Major histocompatibility complex class II molecule expression on muscle cells is regulated by differentiation: implications for the immunopathogenesis of muscle autoimmune diseases.
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.
Mantegazza
R
R
Divisione Malattie Neuromuscolari, Istituto Nazionale Neurologico C. Besta (UNNCB), Milan, Italy. mantega@imiucca.csi.unimi.it
Gebbia
M
M
Mora
M
M
Barresi
R
R
Bernasconi
P
P
Baggi
F
F
Cornelio
F
F
D000199:Actins / Q000235:genetics; D015703:Antigens, CD / Q000235:genetics; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics; D001327:Autoimmune Diseases / Q000276:immunology*; D001483:Base Sequence; D002454:Cell Differentiation / Q000276:immunology; D002459:Cell Fusion / Q000276:immunology; D002478:Cells, Cultured / Q000737:chemistry / Q000187:drug effects / Q000276:immunology; D015870:Gene Expression / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008969:Molecular Sequence Data; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D018482:Muscle, Skeletal / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D009135:Muscular Diseases / Q000276:immunology*; D009218:Myosins / Q000235:genetics; D012333:RNA, Messenger / Q000276:immunology; D017471:Receptors, Interferon / Q000235:genetics; D014158:Transcription, Genetic / Q000276:immunology
D000199:Actins; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000949:Histocompatibility Antigens Class II; D012333:RNA, Messenger; D017471:Receptors, Interferon; C045084:invariant chain; D007371:Interferon-gamma; D009218:Myosins