Escherichia coli pneumonia enhances granulopoiesis and the mobilization of myeloid progenitor cells into the systemic circulation

Crit Care Med. 2004 Aug;32(8):1740-6. doi: 10.1097/01.ccm.0000132900.84627.90.


Objective: The process by which hematopoietic tissues respond to a pulmonary infection remains poorly understood. This study investigated the potential role of lung-derived granulopoietic cytokines in facilitating this response.

Design: Laboratory investigation.

Setting: University laboratory.

Subjects: Male Balb/c mice.

Interventions: Mice were challenged with intratracheal Escherichia coli or granulocyte colony-stimulating factor (G-CSF). Bone marrow cells were isolated from normal mice and treated in vitro with G-CSF.

Measurements and main results: Bronchoalveolar lavage fluid concentrations of G-CSF, macrophage inflammatory protein-2, and keratinocyte-derived chemokine were elevated 3 and 6 hrs after intratracheal E. coli. The increases in intrapulmonary G-CSF and keratinocyte-derived chemokine were associated with increases of their concentrations in the plasma. The numbers of granulocyte-macrophage colony forming units in bone marrow, spleen, and blood were increased 48 hrs after intratracheal E. coli or G-CSF. In addition, plasma G-CSF and the number of progenitor cells (lin-ckit+Sca-1(-)) in the blood were increased at 30 mins and 48 hrs, respectively, following intratracheal G-CSF. Signal transducer and activator of transcription-3 in bone marrow cells was activated following intratracheal E. coli or G-CSF in addition to activation by in vitro G-CSF stimulation.

Conclusions: During pulmonary infection, locally produced cytokines enter the circulation and may play an important role in initiating a granulopoietic response.

Publication types

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

MeSH terms

  • Animals
  • Chemokine CXCL2
  • Chemokines / metabolism
  • Disease Models, Animal
  • Escherichia coli Infections / blood*
  • Escherichia coli Infections / immunology
  • Granulocyte Colony-Stimulating Factor / metabolism
  • Granulocytes / metabolism*
  • Hematopoiesis
  • Lung / immunology
  • Lung / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Monokines / metabolism
  • Myeloid Progenitor Cells / metabolism*
  • Phosphorylation
  • Pneumonia, Bacterial / blood*
  • Pneumonia, Bacterial / immunology


  • Chemokine CXCL2
  • Chemokines
  • Monokines
  • Granulocyte Colony-Stimulating Factor