Abstract: Systemic sclerosis (SSc) is an autoimmune disease characterized by progressive fibrosis of the skin and various internal organs. The innate immunity is crucial in the activation of inflammatory response and onset of fibrosis in the pathogenesis of SSc. On one hand, the innate immune system regulates the activation of adaptive immune system through antigen presentation, and on the other hand, it promotes local inflammation and matrix accumulation via production of various proinflammatory cytokines. This review aims at the important role of monocytes/macrophages, mast cells, neutrophils and dendritic cells in innate immune system, as well as Toll-like receptors and their ligands and proinflammatory cytokines (including IL-4, IL-6 and TGF-β) in SSc. The elaboration of innate immunity in the pathogenesis of SSc will contribute to the clinical implications and the therapeutic targeting of effector molecules.

Key words: systemic sclerosis, innate immunity, monocyte/macrophages, mast cells, toll-like receptors, Interleukin-4, transforming growth factor-β