Confocal Imaging of Trans‐epithelial Trafficking by Immune and Umbilical Cord Stem Cells in the Neonatal Porcine Intestine

Abstract

Maternal colostral leucocytes (CL) and peripheral blood mononuclear cells (PBMC) enter the neonatal circulation after ingestion in pigs and cattle. Porcine umbilical cord matrix stem cells (PUCs) are relatively non-immunogenic after initial allogeneic transplantation. Using intestinal explant cultures incubated with labelled cells and confocal microscopy, we demonstrated trans-epithelial trafficking of exogenous CL, PBMC and PUCs below the luminal surface after 72 h of culture. We orally administered PBMC and PUCs to pre-colostral neonatal pigs and tracked their location 8 or 24 h later. Both PBMC and PUCs were found in the intestinal wall of all samples. Exposure to 25% of acellular colostrum had no detected effect on trafficking. Labelled PUCs and PBMC were detected on the surface of the epithelium and in the lamina propria 8 h post-treatment and PBMC were also in the superficial submucosa. At 24 h, PUCs and PBMC were observed on the surface of the epithelium, in the lamina propria, superficial submucosa and deep submucosa. Our findings show the potential of PUCs for allogeneic engraftment in the neonatal intestine and may lead to cell-based delivery of therapeutics.