Abstract
Major histocompatibility complex (MHC) class II molecules are expressed on myoblasts after interferon-gamma (IFN-gamma) treatment, suggesting a muscle cell involvement in antigen presentation in inflammatory myopathies. However, they were not observed on normal or pathological myofibers. This discrepancy might be related to different responsiveness of developmentally differentiated muscle cells to IFN-gamma. Myoblasts expressed class II transcripts and proteins after IFN-gamma, while myotubes and innervated contracting muscle cells did not show staining for class II molecules. At all cell stages no loss of IFN-gamma receptor was detected indicating that myofiber maturation blocks their capacity to express MHC class II molecules. This suggests that completely differentiated myofibers cannot participate in class II restricted immunological reactions.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Actins / genetics
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Antigens, CD / genetics
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Antigens, Differentiation, B-Lymphocyte / genetics
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Autoimmune Diseases / immunology*
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Base Sequence
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Cell Differentiation / immunology
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Cell Fusion / immunology
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Cells, Cultured / chemistry
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Cells, Cultured / drug effects
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Cells, Cultured / immunology
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Gene Expression / immunology
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Histocompatibility Antigens Class II / genetics*
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Histocompatibility Antigens Class II / immunology*
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Humans
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Interferon-gamma / pharmacology
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Molecular Sequence Data
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Muscle Fibers, Skeletal / cytology
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Muscle Fibers, Skeletal / drug effects
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Muscle Fibers, Skeletal / immunology
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Muscle, Skeletal / chemistry
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Muscle, Skeletal / cytology
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Muscle, Skeletal / immunology*
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Muscular Diseases / immunology*
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Myosins / genetics
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RNA, Messenger / immunology
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Receptors, Interferon / genetics
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Transcription, Genetic / immunology
Substances
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Actins
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Antigens, CD
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Antigens, Differentiation, B-Lymphocyte
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Histocompatibility Antigens Class II
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RNA, Messenger
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Receptors, Interferon
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invariant chain
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Interferon-gamma
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Myosins