The Chameleon Within: Improving Antigen Delivery

摘要

The spaces inside the gut and the lungs are continuous with the outside world, exposing the adjacent tissues to toxic and pathogenic threats from the environment. The body protects these tissues by lining the airways and intestines with a single layerof epithelial cells, joined cell to cell by gasketlike intercellular tight junctions. This surface barrier protects the organism, but also prevents the efficient uptake of environmental antigens that is required for successful oral vaccination and immunization. Normally, antigens and pathogens in the gut can only penetrate the barrier through infrequent gateway cells called M cells. Now on page 949 of this issue, Kernels ea al. (I) point the way toward manipulating these essential participants of the immunization process. The authors describe how to stimulate the conversion of the epithelial cells that normally line .the intestine (enterocytes) to an M cell lineage, which can efficiently transport antigens across the intestinal barrier to the underlying immune system.