Modifications of the follicle-associated epithelium by short-term exposure to a non-intestinal bacterium

J Pathol. 1996 Nov;180(3):326-32. doi: 10.1002/(SICI)1096-9896(199611)180:3<326::AID-PATH656>3.0.CO;2-6.


This study was undertaken in order to study the effects of short-term exposure of the follicle-associated epithelium (FAE) of rabbit Peyer's patches to a non-intestinal, Gram-positive bacterium. Isolated ileal loops, each containing one Peyer's patch (PP), were stimulated for short periods of time (30 and 60 min) with Streptococcus pneumoniae R36a, a micro-organism normally not present in the intestinal area. Samples from antigen-stimulated and control Peyer's patches were analysed by light (LM), transmission electron (TEM), and scanning electron microscopy (SEM). Stimulation with living pneumococci induced dramatic changes in FAE architecture and morphology. A massive passage of cells from lymphoid tissue to the FAE was rapidly detectable, accompanied by alterations of the FAE surface, with a marked increase of M-cell area. Furthermore, TEM analysis revealed that M cells were able to internalize living pneumococci. S. pneumoniae R36a is a valid experimental model for the further study of the unique antigen sampling function which characterizes the highly specialized FAE in Peyer's patches.

MeSH terms

  • Animals
  • Antigens, Bacterial / immunology*
  • Immunity, Mucosal
  • Intestinal Mucosa / immunology*
  • Intestinal Mucosa / ultrastructure
  • Male
  • Microscopy, Electron
  • Microscopy, Electron, Scanning
  • Models, Immunological
  • Peyer's Patches / immunology*
  • Peyer's Patches / ultrastructure
  • Rabbits
  • Streptococcus pneumoniae / immunology*


  • Antigens, Bacterial