CD1D IS INVOLVED IN T-CELL INTESTINAL EPITHELIAL-CELL INTERACTIONS

We assessed the role of the nonclassical class I molecule, CD1d, in th e interaction between intestinal epithelial cells and T cells. In a mi xed lymphocyte reaction (MLR) system where the stimulator cells were i rradiated normal intestinal cells, the anti-CD1d monoclonal antibody ( mAb) 3C11 inhibited T cell proliferation. In contrast, no inhibition w as seen when mAb 3C11 was added to conventional MLR cultures (non T ce ll stimulators). Furthermore, no inhibition was seen when either airwa y epithelial cells were used as stimulator cells or lamina propria lym phocytes were used as responder cells. These latter two conditions alo ng with a conventional MLR favor CD4+ T cell proliferation. However, w e have previously shown that normal intestinal epithelial cells stimul ate CD8+ T cells under similar culture conditions. Thus, CD1d expresse d on intestinal epithelial cells may be an important ligand in CD8+ T cell-epithelial cell interactions.