Actin accumulation at sites of attachment of indigenous apathogenic segmented filamentous bacteria to mouse ileal epithelial cells.

Selective attachment of indigenous, apathogenic, segmented filamentous bacteria to follicle-associated epithelia of terminal ileal Peyer's patches involves both the specialized M cells and normal enterocytes. A striking, highly localized cytoplasmic accumulation of polymerized actin, which resembles that associated with adherence of enteropathogenic Escherichia coli to cultured epithelial cells, occurs at attachment sites of segmented filamentous bacteria. The epithelial response to the attachment of microorganisms may thus involve mechanisms which are the same for diverse microorganisms.