Chemokine CXCL12 Uses CXCR4 and a Signaling Core Formed by Bifunctional Akt, Extracellular Signal-regulated Kinase (ERK)1/2, and Mammalian Target of Rapamycin Complex 1 (mTORC1) Proteins to Control Chemotaxis and Survival

CXCR4 may use a specific signaling signature to regulate the functions of dendritic cells.Chemokinescontrolseveralcellfunctionsinadditiontoche-motaxis. Although much information is available on theinvolvementofspecificsignalingmoleculesinthecontrolofsin-gle functions controlled by chemokines, especially chemotaxis,the mechanisms used by these ligands to regulate several cellfunctions simultaneously are completely unknown. Maturedendriticcells(maDCs)migratethroughtheafferentlymphaticvesselstothelymphnodes,wheretheyregulatetheinitiationofthe immune response. As maDCs are exposed to chemokineCXCL12 (receptors CXCR4 and CXCR7) during their migra-tion, its functions are amenable to be regulated by this ligand.We have used maDCs as a model system to analyze the mecha-nisms whereby CXCL12 simultaneously controls chemotaxisandsurvivalinmaDCs.WeshowthatCXCL12usesCXCR4,butnot CXCR7, and the components of a signaling core thatincludes G