Nitric oxide and cGMP protein kinase (cGK) regulate dendritic-cell migration toward the lymph-node-directing chemokine CCL19.
Dendritic-cell (DC) migration to secondary lymphoid organs is crucial for the initiation of adaptive immune responses. Although LPS up-regulates CCR7 on DCs, a second signal is required to enable them to migrate toward the chemokine CCL19 (MIP-3beta). We found that the nitric oxide (NO) donor NOR4 provides a signal allowing LPS-stimulated DCs to migrate toward CCL19. NO affects DC migration through both the initial activation of the cGMP/cGMP kinase (cGMP/cGK) pathway and a long-term effect that reduced cGK activity via negative feedback. Indeed, migration of DCs toward CCL19, unlike migration toward CXCL12 (SDF-1alpha), required inhibition of cGK. LPS increased both cGK expression and cGK activity as measured by phosphorylation of the key cGK target vasodilator-stimulated phosphoprotein (VASP). Because cGK phosphorylation of VASP can disrupt focal adhesions and inhibit cell migration, LPS-induced VASP phosphorylation may prevent DCs from migrating without a second signal. Long-term NOR4 treatment inhibited the increase in cGK-dependent VASP phosphorylation, releasing this brake so that DCs can migrate. NO has been implicated in the regulation of autoimmunity through its effect on T cells. Our results suggest that NO regulation of DC migration and cytokine production may contribute to the protective effects of NO in autoimmune disorders.
Giordano
Daniela
D
Department of Immunology, University of Washington, Box 357330, 1959 NE Pacific St, Seattle, WA 98195, USA. giordano@u.washington.edu
Magaletti
Dario M
DM
Clark
Edward A
EA
D002465:Cell Movement / Q000187:drug effects; D054415:Chemokine CCL19; D019742:Chemokines, CC / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D016207:Cytokines / Q000032:analysis / Q000097:blood; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008198:Lymph Nodes / Q000276:immunology*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011725:Pyridines / Q000494:pharmacology*
C515460:CCL19 protein, human; D054415:Chemokine CCL19; D019742:Chemokines, CC; D016207:Cytokines; D008070:Lipopolysaccharides; C102260:NOR 4; D020030:Nitric Oxide Donors; D011725:Pyridines; D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D006152:Cyclic GMP