title: Central role of JC virus-specific CD4+ lymphocytes in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome.
abstract: Progressive multi-focal leucoencephalopathy and progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are caused by infection of the central nervous system with the JC polyoma virus. Both are complications of monoclonal antibody therapy in multiple sclerosis and other autoimmune diseases. Progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome can obscure the diagnosis of progressive multi-focal leucoencephalopathy and lead to severe clinical disability and possibly death. Different from progressive multi-focal leucoencephalopathy, in which demyelination results from oligodendrocyte lysis by JC virus in the absence of an immune response, tissue destruction in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome is caused by a vigorous immune response within the brain. The cells and mediators that are involved in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are as yet poorly understood. We examined two patients with multiple sclerosis, who developed progressive multi-focal leucoencephalopathy and later progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome under natalizumab therapy. Due to initially negative JC viral deoxyribonucleic acid testing in the cerebrospinal fluid, a diagnostic brain biopsy was performed in one patient. Histopathology revealed brain inflammation characterized by a prominent T cell infiltrate (CD4(+)> CD8(+) T cells), but also B/plasma cells and monocytes. Despite very low JC viral load, both patients showed high intrathecal anti-JC virus antibodies. Brain-infiltrating CD4(+) T cells were studied regarding antigen specificity and function. CD4(+) T cells were highly specific for peptides from several JC virus proteins, particularly the major capsid protein VP1. T cell phenotyping revealed CD4(+) Th1 and bifunctional Th1-2 cells. The latter secrete large amounts of interferon-γ and interleukin-4 explaining the strong brain inflammation, presence of plasma cells and secretion of intrathecal anti-VP1 antibodies. The functional phenotype of brain-infiltrating JC virus-specific CD4(+) T cells was confirmed and extended by examining brain-derived JC virus-specific CD4(+) T cell clones. Our data provide novel insight into the pathogenesis of progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome and indicate that JC virus-specific CD4(+) T cells play an important role in both eliminating JC virus from the brain, but also in causing the massive inflammation with often fatal outcome.
authors: Department of Clinical Neuroimmunology and Multiple Sclerosis Research, Neurology Clinic, University Hospital Zürich, University of Zürich, Frauenklinikstrasse 26, 8091 Zürich, Switzerland.
authors: Lilian
authors: L
authors: Aly
authors: Sara
authors: S
authors: Yousef
authors: Sven
authors: S
authors: Schippling
authors: Ilijas
authors: I
authors: Jelcic
authors: Petra
authors: P
authors: Breiden
authors: Jakob
authors: J
authors: Matschke
authors: Robert
authors: R
authors: Schulz
authors: Silvia
authors: S
authors: Bofill-Mas
authors: Louise
authors: L
authors: Jones
authors: Viktorya
authors: V
authors: Demina
authors: Michael
authors: M
authors: Linnebank
authors: Graham
authors: G
authors: Ogg
authors: Rosina
authors: R
authors: Girones
authors: Thomas
authors: T
authors: Weber
authors: Mireia
authors: M
authors: Sospedra
authors: Roland
authors: R
authors: Martin
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D001921:Brain / Q000166:cytology / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D003937:Diagnosis, Differential; D006801:Humans; D054019:Immune Reconstitution Inflammatory Syndrome / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000821:virology*; D007577:JC Virus / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D007968:Leukoencephalopathy, Progressive Multifocal / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000821:virology; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology; D000069442:Natalizumab; D019562:Viral Load
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000069442:Natalizumab