The functional expression of P-glycoprotein has been studied in confluent epithelial layers human Caco-2 cells, a polarized, highly differentiated cell line demonstrating an intestinal absorptive phenotype. Expression was localized, by indirect immunofluorescence with monoclonal antibody MRK16, to the apical brush-border, approximately 20 microns above base cells. Functional, high capacity demonstrated saturable secretion vinblastine, typical substrate, from basolateral surfaces: Km 18.99...

ABSTRACT Quantitative analysis of Yersinia pseudotuberculosis infection murine gut loops revealed that significantly more wild-type bacteria associated with Peyer’s patch M cells than dome enterocytes or goblet cells. An invasin-deficient mutant was attenuated for M-cell invasion, while β1 integrin expression demonstrated in the apical membranes but not enterocytes. targeting by vivo may, therefore, be mediated primarily interaction invasin cell surface integrins.

We investigated the binding of four lectins to follicle-associated epithelium (FAE) overlying fixed mouse small intestinal Peyer's patches identify M-cell-specific surface markers. Wheat germ agglutinin and peanut displayed heterogeneous staining patterns, most avidly intestine goblet cells. In contrast, Ulex europaeus 1 (UEA 1) Psophocarpus tetragonolobus (winged bean; WBA) were almost exclusively M-cell specific. When confocal laser scanning images tissues stained with fluorescein...

Very little is known about the biological functions of pili that have recently been found to be expressed by important Gram-positive pathogens such as Corynebacterium diphtheriae, Streptococcus agalacticae, S. pneumoniae and pyogenes. Using various ex vivo tissue cellular models, here we show mediate adhesion serotype M1 pyogenes strain SF370 both human tonsil epithelium primary keratinocytes, which represent two main sites infection this human-specific pathogen. Mutants lacking minor pilus...

Molecular mechanisms underlying physiological adaptation to increased levels of dietary peptides have been elucidated by studying the response substrate glycyl‐L‐glutamine (Gly‐Gln) proton‐coupled peptide transporter, hPepT1, in Caco‐2 human intestinal cell line. V max for apical uptake [ 14 C]glycyl‐[ C]sarcosine was 1.64 (± 0.34)‐fold after incubation cells 3 days a peptide‐rich medium (4 mM Gly‐Gln replacing 4 Gln). A full‐length hPepT1 cDNA clone identical small with exception single...

A genomic library of Clostridium thermocellum DNA constructed in lambda ZAPII was screened for xylanase-expressing clones. Cross-hybridization experiments revealed a new xylanase gene isolated from the library, which designated xyn Y. The encoded enzyme, Y (XYLY), displayed features characteristic an endo-beta1,4-xylanase: enzyme rapidly hydrolysed oat spelt, wheat and rye arabinoxylans active against methyl-umbelliferyl-beta-D-cellobioside, but did not hydrolyse any cellulosic substrates....

Multidrug resistance-associated protein (MRP) isoforms 1 through 6 mRNA are expressed in the human intestine and Caco-2 cells. In cells, rank order for expression was MRP2 ≥ MRP6 > MRP4 MRP3 MRP1 = MRP5. The functional of MRP-like activity quantified as efflux fluorescent probe calcein from confluent, polarized monolayers Calcein sensitive to temperature, energy depletion, MRP antagonist MK571 [3-[[3-[2-(7-chloroquinolin-2-yl)vinyl]phenyl]-(2-dimethylcarbamoylethylsulfanyl)methylsulfanyl]...

Glycylsarcosine (Gly-Sar) transport in human intestinal epithelial (Caco-2) cells has been investigated.Gly-Sar transport, from apical to basal surfaces (Ja+), and intracellular accumulation are greatest when the medium is acidified (apical pH 6.0, 7.4).Both susceptible saturation competition.Similarly, Gly-Sar (JbJ, increased with acidification of (basal 7.4).Apical addition 20 m M (pH 6.0) Caco-2 cell monolayers loaded indicator BCECF (2',7'-bis(Z-~arboxyethyl)-5-(6)carboxyfluorescein)...

Short-term infection of MDCK II monolayers with Salmonella typhimurium SL1344 caused a progressive decrease in transepithelial electrical resistance concomitant decreased cation permselectivity and increased paracellular inulin flux. Cytochemical staining F-actin, E-cadherin, ZO-1 revealed the concentration each junctional protein invaded cells as result contraction at their apical poles resultant distortion adjacent uninvaded cells.

The interaction of poly(dl-lactide-co-glycolide) (PLG) and polystyrene microspheres with the follicle-associated epithelium (FAE) rabbit Peyer's patches was compared. Binding by PLG to FAE an order magnitude lower than that equivalent size (0.5–0.6 μm diameter). Although microspheres, are not selectively targeted M cell surface, as is case a high proportion those bind cells transcytosed, resulting in transepithelial delivery 1.5×104 microspheres/mm2 FAE. This represents first direct...

The transepithelial transport of three fluoroquinolones, norfloxacin, ciprofloxacin and pefloxacin has been compared by using cultured human intestinal Caco-2 cell-layers. Absorptive (apical-basal) fluxes norfloxacin are small relative to basal apical fluxes. Norfloxacin thus subject active secretion. Active net secretion displays saturation kinetics with Vmax Km values 36.2 +/- 6.9 nmol.cm-2.hr-1 1.42 0.79 mM. In contrast, large, show marked while the direction flux is variable Norfloxacin,...