Although the authors have not further analyzed the T helper cell activation, DSS colitis has been shown to involve Th1/Th17-mediated acute inflammation, thereby indirectly suggesting a role for inflammatory DCs in Th17 selleck screening library activation. Siddiqui

et al. [34] recently identified a subset of E-cadherin+ DCs (E-cadherin is the receptor of CD103), which accumulated in a T-cell transfer, but not innate, model of colitis. This E-cadherin+ subset arose from monocytes and produced colitogenic cytokines upon activation in vitro. The authors transferred DCs generated in vitro from bone marrow into mice undergoing T-cell-mediated colitis, and found that recipients of E-cadherin+ DCs developed a more severe pathology and higher frequencies of IL-17+ CD4+ T cells in the intestine and the gut-associated lymphoid tissues, in comparison with recipients of E-cadherin− DCs, suggesting indirectly that a subset of inflammatory DCs may promote Th17-type responses in vivo. Moreover, in the lung, Fei et al. [35] examined the mechanisms underlying Aspergillus-induced neutrophilia and airway inflammation, and reported that TNF-α from inflammatory DCs acted as a molecular switch to regulate neutrophil/eosinophil influx and regulated the level of IL-17. Finally, in 2000, a report demonstrated

that CCR2 expression on host-derived mononuclear cells but not on transferred myelin oligodendrocyte glycoprotein (MOG)-specific T lymphocytes, was required for the induction of experimental autoimmune encephalomyelitis [36], but the role of inflammatory DCs was not studied. It was subsequently this website shown [37] that CNS glial Vitamin B12 expression of CCL2 (ligand for CCR2) was required

for maximum disease development. Using chimeric mice, the authors demonstrated that CCL2 deficiency in CNS (but not leukocytes) resulted in a reduction in the number of macrophages and “myeloid” DCs expressing iNOS and TNF (presumably inflammatory DCs) in the CNS. However, equal frequencies of both IFN-γ- and IL-17-producing T cells were measured in WT and CNS-CCL2-deficient mice, suggesting that recruited inflammatory APCs do not influence experimental autoimmune encephalomyelitis by altering Th1/Th17 differentiation [37]. An interesting observation was made in humans [38]: a subset of CD14+ monocytes was shown to migrate in a Boyden chamber in which human BBB-endothelial cells separate the upper and lower chambers. A total of 15% of the CD14+ monocytes seeded on BBB-endothelial cells transmigrated to the lower chamber, whereas 45% were associated with Blood-brain-barrier (BBB)-endothelial cells in the subendothelial space. These endothelial-associated cells acquired a partial DC phenotype, had the ability to secrete IL-6, IL-12p70, and TGF-β, and favored the production of IL-17 or IFN-γ by CD4+ T lymphocytes in an allo-MLR assay in vitro.