scholarly journals M CELLS ARE THE IMPORTANT POST IN THE INITIATION OF IMMUNE RESPONSE IN INTESTINE

2018 ◽  
Vol 8 (3) ◽  
pp. 263-272
Author(s):  
A. S. Bykov ◽  
A. V. Karaulov ◽  
D. A. Tsomartova ◽  
N. L. Kartashkina ◽  
V. L. Goriachkina ◽  
...  
Keyword(s):  
Immune System ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Targeted Delivery ◽  
Oral Vaccine ◽  
Critical Event ◽  
M Cells ◽  
M Cell ◽  
Antigen Uptake ◽  
And Function

Microfold cells (M cells) are specialized intestinal epithelial cells that initiate mucosal immune responses. These unique phagocytic epithelial cells are specialized for the transfer of a broad range of particulate antigens and microorganisms across the follicle-associated epithelium (FAE) into the gut-associated lymphoid tissue (GALT) by a process termed transcytosis. The molecular basis of antigen uptake by M cells has been gradually identified in the last decade. Active sampling of intestinal antigen initiates regulated immune responses that ensure intestinal homeostasis. The delivery of luminal substances across the intestinal epithelium to the immune system is a critical event in immune surveillance resulting in tolerance to dietary antigens and immunity to pathogens (e.g., bacteria, viruses, and parasites) and their toxins. Several specialized mechanisms transport luminal antigen across the gut epithelium. Discovery of M cell-specific receptors are of great interest, which could act as molecular tags for targeted delivery oral vaccine to M cells. Recent studies demonstrated that M cells utilize several receptors to recognize and transport specific luminal antigens. Vaccination through the mucosal immune system can induce effective systemic immune responses simultaneously with mucosal immunity. How this process is regulated is largely unknown. This review aims to show a new understanding of the factors that influence the development and function of M cells; to show the molecules expressed on M cells which appear to be used as immunosurveillance receptors to sample pathogenic microorganisms in the gut; to note how certain pathogens appear to exploit M cells to inject the host; and, finally, how this knowledge is used to specifically "target" antigens to M cells to attempt to improve the efficacy of mucosal vaccines. Recently, substantial progress has been made in our understanding of the factors that influence the development and function of M cells.

scholarly journals Role of the glycocalyx in regulating access of microparticles to apical plasma membranes of intestinal epithelial cells: implications for microbial attachment and oral vaccine targeting.

1996 ◽  
Vol 184 (3) ◽  
pp. 1045-1059 ◽  
Author(s):  
A Frey ◽  
K T Giannasca ◽  
R Weltzin ◽  
P J Giannasca ◽  
H Reggio ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Plasma Membranes ◽  
Intestinal Epithelial Cells ◽  
Oral Vaccine ◽  
M Cells ◽  
Intestinal Epithelial ◽  
M Cell ◽  
Antigen Uptake ◽  
Apical Membranes

Transepithelial transport of antigens and pathogens across the epithelial barrier by M cells may be a prerequisite for induction of mucosal immunity in the intestine. Efficient transport of antigens and pathogens requires adherence to M cell apical surfaces. Coupling of antigen-containing particles to the pentameric binding subunit of cholera toxin (CTB) has been proposed as a means for increasing antigen uptake because the CTB receptor, ganglioside GM1, is a glycolipid present in apical membranes of all intestinal epithelial cells. To test the accessibility of enterocyte and M cell membrane glycolipids to ligands in the size ranges of viruses, bacteria, and particulate mucosal vaccines, we analyzed binding of CTB probes of different sizes to rabbit Peyer's patch epithelium. Soluble CTB-fluorescein isothiocyanate (diameter 6.4 nm) bound to apical membranes of all epithelial cells. CTB coupled to 14 nm colloidal gold (final diameter, 28.8 nm) failed to adhere to enterocytes but did adhere to M cells. CTB-coated, fluorescent microparticles (final diameter, 1.13 microns) failed to adhere to enterocytes or M cells in vivo or to well-differentiated Caco-2 intestinal epithelial cells in vitro. However, these particles bound specifically to GM1 on BALB/c 3T3 fibroblasts in vitro and to undifferentiated Caco-2 cells that lacked brush borders and glycocalyx. Measurements of glycocalyx thickness by electron microscopy suggested that a relatively thin (20 nm) glycocalyx was sufficient to prevent access of 1-micron microparticles to glycolipid receptors. Thus, the barrier function of the intestinal epithelial cell glycocalyx may be important in limiting microbial adherence to membrane glycolipids, and in CTB-mediated targeting of vaccines to M cells and the mucosal immune system.

scholarly journals M-cells in the rabbit tonsil exhibit distinctive glycoconjugates in their apical membranes.

1996 ◽  
Vol 44 (9) ◽  
pp. 1033-1042 ◽  
Author(s):  
A Gebert
Keyword(s):  
Epithelial Cells ◽  
Immune Responses ◽  
Cell Types ◽  
Lectin Histochemistry ◽  
Lymphoid Cells ◽  
M Cells ◽  
M Cell ◽  
Double Labeling ◽  
Specific Composition ◽  
Apical Membranes

The tonsil crypt epithelium contains membranous (M)-cells that transport antigens from the lumen to underlying lymphoid cells, thereby initiating specific immune responses. Mechanisms mediating the adhesion of antigens to the M-cell surface are important for effective and selective uptake of potential pathogens but are still poorly understood. Therefore, the carbohydrates present on crypt epithelial cells of the rabbit palatine tonsil were studied by lectin histochemistry. Ultrathin LR White sections were incubated with a panel of eight lectins conjugated to colloidal gold or biotin. The glycocalyx of the apical membrane of M-cells was selectively labeled by UEA-I, LTA, HPA, and VVA, whereas that of the remaining squamous epithelial cells preferentially bound RCA-I and PNA. WGA and ConA showed only little binding, with no discernible preference for any of the cell types. Double labeling of UEA-1 together with anti-vimentin antibodies revealed that UEA-I-positive epithelial cells also contained the rabbit M-cell marker vimentin, and vice versa. The results show that a specific composition of glycoconjugates, which differs from that on squamous epithelial cells, is found on M-cells of the rabbit tonsil. The M-cell-specific glycoproteins and glycolipids could be selectively targeted by microorganisms that adhere to M-cells and enter the host along this pathway.

scholarly journals A novel M cell–specific carbohydrate-targeted mucosal vaccine effectively induces antigen-specific immune responses

2007 ◽  
Vol 204 (12) ◽  
pp. 2789-2796 ◽  
Author(s):  
Tomonori Nochi ◽  
Yoshikazu Yuki ◽  
Akiko Matsumura ◽  
Mio Mejima ◽  
Kazutaka Terahara ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Oral Vaccine ◽  
Goblet Cells ◽  
Carbohydrate Moiety ◽  
Mucosal Vaccine ◽  
M Cells ◽  
M Cell ◽  
Lethal Challenge ◽  
New Strategy ◽  
High Level

Mucosally ingested and inhaled antigens are taken up by membranous or microfold cells (M cells) in the follicle-associated epithelium of Peyer's patches or nasopharynx-associated lymphoid tissue. We established a novel M cell–specific monoclonal antibody (mAb NKM 16–2-4) as a carrier for M cell–targeted mucosal vaccine. mAb NKM 16–2-4 also reacted with the recently discovered villous M cells, but not with epithelial cells or goblet cells. Oral administration of tetanus toxoid (TT)– or botulinum toxoid (BT)–conjugated NKM 16–2-4, together with the mucosal adjuvant cholera toxin, induced high-level, antigen-specific serum immunoglobulin (Ig) G and mucosal IgA responses. In addition, an oral vaccine formulation of BT-conjugated NKM 16–2-4 induced protective immunity against lethal challenge with botulinum toxin. An epitope analysis of NKM 16–2-4 revealed specificity to an α(1,2)-fucose–containing carbohydrate moiety, and reactivity was enhanced under sialic acid–lacking conditions. This suggests that NKM 16–2-4 distinguishes α(1,2)-fucosylated M cells from goblet cells containing abundant sialic acids neighboring the α(1,2) fucose moiety and from non-α(1,2)-fucosylated epithelial cells. The use of NKM 16–2-4 to target vaccine antigens to the M cell–specific carbohydrate moiety is a new strategy for developing highly effective mucosal vaccines.

scholarly journals Sox8 is essential for M cell maturation to accelerate IgA response at the early stage after weaning in mice

2019 ◽  
Vol 216 (4) ◽  
pp. 831-846 ◽  
Author(s):  
Shunsuke Kimura ◽  
Nobuhide Kobayashi ◽  
Yutaka Nakamura ◽  
Takashi Kanaya ◽  
Daisuke Takahashi ◽  
...  
Keyword(s):  
Immune Responses ◽  
Early Stage ◽  
Biological Significance ◽  
M Cells ◽  
M Cell ◽  
Antigen Uptake ◽  
Molecular Machinery ◽  
Iga Response ◽  
Genetic Deletion ◽  
Mucosal Immune Responses

Microfold (M) cells residing in the follicle-associated epithelium (FAE) of the gut-associated lymphoid tissue are specialized for antigen uptake to initiate mucosal immune responses. The molecular machinery and biological significance of M cell differentiation, however, remain to be fully elucidated. Here, we demonstrate that Sox8, a member of the SRY-related HMG box transcription factor family, is specifically expressed by M cells in the intestinal epithelium. The expression of Sox8 requires activation of RANKL-RelB signaling. Chromatin immunoprecipitation and luciferase assays revealed that Sox8 directly binds the promoter region of Gp2 to increase Gp2 expression, which is the hallmark of functionally mature M cells. Furthermore, genetic deletion of Sox8 causes a marked decrease in the number of mature M cells, resulting in reduced antigen uptake in Peyer’s patches. Consequently, juvenile Sox8-deficient mice showed attenuated germinal center reactions and antigen-specific IgA responses. These findings indicate that Sox8 plays an essential role in the development of M cells to establish mucosal immune responses.

Cell-Penetrating Peptide-Mediated Nanovaccine Delivery

2021 ◽  
Vol 22 ◽  
Author(s):  
Jizong Jiang
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Cell Penetrating Peptide ◽  
Antigen Delivery ◽  
Efficient Manner ◽  
Antigen Uptake ◽  
Cell Penetrating ◽  
The Stability ◽  
Antigen Presenting

Abstract: Vaccination with small antigens, such as proteins, peptides, or nucleic acids, is used to activate the immune system and trigger the protective immune responses against a pathogen. Currently, nanovaccines are undergoing development instead of conventional vaccines. The size of nanovaccines is in the range of 10–500 nm, which enables them to be readily taken up by cells and exhibit improved safety profiles. However, low-level immune responses, as the removal of redundant pathogens, trigger counter-effective activation of the immune system invalidly and present a challenging obstacle to antigen recognition and its uptake via antigen-presenting cells (APCs). In addition, toxicity can be substantial. To overcome these problems, a variety of cell-penetrating peptide (CPP)-mediated vaccine delivery systems based on nanotechnology have been proposed, most of which are designed to improve the stability of antigens in vivo and their delivery into immune cells. CPPs are particularly attractive components of antigen delivery. Thus, the unique translocation property of CPPs ensures that they remain an attractive carrier with the capacity to deliver cargo in an efficient manner for the application of drugs, gene transfer, protein, and DNA/RNA vaccination delivery. CPP-mediated nanovaccines can enhance antigen uptake, processing, and presentation by APCs, which are the fundamental steps in initiating an immune response. This review describes the different types of CPP-based nanovaccines delivery strategies.

scholarly journals Mutual Interplay of Host Immune System and Gut Microbiota in the Immunopathology of Atherosclerosis

2020 ◽  
Vol 21 (22) ◽  
pp. 8729 ◽  
Author(s):  
Chih-Fan Yeh ◽  
Ying-Hsien Chen ◽  
Sheng-Fu Liu ◽  
Hsien-Li Kao ◽  
Ming-Shiang Wu ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Cytokine Production ◽  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Inflammasome Activation ◽  
Host Immune System ◽  
Gut Permeability ◽  
And Function ◽  
Progression Of Atherosclerosis

Inflammation is the key for the initiation and progression of atherosclerosis. Accumulating evidence has revealed that an altered gut microbiome (dysbiosis) triggers both local and systemic inflammation to cause chronic inflammatory diseases, including atherosclerosis. There have been some microbiome-relevant pro-inflammatory mechanisms proposed to link the relationships between dysbiosis and atherosclerosis such as gut permeability disruption, trigger of innate immunity from lipopolysaccharide (LPS), and generation of proatherogenic metabolites, such as trimethylamine N-oxide (TMAO). Meanwhile, immune responses, such as inflammasome activation and cytokine production, could reshape both composition and function of the microbiota. In fact, the immune system delicately modulates the interplay between microbiota and atherogenesis. Recent clinical trials have suggested the potential of immunomodulation as a treatment strategy of atherosclerosis. Here in this review, we present current knowledge regarding to the roles of microbiota in contributing atherosclerotic pathogenesis and highlight translational perspectives by discussing the mutual interplay between microbiota and immune system on atherogenesis.

scholarly journals Comparative Analysis of EspF Variants in Inhibition of Escherichia coli Phagocytosis by Macrophages and Inhibition of E. coli Translocation through Human- and Bovine-Derived M Cells

2011 ◽  
Vol 79 (11) ◽  
pp. 4716-4729 ◽  
Author(s):  
Amin Tahoun ◽  
Gabriella Siszler ◽  
Kevin Spears ◽  
Sean McAteer ◽  
Jai Tree ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
M Cells ◽  
Binding Assays ◽  
M Cell ◽  
Content Type ◽  
E Coli ◽  
Coculture System

ABSTRACTThe EspF protein is secreted by the type III secretion system of enteropathogenic and enterohemorrhagicEscherichia coli(EPEC and EHEC, respectively). EspF sequences differ between EHEC O157:H7, EHEC O26:H11, and EPEC O127:H6 in terms of the number of SH3-binding polyproline-rich repeats and specific residues in these regions, as well as residues in the amino domain involved in cellular localization. EspFO127is important for the inhibition of phagocytosis by EPEC and also limits EPEC translocation through antigen-sampling cells (M cells). EspFO127has been shown to have effects on cellular organelle function and interacts with several host proteins, including N-WASP and sorting nexin 9 (SNX9). In this study, we compared the capacities of differentespFalleles to inhibit (i) bacterial phagocytosis by macrophages, (ii) translocation through an M-cell coculture system, and (iii) uptake by and translocation through cultured bovine epithelial cells. TheespFgene fromE. coliserotype O157 (espFO157) allele was significantly less effective at inhibiting phagocytosis and also had reduced capacity to inhibitE. colitranslocation through a human-derivedin vitroM-cell coculture system in comparison toespFO127andespFO26. In contrast,espFO157was the most effective allele at restricting bacterial uptake into and translocation through primary epithelial cells cultured from the bovine terminal rectum, the predominant colonization site of EHEC O157 in cattle and a site containing M-like cells. Although LUMIER binding assays demonstrated differences in the interactions of the EspF variants with SNX9 and N-WASP, we propose that other, as-yet-uncharacterized interactions contribute to the host-based variation in EspF activity demonstrated here.

scholarly journals Development of intestinal M cells and follicle-associated epithelium is regulated by TRAF6-mediated NF-κB signaling

2018 ◽  
Vol 215 (2) ◽  
pp. 501-519 ◽  
Author(s):  
Takashi Kanaya ◽  
Sayuri Sakakibara ◽  
Toshi Jinnohara ◽  
Masami Hachisuka ◽  
Naoko Tachibana ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Tumor Necrosis Factor Receptor ◽  
M Cells ◽  
M Cell ◽  
Antigen Uptake ◽  
Conditional Deletion ◽  
Follicle Associated Epithelium ◽  
Necrosis Factor

M cells are located in the follicle-associated epithelium (FAE) that covers Peyer’s patches (PPs) and are responsible for the uptake of intestinal antigens. The differentiation of M cells is initiated by receptor activator of NF-κB. However, the intracellular pathways involved in M cell differentiation are still elusive. In this study, we demonstrate that the NF-κB pathway activated by RANK is essential for M cell differentiation using in vitro organoid culture. Overexpression of NF-κB transcription factors enhances the expression of M cell–associated molecules but is not sufficient to complete M cell differentiation. Furthermore, we evaluated the requirement for tumor necrosis factor receptor–associated factor 6 (TRAF6). Conditional deletion of TRAF6 in the intestinal epithelium causes a complete loss of M cells in PPs, resulting in impaired antigen uptake into PPs. In addition, the expression of FAE-associated genes is almost silenced in TRAF6-deficient mice. This study thus demonstrates the crucial role of TRAF6-mediated NF-κB signaling in the development of M cells and FAE.

scholarly journals Identifying human and murine M cells in vitro

2019 ◽  
Vol 244 (7) ◽  
pp. 554-564 ◽  
Author(s):  
Ana Klisuric ◽  
Benjamin Thierry ◽  
Ludivine Delon ◽  
Clive A Prestidge ◽  
Rachel J Gibson
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
In Vitro Models ◽  
Oral Drug ◽  
M Cells ◽  
Cell Marker ◽  
M Cell ◽  
Follicle Associated Epithelium

M cells are an epithelial cell population found in the follicle-associated epithelium overlying gut-associated lymphoid tissues. They are specialized in the transcytosis of luminal antigens. Their transcytotic capacity and location in an immunocompetent environment has prompted the study of these cells as possible targets for oral drug delivery systems. Currently, the models most commonly used to study M cells are restricted to in vivo experiments conducted in mice, and in vitro studies conducted in models comprised either of primary epithelial cells or established cell lines of murine or human origin. In vitro models of the follicle-associated epithelium can be constructed in several ways. Small intestinal Lgr5+ stem cells can be cultured into a 3D organoid structure where M cells are induced with RANKL administration. Additionally, in vitro models containing an “M cell-like” population can be obtained through co-culturing intestinal epithelial cells with cells of lymphocytic origin to induce the M cell phenotype. The evaluation of the efficiency of the variations of these models and their relevance to the in vivo human system is hampered by the lack of a universal M cell marker. This issue has also hindered the advancement of M cell-specific targeting approaches aimed at improving the bioavailability of orally administered compounds. This critical review discusses the different approaches utilized in the literature to identify M cells, their efficiency, reliability and relevance, in the context of commonly used models of the follicle-associated epithelium. The outcome of this review is a clearly defined and universally recognized criteria for the assessment of the relevance of models of the follicle-associated models currently used. Impact statement The study of M cells, a specialized epithelial cell type found in the follicle-associated epithelium, is hampered by the lack of a universal M cell marker. As such, many studies lack reliable and universally recognized methods to identify M cells in their proposed models. As a result of this it is difficult to ascertain whether the effects observed are due to the presence of M cells or an unaccounted variable. The outcome of this review is the thorough evaluation of the many M cell markers that have been used in the literature thus far and a proposed criterion for the identification of M cells for future publications. This will hopefully lead to an improvement in the quality of future publications in this field.

scholarly journals Optimizing Dendritic Cell-Based Immunotherapy: Tackling the Complexity of Different Arms of the Immune System

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Ilse Van Brussel ◽  
Zwi N. Berneman ◽  
Nathalie Cools
Keyword(s):  
Immune System ◽  
Dendritic Cell ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Cellular Mechanisms ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
New Ideas ◽  
And Function

Earlier investigations have revealed a surprising complexity and variety in the range of interaction between cells of the innate and adaptive immune system. Our understanding of the specialized roles of dendritic cell (DC) subsets in innate and adaptive immune responses has been significantly advanced over the years. Because of their immunoregulatory capacities and because very small numbers of activated DC are highly efficient at generating immune responses against antigens, DCs have been vigorously used in clinical trials in order to elicit or amplify immune responses against cancer and chronic infectious diseases. A better insight in DC immunobiology and function has stimulated many new ideas regarding the potential ways forward to improve DC therapy in a more fundamental way. Here, we discuss the continuous search for optimal in vitro conditions in order to generate clinical-grade DC with a potent immunogenic potential. For this, we explore the molecular and cellular mechanisms underlying adequate immune responses and focus on most favourable DC culture regimens and activation stimuli in humans. We envisage that by combining each of the features outlined in the current paper into a unified strategy, DC-based vaccines may advance to a higher level of effectiveness.

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