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

Blood. 2001 Nov 15;98(10):2909-16. doi: 10.1182/blood.v98.10.2909.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calcium / physiology
  • Calcium Channel Blockers / pharmacology
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cell Differentiation / drug effects
  • Cells, Cultured
  • Chelating Agents / pharmacology
  • Chemokine CCL2 / metabolism
  • Chemokine CCL4
  • Egtazic Acid / pharmacology
  • Enzyme Activation / drug effects
  • Focal Adhesion Kinase 2
  • HIV Envelope Protein gp120 / pharmacology
  • HIV Envelope Protein gp120 / physiology*
  • Humans
  • JNK Mitogen-Activated Protein Kinases
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology*
  • Macrophage Activation / drug effects
  • Macrophage Inflammatory Proteins / metabolism
  • Macrophages / metabolism
  • Macrophages / virology*
  • Mitogen-Activated Protein Kinases / metabolism*
  • Monocytes / drug effects
  • Pertussis Toxin
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Protein-Tyrosine Kinases / metabolism*
  • Receptors, CCR5 / drug effects
  • Receptors, CCR5 / physiology*
  • Receptors, CXCR4 / drug effects
  • Receptors, CXCR4 / physiology*
  • Recombinant Proteins / pharmacology
  • Virulence Factors, Bordetella / pharmacology
  • p38 Mitogen-Activated Protein Kinases

Substances

  • Calcium Channel Blockers
  • Chelating Agents
  • Chemokine CCL2
  • Chemokine CCL4
  • HIV Envelope Protein gp120
  • Macrophage Inflammatory Proteins
  • Receptors, CCR5
  • Receptors, CXCR4
  • Recombinant Proteins
  • Virulence Factors, Bordetella
  • Egtazic Acid
  • Pertussis Toxin
  • Protein-Tyrosine Kinases
  • Focal Adhesion Kinase 2
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Calcium