Surfactant protein D modulates pulmonary clearance of pollen starch granules

Exp Lung Res. 2010 Nov;36(9):522-30. doi: 10.3109/01902141003790148.

Abstract

Pollen starch granules (PSGs) are allergen particles that get into contact with pulmonary surfactant and phagocytes in the terminal airways. In this study, the effects of surfactant protein D (SP-D) on the interaction of PSGs with phagocytes and on the pulmonary clearance of PSGs were determined. Fluorescently labeled PSGs were incubated in vitro with murine lung macrophages or dendritic cells (DCs) ± recombinant rat SP-D (rrSP-D). In addition, the effect of SP-D on uptake of PSGs by lung macrophages and DCs was studied in vivo. Furthermore, PSGs were instilled in Balb/c mice and the effects of SP-D on total lung clearance were assessed by optical imaging. SP-D treatment increased the number of PSG-positive macrophages and DCs in vitro. Furthermore, SP-D accelerated uptake/binding by alveolar macrophages and reduced the number of PSG-positive tissue macrophages and DCs at 24 hours. However, SP-D did not affect total lung clearance of PSGs and it did not enhance the T-cell proliferation induced by PSG-positive DCs. In conclusion, SP-D increased PSG-positive cells in vitro and accelerated PSG binding/uptake in vivo. The observed effects were limited to cellular clearance mechanisms and did not affect the total clearance of PSGs from the lung.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / immunology
  • Allergens / metabolism*
  • Animals
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Female
  • Flow Cytometry
  • Lung / drug effects*
  • Lung / immunology
  • Lung / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Fluorescence
  • Mucociliary Clearance / drug effects*
  • Phagocytosis / drug effects
  • Phagocytosis / immunology
  • Pollen / immunology
  • Pollen / metabolism*
  • Pulmonary Surfactant-Associated Protein D / pharmacology*
  • Rats
  • Recombinant Proteins
  • Starch / immunology
  • Starch / metabolism*
  • T-Lymphocytes / cytology
  • T-Lymphocytes / drug effects

Substances

  • Allergens
  • Pulmonary Surfactant-Associated Protein D
  • Recombinant Proteins
  • Starch