Muscle inflammation and MHC class I up-regulation in muscular dystrophy with lack of dysferlin: an immunopathological study.

Department of Neuromuscular Diseases, Istituto Nazionale Neurologico Carlo Besta, via Celoria 11, 20133 Milan, Italy.
Journal of Neuroimmunology (Impact Factor: 3.03). 10/2003; 142(1-2):130-6. DOI: 10.1016/S0165-5728(03)00255-8
Source: PubMed

ABSTRACT Muscle inflammation is characteristic of inflammatory myopathies but also occurs in muscular dystrophy with lack of the sarcolemmal protein dysferlin. We quantified inflammatory cells and major histocompatibility complex (MHC) expression in muscle from 10 patients with dysferlinopathy. Infiltrating cells were always present although numbers varied considerably; macrophages were more common than T cells, T cytotoxicity was absent, and MHC class I was overexpressed on muscle fibers. These findings differ from polymyositis (PM) but are closely similar to those in SJL/J mice (which lack dysferlin) and emphasize the relationship between absence of dysferlin and immune system abnormalities in muscle.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Mutations in the dysferlin gene result in the development of a range of early adult-onset, progressive muscular dystrophies, collectively known as the dysferlinopathies. There is currently no effective treatment for these disorders. Several spontaneous and engineered alleles at the mouse dysferlin locus have been isolated and these dysferlin-deficient mouse strains are providing valuable insights into the role dysferlin plays in skeletal muscle physiology, heart function, and the regulation of the innate immune system. In addition, mouse models of dysferlinopathy are now widely used to test novel therapeutic strategies. Each dysferlin-deficient mouse strain has been characterised to varying degrees using a variety of histological and functional assays, occasionally producing results inconsistent with other strains. Here, we review each mouse model and physiological changes in various systems which accompany their muscle disease with emphasis on the how the disease process develops in different mouse models of dysferlinopathy. This review highlights the urgent requirement for standardised assays and outcome measures that will unify and coordinate research efforts throughout the field, procedures that are necessary if potential therapies are to be tested efficiently and effectively.
    Neuromuscular Disorders 03/2013; · 3.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cells encounter many physical, chemical and biological stresses that perturb plasma membrane integrity, warranting an immediate membrane repair response to regain cell homeostasis. Failure to respond properly to such perturbation leads to individual cell death, which may also produce systemic influence by triggering sterile immunological responses. In this review, we discuss recent progress on understanding the mechanisms underlying muscle cell membrane repair and the potential mediators of innate immune activation when membrane repair system is defective, specifically focusing on pathology associated with dysferlin deficiency. © 2013 The Authors Journal compilation © 2013 FEBS.
    FEBS Journal 03/2013; · 4.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Muscle fibers do not normally express major histocompatibility complex class I (MHC-I) molecules, and their reexpression is a hallmark of inflammatory myopathies. It has been shown in mice that overexpression of MHC-I induces a poorly inflammatory myositis accompanied by the unfolded protein response (UPR), but it is unclear whether it is attributable to T-cell-mediated MHC-I-dependent immune responses or to MHC-I forced expression per se. Indeed, besides presenting antigenic peptides to CD8(+) T cells, MHC-I may also possibly exert nonimmunologic, yet poorly understood pathogenic effects. Thus, we investigated the pathogenicity of MHC-I expression in muscle independently of its immune functions. HT transgenic mice that conditionally overexpress H-2K(b) in muscle were bred to an immunodeficient Rag2(-/-) background. The muscle proteome was analyzed by label-free high-resolution protein quantitation and Western blot. Despite the absence of adaptive immunity, HT Rag2(-/-) mice developed a very severe myopathy associated with the cytoplasmic accumulation of H-2K(b) molecules. The UPR was manifest by up-regulation of characteristic proteins. In humans, we found that HLA class I molecules not only were expressed at the sarcolemma but also could accumulate intracellularly in some patients with inclusion body myositis. Accordingly, the UPR was triggered as a function of the degree of HLA accumulation in myofibers. Hence, reexpression of MHC-I in normally negative myofibers exerts pathogenic effects independently of its immune function.
    American Journal Of Pathology 07/2013; · 4.60 Impact Factor