Oral and Intestinal Mucosal Immune System Flashcards
describe the epithelial layer of the oral mucosa
stratified squamous epithelium instead of a single layer
describe the lamina propria of the oral mucosa
a thin layer of connective tissue rich in vascular networks, lymphatic vessels and immune cells and a key place for immune responses
describe the mucosal-associated lymphoid tissue (MALT) of the small intestines and oral pharyngeal cavity
- peyers patches
- organized lymphoid follicles (tonsils and adenoids)
what cells are present within the epithelial layer that contribute to innate immunity?
- microfold cells
- tuffs cells
- paneth cells
what are microfold cells?
cells that transfer antigens to antigen presenting cells
what are tuffs cells?
chemosensor cells
what are paneth cells?
cells that secrete antimicrobials only in the small intestines
how do NK cells and ILCs in the epithelium act as sentinels at the frontline of the innate immune response?
quickly producing IFN-gamma in response to pathogens
what are the 3 functional subsets of ILCs and which T helper cells are they most similar to?
ILC1 most similar to Th1
ILC2 most similar to Th2
ILC3 most similar to Th17
what are the two ILCs that are the major subsets in the oral cavity? in the intestines?
- ILC1 and ILC3 are major subsets in the oral mucosa
- ILC2 are in the intestines not the oral cavity
what are peyers patches?
group of well-organized lymphoid follicles located in the lamina propria and submucosa of the distal portion of the small intestine—the ileum and jejunum and sometimes in the duodenum
what is the T cell response in the small intestine?
Dendritic Cells (DCs) in the lamina propria extend dendrites into the gut epithelium to capture antigens and then migrate to Peyer’s patches, where they present the antigens to naive T cells, priming them for an immune response.
where are T-alpha-beta lymphocytes primarily found?
parafollicular zone of Peyer’s patches
what is the role of T helper 17 and T-gamma-delta?
Produce IL-17, a potent pro inflammatory cytokine important for defense against fungi (e.g., Candida) and controlling oral diseases like periodontitis and candidiasis
where are B lymphocytes primarily located?
in the germinal centers of lymphoid follicles, such as those in Peyer’s patches and other mucosal tissues.
what happens to the IgM-producing B cells within the lamina propria?
they differentiate into IgA-secreting plasma cells that produce immunoglobulin A (IgA), which is crucial for mucosal immunity.
which pathways of the complement system can IgA activate?
only the alternative and lectin pathways
in the intestinal tract, what must the immune system have?
tolerance to the normal intestinal flora, yet respond to pathogenic microorganisms
what is the role of Treg cells in the intestinal tract?
play a critical role in maintaining immune tolerance and preventing excessive immune responses as well as maintain a delicate balance between active immunity and immunological tolerance
what is the role of TGF-beta in the intestinal tract?
stimulates the production of IgA antibodies, which maintain the mucosal immunity.
