title: Cellular plasticity of inflammatory myeloid cells in the peritoneal foreign body response.
abstract: Implantation of sterile foreign objects in the peritoneal cavity of an animal initiates an inflammatory response and results in encapsulation of the objects by bone marrow-derived cells. Over time, a multilayered tissue capsule develops with abundant myofibroblasts embedded in extracellular matrix. The present study used the transgenic MacGreen mouse to characterize the time-dependent accumulation of monocyte subsets and neutrophilic granulocytes in the inflammatory infiltrate and within the tissue capsule by their differential expression of the csf1r-EGFP transgene, F4/80, and Ly6C. As the tissue capsule developed, enhanced green fluorescent protein-positive cells changed from rounded to spindle-shaped morphology and began to co-express the myofibroblast marker alpha-smooth muscle actin. Expression increased with time: at day 14, 11.13 +/- 0.67% of tissue capsule cells co-expressed these markers, compared with 50.77 +/- 12.85% of cells at day 28. The importance of monocyte/macrophages in tissue capsule development was confirmed by clodronate-encapsulated liposome removal, which resulted in almost complete abrogation of capsule development. These results confirm the importance of monocyte/macrophages in the tissue response to sterile foreign objects implanted in the peritoneal cavity. In addition, the in vivo plasticity of peritoneal macrophages and their ability to transdifferentiate from a myeloid to mesenchymal phenotype is demonstrated.
authors.affiliation: Centre for Research in Vascular Biology, Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St. Lucia, QLD 4072, Australia.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Mooney
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Rolfe
authors.forename: Geoffrey W
authors.initials: GW
authors.lastname: Osborne
authors.forename: David P
authors.initials: DP
authors.lastname: Sester
authors.forename: Nico
authors.initials: N
authors.lastname: van Rooijen
authors.forename: Gordon R
authors.initials: GR
authors.lastname: Campbell
authors.forename: David A
authors.initials: DA
authors.lastname: Hume
authors.forename: Julie H
authors.initials: JH
authors.lastname: Campbell
mesh_terms: D000818:Animals; D002465:Cell Movement; D048430:Cell Shape; D054338:Cell Transdifferentiation; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D005547:Foreign Bodies / Q000473:pathology; D005549:Foreign-Body Reaction / Q000473:pathology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D020007:Implants, Experimental; D008264:Macrophages / Q000166:cytology; D008297:Male; D051379:Mice; D022423:Myeloid Cells / Q000473:pathology*; D010529:Peritoneal Cavity / Q000473:pathology*; D010533:Peritoneal Lavage
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins