title: HIV-1 gp120 and chemokine activation of Pyk2 and mitogen-activated protein kinases in primary macrophages mediated by calcium-dependent, pertussis toxin-insensitive chemokine receptor signaling.
abstract: Human immunodeficiency virus type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry. It was recently demonstrated that HIV-1 glycoprotein 120 (gp120) elevated calcium and activated several ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. This study shows that chemokine receptor engagement by both CCR5-dependent (R5) and CXCR4-dependent (X4) gp120 led to rapid phosphorylation of the focal adhesion-related tyrosine kinase Pyk2 in macrophages. Pyk2 phosphorylation was also induced by macrophage inflammatory protein-1beta (MIP-1beta) and stromal cell-derived factor-1alpha, chemokine ligands for CCR5 and CXCR4. Activation was blocked by EGTA and by a potent blocker of calcium release-activated Ca++ (CRAC) channels, but was insensitive to pertussis toxin (PTX), implicating CRAC-mediated extracellular Ca++ influx but not Galpha(i) protein-dependent mechanisms. Coreceptor engagement by gp120 and chemokines also activated 2 members of the mitogen-activated protein kinase (MAPK) superfamily, c-Jun amino-terminal kinase/stress-activated protein kinase and p38 MAPK. Furthermore, gp120-stimulated macrophages secreted the chemokines monocyte chemotactic protein-1 and MIP-1beta in a manner that was dependent on MAPK activation. Thus, the gp120 signaling cascade in macrophages includes coreceptor binding, PTX-insensitive signal transduction, ionic signaling including Ca++ influx, and activation of Pyk2 and MAPK pathways, and leads to secretion of inflammatory mediators. HIV-1 Env signaling through these pathways may contribute to dysregulation of uninfected macrophage functions, new target cell recruitment, or modulation of macrophage infection.
authors.affiliation: Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Del Corno
authors.forename: Q H
authors.initials: QH
authors.lastname: Liu
authors.forename: D
authors.initials: D
authors.lastname: Schols
authors.forename: E
authors.initials: E
authors.lastname: de Clercq
authors.forename: S
authors.initials: S
authors.lastname: Gessani
authors.forename: B D
authors.initials: BD
authors.lastname: Freedman
authors.forename: R G
authors.initials: RG
authors.lastname: Collman
mesh_terms: D002118:Calcium / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D018932:Chemokine CCL2 / Q000378:metabolism; D054407:Chemokine CCL4; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D051418:Focal Adhesion Kinase 2; D015699:HIV Envelope Protein gp120 / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008262:Macrophage Activation / Q000187:drug effects; D019402:Macrophage Inflammatory Proteins / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism / Q000821:virology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009000:Monocytes / Q000187:drug effects; D037342:Pertussis Toxin; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D019713:Receptors, CCR5 / Q000187:drug effects / Q000502:physiology*; D019718:Receptors, CXCR4 / Q000187:drug effects / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D002121:Calcium Channel Blockers; D002614:Chelating Agents; D018932:Chemokine CCL2; D054407:Chemokine CCL4; D015699:HIV Envelope Protein gp120; D019402:Macrophage Inflammatory Proteins; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella; D004533:Egtazic Acid; D037342:Pertussis Toxin; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D002118:Calcium