Intratracheal administration of liposomal clodronate accelerates alveolar macrophage reconstitution following fetal liver transplantation

M. Brett Everhart, Wei Man, Kelly S. Parman, Vasiliy V. Polosukhin, Heng Zeng, Ruxana T. Sadikot, Bo Li, Fiona E. Yull, John W. Christman, Timothy S. Blackwell

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

To facilitate study of alveolar macrophages in vivo, we developed a method to rapidly and efficiently replace resident alveolar macrophages with macrophages of a different (donor) genotype. Chimeric mice were generated by lethal irradiation followed by fetal liver transplantation (FLT) using green fluorescent protein (GFP) transgenic reporter mice as donors. Kinetics of peripheral blood monocyte (PBM) and alveolar macrophage reconstitution was determined 4 and 10 weeks post-FLT by quantifying the percentage of GFP+ cells. To enhance the recruitment of donor monocytes into the lung after FLT, mice were treated with intratracheal administration of liposomal clodronate to deplete host alveolar macrophages at 6 weeks post-FLT. PBM reconstitution occurred by 4 weeks after FLT (85.7±1.6% of CD11b+/Gr-1+ monocytes were GFP+), and minimal alveolar macrophage repopulation was observed (9.5% GFP+). By 10 weeks following FLT, 48% of alveolar macrophages were GFP+ by immunostaining of macrophages on lung tissue sections, and 55.1 ± 1.6% of lung lavage macrophages were GFP+ by fluorescein-activated cell sorter analysis. Clodronate treatment resulted in a significant increase in GFP+ alveolar macrophages 10 weeks after FLT. By immunostaining, 90% of macrophages were GFP+ on lung tissue sections and 87.5 ± 1.1% GFP+ in lung lavage (compared with GFP-transgenic controls). The ability of newly recruited alveolar macrophages to clear Pseudomonas aeruginosa and activate nuclear factor-κB in response to Eschericia coli lipopolysaccharide demonstrated normal macrophage function. Optimizing this methodology provides an important tool for the study of specific genes and their contribution to alveolar macrophage function in vivo.

Original languageEnglish (US)
Pages (from-to)173-180
Number of pages8
JournalJournal of Leukocyte Biology
Volume77
Issue number2
DOIs
StatePublished - Feb 2005
Externally publishedYes

Keywords

  • Chimera
  • Green fluorescent protein
  • Lung
  • Mouse transgenic

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Cell Biology

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