Lympho-epithelial interactions in the turtle Chrysemys scrypta elegans.

The morphological relationships present in the areas of lymphoid infiltration found in the esophagus in Chrysemys scripta elegans were studied by the use of light and transmission electron microscopy. These infiltrations are widespread and can be observed in the lamina propria and the covering epithelium. Electron microscopy reveals the presence of epithelial cells with differing characteristics at the apex of the lymphoid infiltrations. The introduction of horseradish peroxidase (HRP) into the esophageal lumen revealed that these cells possess a micropinocytotic activity. On the basis of the morphological and experimental results obtained, a hypothesis is advanced of the existence, also in the turtle, of a local system of uptake of extraneous material, which induces local and systemic immunological processes.