title: High throughput bioassay for beta1-adrenoceptor autoantibody detection.
abstract: BACKGROUND
  While the involvement of adrenergic beta1-autoantibodies (beta1-AABs) in pathogenesis of cardiomyopathies is well established as are the benefits associated with autoantibody removal by immunoapheresis, the development of drugs neutralizing beta1-AABs in-vivo has been slowed due to a lack of high throughput autoantibody analytics. Highly scalable routine diagnostics involving immobilized binding partners have mostly failed in comparison to the laborious bioassays, which are difficult to scale up, but present the most reliable and sensitive tools for detecting the beta1-autoantibodies.
  
  
  METHODS
  A high throughput, image-based assay to measure cardiomyocyte beat rate and contractility was developed and tested for its applicability for detecting adrenergic beta1-autoantibodies. The classical bioassay of spontaneously beating neonatal rat cardiomyocytes was used for comparison.
  
  
  RESULTS
  The high throughout assay using human iPSC-derived cardiomyocytes was able to detect beta1-AAB activity of biological sample material. The results from the high throughput assay were very similar to the data obtained from the original bioassay of spontaneously beating neonatal cardiomyocytes, with one exception, where a control antibody targeting the N-terminal end of the human beta1-receptor induced a response when tested with the high throughput imager, while none was observed by the classical bioassay. This discrepancy may be explained by the differences in host species of cardiomyocytes tested by the two methods.
  
  
  CONCLUSIONS
  The high throughput system using iPSC-derived cardiomyocytes for the detection of beta1-AAB provides a realistic option to overcome the sample-size limitations of the bioassay-based diagnostics.
authors.affiliation: Predictive Biology Inc., 2736 Loker Avenue W., Suite C, Carlsbad, CA 92010, United States.
authors.forename: Shivanjali
authors.initials: S
authors.lastname: Joshi-Barr
authors.affiliation: BerlinCures GmbH, Knesebeckstr.59-61, 10719 Berlin, Germany.
authors.forename: Annekathrin
authors.initials: A
authors.lastname: Haberland
authors.affiliation: BerlinCures GmbH, Knesebeckstr.59-61, 10719 Berlin, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Bartel
authors.affiliation: BerlinCures GmbH, Knesebeckstr.59-61, 10719 Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Müller
authors.affiliation: Predictive Biology Inc., 2736 Loker Avenue W., Suite C, Carlsbad, CA 92010, United States. Electronic address: tchoi@predictivebio.com.
authors.forename: Ted
authors.initials: T
authors.lastname: Choi
authors.affiliation: BerlinCures GmbH, Knesebeckstr.59-61, 10719 Berlin, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Wallukat
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D018342:Receptors, Adrenergic, beta-1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
chemical_list: D000318:Adrenergic beta-Agonists; D001323:Autoantibodies; D018342:Receptors, Adrenergic, beta-1; D007545:Isoproterenol
keywords: Beta1-autoantibody; Bioassay; High-throughput assay