scholarly journals Glycocalyx on Rabbit Intestinal M Cells Displays Carbohydrate Epitopes from Muc2

2001 ◽  
Vol 69 (2) ◽  
pp. 1061-1071 ◽  
Author(s):  
Hugues Lelouard ◽  
Hubert Reggio ◽  
Christian Roy ◽  
Alain Sahuquet ◽  
Paul Mangeat ◽  
...  
Keyword(s):  
Apical Membrane ◽  
Lymphoid Tissues ◽  
M Cells ◽  
Apical Surface ◽  
M Cell ◽  
Luminal Membrane ◽  
Carbohydrate Epitopes ◽  
Intestinal Mucin ◽  
Rabbit Appendix

ABSTRACT It is essential to investigate the apical surface properties of both M cells and dome enterocytes to understand the mechanisms involved in the binding of pathogens to M cells. In rabbit appendix tissue, monoclonal antibodies (MAbs) highlight differences between M cells (MAb 58) and dome enterocytes (MAb 214). Such antibodies ultimately recognized intestinal mucin-related epitopes. To further characterize these differences, the labeling patterns obtained with these MAbs were compared to those obtained with other antibodies to intestinal mucins on dissected domes from all gut-associated lymphoid tissues. A glycoprotein recognized by MAb 58 was purified on a CsCl isopycnic density gradient and microsequenced, and its mRNA expression was localized by in situ hybridization. It was identified as the rabbit homologue of human Muc2, i.e., the major mucin secreted in intestine tissue. Two other Muc2 carbohydrate epitopes were also expressed on M cells, although Muc2 mRNA was not detected. All results indicated that M cells express, on their apical membrane, glycoconjugates bearing at least three glycosidic epitopes from Muc2. MAb 214 and MAb 6G2, which recognized a partially characterized mucin expressed on dome enterocytes, were negative markers for M cells in rabbit gut-associated lymphoid tissues. We propose that the presence, on the surface of M cells, of carbohydrates also expressed on Muc2, together with the absence of an enterocyte-associated mucin, could favor pathogen attachment and accessibility to the M-cell luminal membrane.

Rabbit M cells and dome enterocytes are distinct cell lineages

2001 ◽  
Vol 114 (11) ◽  
pp. 2077-2083
Author(s):  
Hugues Lelouard ◽  
Alain Sahuquet ◽  
Hubert Reggio ◽  
Philippe Montcourrier
Keyword(s):  
Lymphoid Tissues ◽  
M Cells ◽  
Relative Distribution ◽  
M Cell ◽  
Epithelial Surface ◽  
Cell Lineages ◽  
Proliferative Zone ◽  
Early Appearance ◽  
Distinct Cell ◽  
Constant Distribution

We have studied the M cell origin and differentiation pathway in rabbit gut-associated lymphoid tissues. Micro-dissected domes and epithelium isolated by ethylene diamine tetra acetic acid detachment allowed us to view the whole epithelial surface from the bottom of crypts to the top of domes. We used monoclonal antibodies specific to the apex of either M cells or dome enterocytes, lectins, and antibodies to vimentin in appendix, distal Peyer’s patches and caecal patches. The earliest vimentin-labeled M cells were observed in the BrdU-positive proliferative zone of dome-associated crypts. Gradual differentiation of the M cell vimentin cytoskeleton started at this site to progressively give rise to the first pocket-forming M cells in the upper dome. Therefore, these mitotic cells of the crypts appear as the direct precursors of M cells. In addition to an early appearance of M cell markers, a regular mosaic-like relative distribution of M cells and dome enterocytes was already detected in the vicinity of crypts, similar to that observed on the lateral surface of domes where functional M cells lie. This constant distribution implies that there is no trans-differentiation of enterocytes to M cells along the crypt-dome axis. Together, these observations provide very strong evidence in favor of an early commitment in crypts of M cell and enterocyte distinct lineages.

Expression and localization of epithelial sodium channel in mammalian urinary bladder

1998 ◽  
Vol 274 (1) ◽  
pp. F91-F96 ◽  
Author(s):  
Peter R. Smith ◽  
Scott A. Mackler ◽  
Philip C. Weiser ◽  
David R. Brooker ◽  
Yoon J. Ahn ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Urinary Bladder ◽  
Mrna Expression ◽  
Northern Blot ◽  
Apical Membrane ◽  
Bladder Epithelium ◽  
Rat Urinary Bladder ◽  
Luminal Membrane ◽  
Electrophysiological Studies

The mammalian urinary bladder exhibits transepithelial Na+ absorption that contributes to Na+ gradients established by the kidney. Electrophysiological studies have demonstrated that electrogenic Na+ absorption across the urinary bladder is mediated in part by amiloride-sensitive Na+ channels situated within the apical membrane of the bladder epithelium. We have used a combination of in situ hybridization, Northern blot analysis, and immunocytochemistry to examine whether the recently cloned epithelial Na+ channel (ENaC) is expressed in the rat urinary bladder. In situ hybridization and Northern blot analyses indicate that α-, β-, and γ-rat ENaC (rENaC) are expressed in rat urinary bladder epithelial cells. Quantitation of the levels of α-, β-, and γ-rENaC mRNA expression in rat urinary bladder, relative to β-actin mRNA expression, indicates that, although comparable levels of α- and β-rENaC subunits are expressed in the urinary bladder of rats maintained on standard chow, the level of γ-rENaC mRNA expression is 5- to 10-fold lower than α- or β-rENaC mRNA. Immunocytochemistry, using an antibody directed against α-rENaC, revealed that ENaCs are predominantly localized to the luminal membrane of the bladder epithelium. Together, these data demonstrate that ENaC is expressed in the mammalian urinary bladder and suggest that amiloride-sensitive Na+ transport across the apical membrane of the mammalian urinary bladder epithelium is mediated primarily by ENaC.

V. Role of M cells in transepithelial transport of antigens and pathogens to the mucosal immune system

1998 ◽  
Vol 274 (5) ◽  
pp. G785-G791 ◽  
Author(s):  
Marian R. Neutra
Keyword(s):  
Lymphoid Cells ◽  
Transepithelial Transport ◽  
Cell Phenotype ◽  
Lymphoid Tissues ◽  
M Cells ◽  
Complex Interplay ◽  
M Cell ◽  
Molecular Features ◽  
Mucosal Vaccines

Specialized epithelial M cells, a phenotype that occurs only in the epithelium over organized lymphoid follicles, deliver samples of foreign material by transepithelial transport from the lumen to organized lymphoid tissues within the mucosa of the small and large intestines. Mounting evidence indicates that a complex interplay of mucosal lymphoid cells and luminal microorganisms with epithelial cells underlies differentiation of the M cell phenotype. The cellular and molecular features of M cells that promote adherence and transport of antigens and microorganisms are crucial for the design of mucosal vaccines and for understanding the strategies that pathogens use to exploit this pathway.

scholarly journals Mucin-Related Epitopes Distinguish M Cells and Enterocytes in Rabbit Appendix and Peyer’s Patches

1999 ◽  
Vol 67 (1) ◽  
pp. 357-367 ◽  
Author(s):  
Hugues Lelouard ◽  
Hubert Reggio ◽  
Paul Mangeat ◽  
Marian Neutra ◽  
Philippe Montcourrier
Keyword(s):  
Epithelial Cells ◽  
Plasma Membranes ◽  
Secretory Granules ◽  
Lymphoid Cells ◽  
Peyer's Patches ◽  
Lymphoid Tissues ◽  
Peyer’S Patches ◽  
M Cells ◽  
Apical Membranes ◽  
Rabbit Appendix

ABSTRACT The biochemical composition of the apical membranes of epithelial M cells overlying the gut-associated lymphoid tissues (GALT) is still largely unknown. We have prepared monoclonal antibodies (MAbs) directed against carbonate-washed plasma membranes from epithelial cells detached with EDTA from rabbit appendix, a tissue particularly rich in GALT. As determined by immunofluorescence microscopy, several MAbs specifically recognized either M cells or enterocyte-like cells of the domes from rabbit appendix, sacculus rotundus, and Peyer’s patches. M cells were identified by their large ventral pocket containing lymphoid cells and by specific labeling with antivimentin. Among various characterized MAbs, MAb 104 recognized rabbit immunoglobulins and was used as an apical marker for M cells in the rabbit appendix, MAb 58 selectively stained an integral membrane glycoprotein of greater than 205 kDa located at the apex of M cells, and MAb 214 stained a smaller soluble glycoprotein associated with the apical surfaces from neighboring enterocytes. In addition, both MAbs 58 and 214 also labeled luminal mucus and secretory granules in goblet cells. The selective association of mucin-related molecules at the surfaces of either M cells or enterocyte-like cells of the follicle-associated epithelium suggests that specific carbohydrate antigens are differentially expressed by epithelial cells and could account for the differential binding properties of pathogens.

scholarly journals Surface expression of sodium channels and transporters in rat kidney: effects of dietary sodium

2009 ◽  
Vol 297 (5) ◽  
pp. F1249-F1255 ◽  
Author(s):  
Gustavo Frindt ◽  
Lawrence G. Palmer
Keyword(s):  
Rat Kidney ◽  
Biochemical Parameter ◽  
Surface Expression ◽  
Dietary Sodium ◽  
Na Channel ◽  
Apical Surface ◽  
Deficient Diet ◽  
Luminal Membrane ◽  
Epithelial Na Channel

The abundance of Na transport proteins in the luminal membrane of the rat kidney was assessed using in situ biotinylation and immunoblotting. When animals were fed an Na-deficient diet for 1 wk, the amounts of epithelial Na channel (ENaC) β-subunit (β-ENaC) and γ-subunit (γ-ENaC) and Na-Cl cotransporter (NCC) protein in the surface fraction increased relative to controls by 1.9-, 3.5-, and 1.5-fold, respectively. The amounts of the luminal Na/H exchanger (NHE3) and the luminal Na-K-2Cl cotransporter (NKCC2) did not change significantly. The increases in ENaC subunits were mimicked by administration of aldosterone for 1 wk, but the increase in NCC was not. When the animals were fed a high-Na (5% NaCl) diet for 1 wk, the surface expression of β-ENaC increased by 50%, whereas that of the other membrane proteins did not change, relative to controls. The biochemical parameter most strongly affected by dietary Na was the abundance of the 65-kDa cleaved form of γ-ENaC at the surface. This increased by 8.5-fold with Na depletion and decreased by 40% with Na loading. The overall 14-fold change reflected regulation of the total abundance of the subunit as well as the fraction of the subunit protein in the cleaved form. We conclude that cleavage of γ-ENaC and its expression at the apical surface play a major role in the regulation of renal Na reabsorption.

Coexpression of auxiliary Kvβ2 subunits with Kv1.1 channels is required for developmental acquisition of unique firing properties of zebrafish Mauthner cells

2014 ◽  
Vol 111 (6) ◽  
pp. 1153-1164 ◽  
Author(s):  
Takaki Watanabe ◽  
Takashi Shimazaki ◽  
Aoba Mishiro ◽  
Takako Suzuki ◽  
Hiromi Hirata ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Escape Behavior ◽  
Repetitive Firing ◽  
M Cells ◽  
M Cell ◽  
Single Spike ◽  
Low Threshold ◽  
Firing Properties ◽  
Firing Property

Each neuron possesses a unique firing property, which is largely attributed to heterogeneity in the composition of voltage-gated ion channel complexes. Zebrafish Mauthner (M) cells, which are bilaterally paired giant reticulospinal neurons (RSNs) in the hindbrain and induce rapid escape behavior, generate only a single spike at the onset of depolarization. This single spiking is in contrast with the repetitive firing of the M cell's morphologically homologous RSNs, MiD2cm and MiD3cm, which are also involved in escapes. However, how the unique firing property of M cells is established and the underlying molecular mechanisms remain unclear. In the present study, we first demonstrated that the single-spiking property of M cells was acquired at 4 days postfertilization (dpf), accompanied by an increase in dendrotoxin I (DTX)-sensitive low-threshold K+ currents, prior to which the M cell repetitively fires as its homologs. Second, in situ hybridization showed that among DTX-sensitive Kv1 channel α-subunits, zKv1.1a was unexpectedly expressed even in the homologs and the bursting M cells at 2 dpf. In contrast, zKvβ2b, an auxiliary β-subunit of Kv1 channels, was expressed only in the single-spiking M cells. Third, zKv1.1a expressed in Xenopus oocytes functioned as a low-threshold K+ channel, and its currents were enhanced by coexpression of zKvβ2b subunits. Finally, knockdown of zKvβ2b expression in zebrafish larvae resulted in repetitive firing of M cells at 4 dpf. Taken together, these results suggest that associative expression of Kvβ2 subunits with Kv1.1 channels is crucial for developmental acquisition of the unique firing properties of the M cells among homologous neurons.

scholarly journals Microbial Pattern Recognition Receptors Mediate M-Cell Uptake of a Gram-Negative Bacterium

2006 ◽  
Vol 74 (1) ◽  
pp. 625-631 ◽  
Author(s):  
Peter Tyrer ◽  
A. Ruth Foxwell ◽  
Allan W. Cripps ◽  
Michael A. Apicella ◽  
Jennelle M. Kyd
Keyword(s):  
Pattern Recognition ◽  
Cell Types ◽  
Pattern Recognition Receptors ◽  
M Cells ◽  
M Cell ◽  
Gram Negative ◽  
Bacterial Uptake ◽  
Α5β1 Integrin

ABSTRACT The receptors involved in the sampling of particulate microbial antigens by the gut are largely unknown. Here we demonstrate for the first time in an in vitro M-cell model and in situ in isolated murine intestinal segments that the receptors TLR-4, PAF-R, and α5β1 integrin are all involved in mediating bacterial uptake associated with transcytosis. The pattern of expression of TLR-4 and α5β1 integrin differed between M cells and enterocytes. There was increased apical expression of TLR-4 in M-cell cultures, and it was present on the apical surface of murine M cells but not enterocytes in situ. In contrast, PAF-R was expressed equally by both cell types in vitro and was abundantly expressed throughout the intestinal epithelium. Inhibition of TLR-4 and PAF-R, but not TLR-2, reduced gram-negative bacterial uptake by both cell types, whereas inhibition of the apically expressed α5β1 integrin significantly reduced the ability of M cells to translocate bacteria. Hence, the involvement of each receptor was dependent not only on differences in the level of receptor expression but the cellular localization. Using bacteria that had mutations that affected the bacterial lipooligosaccharide structure indicated that the oligosaccharide moiety was important in bacterial uptake. Taken together, the data suggest that pathogen-associated molecular pattern interactions with pattern recognition receptors are key factors in M-cell recognition of intestinal antigens for mucosal immune priming.

scholarly journals THE EFFECT OF EPITHELIAL REMNANT AND WHOLE ORGAN GRAFTS OF THYMUS ON THE RECOVERY OF THYMECTOMIZED IRRADIATED MICE

1969 ◽  
Vol 129 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
Esther F. Hays
Keyword(s):  
Direct Action ◽  
Lymphoid Cells ◽  
Lymphoid Tissues ◽  
Functional Development ◽  
Reticular Cells ◽  
Microscopic Morphology ◽  
Two Parameters ◽  
A Minor ◽  
Cellular Components

Work has been presented which suggests that thymus epithelial reticular cells are not effective in restoring the microscopic morphology of lymphoid tissues and their immunologic capacities. They function in recruiting precursors of thymus lymphocytes from the host animals to produce an organ which, after it becomes architecturally normal, can reconstitute the defective host. Intact thymus grafts in situ from 10–14 days, but not for shorter periods of time, have been shown to result in a return toward normal of these two parameters. Evidence is offered to show that few dividing cellular components in the lymphoid tissue originate from the thymus remnant grafts, and that a minor cellular component is contributed by the intact grafts. These data support the concept that the structural and functional development of the lymphatic tissue in thymectomized animals is dependent on thymus lymphoid cells and/or their products, and that the epithelial-reticular cells do not have a direct action in peripheral lymphoid reconstitution.

The transcytotic pathway of an apical plasma membrane protein (B10) in hepatocytes is similar to that of IgA and occurs via a tubular pericentriolar compartment

1996 ◽  
Vol 109 (6) ◽  
pp. 1215-1227 ◽  
Author(s):  
I. Hemery ◽  
A.M. Durand-Schneider ◽  
G. Feldmann ◽  
J.P. Vaerman ◽  
M. Maurice
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Apical Membrane ◽  
Rat Hepatocytes ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Plasma Membrane Protein ◽  
Microtubule Disruption

In hepatocytes, newly synthesized apical plasma membrane proteins are first delivered to the basolateral surface and are supposed to reach the apical surface by transcytosis. The transcytotic pathway of apical membrane proteins and its relationship with other endosomal pathways has not been demonstrated morphologically. We compared the intracellular route of an apical plasma membrane protein, B10, with that of polymeric IgA (pIgA), which is transcytosed, transferrin (Tf) which is recycled, and asialoorosomucoid (ASOR) which is delivered to lysosomes. Ligands and anti-B10 monoclonal IgG were linked to fluorochromes or with peroxidase. The fate of each ligand was followed by confocal and electron microscopy in polarized primary monolayers of rat hepatocytes. When fluorescent anti-B10 IgG and fluorescent pIgA were simultaneously endocytosed for 15–30 minutes, they both uniformly labelled a juxtanuclear compartment. By 30–60 minutes, they reached the bile canaliculi. Tf and ASOR were also routed to the juxtanuclear area, but their fluorescence patterns were more punctate. Microtubule disruption prevented all ligands from reaching the juxtanuclear area. This area corresponded, at least partially, to the localization of the mannose 6-phosphate receptor, an endosomal marker. By electron microscopy, the juxtanuclear compartment was made up of anastomosing tubules connected to vacuoles, and was organized around the centrioles. B10 and pIgA were mainly found in the tubules, whereas ASOR was segregated inside the vacuolar elements and Tf within thinner, recycling tubules. In conclusion, transcytosis of the apical membrane protein B10 occurs inside tubules similar to those carrying pIgA, and involves passage via the pericentriolar area. In the pericentriolar area, the transcytotic tubules appear to maintain connections with other endosomal elements where sorting between recycled and degraded ligands occurs.

Correlation of the startle reflex and Mauthner cell auditory responses in unrestrained goldfish

1977 ◽  
Vol 66 (1) ◽  
pp. 243-254 ◽  
Author(s):  
S. J. Zottoli
Keyword(s):  
Stainless Steel ◽  
Startle Reflex ◽  
Sound Stimulus ◽  
M Cells ◽  
M Cell ◽  
Mauthner Cell ◽  
Auditory Responses ◽  
Cell Electrode ◽  
Steel Electrodes

Stainless-steel electrodes were implanted near the left or right. Mauthner cells (M-cells) of goldfish to determine if these cells can initiate the startle reflex evoked by a brief sinusoidal sound stimulus. Recordings of the M-cell extracellular spike were obtained for the duration of 10 experiments. Fish with chronic implants were allowed to free-swim and exposed to at least 10 consecutive sound stimuli consisting of 2 cycles of 200 Hz. Seventy-three startle responses were analysed. In 34 cases the implanted M-cell electrode was contralateral to the contracting musculature, and in each of these cases, a M-cell spike preceded the EMG response by 1-1-2-1 ms. In the reamining 39 cases the electrode was ipsilateral to the active musculature, and the M-cell only fired in one of these trails. There were no startle responses and no M-cell firings in an additional 52 tests. Since the M-cell activates contralateral motoneurones, the results indicate it is responsible for initiation of the startle reflex.

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