Project description:This study dermined the temporal gene expression profile of myeloid subpopulations recruited to the peritoneal cavity to encapsulate implanted foreign material.
Project description:This study dermined the temporal gene expression profile of myeloid subpopulations recruited to the peritoneal cavity to encapsulate implanted foreign material. Sterile foreign objects were inserted into the peritoneal cavities of MacGreen mice (in which the Csf1r promoter directs myeloid-specific EGFP expression). At various time-points post-surgery (days 2, 4, 7, 14), mice were euthanased, and peritoneal exudate cells removed by lavage. Peritoneal exudate cells from MacGreen mice that had not received implants were used as controls (day 0; 'unstimulated'). Free-floating objects encapsulated with tissue were removed from the peritoneal cavities of different mice at days 7, 14, 21, 28 days, and single cell suspensions obtained by collagenase digestion. Single-cell suspensions from peritoneal exudate or tissue capsules were separated on the basis of size/granularity and EGFP fluorescence using FacsVantage SE Diva. Total RNA was extracted from FACS-sorted EGFP-hi cells.
Project description:Polypropylene meshes that are commonly used for surgical groin hernia repair may trigger granulomatous foreign body reactions. Here, we show that asymptomatic patients display mesh-associated inflammatory granulomas long after surgery, which are dominated by monocyte-derived macrophages. In mice, subdermal mesh implantation induces a rapid and strong myeloid cell accumulation, without substantial attenuation for up to 90 days. Myeloid cells segregate into distinct macrophage subsets with separate spatial distribution, activation profiles and functional properties. Protein mass spectrometry confirms the inflammatory nature of the foreign body reaction, as characterized by cytokines, complement activation and immunoglobulin deposition.
