Peyer's patches constitute both an inductive immune site and an enteropathogen invasion route. Peyer's patch mucosae from porcine jejunum were mounted in Ussing chambers, and either Salmonella choleraesuis vaccine strain SC-54 or non-pathogenic rodent and porcine Escherichia coli strains contacted the Peyer's patch mucosa for 90 min. Internalized bacteria were quantified by a gentamicin resistance assay. Monodansylcadaverine (300 μM, luminal addition), an inhibitor of clathrin-mediated endocytosis, significantly inhibited internalization of both E. coli strains relative to tissues untreated with the inhibitor; internalization of SC-54 was unaffected. The actin-disrupting agent cytochalasin D (10 μM, luminal addition), inhibited internalization of pig-adapted E. coli but not that of rodent-adapted E. coli or SC-54. Internalization of SC-54 and non-pathogenic E. coli in Peyer's patches appears to occur through different cellular routes.
Bibliographical noteFunding Information:
This work was supported in part by National Institutes of Health grants R01 DA-10200 and T32 DA-007239. The authors thank Dr. Carol L. Wells (Department of Laboratory Medicine and Pathology, University of Minnesota) for generously providing the M-21 strain of E. coli for this investigation, Dr. Sanford Weisberg (University of Minnesota Statistical Consulting Service) for expert advice on data analysis and Lisa Price for excellent technical assistance.
- Cytochalasin D
- Escherichia coli
- Intracellular internalization
- Mucosal immunity
- Salmonella choleraesuis