Preferential infiltration of interleukin-4-producing CXCR4+ T cells in the lesional muscle but not skin of patients with dermatomyositis

Abstract

SummaryDermatomyositis (DM) and polymyositis (PM) are collectively termed autoimmune myopathy. To investigate the difference between muscle-and skininfiltrating T cells and to address their role for myopathy, we characterized T cells that were directly expanded from the tissues. Enrolled into this study were 25 patients with DM and three patients with PM. Muscle and skin biopsied specimens were immersed in cRPMI medium supplemented with interleukin ( Our study suggests that T cell populations in the muscle and skin are different, and the Th2 cell infiltrate in the muscle is associated with the low severity of myositis in DM.

Elevated IL-4 and IFN-γ Levels in Muscle Tissue of Patients with Dermatomyositis

“…Increased IL-17 levels have been shown in serum, PBMCs and muscle cell-infiltrating T-cells of patients with DM (2,8,9). However, we failed to show an increase in IL-17…”

“…Infiltrating lymphocytes producing interferon (IFN)-γ, interleukin (IL)-4 and IL-17 have been demonstrated in muscle biopsy specimens from patients with DM, signifying the involvement of different Th types in this disease (2,3). Myocytes and endothelial cells are known to produce cytokines, particularly under inflammatory conditions, and undergo cell death when exposed to inflammatory cytokines (4-6).…”

The role of interleukin‐4 in rheumatic diseases

“…Polymyositis (PM) and dermatomyositis (DM) are autoimmune inflammatory systemic diseases, the clinical manifestations of skeletal muscle involvement, sometimes associated with fatal interstitial pneumonia . A large amount of IL‐4 was found in the supernatant of skin and muscle‐derived T cells . Compared with the control group, the level of IL‐4 in DM increased significantly, but the level of IL‐4 in PM decreased .…”

Cytokines in immune-mediated inflammatory myopathies: cellular sources, multiple actions and therapeutic implications

“…Conversely, a Th2 cell infiltrate in DM muscle has been associated with a lower severity of disease [60]. This is due possibly to the generation of M2 macrophages by Th2 cytokines leading to tissue repair [9].…”