Intestinal uptake of amyloid B protein through columnar epithelial cells in suckling mice

The mechanism of transmission of amyloid protein, especially the dynamics in the intestine, is still largely unknown. In the present study, a fusion protein (Aß-EGFP) that combined enhanced green fluorescent protein with amyloid-ß protein (Aß) was orally administered to mice before and after weaning, and the uptake and kinetics of amyloid protein within the intestine were elucidated through histopathology. Aß- EGFP was incorporated into the cytoplasm of columnar epithelial cells, rather than M cells, at 3 h after administration and thereafter. Aß-EGFP then accumulated in the crypt, Peyer's patch, and even the spleen. However, this uptake was not observed in weaned mice. These results suggest that a specific tolerant mechanism for incorporation of Aß escaped from the digestion exists during suckling periods. This age-dependent uptake is important for estimating the risk of transmission