52 - Communication libre
Transplantation and regeneration
3 juin 2021, 13:50 - 15:20, Stream 4: Video Invited, SST, SSCViscérale & ARS
Systemic effect of peritoneal cavity macrophages
L. Salm, D. Candinas, D. Stroka, G. Beldi, Presenter: L. Salm (Bern)
The skin protects internal tissues from mechanical damage, microbial infection, ultraviolet radiation and extreme temperature, therefore early repair of the skin is a fundamental goal of our organism. Peritoneal cavity macrophages contribute to inflammatory and reparative responses during infection and are known for their properties of intraabdominal wound healing. We have observed accelerated wound healing after simultaneous activation of the peritoneal macrophages.
Peritoneal activation skin injury (PASI) model was performed in 8-10-week old female mice (C57/BL6). The wound closure rate was calculated using the equation [(Ai-Af)/Ai], where Ai represents the initial wound area and Af represents the final wound area. Peritoneal macrophages were depleted by the i.p administration of 100ul Clodronate-loaded liposomes. Tissue and blood were harvested at 2 hours, 6 hours and 24 hours for flow cytometry, histology, bulk sequencing and cytokine mesoscale assay.
Significant accelerated skin wound healing rate after sterile or infectious activation of peritoneal cavity macrophages. This accelerated wound healing phenotype is impaired in germfree mice versus colonized mice. Cytokine mesoscale assay revealed significant higher serum IL-21 two hours after activation of peritoneal macrophages trough sterile injury. In vivo IL-21 neutralization impaired the fast wound healing phenotype. Cutaneous healing was impaired after depletion of peritoneal cavity macrophages and restored by adoptive transfer of large peritoneal macrophages. Tracking of peritoneal macrophages using adoptive transfer of CD45.1+ peritoneal cells revealed invasion of such macrophages in the wound.
Here we demonstrate the systemic effect of cavity macrophages.