L2 Flashcards
Explain the mucosal layers for barriers
Outer lauer is the non aterile part where microbiota utilise the wf carbs from the mucin glycoprotein.
Inner layer is mroe sterile, fontains secretions like amps, cytokines, iga etc , lectins for mbl
Surface mucus is mucin which is o glycosylated part of the glycocalyx on epithelial cells surface
Whoch crlls ade in the crypt of villi
Paneth which wre singly differentiated
What did lei et al 2019 find aboout amps
2 groups defensins and cathelicidins
A defensins are the major troup in si by paneth cells
All stabilised cationic proteins wirh 3 s-s bonds
Anchor to membrqne to form pores
What did smith 2013 find about leukocytes role with goblet cells
Induce goblet cell hyperplasia eg via th1 and th2 xytokines allowing more mucus production
What did mcguckin et al 2011 find about mucins
Cell surface mucons are o glycosylated and prefent psthogen adhesion
Microbiota influence ratw of mucin production eg goblet cell proliferation
Mucin in small intestine usually muc2 producing mucus
What are inductive sites
Where ag is captured and presented to naive b and t cells wg in the peyers patch within the SI
Where do immune cells need to migrate to from inductive sites
Effector sites where its rhe place of origin eg lamina propria elsewhere or exocrine glands/salivary or mammary
What are epithelial cells due to tight junctions
Polarised apical facing thr air or gut lumen (villi)
Or basolateral side facing basement membrane and lamina propria and below blood circulation
What is the importwnce of lamina propria connective tissue
Parts of ecm like collagen needed to maintain the mcuosal epithelial barrier
Whoch deficeicy causes lack of collagen in LP
Vitamin c eg via scurvy
What is cell trafficking in mucosal battier
Transcytosis
Explain briefly how traffickint can occur eg from baso to apical when iga secreted
Receptor endocytosis, into early endosome then either dehrwded in lysosome, recycled or goes to apucal via transcyotsis in vesicle
Which 2 cells can do antigen sampling (presentint ag through the epithelial barrier to the malt)
M cells or cross epithelial dendritic cells
Ehat are m cells and how do they work
Specialised epi cells in the galt which endocytose or phagocytose ag. Then undergoes transcytosis to the basolateral side for ag presentation
How do cross epithelial crlls do antigen sampling
Theough their extensions can etebd to the gut lumen and then present them in basolateral side
What did miller 2007 find about m cells
They detect ag throygh cellular prion protein receptors
How is the barrier ovetcome by another solution in immune function
Iga, igm and igg and igd can be transcytosed to the lumen
What is malt
Mucosa associated lympoid tissue. Where adaptice response begins
Where is NALT
nasopharyngeal. Forms ring around mouth airway and gut.
In adenoids and tonsils
Which malt is onlt present in chuodren
BALT in respiratory tract bronchus
Where in the gut is malt
Peyers patch (below the epithelial barrier)
Which mucosa area has no malt to protect embryo
Urogenital tract
What is needed in mucosal immune sites to blockninflammation
Suppresive mechanisms eg by microbiota
What did holmgren 2005 find about mucosal suppression
Insuction of t regs, anergy of T cells, cd8 IEC have tolerance , increased il 10 supprwssive cytokine
