Immunomodulation by semi-mature dendritic cells: a novel role of Toll-like receptors and interleukin-6.
Dendritic cells (DCs) are key players in activation of the adaptive immune system by their ability of antigen presentation to and priming of T cells. An increasing body of evidence suggests that DCs may also play an important role in induction of tolerance, predominantly by induction of regulatory T cells (T(reg)). More recently, data have been published on how Toll-like receptor (TLR) ligands and cytokines affect DC differentiation, and how DC subsets might be involved in immunoregulation and tolerance rather than in T cell activation. The most important features of tolerance-inducing DCs appear to be their maturation state and their cytokine secretion pattern. The following types of tolerance-inducing DCs have been reported: immature DCs (DCs(im)) or DCs in the steady state (DCs(st)), DCs(IL-10), semi-mature DCs(TNF-alpha), semi-mature DCs(IL-6). With this review article we would like to discuss the aforementioned types of tolerogenic DCs with a focus on semi-mature DCs(IL-6) and discuss their potential role in maintenance of (hepatic or intestinal) immune homeostasis and inflammatory diseases such as inflammatory bowel disease.
Institute of Medical Microbiology and Hygiene, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Strasse 6, D-72076 Tübingen, Germany. julia-stefanie.frick@med.uni-tuebingen.de
Julia-Stefanie
JS
Frick
Frank
F
Grünebach
Ingo B
IB
Autenrieth
D003713:Dendritic Cells / Q000276:immunology*; D006706:Homeostasis; D006801:Humans; D056747:Immunomodulation; D015850:Interleukin-6 / Q000276:immunology*; D008954:Models, Biological; D051193:Toll-Like Receptors / Q000276:immunology*
D015850:Interleukin-6; D051193:Toll-Like Receptors