Chemokines and dendritic cells in inflammatory myopathies.

This review focuses on the contribution of the local production of chemokines and cytokines and of dendritic cells (DC) to the pathogenesis of inflammatory myopathies. DC are the most efficient professional antigen-presenting cells (APC), which are critical for the development of innate and adaptive immune responses. Chemokines are important mediators of the immune response as they regulate leucocyte recruitment to tissue and play a key role in inflammatory diseases by acting on T-cell and DC migration. Recent advances indicate that the muscle cell itself could participate in the inflammatory process. Furthermore, the T-helper (Th) type 1 and Th17 proinflammatory cytokines, present in myositis samples, are associated with the migration, differentiation and maturation of inflammatory cells and allow a network of interactions between all the components of the immune response. An understanding of such interactions is essential because it can lead to therapeutic applications.