Functional Dyspepsia and Food: Immune Overlap with Food Sensitivity Disorders.

PURPOSE OF REVIEW: Functional dyspepsia (FD) is a chronic functional gastrointestinal disorder characterised by upper gastrointestinal symptoms. Here, we aimed to examine the evidence for immune responses to food in FD and overlap with food hypersensitivity conditions. RECENT FINDINGS: A feature of FD in a subset of patients is an increase in mucosal eosinophils, mast cells, intraepithelial cytotoxic T cells and systemic gut-homing T cells in the duodenum, suggesting that immune dysfunction is characteristic of this disease. Rates of self-reported non-celiac wheat/gluten sensitivity (NCW/GS) are higher in FD patients. FD patients commonly report worsening symptoms following consumption of wheat, fermentable oligosaccharides, disaccharides, monosaccharides, or polyols (FODMAPs), high-fat foods and spicy foods containing capsaicin. Particularly, wheat proteins and fructan in wheat may drive symptoms. Immune mechanisms that drive responses to food in FD are still poorly characterised but share key effector cells to common food hypersensitivities including non-IgE-mediated food allergy and eosinophilic oesophagitis.

Determining the monosaccharides of the sea urchin (Paracentrotus lividus) coelomocytes via the CapLC-ESI-MS/MS system and the lectin histochemistry.

The essential mechanism within immune systems is the recognition of pathogens and parasites by the immune system cells, which attach to their targets and destroy them. Glycans are fundamental macromolecular components of all cells, and are important in the vertebrate immunity. But, glycans have been investigated rarely in coelomocytes of echinoids. Hence, the aim of this study is to determine the monosaccharides which form glycan chains on the sea urchin immune system cells, coelomocytes, via analytical and lectin histochemistry methods. The study material is the coelomocytes obtained from adult sea urchin Paracentrotus lividus. In order to analyze the monosaccharides with the Capillary Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (CapLC-ESI-MS/MS) system, the samples underwent hydrolysation, reacetylation and derivatization steps. In order to determine the monosaccharides with the lectin histochemistry, the cells were incubated with fluorescein isothiocyanate (FITC) conjugated PNA, HPA, WGA-suc, WGA, and PSL lectins and then photographed with the fluorescence microscope. As a result of the CapLC-ESI-MS/MS analysis; mannose, ribose, N-acetylglucosamine, glucose, N-acetylgalactosamine, galactose, arabinose, xylose and fucose monosaccharides were detected. A peak area calculation analysis revealed the most prevalent saccharides as glucose, galactose and fucose, respectively. Lectin histochemistry came out with higher intensity emission signals obtained from the FITC-conjugated lectin WGA, which is specific to N-acetylglucosamine and sialic acid in comparison to the emission obtained from the sialic acid unspecific WGA-suc lectin. This finding indicates the existence of sialic acid within coelomocytes. Fluorescent emissions from other lectins were detected at lower levels. Determination of the monosaccharides which form glycan chains of the sea urchin coelomocytes and elucidating their similarities among other invertebrate and vertebrate systems is vital in terms of understanding the uncovered complex features of the immune systems of higher vertebrates.

Mechanisms for glycolipid antigen-driven cytokine polarization by Valpha14i NKT cells.

Certain glycolipid Ags for Valpha14i NKT cells can direct the overall cytokine balance of the immune response. Th2-biasing OCH has a lower TCR avidity than the most potent agonist known, alpha-galactosylceramide. Although the CD1d-exposed portions of OCH and alpha-galactosylceramide are identical, structural analysis indicates that there are subtle CD1d conformational differences due to differences in the buried lipid portion of these two Ags, likely accounting for the difference in antigenic potency. Th1-biasing C-glycoside/CD1d has even weaker TCR interactions than OCH/CD1d. Despite this, C-glycoside caused a greater downstream activation of NK cells to produce IFN-gamma, accounting for its promotion of Th1 responses. We found that this difference correlated with the finding that C-glycoside/CD1d complexes survive much longer in vivo. Therefore, we suggest that the pharmacokinetic properties of glycolipids are a major determinant of cytokine skewing, suggesting a pathway for designing therapeutic glycolipids for modulating invariant NKT cell responses.

Variable loop glycan dependency of the broad and potent HIV-1-neutralizing antibodies PG9 and PG16.

The HIV-1-specific antibodies PG9 and PG16 show marked cross-isolate neutralization breadth and potency. Antibody neutralization has been shown to be dependent on the presence of N-linked glycosylation at position 160 in gp120. We show here that (i) the loss of several key glycosylation sites in the V1, V2, and V3 loops; (ii) the generation of pseudoviruses in the presence of various glycosidase inhibitors; and (iii) the growth of pseudoviruses in a mutant cell line (GnT1(-/-)) that alters envelope glycosylation patterns all have significant effects on the sensitivity of virus to neutralization by PG9 and PG16. However, the interaction of antibody is not inhibited by sugar monosaccharides corresponding to those found in glycans on the HIV surface. We show that some of the glycosylation effects described are isolate dependent and others are universal and can be used as diagnostic for the presence of PG9 and PG16-like antibodies in the sera of HIV-1-infected patients. The results suggest that PG9 and PG16 recognize a conformational epitope that is dependent on glycosylation at specific variable loop N-linked sites. This information may be valuable for the design of immunogens to elicit PG9 and PG16-like antibodies, as well as constructs for cocrystallization studies.

Invariant TCR rather than CD1d shapes the preferential activities of C-glycoside analogues against human versus murine invariant NKT cells.

C-glycoside analogues of alpha-galactosylceramide were shown to activate both human and mouse invariant NKT (iNKT) cells. Among these analogues, GCK152, which has an aromatic ring in the acyl chain, exhibited a stronger stimulatory activity against human iNKT cells and a much weaker activity against murine iNKT cells than GCK127 that has an almost identical fatty acyl chain as alpha-galactosylceramide. In this study, we have found that invariant TCR (invTCR) expressed by iNKT cells, but not CD1d expressed by APCs, command the species-specific preferential activity of C-glycosides, and that their preferential activity against human vs murine iNKT cells correlate with the binding affinity of glycolipid-CD1d complex to invTCR of respective iNKT cells rather than that of glycolipid to human or murine CD1d molecules. Overall, the structural difference of invTCR appears to supersede those of CD1d molecule in shaping the strength of the biological activity of C-glycoside analogues.

Strategies for Using Muramyl Peptides - Modulators of Innate Immunity of Bacterial Origin - in Medicine.

The spread of infectious diseases is rampant. The emergence of new infections, the irrational use of antibiotics in medicine and their widespread use in agriculture contribute to the emergence of microorganisms that are resistant to antimicrobial drugs. By 2050, mortality from antibiotic-resistant strains of bacteria is projected to increase up to 10 million people per year, which will exceed mortality from cancer. Mutations in bacteria and viruses are occurring faster than new drugs and vaccines are being introduced to the market. In search of effective protection against infections, new strategies and approaches are being developed, one of which is the use of innate immunity activators in combination with etiotropic chemotherapy drugs. Muramyl peptides, which are part of peptidoglycan of cell walls of all known bacteria, regularly formed in the body during the breakdown of microflora and considered to be natural regulators of immunity. Their interaction with intracellular receptors launches a sequence of processes that ultimately leads to the increased expression of genes of MHC molecules, pro-inflammatory mediators, cytokines and their soluble and membrane-associated receptors. As a result, all subpopulations of immunocompetent cells are activated: macrophages and dendritic cells, neutrophils, T-, B- lymphocytes and natural killer cells for an adequate response to foreign or transformed antigens, manifested both in the regulation of the inflammatory response and in providing immunological tolerance. Muramyl peptides take part in the process of hematopoiesis, stimulating production of colony-stimulating factors, which is the basis for their use in the treatment of oncological diseases. In this review we highlight clinical trials of drugs based on muramyl peptides, as well as clinical efficacy of drugs mifamurtide, lycopid, liasten and polimuramil. Such a multifactorial effect of muramyl peptides and a well-known mechanism of activity make them promising drugs in the treatment and preventing of infectious, allergic and oncological diseases, and in the composition of vaccines.

The immunobiological interplay between Pseudosuccinea columella resistant/susceptible snails with Fasciola hepatica: Hemocytes in the spotlight.

The Fasciola hepatica/Pseudosuccinea columella interaction in Cuba involves a unique pattern of phenotypes; while most snails are susceptible, some field populations are naturally resistant to infection and parasites are encapsulated by snail hemocytes. Thus, we investigated the hemocytes of resistant (R) and susceptible (S) P. columella, in particular morphology, abundance, proliferation and in vitro encapsulation activity following exposure to F. hepatica. Compared to susceptible P. columella, hemocytes from exposed resistant snails showed increased levels of spreading and aggregation (large adherent cells), proliferation of circulating blast-like cells and encapsulation activity of the hemocytes, along with a higher expression of the cytokine granulin. By contrast, there was evidence of a putative F. hepatica-driven inhibition of host immunity, only in susceptible snails. Additionally, (pre-)incubation of naïve hemocytes from P. columella (R and S) with different monosaccharides was associated with lower encapsulation activity of F. hepatica larvae. This suggests the involvement in this host-parasite interaction of lectins and lectins receptors (particularly related to mannose and fucose sensing) in association with hemocyte activation and/or binding to F. hepatica.

Beta-galactosylceramide alters invariant natural killer T cell function and is effective treatment for lupus.

NZB/W female mice spontaneously develop systemic lupus, an autoantibody mediated disease associated with immune complex glomerulonephritis. Natural killer (NK) T cells augment anti-dsDNA antibody secretion by NZB/W B cells in vitro, and blocking NKT cell activation in vivo with anti-CD1 mAb ameliorates lupus disease activity. In the current study, we show that beta-galactosylceramide reduces the in vivo induction of serum IFN-gamma and/or IL-4 by the potent NKT cell agonist alpha-galactosylceramide and reduces NKT cell helper activity for IgG secretion. Treatment of NZB/W mice with the beta-galactosylceramide ameliorated lupus disease activity as judged by improvement in proteinuria, renal histopathology, IgG anti-dsDNA antibody formation, and survival. In conclusion, beta-galactosylceramide, a glycolipid that reduces the cytokine secretion induced by a potent NKT cell agonist ameliorates lupus in NZB/W mice.

Structural characteristics of immunostimulating polysaccharides from lentinus edodes.

There is a significant amount of experimental evidence suggesting that polysaccharides from mushrooms enhance the host immune system by activating various mechanisms in immune cells, including macrophages. In this study, polysaccharides from Lentinus edodes were found to stimulate the functional activation of macrophages to secrete inflammatory mediators and cytokines and increase the phagocytotic uptake. The chemical properties of the stimulatory polysaccharides, CPFN-G-I, CPBN-G, and CPBA-G, were determined based on their monosaccharide composition, which mainly consisted of glucose and mannose. According to FT-IR and GC/MS, the structure of CPFN-G-I, purified from the fruiting body of L. edodes, was found to consist of a beta-1,6-branched-beta-1,4-glucan, whereas CPBN-G and CPBA-G, purified from the liquid.

Co-encapsulation of synthetic lipidated TLR4 and TLR7/8 agonists in the liposomal bilayer results in a rapid, synergistic enhancement of vaccine-mediated humoral immunity.

To increase vaccine immunogenicity, modern vaccines incorporate adjuvants, which serve to enhance immune cross-protection, improve humoral and cell-mediated immunity, and promote antigen dose sparing. Pattern recognition receptors (PRRs), including the Toll-like receptor (TLR) family are promising targets for development of agonist formulations for use as vaccine adjuvants. Combinations of co-delivered TLR4 and TLR7/8 ligands have been demonstrated to have synergistic effects on innate and adaptive immune response. Here, we create liposomes that stably co-encapsulate CRX-601, a synthetic TLR4 agonist, and UM-3004, a lipidated TLR7/8 agonist, within the liposomal bilayer in order to achieve co-delivery, allow tunable physical properties, and induce in vitro and in vivo immune synergy. Co-encapsulation demonstrates a synergistic increase in IL-12p70 cytokine output in vitro from treated human peripheral blood mononuclear cells (hPBMCs). Further, co-encapsulated formulations give significant improvement of early IgG2a antibody titers in BALB/c mice following primary vaccination when compared to single agonist or dual agonists delivered in separate liposomes. This work demonstrates that co-encapsulation of TLR4 and lipidated TLR7/8 agonists within the liposomal bilayer leads to innate and adaptive immune synergy which biases a Th1 immune response. Thus, liposomal co-encapsulation may be a useful and flexible tool for vaccine adjuvant formulation containing multiple TLR agonists.

Glycophorin A is recognized by an antibody population of the rabbit polyclonal antibodies produced against Citrobacter braakii O37.

BACKGROUND AND PURPOSE: Molecular mimicry was found in the case of Citrobacter braakii O37, which shares epitopes with human erythrocytes. It is believed that erythrocyte-membrane proteins band 3 and glycophorin A (GPA) have common epitopes. Band 3 was recognized by the anti-C. braakii O37 lipopolysaccharide antibodies (LPS-Abs) purified on LPS-affinity columns. This study aimed to investigate the role of GPA in this molecular mimicry. METHODS: Immunochemical methods such as immunoblotting, enzyme-linked immunosorbent assay, inhibition of hemagglutination, and affinity columns were employed. RESULTS: GPA when immobilized in an affinity column could purify specific GPA antibodies (GPA-Abs) from whole anti-C. braakii O37 serum. The purified antibodies, in turn, recognized GPA in immunoblotting tests. Treatment of human erythrocytes with sialidase significantly improved the hemagglutination titer by GPA-Abs. Furthermore, hemagglutination was inhibited to a greater extent by asialo-GPA than by the native form. GPA from blood groups M and N could similarly inhibit hemagglutination, and the most significant inhibition was recorded by GPA from the blood group MN. GPA-Abs could not recognize the LPS from C. braakii O37. CONCLUSIONS: Results confirmed that an antibody population in the anti-C. braakii O37 serum recognized GPA. However, there was no reactivity with LPS of C. braakii O37, indicating that the antibodies may be produced against the outer membrane protein of the bacteria.

A human lymphokine released by mononuclear blood cells upon contact with CEA.

As revealed by the macrophage electrophoretic mobility (MEM) technique mononuclear blood cells from certain cancer patients respond to carcinoembryonic antigen (CEA). This phenomenon appeared to be due to a specific lymphokine release. In this study, the lymphokine activity of supernatant pools was stepwise enriched by gel filtration on Sephadex. The mediator activity was recovered within a molecular mass region less than 47 kDA. The lymphokine was highly enriched during further gel filtration steps and showed a single activity peak in the molecular mass region of 23.5 kDa. Gel filtrations of appropriate control supernatants resulted in biologically inactive fractions. The lymphokine was heat-labile at 56 degrees C, showed a clear-cut, dose-dependent effect on macrophages, and could be blocked by fucose. Preparative gel electrophoresis of radiolabeled and unlabeled lymphokine resulted in two corresponding peaks of biological activity and radioactivity.

Effector cell sensitivity to sugar moieties. I. Inhibition of human natural killer cell activity by monosaccharides.

Human natural killer (NK) cells recognize multiple target antigens. The ligands (antigens) involved in the effector-target cell interaction have not been extensively identified. In the present study, assays of NK activity in the presence of a panel of monosaccharides demonstrated inhibition of cytolysis in a dose-response fashion. We propose that NK cell activity involves the recognition of carbohydrate structures on target cells via receptors on the effector cell surface.

Determination of specificities of rabbit antisera against the O-antigenic polysaccharide from Escherichia coli O126.

Rabbit polyclonal antibodies against the lipopolysaccharide of Escherichia coli O126 were serologically characterized by ELISA. The antibody specificities were determined by studying the inhibitory effects of the methyl glycosides of both anomeric configurations of the constituent monosaccharides and the oligosaccharides derived from the O-antigenic polysaccharide of E. coli O126. It was found that, amongst the monosaccharides, beta-D-N-acetyl glucosamine was the most effective inhibitory sugar in the O126 polysaccharide and the major specificity of the polyclonal antibodies was found to be directed against the trisaccharide having the structure alpha-D-Galp (1-->3)-beta-D-GlcpNAc(1-->2)-D-Manp.

The binding of synthetic analogs of the upstream, terminal residue of the O-polysaccharides (O-PS) of Vibrio cholerae O:1 serotypes Ogawa and Inaba to two murine monoclonal antibodies (MAbs) specific for the Ogawa lipopolysaccharide (LPS).

The binding of nineteen analogues of the upstream, terminal, monosaccharide residue of each of the O-polysaccharide (O-PS) of Vibrio cholerae O:1, serotype Ogawa and Inaba, with two murine monoclonal IgG antibodies both specific for the Ogawa LPS were measured using fluorescence spectroscopy. The use of the deoxy and the deoxyfluoro analogs allowed further refinement of the hydrogen-bonding pattern involved in the binding. Based on the binding characteristics observed for some of the ligands in the Inaba series, the binding of the monosaccharide that represents the upstream, terminal unit of the O-PS of V. cholerae O:1 serotype Inaba was redefined. We show for the first time that the upstream, terminal monosaccharide of the Inaba O-PS shows weak binding with these two anti-Ogawa antibodies. The results obtained allow further rationalization of the structural basis for the binding of V. cholerae O:1 antigens to their homologous antibodies.

Synthesis of terminal disaccharide elements corresponding to the Ogawa and Inaba antigenic determinant from Vibrio cholerae O1.

Vibrio cholerae O1 LPS terminal mono- and disaccharide elements were synthesized by reduction of the azido group in several 4-amino-4,6-dideoxy-D-mannose mono- and disaccharide derivatives, followed by coupling with 2, 4-di-O-acetyl-3-deoxy-L-glycero-tetronic acid in the presence of 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline. This compound represents a useful model in order to elucidate the size of the epitopes which define Ogawa and Inaba serotypes from Vibrio cholerae O1.

A monoclonal antibody against carbohydrate moiety of rat gastric surface epithelial cell-derived mucin.

A monoclonal antibody (MAb), designated RGM11, was generated against mucin purified from the surface epithelial layer of rat gastric mucosa. RGM11 reacted with the purified mucin which had been attached to the ELISA well. This reaction was inhibited by the oxidation of the ELISA well with periodate, indicating the carbohydrate moiety of the mucin molecule to be the epitope of RGM11. Treatment of the ELISA well with galactose oxidase also reduced the reaction with this MAb, thus suggesting the peripheral galactose and/or N-acetylgalactosamine residues of the carbohydrate moiety of mucin are involved in the epitope structure. Histochemical observation indicated that this MAb was able to stain the formalin fixed-paraffin embedded sections of rat and was positive to the surface mucous cells of corpus and antral region of the stomach and the villus epithelium of the duodenal mucosa, but other organs and tissues of rat so far examined were all negative to this MAb. These results indicate that this newly established MAb, labelled RGM11, might be useful to estimate the physiological changes in gastric surface mucous cells and the role of surface epithelial cell derived mucus in the gastric mucosal defense mechanisms.

[A new branched-chain monosaccharide from the Yersinia enterocolitica serotype O:4.32 lipopolysaccharide]. / Novyi razvetvlennyi monosakharid iz lipopolisakharida Yersinia enterocolitica serovara O:4,32.

A component of the Yersinia enterocolitica O:4,32 lipopolysaccharide has been shown to be a second representative of the new class of monosaccharides and possess the structure of 3,6-dideoxy-4C-(1-hydroxyethyl)-D-xylo-hexose (yersiniose).

[Localization of the antigenic determinants in carcinoembryonic antigen: the role of the carbohydrate component]. / Lokalizatsiia antigennykh determinant v rakovo-émbrional'nom antigene, rol' uglevodnogo komponenta.

The majority of topographic antigenic determinants of the carcinoembryonic antigen (CEA) representing a glycoprotein were shown to contain sugar residues of the CEA carbohydrate chains. Periodate oxidation of CEA followed by reduction afforded a corresponding CEA derivate (CEA-POR), which retained 3% antigenic activity of CEA. In secondary and tertiary structures CEA-POR was proved to be close to CEA pre heated to 80 degrees C. Formation of borate complexes with sugar residues of CEA decreased the CEA antigenic activity to 5% while a but did not affect the spatial structure of its protein core.

[The structure of O-specific polysaccharide isolated from the lipopolysaccharide of Yersinia intermedia strain 180]. / Struktura O-spetsificheskogo polisakharida, vydelennogo iz lipopolisakharida Yersinia intermedia shtamma 680.

An O-specific polysaccharide from lipopolysaccharide of Yersinia intermedia pathogenic strain 680 has been isolated and shown to be a serologically active fructane. Serological specificity of the lipopolysaccharide and the fructane was studied by reactions of precipitation and of inhibition of passive hemolysis. On the basis of methylation studies, 13C NMR spectroscopy, and immunochemical data the following structure was proposed for the repeating unit of the O-specific polysaccharide: (Formula: see text)