Microfold cell

In M cells (M eng for microfold; . Fold = "fold", micro = " small" ) are specialized epithelial cells in the wall of the small intestine (ileum ), a part of the small intestine and the tonsils occur. They play an important role in the functioning of the immune system.

Occurrence

M cells are part of the so-called follicle -associated epithelium ( FAE), which covers the Peyer's patches, and tonsils. About 10-15 % of the surface of the follicle -associated epithelium is formed by M cells. The rest of the FAE is dominated primarily by slime-forming goblet cells and columnar epithelial cells. The M cells probably go as the rest of the intestinal epithelium produced from stem cells in the crypts. In the differentiation probably among other B- lymphocytes play cell-cell contacts play a role. More M cells occur together with Langerhans cells in the FAE of all tonsils.

Morphology

M cells differ morphologically from the rest of the epithelium of the ileum and from the follicle -associated epithelium ( FAE). They have at the apical side ( towards the gut lumen ), only a small number of microvilli, which are in contrast to those of other cells, and partially branched shorter. The apical side is characterized by many small folds, which are eponymous for the M- cells. The basal side of the M cells ( from the gut lumen path ) is characterized by a plurality of indentations. About this indentations are the T- and B- lymphocytes of the Peyer's patches as well as dendritic cells and macrophages in close contact with the M cells.

Function

The M- cells play an important role in the function of the MALT system (mucosa associated lymphoid tissue, engl. For " mucosa - associated lymphoid tissue" ), which includes among others, the Peyer's patches, and thus also for the immune system. The M cells take on their apical side to antigens via endocytosis. To antigens that can include M- cells, include, apart macromolecules and bacteria, viruses and parasites smaller. Which antigens are released to the basal side of the cells of the adaptive immune system. The exact mechanism is not yet clear. Is also unclear whether the M- cells a processing of antigens takes place and whether and how the antigens are presented to the effector cells of the immune system. Appears to be a major part of the apically captured antigens is unprocessed transported via vesicular transport to the basal and released by exocytosis. About the M- cells, the orally administered vaccines are absorbed into the body.

Swell

  • Thomas Hein Zeller, Carl M. Busing: histology, histopathology and cytology for the entry. Georg Thieme Verlag, 2001, pp. 152 ISBN 978-3-13-126831-0
  • Georg A. Holländer ( eds.): Immunology: Principles for Medical Devices Elsevier, 1st Edition 2005, p 215 ff ISBN 978-3-437-21301-4
  • Detlev Ganten, Klaus jerk Paul: Handbook of Molecular Medicine, 12 vols, Volume 4: Immune System and Infectious Diseases. Springer. -Verlag, 1 edition (1999 ), pp. 107 ff ISBN 978-3-540-62464-6
  • Cell type
  • Small intestine
  • Gastroenterology
  • Immunology
  • Epithelium
Peyer's patch Cellular differentiation B cell Mucosa-associated lymphoid tissue Plasma cell
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