Heather L. lamina propria lamina propriadendritic cell sampling of lumenal antigens by extension of their processes between epithelial cells whilst maintaining barrier integrity through the expression of tight junction (TJ) proteins  and (2) uptake across the characteristic follicle-associated epithelium (FAE) made up of microfold (M) cells . These specialized thin epithelial cells transfer effectively soluble, and especially particulate, antigens such as microorganisms from your lumen to dendritic cell ; (3) further, at least in mice, there is evidence that goblet cells deliver luminal antigen to dendritic cells in the small intestine . Thus, you will find multiple mechanisms by which antigen can traverse the gut wall. A single layer of epithelial cells separates the apical and basolateral domains of the gut mucosa, and intercellular transport is usually regulated by complexes of TJ proteins, adherens, and desmosomes. Of these protein complexes, TJ proteins are located at the AGN 205327 most apical side and play a central role in regulating permeability through the intercellular space within epithelial linens [28C30]. TJs are composed of numerous structural and functional proteins including occludin and Claudin family members [31, 32] which together form a selectively permeable intercellular barrier . Claudin family members have different expression pattern depending on cell type, location, and age, which may not be conserved across species [34C37]. Claudin-2, Claudin-3, and Claudin-4 have been detected in rat intestine [37, 38] and Claudin-1 to Claudin-4, Claudin-7 to Claudin-13, Claudin-15, and Claudin-18 have been detected in murine intestine . Claudin-5 was initially attributed to be an endothelium-specific TJ protein [38, 39] but it AGN 205327 has been specifically identified as an epithelial TJ protein as well [36, 37, 40]. Further, you will find tightening Claudins (such as Claudin-1, Claudin-3, Claudin-4, and Claudin-5) [30, 40C42] as well AGN 205327 as Claudins which meditate paracellular permeability for cations (such as Claudin-2 and Claudin-12) [37, 43]. Finally, mutations or changes in expression or surface localization of TJ proteins may lead to changes in intestinal permeability [30, 42, 44]. For instance, Bergmann et al. (2013) showed that mouse pups stressed for 12 hours showed increased intestinal permeability coincident with translocation of Claudin-4 from the region of the TJ on the surface of villous epithelial cells to the cytoplasm . Age and environmental factors, at least in rodents, clearly impact epithelial cell surface localization of TJ proteins. Whether piglets, which are much more precocious at birth, also experience transitioning of TJ protein expression with age and region of the gut has not been elucidated. We intend to establish whether you will find regional and/or age-specific differences in the expression patterns of genes for FcRn, pIgR, Claudin-4, and Claudin-5. Florescent immunohistochemistry is used to establish patterns of Claudin-4 and Claudin-5 surface localization within unique regions in the pig intestine over time to determine whether their surface localization changes are coincident with changes in intestinal permeability as the newborn gut matures. Claudin-4 and Claudin-5 were selected as a representative tightening AGN 205327 TJ proteins found on intestinal epithelial cells and blood vessel endothelial cells, respectively. Because the gut of the NUDT15 newborn is usually sterile and microbiota contributes to maturation of the gut [45C48], we further investigated the role of commensal microbiota on tight junction protein surface localization. 2. Materials and Methods 2.1. Animal Use and Ethics and Description This work was approved by the University or college of Saskatchewan’s Animal Research Ethics Table.