Oral Delivery of Transformed Yeast Cells into the Mouse Intestinal Immune System

Begin with an oral tube containing a suspension of genetically transformed, auxotrophic yeast that are unable to produce uracil nucleobase.

Insert the oral tube into the mouth of a restrained mouse and guide it down to the stomach.

Administer the yeast suspension directly into the stomach, allowing it to eventually reach the small intestine.

The small intestine contains epithelial cells, with underlying Peyer's patches rich in immune cells.

Microfold cells, specialized intestinal epithelial cells near the Peyer's patches, engulf the yeast cells and internalize them into vesicles.

These vesicles move across the cells and release yeast cells into the underlying Peyer's patch.

Isolate the Peyer's patch from the sacrificed mouse intestine and obtain a uniform cell suspension.

Culture this cell suspension on a yeast-selective medium containing uracil.

Auxotrophic yeast utilizes the uracil and multiplies to form colonies, confirming the delivery of transformed yeast cells into the mouse intestinal immune system.