Neuronal surface glycolytic enzymes are autoantigen targets in post-streptococcal autoimmune CNS disease.
Infection with the Group A Streptococcus (GAS) can result in immune mediated brain disease characterised by a spectrum of movement and psychiatric disorders. We have previously described anti-neuronal antibodies in patients that bind to a restricted group of brain antigens with molecular weights 40 kDa, 45 kDa (doublet) and 60 kDa. The aim of this study was to define these antigens using 2-dimensional electrophoresis or ion exchange and hydrophobic interaction chromatography, followed by mass spectrometry. The findings were confirmed using commercial antibodies, commercial antigens and recombinant human antigens. The autoantigens were neuronal glycolytic enzymes--NGE (pyruvate kinase M1, aldolase C, neuronal-specific and non-neuronal enolase). These are multifunctional proteins that are all expressed intracellularly and on the neuronal cell surface. On the neuronal plasma membrane, NGE are involved in energy metabolism, cell signalling and synaptic neurotransmission. Anti-NGE antibodies were more common in the 20 unselected post-streptococcal CNS patients compared to 20 controls. In vitro experiments using cultured neurons showed that commercial anti-NGE antibodies induced apoptosis compared to blank incubation and control anti-HuD antibody. GAS also expresses glycolytic enzymes on cell surfaces that have 0-49% identity with human NGE, suggesting molecular mimicry and autoimmune cross-reactivity may be the pathogenic mechanism in post-streptococcal CNS disease.
Dale
Russell C
RC
Department of Neuroinflammmation, Institute of Neurology, University College London, and Neurosciences Unit, Great Ormond Street Hospital and Institute of Child Health, London WC1N 3JJ, UK.
Candler
Paul M
PM
Church
Andrew J
AJ
Wait
Robin
R
Pocock
Jennifer M
JM
Giovannoni
Gavin
G
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D017209:Apoptosis / Q000187:drug effects; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology*; D015153:Blotting, Western / Q000379:methods; D002352:Carrier Proteins / Q000276:immunology; D016022:Case-Control Studies; D002493:Central Nervous System Diseases; D002845:Chromatography / Q000379:methods; D004452:Echocardiography / Q000379:methods; D005634:Fructose-Bisphosphate Aldolase / Q000276:immunology; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008565:Membrane Proteins / Q000276:immunology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010751:Phosphopyruvate Hydratase / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013290:Streptococcal Infections / Q000150:complications / Q000276:immunology*; D013963:Thyroid Hormones / Q000276:immunology; D000097810:Thyroid Hormone-Binding Proteins
D000906:Antibodies; D001324:Autoantigens; D002352:Carrier Proteins; D005634:Fructose-Bisphosphate Aldolase; D008565:Membrane Proteins; D010751:Phosphopyruvate Hydratase; D012333:RNA, Messenger; D013963:Thyroid Hormones; D000097810:Thyroid Hormone-Binding Proteins