The Role of Autoimmunity-Related Gene CLEC16A in the B Cell Receptor-Mediated HLA Class II Pathway.
J Immunol
; 205(4): 945-956, 2020 08 15.
Article
em En
| MEDLINE
| ID: mdl-32641384
C-type lectin CLEC16A is located next to CIITA, the master transcription factor of HLA class II (HLA-II), at a susceptibility locus for several autoimmune diseases, including multiple sclerosis (MS). We previously found that CLEC16A promotes the biogenesis of HLA-II peptide-loading compartments (MIICs) in myeloid cells. Given the emerging role of B cells as APCs in these diseases, in this study, we addressed whether and how CLEC16A is involved in the BCR-dependent HLA-II pathway. CLEC16A was coexpressed with surface class II-associated invariant chain peptides (CLIP) in human EBV-positive and not EBV-negative B cell lines. Stable knockdown of CLEC16A in EBV-positive Raji B cells resulted in an upregulation of surface HLA-DR and CD74 (invariant chain), whereas CLIP was slightly but significantly reduced. In addition, IgM-mediated Salmonella uptake was decreased, and MIICs were less clustered in CLEC16A-silenced Raji cells, implying that CLEC16A controls both HLA-DR/CD74 and BCR/Ag processing in MIICs. In primary B cells, CLEC16A was only induced under CLIP-stimulating conditions in vitro and was predominantly expressed in CLIPhigh naive populations. Finally, CLIP-loaded HLA-DR molecules were abnormally enriched, and coregulation with CLEC16A was abolished in blood B cells of patients who rapidly develop MS. These findings demonstrate that CLEC16A participates in the BCR-dependent HLA-II pathway in human B cells and that this regulation is impaired during MS disease onset. The abundance of CLIP already on naive B cells of MS patients may point to a chronically induced stage and a new mechanism underlying B cell-mediated autoimmune diseases such as MS.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte de Monossacarídeos
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Linfócitos B
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Receptores de Antígenos de Linfócitos B
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Autoimunidade
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Genes MHC da Classe II
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Lectinas Tipo C
Limite:
Humans
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Holanda