":false},{"id":1456718,"name":"Sameeran Das","orcid":null,"position":9,"is_corresponding":false},{"id":370283,"name":"Amanda Hernandez","orcid":null,"position":10,"is_corresponding":false},{"id":1456334,"name":"L. Aguilar","orcid":"0000-0002-1553-2224","position":11,"is_corresponding":false},{"id":1456335,"name":"Cinta Lleixà","orcid":"0000-0002-9971-0584","position":12,"is_corresponding":false},{"id":257658,"name":"Richard J. Nowak","orcid":"0000-0001-8438-482X","position":13,"is_corresponding":false},{"id":288775,"name":"Luís Querol","orcid":"0000-0002-4289-8264","position":14,"is_corresponding":false},{"id":257659,"name":"Kevin C. O’Connor","orcid":"0000-0002-7056-419X","position":15,"is_corresponding":false},{"id":270895,"name":"Bhaskar Roy","orcid":"0000-0003-3604-6310","position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-19T02:55:13.130091Z","pmid":"40832342","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}