Autoantibodies in canine masticatory muscle myositis recognize a novel myosin binding protein-C family member.
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.
Wu
Xiaohua
X
Department of Pathology, University of California, San Diego 92101, USA.
Li
Zhi-fang
ZF
Brooks
Randolph
R
Komives
Elizabeth A
EA
Torpey
Justin W
JW
Engvall
Eva
E
Gonias
Steven L
SL
Shelton
G Diane
GD
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D002352:Carrier Proteins / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D018076:DNA, Complementary / Q000235:genetics; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004285:Dogs; D016189:Dystrophin / Q000378:metabolism; D006801:Humans; D008410:Masticatory Muscles / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009220:Myositis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000662:veterinary; D011485:Protein Binding; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000099163:Myosin Binding Protein C
D000199:Actins; D001323:Autoantibodies; D002352:Carrier Proteins; D018076:DNA, Complementary; D016189:Dystrophin; D000099163:Myosin Binding Protein C