G Protein-Coupled Chemokine Receptors Induce Both Survival and Apoptotic Signaling Pathways
| Autor: | Carlos V. Paya, Nicholas Vlahakis, Angelina Villasis-Keever, Maria Vanegas, Stacey R. Vlahakis, Timothy S. Gomez |
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| Rok vydání: | 2002 |
| Předmět: |
CD4-Positive T-Lymphocytes
CCR1 Receptors CXCR4 CCR2 Chemokine Cell Survival MAP Kinase Signaling System Immunology Down-Regulation Apoptosis GTP-Binding Protein alpha Subunits Gi-Go Protein Serine-Threonine Kinases Biology p38 Mitogen-Activated Protein Kinases Chemokine receptor Proto-Oncogene Proteins Humans Immunology and Allergy CCL17 CXC chemokine receptors Phosphorylation Cells Cultured Mitogen-Activated Protein Kinase 1 Mitogen-Activated Protein Kinase 3 Cell Death Chemokine CXCL12 Cell biology Enzyme Activation Chemotaxis Leukocyte Caspases biology.protein XCL2 GTP-Binding Protein alpha Subunit Gi2 Mitogen-Activated Protein Kinases Stromal Cells Signal transduction Chemokines CXC Proto-Oncogene Proteins c-akt |
| Zdroj: | The Journal of Immunology. 169:5546-5554 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.169.10.5546 |
| Popis: | Chemokine receptors are essential for triggering chemotaxis to immune cells; however, a number of them can also mediate death when engaged by nonchemokine ligands. When the chemokine receptor CXCR4 is engaged by stromal cell-derived factor (SDF1)α, it triggers cells to chemotax, and in some cell types such as neurons, causes cell death. To elucidate this dual and opposing receptor function, we have investigated whether CXCR4 activation by its chemokine SDF1α could lead to the simultaneous activation of both anti- and proapoptotic signaling pathways; the balance ultimately influencing cell survival. CXCR4 activation in CD4 T cells by SDF1α led to the activation of the prosurvival second messengers, Akt and extracellular signal-regulated protein kinase. Selective inhibition of each signal demonstrated that extracellular signal-regulated protein kinase is essential for mediating SDF1α-triggered chemotaxis but does not confer an antiapoptotic state. In contrast, Akt activation through CXCR4 by SDF1α interactions is necessary to confer resistance to apoptosis. The proapoptotic signaling pathway triggered by SDF1α-CXCR4 interaction involves the Giα protein-independent activation of the proapoptotic MAPK (p38). Furthermore, other chemokines and chemokine receptors also signal chemotaxis and proapoptotic effects via similar pathways. Thus, Giα protein-coupled chemokine receptors can function as death prone receptors and the balance between the above signaling pathways will ultimately mandate the fate of the activated cell. |
| Databáze: | OpenAIRE |
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