Cell-binding IgM in CSF is distinctive of multiple sclerosis and targets the iron transporter SCARA5.
Brain
; 147(3): 839-848, 2024 03 01.
Article
en En
| MEDLINE
| ID: mdl-38123517
ABSTRACT
Intrathecal IgM production in multiple sclerosis is associated with a worse disease course. To investigate pathogenic relevance of autoreactive IgM in multiple sclerosis, CSF from two independent cohorts, including multiple sclerosis patients and controls, were screened for antibody binding to induced pluripotent stem cell-derived neurons and astrocytes, and a panel of CNS-related cell lines. IgM binding to a primitive neuro-ectodermal tumour cell line discriminated 10% of multiple sclerosis donors from controls. Transcriptomes of single IgM producing CSF B cells from patients with cell-binding IgM were sequenced and used to produce recombinant monoclonal antibodies for characterization and antigen identification. We produced five cell-binding recombinant IgM antibodies, of which one, cloned from an HLA-DR + plasma-like B cell, mediated antigen-dependent complement activation. Immunoprecipitation and mass spectrometry, and biochemical and transcriptome analysis of the target cells identified the iron transport scavenger protein SCARA5 as the antigen target of this antibody. Intrathecal injection of a SCARA5 antibody led to an increased T cell infiltration in an experimental autoimmune encephalomyelitis (EAE) model. CSF IgM might contribute to CNS inflammation in multiple sclerosis by binding to cell surface antigens like SCARA5 and activating complement, or by facilitating immune cell migration into the brain.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Inmunoglobulina M
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Encefalomielitis Autoinmune Experimental
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Receptores Depuradores de Clase A
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Esclerosis Múltiple
Límite:
Animals
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Humans
Idioma:
En
Año:
2024
Tipo del documento:
Article