IL-6 in human cytomegalovirus secretome promotes angiogenesis and survival of endothelial cells through the stimulation of survivin

Blood. 2011 Jan 6;117(1):352-61. doi: 10.1182/blood-2010-06-291245. Epub 2010 Oct 7.

Abstract

Human cytomegalovirus (HCMV) is linked to the acceleration of vascular diseases such as atherosclerosis and transplant vasculopathy. One of the hallmarks of these diseases is angiogenesis (AG) and neovessel formation. Endothelial cells (ECs) are an integral part of AG and are sites of HCMV persistence. AG requires multiple synchronous processes that include EC proliferation, migration, and vessel stabilization. Virus-free supernatant (secretome) from HCMV-infected ECs induces AG. To identify factor(s) involved in this process, we performed a human cytokine array. Several cytokines were significantly induced in the HCMV secretomes including interleukin-6 (IL-6), granulocyte macrophage colony-stimulating factor, and IL-8/CXCL8. Using in vitro AG assays, neutralization of IL-6 significantly reduced neovessel formation. Addition of the HCMV secretome to preformed vessels extended neovessel survival, but this effect was blocked by neutralization of IL-6. In these cells, IL-6 prevented apoptosis by blocking caspase-3 and -7 activation through the induction of survivin. Neutralization of IL-6 receptor on ECs abolished the ability of HCMV secretome to increase survivin expression and activated effector caspases. Moreover, survivin shRNA expression induced rapid regression of tubule capillary networks in ECs stimulated with HCMV secretome and activated effector caspases. These observations may explain how CMV accelerates vascular disease despite limited infection in tissues.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Angiogenesis Inducing Agents / metabolism*
  • Apoptosis
  • Blotting, Western
  • Caspase 3 / metabolism
  • Cell Adhesion
  • Cell Movement
  • Cell Proliferation
  • Cells, Cultured
  • Cytomegalovirus / metabolism*
  • Cytomegalovirus Infections / metabolism
  • Endothelium, Vascular / cytology*
  • Endothelium, Vascular / metabolism*
  • Humans
  • Inhibitor of Apoptosis Proteins
  • Interleukin-6 / metabolism*
  • Interleukin-8 / metabolism
  • Macrophage Colony-Stimulating Factor / metabolism
  • Microtubule-Associated Proteins / antagonists & inhibitors
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • RNA, Messenger / genetics
  • RNA, Small Interfering / genetics
  • Receptors, Interleukin-6 / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Survivin
  • Umbilical Veins / cytology
  • Umbilical Veins / metabolism

Substances

  • Angiogenesis Inducing Agents
  • BIRC5 protein, human
  • Inhibitor of Apoptosis Proteins
  • Interleukin-6
  • Interleukin-8
  • Microtubule-Associated Proteins
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptors, Interleukin-6
  • Survivin
  • Macrophage Colony-Stimulating Factor
  • Caspase 3