Inhibitor (IK) of IFN-gamma induced HLA class II antigens expression also inhibits HLA class II constitutive expression in the human Raji B cell line
| Autor: | Raffaele Pereno, Haniaa Bouzinba-Segard, Claude Jasmin, Patricia Krief, Bruno Azzarone, Eric Assier, Dominique Charron, Jocelyn Vedrenne |
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| Rok vydání: | 1997 |
| Předmět: |
Cancer Research
Cytoplasm Genes MHC Class II chemical and pharmacologic phenomena Major histocompatibility complex Antigen Gene expression Genetics CIITA Humans RNA Messenger Antigen-presenting cell Molecular Biology Regulation of gene expression MHC class II B-Lymphocytes biology Nuclear Proteins Transfection HLA-DR Antigens Molecular biology Cell Compartmentation Gene Expression Regulation Immunology biology.protein Trans-Activators Cytokines |
| Zdroj: | Oncogene. 14(12) |
| ISSN: | 0950-9232 |
| Popis: | The expression of major histocompatibility complex (MHC) class II antigens is constitutive in professional antigen presenting cells (APCs) but can also be induced by interferon-gamma (IFN-gamma) on the majority of the non professional APCs (e.g. fibroblasts). We have recently characterised a new factor called IK which is an efficient inhibitor of IFN-gamma induction of MHC class II antigens expression. Here, we demonstrate a novel role for IK in MHC class II expression since over-expression of this protein by stable transfection into human B cells led to a total disappearance of constitutive MHC class II mRNA expression. The class II transactivator (CIITA) is necessary for both constitutive and IFN-gamma induced MHC class II expressions. Examination of CIITA mRNA in IK stably transfected clones revealed a marked reduction of CIITA mRNA transcription. Taken together these results demonstrate that the IK protein plays a key role in the constitutive expression of MHC class II antigens and that inhibition induced by IK is upstream of CIITA in this regulatory pathway. |
| Databáze: | OpenAIRE |
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