title: Constitutive and cytokine-induced expression of human leukocyte antigens and cell adhesion molecules by human myotubes.
abstract: Understanding the immunobiology of muscle is relevant to muscular autoimmune diseases and to gene therapies based on myoblast transfer. We have investigated the constitutive and cytokine-induced intra- and extracellular expression of histocompatibility human leukocyte antigens (HLA) and cell adhesion molecules by multinucleated human myotubes using immunofluorescence microscopy. Myotubes constitutively expressed HLA class I but not HLA class II. Exposure to interferon-gamma, but not tumor necrosis factor-alpha, induced HLA-DR in the cytoplasm and on the surface membrane of approximately 40 to 95% of cultured myotubes. Surface expression was strongest in perinuclear membrane areas, and cytoplasmic expression was strongest at branching points and at the tips of myotubes. HLA-DP and HLA-DQ were not expressed in detectable amounts. Both interferon-gamma and tumor necrosis factor-alpha induced the intercellular adhesion molecule-1 (CD54) in the cytoplasm and on the surface of nearly all myotubes. The distribution of intercellular adhesion molecule-1 and HLA-DR was similar but not identical in double-positive myotubes. The leukocyte function-associated (LFA) adhesion molecules LFA-1 (CD11a/CD18), LFA-2 (CD2), and LFA-3 (CD58) could not be detected in the cytoplasm or on the surface. Our results indicate that cytokine-induced myotubes can participate in immune interactions with T lymphocytes.
authors.affiliation: Department of Neuroimmunology, Max Planck Institute, Martinsried, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Michaelis
authors.forename: N
authors.initials: N
authors.lastname: Goebels
authors.forename: R
authors.initials: R
authors.lastname: Hohlfeld
mesh_terms: D015815:Cell Adhesion Molecules / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009132:Muscles / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D015815:Cell Adhesion Molecules; D006680:HLA Antigens; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma