Novel aspects on the contribution of T cells and dendritic cells in the pathogenesis of myositis

Abstract

This review focuses on recent advances and new hypothesis in the understanding of the T and dendritic cells contribution to the pathogenesis of idiopathic inflammatory myopathies (IIMs), especially polymyositis (PM) and dermatomyositis (DM). The new data show that non-specific amplification of muscle inflammation by T lymphocyte and dendritic cells may result from the local production of cytokines and chemokines. Synergistic interactions between these factors explain some of the clinical features. The potent role of these molecules suggests their potential for therapeutic manipulation using specific inhibitors.

Quantitative T cell subsets profile in peripheral blood from patients with idiopathic inflammatory myopathies: tilting the balance towards proinflammatory and pro-apoptotic subsets

“…Multiple abnormalities in T cell subsets that infiltrate muscle in patients with IIM and some murine models have been reported . However, the profile in peripheral blood has not been addressed fully.…”

Fascin-expressing Dendritic Cells Dominate in Polymyositis and Dermatomyositis

“…The literature on the presence of DC in IIM is limited 5,6,7,8,17,31,32,33 . Some of the results were obtained using cryostat sections, but the pioneering study on DC maturation stage by Page, et al 6 In juvenile DM, DC-LAMP, a marker of mature DC, and BDCA2, a marker produced by immature plasmacytoid DC, were studied in muscles affected for > 2 months 17 .…”

“…Dendritic cells (DC) are considered crucial for the induction of immunization; thus several analyses have been performed to find out whether DC parti-cipate in the immune response in the course of IIM 5 . DC have been reported in muscle tissue, among the inflammatory infiltrating cells in these diseases 6,7 . High interferon-α and ß production by DC in myositis has been implicated in causing characteristic changes in muscles in IIM 5,6,7,8 .…”

“…DC have been reported in muscle tissue, among the inflammatory infiltrating cells in these diseases 6,7 . High interferon-α and ß production by DC in myositis has been implicated in causing characteristic changes in muscles in IIM 5,6,7,8 . In addition to the DC markers, molecules assumed to be lymphocyte or macrophage markers can be detected on the DC cell surface: CD4 of Th cells, CD8 of T suppressor/cytotoxic cells, and CD68 -earlier considered only a macrophage marker 5,6,7,8 .…”

Interstitial Pneumonia Associated with Connective Tissue Disease: An Overview and an Insight

“…PM and DM are sometimes recognized together as they share similar clinical signs and symptoms with exception of cutaneous manifestations such as "heliotrope rash" on the upper eyelids, "mechanic's hands" on the fingers, and "Gottron papules" on the dorsal surface of the hands seen in DM. Pathologically, however, these are distinct entities; PM is T cell-mediated diseases, where CD8-positive cytotoxic T cells invade muscle fibers expressing MHC class I antigens, whereas DM is characterized by a complement-mediated microangiopathy [86][87][88].…”