Medical Wikipedia : The Medical Encyclopedia
Microfold Cells
Microfold Cells or M Cells
Where the M Cells present?
Microfold Cells or M Cells are present in follicle-associated epithelium (FAE)
Follicle -associated epithelium is a specialized epithelium present over Peyer’s patch in small intestine and isolated lymphoid follicles.
M cells are seen in epithelial cells of the mucosa-associated lymphoid tissues.
What is function of the M Cells?
M cells helps to transport antigens from intestinal lumen to immune system cells, and starts
an immune response or tolerance.
M cells function are phagocytosis and transcytosis. M cells are capable of taking up large particulate antigens from the lumen and transporting them intact into the subepithelial space.
What is function of the M Cells in polio virus infection?
M cells express lectin-like molecules in the apical surface. These molecules help to promote binding to specific pathogens such as poliovirus.
What is the mechanism where M cells involved with IgA response in payer patches?
Antigens that bind to the M cell and are transported to the underlying Peyer patches generally elicit a positive (IgA) response.
M cell helps to connect Peyer patches and lymphoid follicles as conduit.
Once antigens enter the Peyer patch, TGF-β-secreting T cells promote B cell isotype switching to IgA.
If Peyer patch B cells are absent then M cells are also absent. [M cells have not seen in B cell–deficient animals, which lack Peyer patches]
Peyer patches have T cell-dependent areas and B cell-dependent/germinal centers typical of lymph nodes, but only efferent lymphatics.