title: Multiple sclerosis: Serum-derived exosomes express myelin proteins.
abstract: Exosomes are small extracellular vesicles that provide cell-to-cell communication and are involved in immunoregulation.
  
  
  
  To investigate serum exosomes for the presence of myelin proteins outside the central nervous system (CNS) and their role in multiple sclerosis (MS).
  
  
  
  Serum, cerebrospinal fluid (CSF), and peripheral blood mononuclear cell (PBMC) samples were collected from 45 patients with relapsing-remitting MS (RRMS), 30 patients with secondary progressive MS (SPMS), and 45 healthy controls. Exosomes were isolated using a polymer formulation method, and their size, concentration, and CNS myelin protein contents were measured by a nanoparticle tracking analysis, enzyme-linked immunosorbent assays, and Western blot.
  
  
  
  We found that exosomes expressed three major myelin proteins, myelin basic protein, proteolipid protein, and myelin oligodendrocyte glycoprotein (MOG). Exosomal content of MOG strongly correlated with disease activity and was highest in RRMS patients in relapse and in SPMS patients. Serum-derived exosomes induced proliferation of MOG-T cell receptor transgenic T cells confirming that serum exosomes maintained MOG immunogenicity.
  
  
  
  Exosomes isolated outside CNS tissue expressed myelin proteins, and the presence of MOG correlated strongly with disease activity. We conclude that exosomes might enhance and/or perpetuate anti-myelin immune reactions in MS and may provide novel markers of disease activity.
authors.affiliation: Laboratory of Neuroimmunology, Department of Neurology, Medical University of Lodz, Lodz, Poland.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Galazka
authors.affiliation: Laboratory of Neuroimmunology, Department of Neurology, Medical University of Lodz, Lodz, Poland.
authors.forename: Marcin P
authors.initials: MP
authors.lastname: Mycko
authors.affiliation: Laboratory of Neuroimmunology, Department of Neurology, Medical University of Lodz, Lodz, Poland.
authors.forename: Igor
authors.initials: I
authors.lastname: Selmaj
authors.affiliation: Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA.
authors.forename: Cedric S
authors.initials: CS
authors.lastname: Raine
authors.affiliation: Laboratory of Neuroimmunology, Department of Neurology, Medical University of Lodz, Lodz, Poland.
authors.forename: Krzysztof W
authors.initials: KW
authors.lastname: Selmaj
mesh_terms: D000328:Adult; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood* / Q000276:immunology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood; D004676:Myelin Basic Protein / Q000097:blood*; D063308:Myelin-Oligodendrocyte Glycoprotein / Q000097:blood*
chemical_list: C499048:MBP protein, human; D004676:Myelin Basic Protein; D063308:Myelin-Oligodendrocyte Glycoprotein
keywords: Multiple sclerosis; biomarkers; exosome; immunology; myelin oligodendrocyte glycoprotein