RSV-infected airway epithelial cells cause biphasic up-regulation of CCR1 expression on human monocytes

J Leukoc Biol. 2007 Jun;81(6):1487-95. doi: 10.1189/jlb.1006611. Epub 2007 Mar 27.

Abstract

Respiratory syncytial virus (RSV) infection can cause extensive airway inflammation, which is orchestrated by chemokines and their receptors. RSV-infected epithelial cells secrete many cytokines and chemokines, but little is known about regulation of chemokine receptors on target cells. We investigated the effects of conditioned media (CM) from RSV-infected epithelial cells on monocyte CCR1, CCR2, and CCR5 expression. RSV-CM but not control-CM stimulated a biphasic increase in cell-surface CCR1, and levels peaked at 36 h and 96 h poststimulation. Similar CCR1 up-regulation occurred on monocyte-derived macrophages. Cytochlasin D and colchicine blocked both peaks of expression, demonstrating requirement of a functional cytoskeleton. Intracellular staining revealed little internal sequestration of CCR1 protein, and CCR1 up-regulation was inhibited by actinomycin D and cycloheximide, indicating that both waves of RSV-CM-induced surface CCR1 expression were dependent on de novo transcription and protein synthesis. Cytokine-neutralizing experiments showed that the effects of RSV-CM were decreased by blocking TNF-alpha (percent inhibition=51+/-2.3% at 36 h peak and 42+/-7.7% at 96 h peak) and to a lesser extent, IL-1 (percent inhibition=32+/-7.2% at 36 h and 23+/-2.9% at 96 h). In summary, RSV-CM causes a biphasic up-regulation of surface CCR1 on monocytes, which is dependent on an intact cytoskeleton, requires new gene transcription and protein synthesis, and is mediated in part by the proinflammatory cytokines TNF-alpha and IL-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Culture Media, Conditioned
  • Cycloheximide / pharmacology
  • Cytochalasin D / pharmacology
  • Cytoskeleton / metabolism
  • Dactinomycin / pharmacology
  • Epithelial Cells / metabolism*
  • Epithelial Cells / virology
  • Humans
  • Interleukin-1 / physiology
  • Macrophages / immunology
  • Macrophages / virology
  • Monocytes / metabolism*
  • Receptors, CCR1
  • Receptors, CCR2
  • Receptors, CCR3
  • Receptors, Chemokine / biosynthesis*
  • Receptors, Chemokine / metabolism
  • Respiratory Mucosa / metabolism*
  • Respiratory Syncytial Viruses / physiology*
  • Tumor Necrosis Factor-alpha / physiology
  • Up-Regulation

Substances

  • CCR1 protein, human
  • CCR2 protein, human
  • CCR3 protein, human
  • Culture Media, Conditioned
  • Interleukin-1
  • Receptors, CCR1
  • Receptors, CCR2
  • Receptors, CCR3
  • Receptors, Chemokine
  • Tumor Necrosis Factor-alpha
  • Dactinomycin
  • Cytochalasin D
  • Cycloheximide