Wu Xiaohua, Li Zhi-fang, Brooks Randolph, Komives Elizabeth A, Torpey Justin W, Engvall Eva, Gonias Steven L, Shelton G Diane
Department of Pathology, University of California, San Diego 92101, USA.
J Immunol. 2007 Oct 1;179(7):4939-44. doi: 10.4049/jimmunol.179.7.4939.
Inflammatory myopathies are a group of autoimmune diseases that affect muscles. In humans, the most common inflammatory myopathies are polymyositis, dermatomyositis, and inclusion body myositis. Autoantibodies may be found in humans with inflammatory myopathies, and these play an important role in diagnosis and disease classification. However, these Abs are typically not muscle specific. Spontaneously occurring canine inflammatory myopathies may be good parallel disorders and provide insights into human myositis. In dogs with inflammatory myopathy, muscle-specific autoantibodies have been found, especially in masticatory muscle myositis. We have identified the major Ag recognized by the autoantibodies in canine masticatory muscle myositis. This Ag is a novel member of the myosin binding protein-C family, which we call masticatory myosin binding protein-C (mMyBP-C). mMyBP-C is localized not only within the masticatory muscle fibers, but also at or near their cell surface, perhaps making it accessible as an immunogen. The gene for mMyBP-C also exists in humans, and mMyBP-C could potentially play a role in certain human inflammatory myopathies. Understanding the role of mMyBP-C in this canine inflammatory myopathy may advance our knowledge of mechanisms of autoimmune inflammatory muscle diseases, not only in dogs, but also in humans.
炎性肌病是一组影响肌肉的自身免疫性疾病。在人类中，最常见的炎性肌病是多发性肌炎、皮肌炎和包涵体肌炎。炎性肌病患者体内可能会发现自身抗体，这些抗体在诊断和疾病分类中起着重要作用。然而，这些抗体通常并非肌肉特异性的。自发发生的犬类炎性肌病可能是很好的平行病症，有助于深入了解人类肌炎。在患有炎性肌病的犬类中，已发现肌肉特异性自身抗体，尤其是在咀嚼肌肌炎中。我们已经确定了犬类咀嚼肌肌炎中自身抗体所识别的主要抗原。这种抗原是肌球蛋白结合蛋白-C家族的一个新成员，我们将其称为咀嚼肌肌球蛋白结合蛋白-C（mMyBP-C）。mMyBP-C不仅定位于咀嚼肌纤维内，还定位于其细胞表面或附近，这可能使其作为一种免疫原易于获取。mMyBP-C基因在人类中也存在，并且mMyBP-C可能在某些人类炎性肌病中发挥作用。了解mMyBP-C在这种犬类炎性肌病中的作用，不仅可以增进我们对犬类自身免疫性炎性肌肉疾病机制的认识，也有助于我们了解人类相关疾病的机制。
