Regulation of inflammatory monocyte/macrophage recruitment from the bone marrow during murine cytomegalovirus infection: role for type I interferons in localized induction of CCR2 ligands

J Immunol. 2009 Aug 15;183(4):2810-7. doi: 10.4049/jimmunol.0900205. Epub 2009 Jul 20.

Abstract

Monocytes/macrophages are critical early innate immune responders during murine CMV (MCMV) infection. It has been established that inflammatory monocyte/macrophages are released from the bone marrow and into the peripheral blood before entry into infected tissue sites. We previously reported a role for IFN-alpha/beta in promotion of CCR2-mediated recruitment of monocyte/macrophages into the liver in response to MCMV infection. However, the mechanisms that support the migration of monocyte/macrophages from the bone marrow and into the peripheral blood under conditions of MCMV infection have not been elucidated. Herein, we demonstrate an accumulation of monocyte/macrophages in the bone marrow of MCMV-infected CCR2-deficient mice, whereas circulating monocyte/macrophages are profoundly diminished. The CCR2 ligands MCP-1, MCP-3, and MCP-5 are detected in bone marrow and in serum from MCMV-infected mice. Furthermore, bone marrow leukocytes from naive mice produce high levels of MCP-1 and MCP-5, and moderate levels of MCP-3, when stimulated with recombinant IFN-alpha in culture. We identify bone marrow F4/80(+) cells as major producers of MCP-1, MCP-3, and MCP-5. Moreover, induction of CCR2 ligands is dependent on IFN-alpha/beta-mediated signals and MCMV infection. Taken together, the results reveal a critical role for inflammatory cytokines in stimulating production of CCR2-binding chemokines from F4/80(+) cells in the bone marrow, and they suggest that local production of chemokines supports monocyte/macrophage egress from the bone marrow into the blood during a virus infection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow Cells / immunology*
  • Bone Marrow Cells / metabolism
  • Bone Marrow Cells / pathology
  • Cells, Cultured
  • Chemokine CCL2 / biosynthesis
  • Chemokine CCL2 / metabolism
  • Chemotaxis, Leukocyte / immunology
  • Herpesviridae Infections / immunology*
  • Herpesviridae Infections / metabolism
  • Herpesviridae Infections / pathology
  • Inflammation Mediators / physiology*
  • Interferon-alpha / physiology*
  • Interferon-beta / physiology*
  • Ligands
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Monocytes / immunology
  • Monocytes / metabolism
  • Monocytes / pathology
  • Muromegalovirus / immunology*
  • Receptors, CCR2 / biosynthesis*
  • Receptors, CCR2 / deficiency
  • Receptors, CCR2 / metabolism
  • Recombinant Proteins / pharmacology
  • Signal Transduction / immunology

Substances

  • Ccl2 protein, mouse
  • Ccr2 protein, mouse
  • Chemokine CCL2
  • Inflammation Mediators
  • Interferon-alpha
  • Ligands
  • Receptors, CCR2
  • Recombinant Proteins
  • Interferon-beta