Anti-Saccharomyces cerevisiae antibodies are elevated in Graves' disease but not in Hashimoto's thyroiditis

BACKGROUND

Anti-Saccharomyces cerevisiae antibodies (ASCA) had been known to be specific for Crohn's disease, but they had also been found in many other autoimmune diseases.

AIM

The aim of this study was to evaluate the prevalence of ASCA in patients with autoimmune thyroid disease (AITD).

PATIENTS AND METHODS

One hundred and ninety-seven patients with AITD and 160 healthy controls were included in the study. One hundred and nineteen patients had Graves' disease (GD) and 78 patients had Hashimoto's thyroiditis (HT). ASCA IgG and IgA were determined by ELISA.

RESULTS

ASCA IgG were significantly more frequent in patients with GD than in control group (11.8% vs. 3.1%, p = 0.002). In HT, the frequency of ASCA IgG was similar to that of the control group (3.8% and 3.1% respectively). The frequency of ASCA IgA was similar in GD (0.8%), HT (2.6%), and the control group (3.1%). In all GD patients, the frequency of ASCA IgG was significantly higher than that of ASCA IgA (11.8% vs. 0.8%, p = 0.001). These results were also true even in male and female groups (10.4% vs. 1.3%, p = 0.01 and 14.3% vs. 0%, p = 0.01, respectively). ASCA IgG levels were significantly higher in GD patients (6.7 ± 11.1 vs. 2.2 ± 2.8, p = 3 × 10(-6)) and in HT patients (4.2 ± 4.7 vs. 2.2 ± 2.8, p = 0.0002) than those in the control group. ASCA IgA levels were comparable among patients with GD, HT, and the control group. In GD patients, the mean titer of ASCA IgG was significantly higher than that of ASCA IgA (6.7 ± 11.1 vs. 3.6 ± 4.2, p = 0.005).

CONCLUSION

Patients with GD had a higher frequency of ASCA IgG than controls.

Using phage and yeast display to select hundreds of monoclonal antibodies: application to antigen 85, a tuberculosis biomarker

Background

Current diagnostic methods for tuberculosis (TB), a major global health challenge that kills nearly two million people annually, are time-consuming and inadequate. During infection a number of bacterial molecules that play a role in the infective process are released and have been proposed as biomarkers for early TB diagnosis. Antigen 85 (Ag85) is the most abundant secreted TB protein, and a potential target for this diagnostic approach. One of the bottlenecks in the direct detection of such bacterial targets is the availability of robust, sensitive, specific antibodies.

Methods

Using Ag85 as a model, we describe a method to select antibodies against any potential target using a novel combination of phage and yeast display that exploits the advantage of each approach.

Results

The efficiency of this approach was attested to by the 111 specific antibodies identified in initial screens. These were assessed for binding to the different Ag85 subunits, affinity, and activity in sandwich assays.

Conclusions

The novelty of this approach lies in the possibility of screening the entire output of a phage antibody selection in a single experiment by yeast display. This can be considered analogous to carrying out a million ELISAs. The monoclonal antibodies (mAbs) identified in this way show high binding affinity and selectivity for the antigens and offer an advantage over traditional mAbs produced by relatively expensive and time consuming techniques. This approach has wide applicability, and the affinity of selected antibodies can be significantly improved, if required.

Anti-Saccharomyces cerevisiae antibodies associate with phenotypes and higher risk for surgery in Crohn's disease: a meta-analysis

BACKGROUND

Recent studies suggested that anti-Saccharomyces cerevisiae antibody (ASCA) status was associated with diagnostic findings, stratified classification phenotypes, disease activity and clinical course of Crohn's disease (CD). However, the relationship between ASCA status and phenotypes of CD remains controversial in these studies.

AIMS

The purpose of this study was to evaluate whether ASCA status is associated with the phenotypes and the risk of surgery in diverse populations in CD.

METHODS

We conducted a meta-analysis of studies assessing the association of ASCA status with phenotypes and risk of surgery in CD. Three independent reviewers undertook data extraction. We pooled odds ratios separately for the cohort and case-control studies.

RESULTS

We identified ten cohort studies (n = 2,365) and 14 case-control studies (n = 1,887) that investigated the association of ASCA status with phenotypes and risk of surgery in CD. The meta-analysis of the cohort studies showed significant association between the ASCA-positive status and higher risk of early-onset age (OR 2.25, 95 % CI 1.41-3.57, P < 0.001), ileal involvement disease (1.70, 1.05-2.77, P = 0.03), complicated disease behavior (2.09, 1.71-2.57, P < 0.001), perianal disease (1.49, 1.14-1.94, P = 0.004), and risk for surgery (1.61, 1.29-2.01, P < 0.001). Meta-analysis of the case-control studies also showed a significantly higher risk in ileal involvement disease (1.77, 1.25-2.49, P = 0.001), complicated disease behavior (2.13, 1.70-2.68, P < 0.001), perianal disease (1.96, 1.38-2.78, P < 0.001), and risk for surgery (1.71, 1.17-2.49, P = 0.005), except for the early-onset age (1.16, 0.80-1.69, P = 0.44).

CONCLUSIONS

This meta-analysis indicated that positive ASCA status is a risk factor for early-onset age, ileal involvement, complicated behavior, perianal disease and requirement for surgery in CD.

Up-regulation of GITRL on dendritic cells by WGP improves anti-tumor immunity in murine Lewis lung carcinoma

BACKGROUND

β-Glucans have been shown to function as a potent immunomodulator to stimulate innate and adaptive immune responses, which contributes to their anti-tumor property. However, their mechanisms of action are still elusive. Glucocorticoid-induced TNF receptor ligand (GITRL), a member of the TNF superfamily, binds to its receptor, GITR, on both effector and regulatory T cells, generates a positive co-stimulatory signal implicated in a wide range of T cell functions, which is important for the development of immune responses.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, we found that whole β-glucan particles (WGPs) could activate dendritic cells (DCs) via dectin-1 receptor, and increase the expression of GITRL on DCs in vitro and in vivo. Furthermore, we demonstrated that the increased GITRL on DCs could impair the regulartory T cell (Treg)-mediated suppression and enhance effector T cell proliferation in a GITR/GITRL dependent way. In tumor models, DCs with high levels of GITRL were of great potential to prime cytotoxic T lymphocyte (CTL) responses and down-regulate the suppressive activity of Treg cells, thereby leading to the delayed tumor progression.

CONCLUSIONS/SIGNIFICANCE

These findings suggest that particulate β-glucans can be used as an immunomodulator to stimulate potent T cell-mediated adaptive immunity while down-regulate suppressive immune activity via GITR/GITRL interaction, leading to a more efficient defense mechanism against tumor development.

Pattern recognition receptor and autophagy gene variants are associated with development of antimicrobial antibodies in Crohn's disease

BACKGROUND

We sought to investigate whether variants in genes involved in bacterial sensing and autophagy (NOD2, TLR5, IRGM, ATG16L1) and the interleukin-23 signaling pathway (IL12B, IL23R, STAT3) were associated with development of antimicrobial antibodies in patients with Crohn's disease (CD).

METHODS

A cohort of 616 CD patients from a tertiary referral hospital (Mount Sinai Hospital, Toronto) was evaluated. DNA was tested for three CD-associated NOD2 variants (3020insC, G908R, R702W), variants in IRGM, ATG16L1, IL12B, IL23R, STAT3, and a TLR5-stop mutation. Serum was analyzed by enzyme-linked immunosorbent assay (ELISA) for anti-Saccharomyces cerevisiae (ASCA) IgG and IgA, anti-outer membrane porin C (anti-ompC), anti-Cbir1 flagellin, and anti-Pseudomonas fluorescens (anti-I2).

RESULTS

NOD2 3020insC was associated with cumulative seroreactivity by quartile sum (P = 0.003) and number of positive antibodies (P = 0.02). NOD2 G908R was also associated with quartile sum (P = 0.05). Increased ASCA seropositivity was associated with NOD2 3020insC (odds ratio [OR] = 1.9, P = 0.02) and G908R (OR = 1.8, P = 0.05), and ATG16L1 T300A (OR = 1.4, P = 0.01) variants; ASCA-positive patients had an increased cumulative number of NOD2 3020insC and ATG16L1 T300A variants (P = 0.007). TLR5-stop mutation abrogated development of anti-flagellin in a dominant-negative fashion (OR = 0.5, P = 0.009). The IRGM CD risk variant was associated with increased anti-flagellin seropositivity (OR = 1.5, P = 0.03). IL12B, IL23R, and STAT3 variants did not contribute to development of antimicrobial antibodies.

CONCLUSIONS

Variants in innate immune genes involved in pattern recognition and autophagy but not the interleukin-23 signaling pathway influence antimicrobial seroreactivity in CD. In particular, the additive effect of NOD2 3020insC and ATG16L1 T300A suggests a role for autophagy in development of ASCA.

Yeast-surface expressed BVDV E2 protein induces a Th1/Th2 response in naïve T cells

Yeast species such as Saccharomyces cerevisiae are known to be potent activators of the immune system. S. cerevisiae activates the innate immune system by engaging pattern recognition receptors such as toll like receptor 2 (TLR2) and dectin-1. In the current project, we express the immunogenic envelope protein E2 of bovine viral diarrhoea virus (BVDV) on the surface of S. cerevisiae. After successful expression, components of the innate and adaptive immune response induced by the recombinant S. cerevisiaein vitro were analysed to determine if expression in yeast enhances the immunogenicity of the viral protein. Recombinant S. cerevisiae stimulated production of the chemokine CXCL-8 in primary bovine macrophages, but did no stimulate production of reactive oxygen species (ROS) in the same cells. Additionally, bovine macrophages primed with S. cerevisiae expressing viral envelope proteins had a greater capacity for stimulating proliferation of CD4+ T-cells from BVDV-free animals compared to macrophages primed with envelope protein alone or S. cerevisiae without envelope protein expression. Heat inactivation of recombinant S. cerevisiae increased ROS production and capacity to stimulate CD4+ T-cells in macrophages but did not alter CXCL-8 release compared to the live counter-part. Additionally, heat-inactivation of recombinant S. cerevisiae induced less INFγ and IL-4 but equal amounts of IL-10 compared to live yeast T-cell cultures. Our studies demonstrate a use for S. cerevisiae as a vehicle for transporting BVDV vaccine antigen to antigen-presenting cell in order to elicit cell-mediated immunity even in naïve animals.

Serum antibodies and anthropometric data at diagnosis in pediatric Crohn's disease

BACKGROUND

Serum antibodies, including ASCA, anti-OmpC, and ANCA, correlate with disease location and predict disease phenotype in inflammatory bowel disease.

AIM

The objective of this study was to determine relationships between serum antibody status and anthropometric data for children with newly diagnosed Crohn's disease.

METHODS

A retrospective review was conducted on children diagnosed with Crohn's disease at our institution from 2003 to 2008. Patients who had ASCA IgA, ASCA IgG, anti-OmpC, and pANCA antibodies, and anthropometric data measured before diagnosis and therapy were included. Z-scores for height and weight were compared among groups according to the presence of specific antibodies. Spearman's rank correlation was used to assess association between antibodies and growth data.

RESULTS

One hundred and two patients, mean age 11.9 years, met the inclusion criteria. Patients with the presence of any of the four antibodies had lower mean height and weight z-scores than patients without any antibodies present. When individual antibodies were studied, patients with positive ASCA titers had lower mean weight and height z-scores than patients without any antibodies present. Spearman's rank correlation coefficient demonstrated a significant association between increasing ASCA titers and lower weight z-scores, but not lower height z-scores.

CONCLUSIONS

Pediatric patients with newly diagnosed Crohn's disease and the presence of ASCA antibodies have lower mean height and weight z-scores. This study provides evidence that specific subsets of children with Crohn's disease may be at greater risk of growth impairment.

Higher titers of anti-Saccharomyces cerevisiae antibodies IgA and IgG are associated with more aggressive phenotypes in Romanian patients with Crohn's disease

BACKGROUND AND AIMS

Serological markers have been widely used for diagnostic purposes and disease stratification in inflammatory bowel diseases (IBD). The aim of this study was to investigate the seroprevalence and the correlations of anti-Saccharomyces cerevisiae antibodies (ASCA) titers with different clinical phenotypes in Romanian patients with Crohn's disease (CD).

METHODS

The study included 107 CD and 86 ulcerative colitis (UC) patients from the Gastroenterology Departments of three University Hospitals, and 60 healthy subjects. ASCA IgA and IgG titers were determined using ELISA test. For CD patients the phenotype was established according to the Montreal classification. The differences in ASCA titers for different CD phenotypes were assessed using the Mann-Whitney U test.

RESULTS

ASCA prevalence was 33.6% in CD group, 12.8% in UC group and 6.6% in the control group. Significantly higher IgA (p=0.05) and IgG (p=0.03) titers were found in patients from the Montreal A1+A2 groups (age at onset below 40) compared with the older patients (A3). Higher titers were found in patients with extensive ileo-colonic lesions (L3) and upper gastrointestinal tract involvement (L4) than in patients having only colonic disease (L2). Significantly higher IgA (p=0.03) and IgG (p=0.03) titers were observed in patients with stenosing (B2) and penetrating (B3) disease compared with the nonstricturing, nonpenetrating (B1) phenotype. No correlation between ASCA titers and disease duration was found.

CONCLUSION

ASCA seropositivity in Romanian CD patients is lower than in Western Europe. Higher ASCA IgA and IgG titers are associated with a younger age at diagnosis and more aggressive phenotypes.

Cell walls of Saccharomyces cerevisiae differentially modulated innate immunity and glucose metabolism during late systemic inflammation

Background

Salmonella causes acute systemic inflammation by using its virulence factors to invade the intestinal epithelium. But, prolonged inflammation may provoke severe body catabolism and immunological diseases. Salmonella has become more life-threatening due to emergence of multiple-antibiotic resistant strains. Mannose-rich oligosaccharides (MOS) from cells walls of Saccharomyces cerevisiae have shown to bind mannose-specific lectin of Gram-negative bacteria including Salmonella, and prevent their adherence to intestinal epithelial cells. However, whether MOS may potentially mitigate systemic inflammation is not investigated yet. Moreover, molecular events underlying innate immune responses and metabolic activities during late inflammation, in presence or absence of MOS, are unknown.

Methods and Principal Findings

Using a Salmonella LPS-induced systemic inflammation chicken model and microarray analysis, we investigated the effects of MOS and virginiamycin (VIRG, a sub-therapeutic antibiotic) on innate immunity and glucose metabolism during late inflammation. Here, we demonstrate that MOS and VIRG modulated innate immunity and metabolic genes differently. Innate immune responses were principally mediated by intestinal IL-3, but not TNF-α, IL-1 or IL-6, whereas glucose mobilization occurred through intestinal gluconeogenesis only. MOS inherently induced IL-3 expression in control hosts. Consequent to LPS challenge, IL-3 induction in VIRG hosts but not differentially expressed in MOS hosts revealed that MOS counteracted LPS's detrimental inflammatory effects. Metabolic pathways are built to elucidate the mechanisms by which VIRG host's higher energy requirements were met: including gene up-regulations for intestinal gluconeogenesis (PEPCK) and liver glycolysis (ENO2), and intriguingly liver fatty acid synthesis through ATP citrate synthase (CS) down-regulation and ATP citrate lyase (ACLY) and malic enzyme (ME) up-regulations. However, MOS host's lower energy demands were sufficiently met through TCA citrate-derived energy, as indicated by CS up-regulation.

Conclusions

MOS terminated inflammation earlier than VIRG and reduced glucose mobilization, thus representing a novel biological strategy to alleviate Salmonella-induced systemic inflammation in human and animal hosts.

Effects of periodontal therapy on phagocytic activity of peripheral blood neutrophils - evidence for an extrinsic cellular defect

PURPOSE

To compare phagocytic activity of peripheral blood neutrophils from subjects with and without periodontal disease and evaluate the effects of periodontal therapy in individuals with similar levels of resolution of inflammation at the end of treatment.

MATERIALS AND METHODS

To compare the phagocytic activity of neutrophils, peripheral blood was collected from 27 control subjects with a healthy periodontium and 28 periodontitis subjects before and after treatment. The phagocytosis of killed Saccharomyces cerevisiae, pre-sensitised or non-sensitised with fresh serum from the donor, was quantified and a phagocytic index was calculated as the mean number of yeast cells phagocytised by the percentage of neutrophils involved in phagocytosis.

RESULTS

Prior to periodontal treatment, subjects with periodontitis exhibited significantly lower neutrophil phagocytic activity than control subjects with a healthy periodontium. Periodontal treatment significantly improved in clinical periodontal status and resulted in significantly increased phagocytosis of both pre-sensitised (from 113.0 pre- to 157.0 post-treatment, P = 0.02) and non-sensitised S. cerevisiae (from 1.5 pre- to 3.5 post-treatment, P = 0.001), to levels observed in control subjects.

CONCLUSIONS

The phagocytic activity of peripheral blood neutrophils from subjects with periodontal disease was lower than that of healthy controls. Subjects who underwent non-surgical periodontal treatment and strict supportive therapy for 6 months showed improved phagocytic activity in peripheral blood neutrophils. The phagocytic index values from subjects with periodontal disease after treatment achieved those found in the control group.

Wild-type Drosophila melanogaster as a model host to analyze nitrogen source dependent virulence of Candida albicans

The fungal pathogen Candida albicans is a common cause of opportunistic infections in humans. We report that wild-type Drosophila melanogaster (OrR) flies are susceptible to virulent C. albicans infections and have established experimental conditions that enable OrR flies to serve as model hosts for studying C. albicans virulence. After injection into the thorax, wild-type C. albicans cells disseminate and invade tissues throughout the fly, leading to lethality. Similar to results obtained monitoring systemic infections in mice, well-characterized cph1Δ efg1Δ and csh3Δ fungal mutants exhibit attenuated virulence in flies. Using the OrR fly host model, we assessed the virulence of C. albicans strains individually lacking functional components of the SPS sensing pathway. In response to extracellular amino acids, the plasma membrane localized SPS-sensor (Ssy1, Ptr3, and Ssy5) activates two transcription factors (Stp1 and Stp2) to differentially control two distinct modes of nitrogen acquisition (host protein catabolism and amino acid uptake, respectively). Our results indicate that a functional SPS-sensor and Stp1 controlled genes required for host protein catabolism and utilization, including the major secreted aspartyl protease SAP2, are required to establish virulent infections. By contrast, Stp2, which activates genes required for amino acid uptake, is dispensable for virulence. These results indicate that nutrient availability within infected hosts directly influences C. albicans virulence.

No immune responses by the expression of the yeast Ndi1 protein in rats

Background

The rotenone-insensitive internal NADH-quinone oxidoreductase from yeast, Ndi1, has been shown to work as a replacement molecule for complex I in the respiratory chain of mammalian mitochondria. In the so-called transkingdom gene therapy, one major concern is the fact that the yeast protein is foreign in mammals. Long term expression of Ndi1 observed in rodents with no apparent damage to the target tissue was indicative of no action by the host's immune system.

Methodology/Principal Findings

In the present study, we examined rat skeletal muscles expressing Ndi1 for possible signs of inflammatory or immune response. In parallel, we carried out delivery of the GFP gene using the same viral vector that was used for the NDI1 gene. The tissues were subjected to H&E staining and immunohistochemical analyses using antibodies specific for markers, CD11b, CD3, CD4, and CD8. The data showed no detectable signs of an immune response with the tissues expressing Ndi1. In contrast, mild but distinctive positive reactions were observed in the tissues expressing GFP. This clear difference most likely comes from the difference in the location of the expressed protein. Ndi1 was localized to the mitochondria whereas GFP was in the cytosol.

Conclusions/Significance

We demonstrated that Ndi1 expression did not trigger any inflammatory or immune response in rats. These results push forward the Ndi1-based molecular therapy and also expand the possibility of using foreign proteins that are directed to subcellular organelle such as mitochondria.

A new leukocyte cell-derived chemotaxin-2 from marine fish grouper, Epinephelus coioides: molecular cloning and expression analysis

Leukocyte cell-derived chemotaxin-2 (LECT2) is a multifunctional protein involved in cell growth, differentiation and autoimmunity. In this study, a new leukocyte cell-derived chemotaxin-2 (EcLECT2) gene was cloned from grouper, Epinephelus coioides, by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA sequence of EcLECT2 was 595 bp in size, containing a 5'-untranslated region (UTR) of 44 bp and a 3'-UTR of 83 bp. The deduced protein sequence of the open reading frame (465 bp) showed highest similarity (81%) to the LECT2 of the fresh-water fish Larimichthys crocea. An abundant transcription of the determined EcLECT2 mRNA has been detected in liver and skin of grouper, E. coioides. Furthermore, the expression of EcLECT2 was differentially up-regulated in liver after infection with Staphyloccocus aureus, Vibrio vulnificus, Vibrio parahaemolyticus, Saccharomyces cerevisiae and Singapore grouper iridovirus (SGIV), while the expression was down-regulated after stimulation with Concanavalin A (Con A). Recombinant mature EcLECT2 (rEcLECT2) was successfully expressed in Escherichia coli BL21 (DE3), and the antiserum against EcLECT2 was obtained for further investigations. EcLECT2 may be an important molecule in the innate immunity of grouper.

Auto-antibodies in patients with inflammatory bowel disease unclassified

BACKGROUND

Inflammatory bowel disease unclassified (IBDU) is considered to be an aberrant immune response with loss of tolerance to many antigens.

OBJECTIVE

This paper tries to address whether there is any value to test for auto-antibodies in such patients.

METHODS

60 patients with inflammatory bowel disease unclassified participated in the study. Auto-antibodies to nuclear antigen, intestinal goblet cell, exocrine part of pancreatic acinar cells, perinuclear antineutrophil cytoplasmic, cytoplasmic antineutrophil cytoplasmic and Saccharomyces cerevisiae were tested and compared to 20 ulcerative colitis (UC) patients and 30 healthy controls matched for age and sex.

RESULTS

There was a significant difference (p=0.000) between patients and control group in anti-exocrine part of pancreatic acinar cells, perinuclear antineutrophil cytoplasmic and Saccharomyces cerevisiae auto-antibodies. There was also a significant difference between IBDU and UC patients in the auto-antibodies directed against intestinal goblet cells, (p=0.000) exocrine part of pancreas (p=0.000) and anti Saccharomyces cerevisiae antibody (p=0.000).

CONCLUSION

Due to the autoimmune nature of indeterminate colitis, involvement of some antigens from gastrointestinal tract or the bile system in the initiation of this disease is likely.

Antioxidant bioavailability and rapid immune-modulating effects after consumption of a single acute dose of a high-metabolite yeast immunogen: results of a placebo-controlled double-blinded crossover pilot study

The objective of this pilot study was to investigate the acute effects on circulating lymphocyte subsets, antioxidant status, and cytokine profile after consumption of EpiCor(®) (EP) (Embria Health Sciences, Ankeny, IA, USA), a dried fermentate produced from Saccharomyces cerevisiae, using a placebo-controlled randomized crossover study design with 12 healthy adult human subjects. EP contains high levels of bioavailable antioxidants and strongly activates natural killer (NK) cells in vitro. EP consumption has been shown to increase erythrocyte hematocrit levels, boost mucosal immune protection, reduce cold/flu symptoms, reduce seasonal allergy symptoms and the need for rescue medication, and increase salivary secretory immunoglobulin A levels. This warranted further study on immune effects in humans. A within-subject analysis of data collected before and at 1 and 2 hours after consumption of a single dose of 500 mg of EP versus placebo was performed. A transient reduction in circulating T and NK cell numbers was observed 2 hours post-consumption, suggesting that homing and recirculation of these cells, as part of healthy immune surveillance, were supported by EP. The increased expression of activation markers on the CD3(-) CD56(+) NK cell population was significant for CD69 at 1 hour post-consumption (CD25, P<.07; CD69, P<.05), whereas for CD25 it was significant at 2 hours after consumption (CD25, P<.03; CD69, P<.15). A rapid increase in serum interferon-γ was observed at 1 hour post-consumption (P<.07; after removal of two outlying data sets, P<.05) and may have contributed to the effects seen on NK and T cell subsets. Significant increase in serum antioxidant protection was seen 2 hours after consumption (P<.04). Thus consumption of a single 500 mg dose of EP provides a rapid and transient effect on the trafficking and activation status of specific lymphocyte subsets, as well as increased antioxidant protection.

Serum antibodies to Mycobacterium avium subspecies paratuberculosis combined with anti-Saccharomyces cerevisiae antibodies in Crohn's disease patients: prevalence and diagnostic role

BACKGROUND

Because Mycobacterium avium subspecies paratuberculosis (MAP), the etiologic agent of Johne's disease in ruminant, has been identified in the mucosal layer and deeper bowel wall in CD patients, the seroactivity against MAP may define a distinct subset of patients requiring individual treatment. The aim of this study was to assess the performance of anti-MAP antibodies in the diagnostic strategy for CD.

METHODS

Two hundred seventy-two individuals were included: 81 with CD, 36 with ulcerative colitis, 35 with coeliac diseases and 120 healthy blood donors. Anti-MAP were detected by ELISA using a purified protein derivative from MAP. Anti-Saccharomyces cerevisiae antibodies (ASCA) were detected by indirect immunofluorescence.

RESULTS

The sensitivity and specificity of anti-MAP and ASCA for CD diagnosis were similar (sensitivity: 0.33 ± 0.10 and 0.31 ± 0.10; specificity: 0.96 ± 0.03 and 0.98 ± 0.02, respectively). A combination of these two tests enabled an increase in sensitivity (0.53 ± 0.10), although specificity remained unchanged (0.95 ± 0.04). No correlation was found between anti-MAP positivity and clinical features such as age at onset and the duration of CD, disease location, or intestinal complications. Conversely, extra-intestinal manifestations of CD were statistically associated with a positivity of anti-MAP (48% vs. 24%, P = 0.028), mostly with respect to arthritis (44.5% vs. 13%, P < 0.002). Interestingly, anti-MAP and ASCA were also found in an active form of coeliac disease.

CONCLUSION

Our results suggest a complementary role of ASCA and anti-MAP for CD diagnosis and a possible common role of bacteria in small intestinal mucosal damage in CD and coeliac disease.

Serum anti-Saccharomyces cerevisiae antibodies in Greek patients with Behcet's disease

We tested 59 Greek patients with Behcet's Disease (BD) for serum anti-Saccharomyces cerevisiae antibodies. No increase of these antibodies was detected in the cases compared to 55 healthy unrelated blood donors from the same population. This finding is in contrast with the correlation between Saccharomyces cerevisiae antibodies and BD as reported in other populations. It seems that environmental factors may contribute to disease expression in different populations, producing different effects according to the individual's genetic predisposition. Saccharomyces cerevisiae antibodies do not seem to be of any significance in the Greek population.

Saccharomyces cerevisiae decreases inflammatory responses induced by F4+ enterotoxigenic Escherichia coli in porcine intestinal epithelial cells

Probiotic yeasts may provide protection against intestinal inflammation induced by enteric pathogens. In piglets, infection with F4+ enterotoxigenic Escherichia coli (ETEC) leads to inflammation, diarrhea and intestinal damage. In this study, we investigated whether the yeast strains Saccharomyces cerevisiae (Sc, strain CNCM I-3856) and S. cerevisiae variety boulardii (Sb, strain CNCM I-3799) decreased the expression of pro-inflammatory cytokines and chemokines in intestinal epithelial IPI-2I cells cultured with F4+ ETEC. Results showed that viable Sc inhibited the ETEC-induced TNF-α gene expression whereas Sb did not. In contrast, killed Sc failed to inhibit the expression of pro-inflammatory genes. This inhibition was dependent on secreted soluble factors. Sc culture supernatant decreased the TNF-α, IL-1α, IL-6, IL-8, CXCL2 and CCL20 ETEC-induced mRNA. Furthermore, Sc culture supernatant filtrated fraction < 10 kDa displayed the same effects excepted for TNF-α. Thus, our results extended to Sc (strain CNCM I-3856) the inhibitory effects of some probiotic yeast strains onto inflammation.

Molecular cloning and characterization of two novel hepcidins from orange-spotted grouper, Epinephelus coioides

Orange-spotted grouper, Epinephelus coioides is one of the most important economic species of marine-cultured fish in China and Southeast Asia countries. However, very little information of the innate immune mechanisms against microbial pathogens is available in grouper, Epinephelus sp. Hepcidin, as an antimicrobial peptide (AMP), is a very important component in the innate immune system and widespread in fish. In this study, two novel types of hepcidin gene (designated EC-hepcidin1 and EC-hepcidin2) were cloned from E. coioides. They consist of open reading frames (ORFs) of 267 bp and 263 bp encoding the putative peptides of 88 and 87 amino acids, respectively. The homologous identity of deduced amino acid sequences between EC-hepcidin1 and EC-hepcidin2 is up to 79%, and predicted mature regions of both them have four cysteines residues. Genomic DNAs of both EC-hepcidin1 and EC-hepcidin2 consist of three exons and two introns. RT-PCR results showed that EC-hepcidin1 transcript was most abundant in liver and less in stomach. However, the transcript of EC-hepcidin2 was only detected in liver. The expressions of both EC-hepcidins were up-regulated by microbial and viral challenges, and iron overload, respectively, and EC-hepcidin1 was more responsive. The growth of Gram-negative bacterium of Vibrio vulnificus and Gram-positive bacterium of Staphylococcus aureus was inhibited by synthetic EC-hepcidins, and EC-hepcidin1 displayed stronger antimicrobial activity. The replication of Singapore grouper iridovirus (SGIV) was inhibited in the EC-hepcidin1 and EC-hepcidin2 over-expressed stable transfected fish cell lines (GS/pcDNA-Hep1, GS/pcDNA-Hep2) indicative of the antiviral activity of EC-hepcidins. These data should offer important information on the antimicrobial and antiviral roles of EC-hepcidins, and will be help to the better understanding of molecular mechanisms of grouper innate immunity.

High levels of Crohn's disease-associated anti-microbial antibodies are present and independent of colitis in chronic granulomatous disease

Chronic granulomatous disease (CGD) and inflammatory bowel disease (IBD) have overlapping gastrointestinal manifestations. Serum antibodies to intestinal microbial antigens in IBD are thought to reflect a loss of tolerance in the setting of genetically encoded innate immune defects. CGD subjects studied here, with or without colitis, had considerably higher levels of ASCA IgA, ASCA IgG, anti-OmpC, anti-I2, and anti-CBir1, but absent to low pANCA, compared to IBD-predictive cutoffs. Higher antibody levels were not associated with a history of colitis. Except for higher ASCA IgG in subjects <18 years, antibody levels were not age-dependent. In comparison, 7 HIES subjects expressed negative to low antibody levels to all of these antigens; none had colitis. Our results suggest that markedly elevated levels of antimicrobial antibodies in CGD do not correlate with a history of colitis but may reflect a specific defect in innate immunity in the face of chronic antigenic stimulation.

Anti-Saccharomyces cerevisiae (ASCA) and anti-neutrophil cytoplasmic (ANCA) antibodies are not increased in Takayasu arteritis

OBJECTIVES

Takayasu arteritis (TA) may be associated with inflammatory bowel disease (IBD). As there is such an overlap and since both diseases show granulomatous histopathological lesions we reasoned similar biological pathways might be implicated in both conditions. Therefore, we investigated the prevalence of anti-Saccharomyces cerevisiae (ASCA) and anti-neutrophil cytoplasmic (ANCA) antibodies - serological markers for IBD-among patients with TA.

METHODS

Thirty-two patients with TA, 21 with Crohn's disease (CD), 17 with ulcerative colitis (UC) and 34 healthy controls were studied. Among 32 patients with TA, 2 had CD and one had UC concomitantly. ASCA Ig A and Ig G antibodies were analyzed using a commercial ELISA kit. Immune fluorescence analysis (IFA) was used to assess the presence of ANCA antibodies.

RESULTS

Only patients with CD had significantly higher levels of both ASCA Ig A and Ig G, compared to patients with TA and healthy controls. Similarly, the frequency of ASCA positive patients was higher only among patients with CD. ASCA Ig A and Ig G antibodies were found in 16 % (5/32) of patients with TA. Among 3 patients, in whom TA and IBD co-existed, only one (one with CD) had positive ASCA Ig G and A antibodies. The p-ANCA antibodies were present among patients with UC (35 %) and CD (10 %).

CONCLUSION

ASCA positivity in TA was similar to that found in UC and healthy controls. No ANCA antibodies were detected among patients with TA.

Dietary administration of the probiotic, Saccharomyces cerevisiae P13, enhanced the growth, innate immune responses, and disease resistance of the grouper, Epinephelus coioides

The percent weight gain (PWG) and feeding efficiency (FE) of Epinephelus coioides were calculated. The survival of Saccharomyces cerevisiae P13 in the posterior intestines using a specific primer pair of YMR245w-F/YMR245w-R, non-specific immune parameters of grouper, and its susceptibility to Streptococcus sp. and an iridovirus were determined when the fish were fed diets containing S. cerevisiae at 0 (control), 10(3), 10(5), or 10(7) colony-forming units (cfu) kg(-1) for 4 weeks. Results showed that grouper fed a diet containing S. cerevisiae at the levels of 10(3), 10(5), and 10(7) cfu kg(-1) had significantly increased PGW and FE especially in the 10(7) cfu kg(-1) group which were 211.6% and 1.2, respectively. S. cerevisiae was able to survive in the fish posterior intestines during the S. cerevisiae feeding period. Fish fed a diet containing S. cerevisiae at 10(7) cfu kg(-1) had significantly higher survival rates than those fed the 10(3) cfu kg(-1)S. cerevisiae diet and the control diet after challenge with Streptococcus sp. and an iridovirus, with increased survival rates of 26.6% and 36.6%, respectively, compared to the challenge control group. The phagocytic activity, respiratory burst and superoxide dismutase (SOD) level of head kidney leucocytes as well as serum lysozyme activity and serum alternative complement activity (ACH(50)) of fish fed diets containing S. cerevisiae at 10(5) and 10(7) cfu kg(-1) were significantly higher than those of fish fed the 10(3) cfu kg(-1)S. cerevisiae-contained diet and the control diets after 4 weeks of feeding, and had increased by 20% and 20%, 27.6% and 19.7%, 30.5% and 36.2%, 205.8% and 169.6%, and 90.8% and 80.3%, respectively, compared to the control group. We therefore recommend dietary S. cerevisiae administration of 10(5) and 10(7) cfu kg(-1) to E. coioides to promote growth and enhance immunity and resistance against Streptococcus sp. and an iridovirus especially in the 10(7) cfu kg(-1) group.

Serological markers for inflammatory bowel disease in AIDS patients with evidence of microbial translocation

BACKGROUND

Breakdown of the gut mucosal barrier during chronic HIV infection allows translocation of bacterial products such as lipopolysaccharides (LPS) from the gut into the circulation. Microbial translocation also occurs in inflammatory bowel disease (IBD). IBD serological markers are useful in the diagnosis of IBD and to differentiate between Crohn's disease (CD) and ulcerative colitis (UC). Here, we evaluate detection of IBD serological markers in HIV-infected patients with advanced disease and their relationship to HIV disease markers.

METHODS

IBD serological markers (ASCA, pANCA, anti-OmpC, and anti-CBir1) were measured by ELISA in plasma from AIDS patients (n = 26) with low CD4 counts (<300 cells/µl) and high plasma LPS levels, and results correlated with clinical data. For meta-analysis, relevant data were abstracted from 20 articles.

RESULTS

IBD serological markers were detected in approximately 65% of AIDS patients with evidence of microbial translocation. An antibody pattern consistent with IBD was detected in 46%; of these, 75% had a CD-like pattern. Meta-analysis of data from 20 published studies on IBD serological markers in CD, UC, and non-IBD control subjects indicated that IBD serological markers are detected more frequently in AIDS patients than in non-IBD disease controls and healthy controls, but less frequently than in CD patients. There was no association between IBD serological markers and HIV disease markers (plasma viral load and CD4 counts) in the study cohort.

CONCLUSIONS

IBD serological markers may provide a non-invasive approach to monitor HIV-related inflammatory gut disease. Further studies to investigate their clinical significance in HIV-infected individuals are warranted.

Recognition of yeast by murine macrophages requires mannan but not glucan

The first barrier against infection by Candida albicans involves fungal recognition and destruction by phagocytic cells of the innate immune system. It is well established that interactions between different phagocyte receptors and components of the fungal cell wall trigger phagocytosis and subsequent immune responses, but the fungal ligands mediating the initial stage of recognition have not been identified. Here, we describe a novel assay for fungal recognition and uptake by macrophages which monitors this early recognition step independently of other downstream events of phagocytosis. To analyze infection in live macrophages, we validated the neutrality of a codon-optimized red fluorescent protein (yEmRFP) biomarker in C. albicans; growth, hyphal formation, and virulence in infected mice and macrophages were unaffected by yEmRFP production. This permitted a new approach for studying phagocytosis by carrying out competition assays between red and green fluorescent yeast cells to measure the efficiency of yeast uptake by murine macrophages as a function of dimorphism or cell wall defects. These competition experiments demonstrate that, given a choice, macrophages display strong preferences for phagocytosis based on genus, species, and morphology. Candida glabrata and Saccharomyces cerevisiae are taken up by J774 macrophage cells more rapidly than C. albicans, and C. albicans yeast cells are favored over hyphal cells. Significantly, these preferences are mannan dependent. Mutations that affect mannan, but not those that affect glucan or chitin, reduce the uptake of yeast challenged with wild-type competitors by both J774 and primary murine macrophages. These results suggest that mannose side chains or mannosylated proteins are the ligands recognized by murine macrophages prior to fungal uptake.