Microbial products, including lipopolysaccharide (LPS), an agonist of Toll-like receptor 4 (TLR4), regulate the lifespan of dendritic cells (DCs) by largely undefined mechanisms. Here, we identify a role for calcium-calmodulin–dependent kinase IV (CaMKIV) in this survival program. The pharmacologic inhibition of CaMKs as well as ectopic expression of kinase-inactive CaMKIV decrease the viability of monocyte-derived DCs exposed to bacterial LPS. The defect in TLR4 signaling includes a failure to accumulate the phosphorylated form of the cAMP response element-binding protein (pCREB), Bcl-2, and Bcl-xL. CaMKIV null mice have a decreased number of DCs in lymphoid tissues and fail to accumulate mature DCs in spleen on in vivo exposure to LPS. Although isolated Camk4−/− DCs are able to acquire the phenotype typical of mature cells and release normal amounts of cytokines in response to LPS, they fail to accumulate pCREB, Bcl-2, and Bcl-xL and therefore do not survive. The transgenic expression of Bcl-2 in CaMKIV null mice results in full recovery of DC survival in response to LPS. These results reveal a novel link between TLR4 and a calcium-dependent signaling cascade comprising CaMKIV-CREB-Bcl-2 that is essential for DC survival.

Illario, M., Giardino Torchia, M., Sankar, U., Ribar, T., Galgani, M., Vitiello, L., Masci, A., Bertani, F., Ciaglia, E., Astone, D., Maulucci, G., Cavallo, A., Vitale, M., Cimini, V., Pastore, L., Means, A., Rossi, G., Racioppi, L., Calmodulin-dependent kinase IV links Toll-like receptor 4 signaling with survival pathway of activated dendritic cells, <<BLOOD>>, 2008; 111 (2): 723-731. [doi:10.1182/blood-2007-05-091173] [http://hdl.handle.net/10807/10664]

Calmodulin-dependent kinase IV links Toll-like receptor 4 signaling with survival pathway of activated dendritic cells

Maulucci, Giuseppe;
2008

Abstract

Microbial products, including lipopolysaccharide (LPS), an agonist of Toll-like receptor 4 (TLR4), regulate the lifespan of dendritic cells (DCs) by largely undefined mechanisms. Here, we identify a role for calcium-calmodulin–dependent kinase IV (CaMKIV) in this survival program. The pharmacologic inhibition of CaMKs as well as ectopic expression of kinase-inactive CaMKIV decrease the viability of monocyte-derived DCs exposed to bacterial LPS. The defect in TLR4 signaling includes a failure to accumulate the phosphorylated form of the cAMP response element-binding protein (pCREB), Bcl-2, and Bcl-xL. CaMKIV null mice have a decreased number of DCs in lymphoid tissues and fail to accumulate mature DCs in spleen on in vivo exposure to LPS. Although isolated Camk4−/− DCs are able to acquire the phenotype typical of mature cells and release normal amounts of cytokines in response to LPS, they fail to accumulate pCREB, Bcl-2, and Bcl-xL and therefore do not survive. The transgenic expression of Bcl-2 in CaMKIV null mice results in full recovery of DC survival in response to LPS. These results reveal a novel link between TLR4 and a calcium-dependent signaling cascade comprising CaMKIV-CREB-Bcl-2 that is essential for DC survival.
Inglese
Illario, M., Giardino Torchia, M., Sankar, U., Ribar, T., Galgani, M., Vitiello, L., Masci, A., Bertani, F., Ciaglia, E., Astone, D., Maulucci, G., Cavallo, A., Vitale, M., Cimini, V., Pastore, L., Means, A., Rossi, G., Racioppi, L., Calmodulin-dependent kinase IV links Toll-like receptor 4 signaling with survival pathway of activated dendritic cells, <<BLOOD>>, 2008; 111 (2): 723-731. [doi:10.1182/blood-2007-05-091173] [http://hdl.handle.net/10807/10664]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10807/10664
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