Background & Aims-Lymphoepithelial interactions in the gut can occur in the epithelium and the sub-epithelial space. We asked whether Normal, Crohn's Disease (CD) or Ulcerative colitis (UC) lamina propria lymphocytes (LPL) could promote intestinal epithelial cell (IEC) growth and differentiation.

BACKGROUND-CEACAM1, CEACAM5 and CEACAM6 represent three of the CEACAM subfamily members expressed on intestinal epithelial cells (IECs). Deficiency in their expression, as seen in inflammatory bowel disease (IBD), results in the lack of activation of CD8+ regulatory T cells in the mucosa. Since CEACAM expression was shown to be regulated by the transcription factor SOX9, we sought to determine whether the defect in CEACAM expression in IBD was related to aberrant SOX9 expression.