title: Anti-Yo antibody uptake and interaction with its intracellular target antigen causes Purkinje cell death in rat cerebellar slice cultures: a possible mechanism for paraneoplastic cerebellar degeneration in humans with gynecological or breast cancers.
abstract: Anti-Yo antibodies are immunoglobulin G (IgG) autoantibodies reactive with a 62 kDa Purkinje cell cytoplasmic protein. These antibodies are closely associated with paraneoplastic cerebellar degeneration in the setting of gynecological and breast malignancies. We have previously demonstrated that incubation of rat cerebellar slice cultures with patient sera and cerebrospinal fluid containing anti-Yo antibodies resulted in Purkinje cell death. The present study addressed three fundamental questions regarding the role of anti-Yo antibodies in disease pathogenesis: 1) Whether the Purkinje cell cytotoxicity required binding of anti-Yo antibody to its intraneuronal 62 kDa target antigen; 2) whether Purkinje cell death might be initiated by antibody-dependent cellular cytotoxicity rather than intracellular antibody binding; and 3) whether Purkinje cell death might simply be a more general result of intracellular antibody accumulation, rather than of specific antibody-antigen interaction. In our study, incubation of rat cerebellar slice cultures with anti-Yo IgG resulted in intracellular antibody binding, and cell death. Infiltration of the Purkinje cell layer by cells of macrophage/microglia lineage was not observed until extensive cell death was already present. Adsorption of anti-Yo IgG with its 62 kDa target antigen abolished both antibody accumulation and cytotoxicity. Antibodies to other intracellular Purkinje cell proteins were also taken up by Purkinje cells and accumulated intracellularly; these included calbindin, calmodulin, PCP-2, and patient anti-Purkinje cell antibodies not reactive with the 62 kDa Yo antigen. However, intracellular accumulation of these antibodies did not affect Purkinje cell viability. The present study is the first to demonstrate that anti-Yo antibodies cause Purkinje cell death by binding to the intracellular 62 kDa Yo antigen. Anti-Yo antibody cytotoxicity did not involve other antibodies or factors present in patient serum and was not initiated by brain mononuclear cells. Purkinje cell death was not simply due to intraneuronal antibody accumulation.
authors.affiliation: Neurology Service, George E. Wahlen Veterans Affairs Health Care System, Salt Lake City, Utah, United States of America; Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: John E
authors.initials: JE
authors.lastname: Greenlee
authors.affiliation: Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Clawson
authors.affiliation: Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Hill
authors.affiliation: Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Blair
authors.initials: B
authors.lastname: Wood
authors.affiliation: Neurology Service, George E. Wahlen Veterans Affairs Health Care System, Salt Lake City, Utah, United States of America; Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Clardy
authors.affiliation: Department of Microbiology and Immunology Center for Molecular and Tumor Virology (CMTV), Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Tsunoda
authors.affiliation: Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America; Geriatric Research, Education, and Care Center (GRECC), George E. Wahlen Veterans Affairs Health Care System, Salt Lake City, Utah, United States of America; Research Service, George E. Wahlen Veterans Affairs Health Care System, Salt Lake City, Utah, United States of America; Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Noel G
authors.initials: NG
authors.lastname: Carlson
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D016923:Cell Death / Q000276:immunology*; D002531:Cerebellum / Q000276:immunology / Q000473:pathology; D005260:Female; D005833:Genital Neoplasms, Female / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D009419:Nerve Tissue Proteins / Q000276:immunology*; D020362:Paraneoplastic Cerebellar Degeneration / Q000276:immunology* / Q000473:pathology; D011689:Purkinje Cells / Q000276:immunology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001323:Autoantibodies; C095184:CDR2 protein, human; D007074:Immunoglobulin G; D009419:Nerve Tissue Proteins