title: Dysregulation of B Cell Repertoire Formation in Myasthenia Gravis Patients Revealed through Deep Sequencing.
abstract: Myasthenia gravis (MG) is a prototypical B cell-mediated autoimmune disease affecting 20-50 people per 100,000. The majority of patients fall into two clinically distinguishable types based on whether they produce autoantibodies targeting the acetylcholine receptor (AChR-MG) or muscle specific kinase (MuSK-MG). The autoantibodies are pathogenic, but whether their generation is associated with broader defects in the B cell repertoire is unknown. To address this question, we performed deep sequencing of the BCR repertoire of AChR-MG, MuSK-MG, and healthy subjects to generate ∼518,000 unique VHand VLsequences from sorted naive and memory B cell populations. AChR-MG and MuSK-MG subjects displayed distinct gene segment usage biases in both VHand VLsequences within the naive and memory compartments. The memory compartment of AChR-MG was further characterized by reduced positive selection of somatic mutations in the VHCDR and altered VHCDR3 physicochemical properties. The VLrepertoire of MuSK-MG was specifically characterized by reduced V-J segment distance in recombined sequences, suggesting diminished VLreceptor editing during B cell development. Our results identify large-scale abnormalities in both the naive and memory B cell repertoires. Particular abnormalities were unique to either AChR-MG or MuSK-MG, indicating that the repertoires reflect the distinct properties of the subtypes. These repertoire abnormalities are consistent with previously observed defects in B cell tolerance checkpoints in MG, thereby offering additional insight regarding the impact of tolerance defects on peripheral autoimmune repertoires. These collective findings point toward a deformed B cell repertoire as a fundamental component of MG.
authors.affiliation: Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511.
authors.forename: Jason A
authors.identifier: 0000-0002-1474-310X
authors.initials: JA
authors.lastname: Vander Heiden
authors.affiliation: Department of Neurology, Yale School of Medicine, New Haven, CT 06511.
authors.forename: Panos
authors.initials: P
authors.lastname: Stathopoulos
authors.affiliation: Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511.
authors.forename: Julian Q
authors.identifier: 0000-0001-9602-2092
authors.initials: JQ
authors.lastname: Zhou
authors.affiliation: Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511.
authors.forename: Luan
authors.initials: L
authors.lastname: Chen
authors.affiliation: AbVitro, Inc., Boston, MA 02210.
authors.forename: Tamara J
authors.initials: TJ
authors.lastname: Gilbert
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Bolen
authors.affiliation: Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160.
authors.forename: Richard J
authors.identifier: 0000-0002-0383-6845
authors.initials: RJ
authors.lastname: Barohn
authors.affiliation: Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160.
authors.forename: Mazen M
authors.identifier: 0000-0002-7148-989X
authors.initials: MM
authors.lastname: Dimachkie
authors.affiliation: Department of Neurology, University of Rochester School of Medicine, Rochester, NY 14642.
authors.forename: Emma
authors.initials: E
authors.lastname: Ciafaloni
authors.affiliation: AbVitro, Inc., Boston, MA 02210.
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Broering
authors.affiliation: AbVitro, Inc., Boston, MA 02210.
authors.forename: Francois
authors.identifier: 0000-0001-5634-5794
authors.initials: F
authors.lastname: Vigneault
authors.affiliation: Department of Neurology, Yale School of Medicine, New Haven, CT 06511.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Nowak
authors.affiliation: Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511; kevin.oconnor@yale.edu steven.kleinstein@yale.edu.|Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511; and.|Department of Pathology, Yale School of Medicine, New Haven, CT 06511.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Kleinstein
authors.affiliation: Department of Neurology, Yale School of Medicine, New Haven, CT 06511; kevin.oconnor@yale.edu steven.kleinstein@yale.edu.
authors.forename: Kevin C
authors.identifier: 0000-0002-7056-419X
authors.initials: KC
authors.lastname: O'Connor
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000473:pathology / Q000502:physiology; D005260:Female; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D006801:Humans; D007108:Immune Tolerance; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000276:immunology* / Q000503:physiopathology; D011494:Protein Kinases / Q000276:immunology; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000235:genetics* / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D011947:Receptors, Antigen, B-Cell; D011950:Receptors, Cholinergic; D011494:Protein Kinases; C034961:acetylcholine receptor kinase; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases