@phdthesis{vonWardenburg2021,
  author    = {von Wardenburg, Niels Oliver},
  title     = {Investigations into the Pathogenic Antibody-Antigen-Interference of Glycine Receptor Autoantibodies},
  doi       = {10.25972/OPUS-24721},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-247217},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Anti-glycine receptor (GlyR) autoantibodies belong to the novel group of autoantibodies that target neuronal cell-surface antigens (NCS), which are accompanied with various neurologic and neuropsychiatric conditions. The inhibitory ionotropic GlyR is one of the major inhibitory neurotransmitter receptors and therefore involved in maintaining homeostasis of neuronal excitation levels at brain stem and spinal cord. Anti-GlyR autoantibodies are associated with progressive encephalomyelitis with rigidity and myoclonus or stiff person syndrome. These neuromotor disorders are characterized by exaggerated startle, muscle stiffness, and painful spasms, leading to immobility and fatal outcome in some cases. It was hypothesized that imbalance of motoneuronal inhibition by functional impairment of GlyR and receptor internalization are direct consequences of antibody-antigen interference. Here, serum samples of four patients were tested for anti-GlyR autoantibodies and were used for the analysis of the functional impact on the electrophysiological properties of recombinant GlyRs, transiently expressed in HEK293 cells. Furthermore, the recognition pattern of anti- GlyR autoantibodies to human, zebrafish and chimeric GlyRα1 located the epitope to the far N-terminal region. The pathogenicity of anti-GlyR autoantibodies and thereby the autoimmunologic etiology of the disease was confirmed by passive transfer of patient serum to zebrafish (Danio rerio) larvae, that yielded an abnormal escape response - a brain stem reflex that corresponds to the exaggerated startle of afflicted patients. The phenotype was accompanied by profound reduction of GlyR clusters in spinal cord cryosections of treated zebrafish larvae. Together, these novel insights into the pathogenicity of GlyR autoantibodies confirm the concept of a novel neurologic autoimmune disease and might contribute to the development of innovative therapeutic strategies.},
  language  = {en}
}
@article{RauschenbergervonWardenburgSchaeferetal.2020,
  author    = {Rauschenberger, Vera and von Wardenburg, Niels and Schaefer, Natascha and Ogino, Kazutoyo and Hirata, Hiromi and Lillesaar, Christina and Kluck, Christoph J. and Meinck, Hans-Michael and Borrmann, Marc and Weishaupt, Andreas and Doppler, Kathrin and Wickel, Jonathan and Geis, Christian and Sommer, Claudia and Villmann, Carmen},
  title     = {Glycine Receptor Autoantibodies Impair Receptor Function and Induce Motor Dysfunction},
  series = {Annals of Neurology},
  volume    = {88},
  journal   = {Annals of Neurology},
  number    = {3},
  doi       = {10.1002/ana.25832},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216005},
  pages     = {544 -- 561},
  year      = {2020},
  abstract  = {Objective Impairment of glycinergic neurotransmission leads to complex movement and behavioral disorders. Patients harboring glycine receptor autoantibodies suffer from stiff-person syndrome or its severe variant progressive encephalomyelitis with rigidity and myoclonus. Enhanced receptor internalization was proposed as the common molecular mechanism upon autoantibody binding. Although functional impairment of glycine receptors following autoantibody binding has recently been investigated, it is still incompletely understood. Methods A cell-based assay was used for positive sample evaluation. Glycine receptor function was assessed by electrophysiological recordings and radioligand binding assays. The in vivo passive transfer of patient autoantibodies was done using the zebrafish animal model. Results Glycine receptor function as assessed by glycine dose-response curves showed significantly decreased glycine potency in the presence of patient sera. Upon binding of autoantibodies from 2 patients, a decreased fraction of desensitized receptors was observed, whereas closing of the ion channel remained fast. The glycine receptor N-terminal residues \(^{29}\)A to \(^{62}\)G were mapped as a common epitope of glycine receptor autoantibodies. An in vivo transfer into the zebrafish animal model generated a phenotype with disturbed escape behavior accompanied by a reduced number of glycine receptor clusters in the spinal cord of affected animals. Interpretation Autoantibodies against the extracellular domain mediate alterations of glycine receptor physiology. Moreover, our in vivo data demonstrate that the autoantibodies are a direct cause of the disease, because the transfer of human glycine receptor autoantibodies to zebrafish larvae generated impaired escape behavior in the animal model compatible with abnormal startle response in stiff-person syndrome or progressive encephalitis with rigidity and myoclonus patients.},
  language  = {en}
}