Reduced expression of SLA Class 1 antigens by intestinal epithelium of newborn piglets

Expression of major histocompatibility complex Class 1 by the small intestine mucosa of piglets was compared by indirect immunofluorescence during the 4 days following birth with both maternal and artificial feeding. The duodenal epithelium did not express Class 1 antigen during these 4 days. The jejunal epithelium did not express Class 1 antigen at Day 0 after birth but expression developed from Day 1. However ileal epithelium expressed Class 1 antigen throughout the study period. In constrast, cells from the lamina propria of all samples expressed Class 1 antigen. There was no difference between piglets receiving maternal colostrum and artificially reared piglets. This lack of Class 1 expression occurs at a time when the intestinal epithelium constitutes an interface between piglet and colostral maternal cells. This can be of biological relevance for mother-newborn interactions.