Dynamics of neutrophil infiltration during cutaneous wound healing and infection using fluorescence imaging

J Invest Dermatol. 2008 Jul;128(7):1812-20. doi: 10.1038/sj.jid.5701223. Epub 2008 Jan 10.

Abstract

Neutrophil influx is an early inflammatory response that is essential for the clearance of bacteria and cellular debris during cutaneous wounding. A non-invasive real-time fluorescence imaging technique was developed to examine the kinetics of enhanced green fluorescence protein-polymorphonuclear leukocyte (EGFP-PMN) influx within a wound. We hypothesized that infection or systemic availability would directly regulate the dynamics of EGFP-PMN recruitment and the efficiency of wound closure. Neutrophil recruitment increased dramatically over the first 24 hours from 10(6) at 4 hours up to a maximum of 5 x 10(6) EGFP-PMNs at 18 hours. A high rate of EGFP-PMN turnover was evidenced by approximately 80% decrease in EGFP signal within 6 hours. In response to wound colonization by Staphylococcus aureus or injection of GM-CSF, systemic PMNs increased twofold above saline control. This correlated with an increase in EGFP-PMN recruitment up to approximately 10(7) within the wound. Despite this effect by these distinct inflammatory drivers, wound closure occurred at a rate similar to the saline-treated control group. In summary, a non-invasive fluorescence-based imaging approach combined with genetic labeling of neutrophils provides a dynamic inner view of inflammation and the kinetics of neutrophil infiltration into the wounded skin over extended durations.

Publication types

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

MeSH terms

  • Animals
  • Female
  • Fluorescence
  • Granulocyte-Macrophage Colony-Stimulating Factor / pharmacology
  • Mice
  • Mice, Inbred C57BL
  • Neutrophil Infiltration*
  • Skin / pathology*
  • Staphylococcal Skin Infections / immunology*
  • Wound Healing / immunology*

Substances

  • Granulocyte-Macrophage Colony-Stimulating Factor