CX3CR1 activation was the dominant pertussis-sensitive phosphatase inhibitor library mechanism controlling transendothelial migration under flow, and expression of the CX3CR1 ligand CX3CL1 is increased on hepatic sinusoids in chronic inflammatory liver disease. Exposure of CD16+ monocytes to immobilized purified CX3CL1 triggered β1-integrin-mediated adhesion to vascular cell adhesion molecule-1 and induced the development of a migratory phenotype. Following

transmigration or exposure to soluble CX3CL1, CD16+ monocytes rapidly but transiently lost expression of CX3CR1. Adhesion and transmigration across HSECs under flow was also dependent on vascular adhesion protein-1 (VAP-1) on the HSECs. Conclusion: Our data suggest that

CD16+ monocytes are recruited by a combination of adhesive signals involving VAP-1 and CX3CR1 mediated integrin-activation. learn more Thus a novel combination of surface molecules, including VAP-1 and CX3CL1 promotes the recruitment of CD16+ monocytes to the liver, allowing them to localize at sites of chronic inflammation and fibrosis. (Hepatology 2010) The liver contains bone marrow-derived myeloid dendritic cells (mDCs) and macrophages (Kupffer cells) that are recruited from blood via the hepatic sinusoids. They act as immune sentinels to detect and coordinate responses to invading pathogens and antigens entering the liver through the portal vein.1-3 Under basal conditions, these cells are replenished by recruitment of precursors from

blood, which increases with inflammation. The exact nature of the precursor cells is unclear, but they likely reside within the circulating CD16+ monocyte population.4-7 mDCs arise from bone marrow-derived progenitors within the monocyte pool.8-10 Several populations selleck chemicals llc of precursors have been proposed, including lineage-negative CD11c+ monocytes, CD34+ progenitors,11 and human CD16+ monocytes.12 Human monocytes display heterogeneity defined by expression of chemokine receptors, adhesion molecules, CD14, and CD16.13-15 The CD14+CD16++ subset expresses high levels of the chemokine receptor CX3CR1 and is believed to give rise to DCs with potent antigen-presenting capabilities16 and inflammatory tissue macrophages.15, 17 Furthermore, transendothelial migration of CD16+ monocytes in vitro induces differentiation into functional DCs, suggesting that recruitment itself may shape their subsequent differentiation.18 Integral to mDC function is the capacity to traffic from one anatomical compartment to another. In the liver, this involves a pathway that traverses the space of Disse and takes the cells along the hepatic sinusoids to the portal tract lymphatics.19-21 The recruitment of precursor mDCs from the blood into tissues across endothelium is poorly understood.

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