IL-6 regulates MCP-1, ICAM-1 and IL-6 expression in human myoblasts

The inflammatory reaction ill autoimmune polymyositis and rejection of transplanted myoblasts is characterized by mononuclear cell infiltration. In other settings monocytes are locally recruited by all IL-6-induced IL-8-to-MCP-1 switch. IL-6, upon binding to soluble gp80 (sIL-6R), can interact with membrane-bound ubiquitously expressed gp130 and activate virtually all cells (transsignaling). We found that human myoblasts could use transsignaling to produce IL-6, MCP-1 and ICAM-1; the addition of sIL-6R, binding to IL-1 beta-induced IL-6, greatly increases IL-6 production. These in vitro data support the hypothesis that locally secreted IL-6 can target monocyte chemotaxis and leukocytes trafficking through an IL-6, MCP-1 and ICAM-1 modulation. (C) 2008 Elsevier B.V. All rights reserved.