Effect of mature lymphocytes and lymphotoxin on the development of the follicle-associated epithelium and M cells in mouse Peyer's patches.
Journal - Gastroenterology (United States )
BACKGROUND AND AIMS: Mechanisms regulating M-cell formation are still poorly understood. In vitro studies showed that lymphocytes trigger the conversion of enterocyte cell lines into M cell-like cells on coculture, whereas in vivo their role in M cell differentiation is still elusive. Our aim was first to examine Rag-1-/- mice, lacking B and T lymphocytes, for the presence of intestinal M cells. Second, we investigated the role of lymphotoxin alphabeta signaling on M-cell formation, given its pivotal role in the development of mouse Peyer's patches. METHODS: Small intestines of Rag-1-/- mice, injected or not with soluble lymphotoxin beta receptor-immunoglobulin fusion protein, were analyzed morphologically using whole mount cytochemical staining, immunohistochemistry, and electron microscopy. RESULTS: Small Peyer's patch-like aggregates were found in Rag-1-/- mice in normal number and location. The overlying epithelium of such aggregates was reduced in size but still harbored M cells. In vivo neutralization of lymphotoxin beta-receptor signaling partially reduced the percentage of M cells. CONCLUSIONS: The absence of mature lymphocytes does not prevent the formation of M cells, indicating that the signaling molecules that support M-cell differentiation, such as lymphotoxin alphabeta, may also be supplied by non-B and non-T cells. Mature B lymphocytes, however, are required for the formation of a full-sized follicle-associated epithelium.
|ISSN : ||0016-5085|
|Mesh Heading : ||Animals B-Lymphocytes Cell Differentiation Female Homeodomain Proteins Intestinal Mucosa Intestine, Small Lymphotoxin beta Receptor Lymphotoxin-alpha Male Mice Mice, Inbred C57BL Mice, Knockout Mice, Nude Microscopy, Electron Microscopy, Electron, Scanning Peyer's Patches Receptors, Tumor Necrosis Factor Signal Transduction T-Lymphocytes immunology genetics ultrastructure cytology immunology ultrastructure immunology immunology|
|Mesh Heading Relevant : ||immunology immunology immunology immunology immunology|
Development of Peyer's patches, follicle-associated epithelium and M cell: lessons from immunodeficient and knockout mice.
Journal - Seminars in immunology (UNITED STATES )
Studies with immunodeficient and knockout mice have revealed that the development of mucosa-associated lymphoid tissues (MALT) and peripheral lymphoid nodes share common mechanisms, but also require distinct signals. Gene disruption of lymphotoxins or their cognate receptors affects both Peyer's patch and lymph node organogenesis. Disruption of the osteoprotegerin TNF-family member gene does not impair Peyer's patch development, but prevents formation of peripheral lymph nodes. Peyer's patch do not form in mice with a deleted gene encoding a B lymphocyte-specific chemokine receptor, while most peripheral lymph nodes, except inguinal, are normal in numbers and architecture. In B or T lymphocyte-deficient mice, Peyer's patches, with their overlying follicle-associated epithelium (FAE), are present although reduced in number and size. No Peyer's patches develop in RAG deficient mice. Formation of FAE with typical M cells has not been analyzed in these mice. M cell formation requires the close association of immune cells with differentiated enterocytes and their conversion appears to be transcriptionally regulated. The development of MALT, FAE and probably M cells is a multistep process that requires signalling pathways common to all secondary lymphoid tissues, but also MALT-specific factors.Copyright 1999 Academic Press.
|ISSN : ||1044-5323|
|Mesh Heading : ||Animals Cell Division Epithelial Cells Intestinal Mucosa Lymphoid Tissue Male Mice Mice, Knockout Mice, SCID Mucous Membrane Peyer's Patches cytology immunology immunology|
|Mesh Heading Relevant : ||cytology cytology cytology|