Effect of dietary anti-urease immunoglobulin Y on Helicobacter pylori infection in Mongolian gerbils

Oral immunotherapy for Helicobacter pylori: Can it be trusted? A systematic review

BACKGROUND

Helicobacter pylori (H. pylori) is a rod-shaped, gram-negative, microaerophilic bacterium that can be identified by gram staining. Its relationship with cancer is significant since it is involved in approximately 80% of gastric cancers and 5.5% of all malignant cancers. Two lines of treatment have been defined for H. pylori, but almost 40% of patients do not respond to the first line. Recent trials have investigated oral Immunotherapy as a new treatment method. The aim of this systematic review was to investigate the potential effects of oral Immunotherapy on eradication rate of H. pylori in human studies.

METHODS

The systematic review was performed according to PRISMA guidelines. We searched online databases, including Scopus, PubMed, and Web of Science (ISI). Our search strategy was limited to English articles and studies on human populations that use oral immunotherapy for H. pylori.

RESULTS

The total number of primary research records in different databases was 2775. After removing duplicate articles (n = 870), we excluded 1829 for reasons including non-human studies, irrelevance to our study objective, non-English language, or lack of information. Of the remaining 76 articles, only seven had sufficient information, and the rest were excluded. The studies were divided into two groups: those that used bovine antibody and those that used immunoglobulin Y to eradicate H. pylori.

CONCLUSION

In the group of Immunoglobulin Y, three out of four studies suggest that using Immunoglobulin Y for the treatment of H. pylori infection is significant. However, the group using bovine antibody for the treatment of H. pylori infection has various results, as two out of three studies concluded that bovine antibody therapy is not significant.

IgYs: on her majesty's secret service

There has been an increasing interest in using Immunoglobulin Y (IgY) antibodies as an alternative to "classical" antimicrobials. Unlike traditional antibiotics, they can be utilized on a continual basis without leading to the development of resistance. The veterinary IgY antibody market is growing because of the demand for minimal antibiotic use in animal production. IgY antibodies are not as strong as antibiotics for treating infections, but they work well as preventative agents and are natural, nontoxic, and easy to produce. They can be administered orally and are well tolerated, even by young animals. Unlike antibiotics, oral IgY supplements support the microbiome that plays a vital role in maintaining overall health, including immune system function. IgY formulations can be delivered as egg yolk powder and do not require extensive purification. Lipids in IgY supplements improve antibody stability in the digestive tract. Given this, using IgY antibodies as an alternative to antimicrobials has garnered interest. In this review, we will examine their antibacterial potential.

Egg yolk antibody combined with bismuth-based quadruple therapy in Helicobacter pylori infection rescue treatment: a single-center, randomized, controlled study

Background

The increasing antibiotic resistance is the main issue causing Helicobacter pylori (H. pylori) eradication failure. As a nutritional supplement, Egg Yolk Antibody (Ig Y) provides a new approach for H. pylori infection rescue therapy.

Methods

In this randomized, controlled study, 100 H. pylori-positive patients with previous H. pylori eradication treatment were included. All individuals received standard bismuth-containing quadruple therapy twice daily (5 mg ilaprazole, 100 mg doxycycline, 500 mg clarithromycin or 1 g amoxicillin or 100 mg furazolidone, and 220 mg colloidal bismuth tartrate) for 14 days and were randomized to receive either twice daily 7 g Ig Y-H. pylori treatment (study group) or not (control group). 4 weeks after the end of treatment, urea breath tests were used to assess the H. pylori eradication rate. All participants scored by the Global Overall Symptom scale (GOS) and recorded adverse events during the trial.

Results

The H. pylori eradication rates were 84.0% (95% CI 73.5-94.5%) vs. 80.0% (95% CI 68.5-91.5%) in the study and control groups at intention-to-treat (ITT) analysis and 85.7% (95% CI 75.6-95.9%) vs. 80.0% (95% CI 68.5-91.5%) at per-protocol (PP) analysis, respectively. The number of over 80% symptom relief after treatment in the two groups was 27 (60%) and 12 (29.2%) (p < 0.05), and the incidences of adverse events were 4 (8%) and 6 (12%), respectively.

Conclusion

Both groups achieved satisfactory eradication efficiency in H. pylori rescue therapy and Ig Y-H. pylori effectively alleviates the symptoms with good compliance and fewer adverse effects.

IgY antibodies: The promising potential to overcome antibiotic resistance

Antibiotic resistant bacteria are a growing threat to global health security. Whilst the emergence of antimicrobial resistance (AMR) is a natural phenomenon, it is also driven by antibiotic exposure in health care, agriculture, and the environment. Antibiotic pressure and inappropriate use of antibiotics are important factors which drive resistance. Apart from their use to treat bacterial infections in humans, antibiotics also play an important role in animal husbandry. With limited antibiotic options, alternate strategies are required to overcome AMR. Passive immunization through oral, nasal and topical administration of egg yolk-derived IgY antibodies from immunized chickens were recently shown to be effective for treating bacterial infections in animals and humans. Immunization of chickens with specific antigens offers the possibility of creating specific antibodies targeting a wide range of antibiotic-resistant bacteria. In this review, we describe the growing global problem of antimicrobial resistance and highlight the promising potential of the use of egg yolk IgY antibodies for the treatment of bacterial infections, particularly those listed in the World Health Organization priority list.

Synbiotic-IgY Therapy Modulates the Mucosal Microbiome and Inflammatory Indices in Dogs with Chronic Inflammatory Enteropathy: A Randomized, Double-Blind, Placebo-Controlled Study

Chronic inflammatory enteropathy (CE) is a common cause of persistent gastrointestinal signs and intestinal inflammation in dogs. Since evidence links dysbiosis to mucosal inflammation, probiotics, prebiotics, or their combination (synbiotics) may reduce intestinal inflammation and ameliorate dysbiosis in affected dogs. This study's aim was to investigate the effects of the synbiotic-IgY supplement on clinical signs, inflammatory indices, and mucosal microbiota in dogs with CE. Dogs with CE were enrolled in a randomized prospective trial. Twenty-four client-owned dogs were fed a hydrolyzed diet and administered supplement or placebo (diet) for 6 weeks. Dogs were evaluated at diagnosis and 2- and 6-week post-treatment. Outcome measures included clinical activity, endoscopic and histologic scores, inflammatory markers (fecal calprotectin, C-reactive protein), and composition of the mucosal microbiota via FISH. Eleven supplement- and nine placebo-treated dogs completed the trial. After 6 weeks of therapy, clinical activity and endoscopic scores decreased in both groups. Compared to placebo-treated dogs, dogs administered supplement showed decreased calprotectin at 2-week post-treatment, decreased CRP at 2- and 6-week post-treatment increased mucosal Clostridia and Bacteroides and decreased Enterobacteriaceae in colonic biopsies at trial completion. Results suggest a beneficial effect of diet and supplements on host responses and mucosal microbiota in dogs with CE.

Potential Therapeutic Effects of Egg Yolk Antibody (IgY) in Helicobacter pylori Infections─A Review

Currently, the infection with Helicobacter pylori affects about half of the world's population, and the most common therapy to treat H. pylori is the first line clarithromycin-based triple therapy or the quadruple therapy. However, drug resistance, eradication in a low level, high rate of reinfection, and gastrointestinal side effects among the causative organisms for H. pylori infection pose a critical challenge to the global health care community. Therefore, new approaches to treat H. pylori infections are urgently needed. Chicken egg yolk constituting a source of immunoglobulin Y (IgY) has attracted noticeable attention for its advantages of cost-effective extraction, minimization of animal harm and suffering, and induction of no specific resistance and is, therefore, being regarded as an alternative therapy for H. pylori infection. This review is intended to summarize various H. pylori antigens for IgY preparation in terms of their application, mechanism, and limitations.

Dietary multivalent anti-Helicobacter pylori immunoglobulin Y significantly increase the H. pylori eradication and improve the clinical symptoms in patients

BACKGROUND

The oral chicken immunoglobulin Y (IgY) as a novel model of immunotherapy to control Helicobacter pylori (H. pylori, Hp) infection has gained much interest in recent years. However, none of the current IgY therapies showed a total eradication of H. pylori on patients.

METHODS

In this report, the recombinant antigens of H. pylori, including UreB (1710 bp), BabA2 (1269 bp), and FlaA (399 bp), were, respectively, expressed and purified, and then mixed and subjected to immunize laying hens for the preparation of multivalent anti-H. pylori immunoglobulin Y (anti-Hp mIgY). Next, the biological activities of anti-Hp mIgY, including the recognition to antigens and the inhibition on H. pylori growth, were tested. Moreover, to perform a clinical trial, 94 Hp-infected patients, according to the values of ¹³ C urea breath test and the characteristics of gastroscopy of volunteers, were enrolled to evaluate the effects of dietary anti-Hp mIgY against H. pylori infection. After continuous dietary of anti-Hp mIgY for 2 weeks, the oral administration was terminated. The clinical symptoms of the patients were followed up at 2nd, 4th, and 6th week, respectively, and the ¹³ C urea breath test were re-examined at 6th week.

RESULTS

The anti-Hp mIgY could bind to recombinant antigens very well, and the titers of anti-Hp mIgY to UreB, Baba2, and FlaA, are 62.5, 125, and 250 μg/ml, respectively. The in vitro antibacterial test showed that the 2 mg/ml of anti-Hp mIgY could completely inhibit the H. pylori growth for 36 h. After a 2-week dietary of anti-Hp mIgY, the value of ¹³ C urea breath test was significantly decreased by 56.0% (25.9 ± 14.1 vs 11.4 ± 9.78, p < 0.001), the total improvement rate of clinical symptoms in volunteers was 87.3%, and the H. pylori eradication rate was 30.6%.

CONCLUSION

Two-week dietary of anti-Hp mIgY greatly improved the clinical symptoms and the quality of life of Hp-infected patients, and the H. pylori eradication rate reached up to 30.6%.

Immunoglobulin Y for Potential Diagnostic and Therapeutic Applications in Infectious Diseases

Antiviral, antibacterial, and antiparasitic drugs and vaccines are essential to maintaining the health of humans and animals. Yet, their production can be slow and expensive, and efficacy lost once pathogens mount resistance. Chicken immunoglobulin Y (IgY) is a highly conserved homolog of human immunoglobulin G (IgG) that has shown benefits and a favorable safety profile, primarily in animal models of human infectious diseases. IgY is fast-acting, easy to produce, and low cost. IgY antibodies can readily be generated in large quantities with minimal environmental harm or infrastructure investment by using egg-laying hens. We summarize a variety of IgY uses, focusing on their potential for the detection, prevention, and treatment of human and animal infections.

Preventive effect of anti-VacA egg yolk immunoglobulin (IgY) on Helicobacter pylori-infected mice

BACKGROUND

Helicobacter pylori, a gram-negative bacterium, is the causative agent of gastric disorders and gastric cancer in the human stomach. Vacuolating cytotoxin A (VacA) is among the multi-effect protein toxins released by H. pylori that enables its persistence in the human stomach.

METHODS

To evaluate the effect of anti-VacA egg yolk immunoglobulin (anti-VacA IgY) on H. pylori infection, a highly specific anti-VacA IgY was produced from egg yolks of hens immunized with a mixture of two purified recombinant VacAs. Female C57BL/6 mice were supplemented anti-VacA IgY daily with drinking water for 2 weeks before and 4 weeks after H. pylori ATCC 43504 inoculation. Anti-VacA IgY recognized both native and denatured structures of VacA by enzyme-linked immunosorbent assay and immunoblotting analyses, respectively.

RESULTS

Oral administration of anti-VacA IgYs significantly (p < .05) reduced the serum levels of anti-H. pylori antibodies compared to those in the H. pylori-infected, untreated group. The reduction in the immune response was accompanied by a significant (p < .05) decrease in eosinophilic infiltration of the stomach in anti-VacA IgY treated group compared to other groups. Concomitantly, H. pylori-induced histological changes and H. pylori antigen-positivity in gastric tissues were decreased significantly (p < .05) in anti-VacA IgY treated group similar to the control group.

CONCLUSIONS

Oral administration of anti-VacA IgY is correlated with a protective effect against H. pylori colonization and induced histological changes in gastric tissues. Our experimental study has proved that it is expected to be a new drug candidate of Hp infection by further study.

Anti-Vibriocholerae IgY Antibody Inhibits Mortality in Suckling Mice Model

BACKGROUND

Regarding to the importance of cholera in Iran and the potential advantages of egg yolk antibody (IgY) for immunotherapy, the aim of this study was to produce IgY antibody against V. cholerae Lipopolysaccharide (LPS) and determine its potential for V. cholerae treatment.

METHODS

LPS was prepared, and the Anti-V. cholerae LPS IgY was purified from egg yolk and serially diluted in phosphate-buffered saline (PBS), mixed with V. cholerae and then gavaged into several groups of suckling mice.

RESULTS

The yield of Anti-LPS IgY extraction was 40 mg/Egg yolk. The results demonstrated that up to approximately 75 ng of IgY can detect specifically V. cholerae. The lowest protective dose of anti-V. cholerae LPS IgY was 2.5 μg.

CONCLUSIONS

The produced anti-Vibrio LPS specific IgY showed a good reactivity with its specific antigen and it may use as a complimentary oral immunotherapy for cholera disease.

Inhibitory effects of rHP-NAP IgY against Helicobacter pylori attachment to AGS cell line

Helicobacter pylori is a major human pathogen related to gastric adenocarcinoma and gastroduodenal diseases. Treatment of H. pylori infections is complicated by the rise of antibiotic resistance, necessitating investigation of alternative therapies. One such alternative is passive immunization by oral administration of antibacterial immunoglobulin. In the present study, chicken immunoglobulin (IgY) was used for passive immunotherapy against a major virulence factor of H. pylori, namely recombinant HP-Nap protein. Recombinant HP-Nap was prepared and used to immunize hens. IgY was purified from the eggs by polyethylene glycol precipitation method with a total IgY-HP-NAP yield of 30 mg per egg. The inhibitory effect of specific IgY on H. pylori attachment was investigated in AGS cell line infected by the bacteria. The results demonstrate the potent effect of IgY- HP-NAP in inhibition of H. pylori attachment to the AGS cells.

Production of specific IgY Helicobacter pylori recombinant OipA protein and assessment of its inhibitory effects towards attachment of H. pylori to AGS cell line

Purpose

The common triple therapy for Helicobacter pylori is challenged by the increasing cases of antibiotic resistant infections, raising the need to explore alternative therapies. Oral administration of egg yolk immunoglobulin Y (IgY) has been previously reported as a means of passive immunization therapy for H. pylori infections. In this work, we investigated the inhibitory effect of IgY on the attachment of H. pylori to AGS cell line.

Materials and Methods

Recombinant OipA was prepared. Hens were immunized with recombinant protein three times. IgY was purified from egg yolks of immunized hens using polyethylene glycol precipitation method. The inhibitory effect of the specific immunoglobulin was evaluated in AGS cell line infected with H. pylori.

Results

The presence of recombinant OipA (30 kD) was confirmed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunization of hens was confirmed using enzyme-linked immunosorbent assay. The purified IgY from egg yolks were assessed using SDS-PAGE and confirmed by western blot.

Conclusion

The results showed that IgY-OipA had inhibitory effect on attachment of H. pylori to AGS cell line and may be utilized as a therapeutic or prophylaxis material.

Passive Immunization

Whereas active immunity refers to the process of exposing the individual to an antigen to generate an adaptive immune response, passive immunity refers to the transfer of antibodies from one individual to another. Passive immunity provides immediate but short-lived protection, lasting several weeks up to 3 or 4 months. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta or from breast milk to the gut of the infant. It can also be produced artificially, when antibody preparations derived from sera or secretions of immunized donors or, more recently, different antibody producing platforms are transferred via systemic or mucosal route to nonimmune individuals. Passive immunization has recently become an attractive approach because of the emergence of new and drug-resistant microorganisms, diseases that are unresponsive to drug therapy and individuals with an impaired immune system who are unable to respond to conventional vaccines. This chapter addresses the contributions of natural and artificial acquired passive immunity in understanding the concept of passive immunization. We will mainly focus on administration of antibodies for protection against various infectious agents entering through mucosal surfaces.

Use of Candida-specific chicken egg yolk antibodies to inhibit the adhering of Candida to denture base materials: prevention of denture stomatitis

OBJECTIVES

Polyclonal anti-Candida chicken egg yolk antibodies (anti-IgY) were used to investigate the prevention of adherence of Candida species to denture base material in vitro.

BACKGROUND

Candida is a potential virulence factor that can cause systemic infection and even death in immunocompromised individuals. Because long-term antifungal treatment may lead to the emergence of drug-resistant strains, it is necessary to develop novel preventive measures and treatments for candidiasis.

MATERIALS AND METHODS

Three types of chicken egg yolk antibodies were used in this study: non-specific antibody (control IgY), Candida albicans-specific antibody (anti-C.a.IgY) and Candida glabrata-specific antibody (anti-C.g.IgY). A mixture of different dilutions of each antibody with a suspension of Candida species and denture base material was incubated for 3 h, and then the colony-forming units of Candida on the denture base material were counted.

RESULTS

Compared with control IgY, anti-C.a.IgY and anti-C.g.IgY significantly inhibited the adherence of C. albicans, but anti-C.a.IgY tended to be more potent than anti-C.g.IgY. The adherence of C. glabrata was also inhibited significantly by anti-C.a.IgY and anti-C.g.IgY with almost equivalent potency, indicating that their actions against C. glabrata were comparable.

CONCLUSIONS

This study revealed the inhibitory effects of anti-C.a.IgY and anti-C.g.IgY against the adherence of C. albicans and C. glabrata to denture base material. This finding indicates the possibility of a beneficial effect of IgYs for the prevention of denture stomatitis and candidiasis in clinical settings.

Clinical significance of expression of microRNA-34a and Notch1 in hepatocellular carcinoma

AIM: To detect the expressions of microRNA-34a and Notch1 in hepatocellular carcinoma (HCC) and to explore their relationships with HCC occurrence and development and the clinical and pathological features of HCC.

METHODS: Real-time RT-PCR and immunohistochemistry were used to detect the expression of microRNA-34a and Notch1 protein in 132 HCC tissues, matched tumor-adjacent tissues and 49 normal liver tissues, respectively.

RESULTS: The expression of microRNA-34a in HCC tissues were significantly lower than that in tumor-adjacent tissues (P = 0.003) and normal liver tissues (P < 0.001). The expression of microRNA-34a in HCC tissues with metastasis was significantly lower than that in HCC tissues without metastasis (P = 0.014). The expression of Notch1 was significantly higher in HCC tissues than in tumor-adjacent tissues (P = 0.001) and normal liver tissues (P < 0.001). The expression of Notch1 in HCC tissues with metastasis was significantly lower than that in HCC tissues without metastasis (P = 0.008). The expression of microRNA-34a was negatively correlated with that of Notch1 in HCC and tumor-adjacent tissues (r = -0.259, P = 0.003; r = -0.274, P = 0.002). The expression of microRNA-34a and Notch1 in HCC had no correlation with patient age, gender, liver cirrhosis, tumor site, viral hepatitis, or AFP (P > 0.05 for all), but was closely correlated with tumor malignancy, tumor size, lymph node metastasis, tumor number, infiltration depth, and TNM stage (P < 0.05 for all). The 3-year survival rate in the group with low expression of microRNA-34a and high expression of Notch1 (11.3%) was significantly lower than that in the group with high expression of microRNA-34a and low expression of Notch1 (34.7%)(χ² = 38.163, P = 0.011).

CONCLUSION: The expression of microRNA-34a is significantly down-regulated in HCC tissues, which may reversely regulate its target protein Notch1. Detecting the expression of microRNA-34a and Notch1 in HCC had a potential significance for diagnosis, therapy and prognosis of HCC.

Effectiveness of egg yolk antibody against shiga toxin II variant toxicity in vitro and in vivo

We prepared anti-Shiga toxin II variant (Stx2e) and anti-Stx2e B antibodies in chicken egg yolk and investigated their effectiveness in vitro and in vivo. Both Egg yolk antibodies (IgY) reduced the cytotoxic effects of Stx2e to Vero cells. The protective efficacy of anti-Stx2e IgY and anti-Stx2e B IgY was investigated in clean Kunming mice, which were experimentally induced with Stx2e. Peritoneal injection of anti-Stx2e IgY and anti-Stx2e B IgY apparently reduced the lethal effect of Stx2e to mice. These results indicate that both anti-Stx2e IgY and anti-Stx2e B IgY could protect mice from Stx2e challenge. Therefore, anti-Stx2e IgY or anti-Stx2e B IgY might be considered as potential candidate for therapeutics for porcine edema disease.

Designer foods and their benefits: A review

Designer foods are normal foods fortified with health promoting ingredients. These foods are similar in appearance to normal foods and are consumed regularly as a part of diet. In this article we have reviewed the global regulatory status and benefits of available designer foods such as designer egg, designer milk, designer grains, probiotics, designer foods enriched with micro and macronutrients and designer proteins. Designer foods are produced by the process of fortification or nutrification. With the advances in the biotechnology, biofortification of foods using technologies such as recombinant DNA technology and fermentation procedures are gaining advantage in the industry. The ultimate acceptability and extensive use of designer foods depend on proper regulation in the market by the regulatory authorities of the country and by creating consumer awareness about their health benefits through various nationwide programs.

Oral passive IgY-based immunotherapeutics: a novel solution for prevention and treatment of alimentary tract diseases

This commentary summarizes the laboratory investigations and clinical trials published recently involving per-oral application of IgY supplemented food for specific orogastrointestinal disease prevention and control purposes. The prolonged use and misuse of conventional antibacterial drugs has spawned antibiotic resistant microbes prompting scientists to search for other germ-killing options. In particular, the use of IgY as a novel mode of immunotherapy using oral chicken immunoglobulin (IgY) to confer passive immunity has gained much interest as an inexpensive non-antibiotic alternative for the prophylaxis and treatment of a wide variety of infectious diseases. The stability of IgY in the orogastrointestinal tract and its safety profile has been well-documented. IgY has been used in the treatment or prevention of dental caries, periodontitis and gingivitis, gastritis and gastric ulcer, oral thrush and infant rotavirus diarrhea. The recent clinical trials on IgY with encouraging results has catapulted into the market novel nutraceutical or health supplements for therapeutic or prophylactic intervention based on the consumption of mono-specific or mixed IgY formulations. With recent trends in consumer preference for natural materials to alleviate health concerns, the increasing healthcare costs and the recent advances in drug delivery systems, IgY is likely to shift from its mainly functional food status toward pharmaceuticalization in the foreseeable future.

Avian IgY antibodies and their recombinant equivalents in research, diagnostics and therapy

The generation and use of avian antibodies is of increasing interest in a wide variety of applications within the life sciences. Due to their phylogenetic distance, mechanisms of immune diversification and the way in which they deposit IgY immunoglobulin in the egg yolk, chickens provide a number of advantages compared to mammals as hosts for immunization. These advantages include: the one-step purification of antibodies from egg yolk in large amounts facilitates having a virtually continuous supply; the epitope spectrum of avian antibodies potentially grants access to novel specificities; the broad absence of cross-reactivity with mammalian epitopes avoids assay interference and improves the performance of immunological techniques. The polyclonal nature of IgY antibodies has limited their use since avian hybridoma techniques are not well established. Recombinant IgY, however, can be generated from mammalian monoclonal antibodies which makes it possible to further exploit the advantageous properties of the IgY scaffold. Moreover, cloning and selecting the immune repertoire from avian organisms is highly efficient, yielding antigen-specific antibody fragments. The recombinant approach is well suited to circumvent any limitations of polyclonal antibodies. This review presents comprehensive information on the generation, purification, modification and applications of polyclonal and monoclonal IgY antibodies.

Stimulation of IgY responses in gene gun immunized laying hens by combined administration of vector DNA coding for the target antigen Botulinum toxin A1 and for avian cytokine adjuvants

DNA immunization is a convenient and effective way of inducing a specific antibody response. In mammals, co-administration of vectors encoding immunostimulatory cytokines can enhance the humoral response resulting in elevated antibody titers. We therefore set out to investigate the effect using avian interleukin 1β (IL-1β) and avian interleukin 6 (IL-6) as genetic adjuvants when immunizing laying hens. A BoNT A1 holotoxoid DNA immunogen carrying two inactivating mutations was evaluated for its ability to induce a specific and sustained IgY antibody response. Both the holotoxoid and the cytokine sequences were codon-optimized. In vitro, the proteins were efficiently expressed in transfected HEK 293T cells and the cytokines were secreted into the culture supernatants. Whereas eggs from hens immunized via gene gun using a prime boost strategy showed no differences in their total IgY content, the specific αBoNT A1 response was slightly elevated up to 1.4× by the IL-1β adjuvant vector and increased by 3.8× by the IL-6 vector. Finally, although hens receiving the IL-1β adjuvant had laying capacities above the average, hens receiving the IL-6 adjuvant experienced laying problems.

Anti-Helicobacter pylori effects of IgY from egg york of immunized hens

Effects of egg york containing IgY specific for Helicobacter pylori on the bacterial growth and intragastric infection were investigated in comparison with a proton-pump inhibitor pantoprazole. For in vitro anti-bacterial activity test, H. pylori (1×10(8) CFU/mL) was incubated with a serially diluted IgY for 3 days. As a result, IgY fully inhibited the bacterial growth at 16 mg/mL, which was determined to a minimal inhibitory concentration. In vivo elimination study, male C57BL/6 mice were infected with the bacteria by intragastric inoculation (1×10(8) CFU/mouse) 3 times at 2-day intervals, and 2 weeks later, orally treated twice a day with 50, 100, 200 or 500 mg/kg IgY for 18 days. After the final administration, biopsy sample of the gastric mucosa was assayed for the bacterial identification via urease, oxidase, catalase, nitrate reduction and H(2)S tests in addition to microscopic examination for mucosal inflammation. In CLO kit test, 75, 50, 12.5 and 12.5% of the animals revealed positive reaction following treatment with 50, 100, 200 and 500 mg/kg IgY, respectively, resulting in a superior efficacy at 200 mg/kg than 30 mg/kg pantoprazole that displayed 75% elimination. The CLO test results were confirmed by bacterial identification. Microscopic examination revealed that H. pylori infection caused severe gastric mucosal inflammation, which were not observed in the CLO-negative mice following treatment with IgY or pantoprazole. Taken together, IgY inhibited the growth of H. pylori, and improved gastritis and villi injuries by eliminating the bacteria from the stomach. The results indicate that IgY could be a good candidate overcoming tolerance of antibiotics for the treatment of H. pylori-mediated gastric ulcers.

Treatment of Helicobacter pylori infection in mice with oral administration of egg yolk-driven anti-UreC immunoglobulin

BACKGROUND

Helicobacter pylori, the causative agent of gastritis and gastric ulcer, plays a crucial role in development of gastric carcinomas. Antibiotic therapy fails in almost 20% of cases due to development of antibiotic resistance. Development of antibodies against specific H. pylori targets could have significant therapeutic effect. In the present research attempts have been made to study the effect of IgY purified from egg yolk of hens immunized with recombinant UreC in treatment of mice infected with H. pylori.

MATERIALS AND METHODS

Purified IgY-HpUc was used in two forms: powdered and PBS dissolved. 10(9) bacteria in BHI were orally administered to C57BL6/j mice three times on alternate day intervals. Eight weeks after the last inoculation, the serum was assayed for infection rate by ELISA. The severity of gastritis was analyzed histopathologically. Infected mice were randomly divided into three groups. Groups one and two were treated with dietary IgY-HpUc and IgY-HpUc dissolved in PBS respectively for 28 days. The untreated group served as control.

RESULTS

Serology and histopathology confirmed the establishment of the infection. Indirect ELISA results in the treated animals showed considerable reduction of H. pylori specific antibodies in their sera. Pathological examination of gastric mucosa of infected mice treated with IgY-HpUc showed considerable reduction of inflammation in the stomach tissues. The bacterial presence on mucosal layer of the stomach was considerably reduced.

CONCLUSIONS

UreC-induced IgY is specifically successful in inhibition of H. pylori infection and could be an alternative to antibiotic treatment.

Preparation of immunoglobulin Y (IgY) against lipopolysaccharide using gel chromatography from the yolks of eggs laid by immunized hens

The objective is to prevent and treat injuries caused by lipopolysaccharide (LPS) from gram negative bacteria in animals and humans, we produced antibodies against LPS from egg yolk. LPS from E. coli (O111:B4) mixed with Freund's Adjuvant was used as the immunogen to immunize Roman hens. Immunized eggs were collected, and immunoglobulin Y (IgY) was purified using a water solution, salt precipitation and gel chromatography. The molecular weight and purity were determined by SDS-PAGE, the antibody titer by noncompetitive enzyme-linked immunosorbent assay (ELISA) and antibody activity against LPS by the mortality of mice intraperitoneally injected with LPS or LPS-IgY solutions. IgY against LPS showed two protein bands at 68 and 26 kDa on the gel; the antibody titer was almost 1:25,600. After incubation with LPS, IgY decreased the mortality of mice challenged with LPS. This study provided an efficient way to produce high-titer egg yolk antibodies, which could attenuate lethal effects of LPS, by immunizing hens. Furthermore, the LPS antibody was purified well using a water solution, salting-out and gel chromatography.

Analysis of the microflora in the stomach of Mongolian gerbils infected with Helicobacter pylori

BACKGROUND AND AIMS

Mongolian gerbils are frequently used to study Helicobacter pylori-induced gastritis and its consequences. The presence of some gastric flora with a suppressive effect on H. pylori suggests inhibitory microflora against H. pylori infection. The aim of the present study was to analyze the microflora in the stomach of Mongolian gerbils with H. pylori infection.

METHODS

H. pylori ureA was detected by polymerase chain reaction (PCR) in the fecal samples of infected Mongolian gerbils. H. pylori was isolated from the gastric mucosa of the gerbils by microaerophilic cultivation. Gastric microflora were isolated by aerobic and anaerobic culture, and the identification of gastric bacterial species was performed by API20E and API20A.

RESULTS

Oral administration of H. pylori TK1402 induced colonization and gastric inflammation of the stomach of the Mongolian gerbils. According to the frequency of detection of H. pylori ureA in fecal samples, the gerbils were divided into three groups (frequently detected, moderately detected and infrequently detected). According to the analysis of the gastric microflora in the frequently and infrequently detected groups, Lactobacillus spp. and Eubacterium limosum were isolated from the former and latter group, respectively.

CONCLUSION

Some gastric flora, such as Lactobacillus spp., may inhibit colonization by H. pylori.

Antibody-mediated protection against infection with Helicobacter pylori in a suckling mouse model of passive immunity

Studies of active immunization against Helicobacter pylori indicate that antibodies play a minor role in immunity. There is also evidence, however, that the translocation of antibodies in the stomach may be insufficient to achieve functional antibody levels in the gastric lumen. We have used a suckling mouse model of passive immunity to determine if perorally delivered antibodies can protect against infection with H. pylori. Female C57BL/6 mice were immunized parenterally with formalin-fixed cells of three clinical isolates of H. pylori (3HP) or the mouse-adapted H. pylori strain SS1 before mating. Their pups were challenged with the SS1 strain at 4 days of age and left to suckle before determination of bacterial loads 14 days later. Compared to age-matched controls, pups suckled by 3HP-vaccinated dams were significantly protected against infection (>95% reduction in median bacterial load; P<0.0001). Pups suckled by SS1-vaccinated dams were also significantly protected in terms of both median bacterial load (>99.5% reduction; P<0.0001) and the number of culture-negative pups (28% versus 2% for immune and nonimmune cohorts, respectively; P<0.0001). Similar results were obtained with pups suckled by dams immunized with a urease-deficient mutant of SS1. Fostering experiments demonstrated that protection was entirely attributable to suckling from an immunized dam, and antibody isotype analysis suggested that protection was mediated by the immunoglobulin G fraction of immune milk. Analysis of the bacterial loads in pups sampled before and after weaning confirmed that infection had been prevented in culture-negative animals. These data indicate that antibodies can prevent colonization by H. pylori and suppress the bacterial loads in animals that are colonized.

In vitro and in vivo effectiveness of egg yolk antibody against Candida albicans (anti-CA IgY)

We prepared anti-Candida albicans antibody in chicken egg yolk (anti-CA IgY) and investigated its in vitro and in vivo effectiveness. Anti-CA IgY significantly reduced the adherence capacity of C. albicans to FaDu cells (human pharynx carcinoma cells) in a dose-dependent manner. The protective efficacy of anti-CA IgY was investigated in experimentally induced oral candidiasis in immunosuppressed mice. Oral administration of anti-CA IgY significantly reduced the number of C. albicans and the scores of the tongue lesions. Moreover, anti-CA IgY reduced the colonization of C. albicans in mice organs. These results indicate that anti-CA IgY has a protective effect against the oral candidiasis of experimentally infected mice and reduces the dissemination of C. albicans. Putting together, these results indicate that anti-CA IgY is effective against C. albicans. This effect might be due to the blocking of the binding of C. albicans to the host cells. Therefore, anti-CA IgY might be considered as a prophylactic immunotherapy or possibly an adjunctive antifungal therapy.

Conventional, regulatory, and unconventional T cells in the immunologic response to Helicobacter pylori

Infection by the gastroduodenal pathogen Helicobacter pylori elicits a complex immunologic response in the mucosa involving neutrophils, plasma cells, eosinophils, and lymphocytes, of which T cells are the principal orchestrators of immunity. While so-called classical T cells (e.g. T-helper cells) that are activated by peptide fragments presented on antigen-presenting cells have received much attention in H. pylori infection, there exists a diverse array of other T cell populations that are potentially important for the outcome of the ensuing immune response, some of which have not been extensively studied in H. pylori infection. Pathogen-specific regulatory T cells that control and prevent the development of immunopathology associated with H. pylori infection have been investigated, but these cells can also benefit the bacterium in helping to prolong the chronicity of the infection by suppressing protective immune responses. An overlooked T cell population, the more recently described Th17 cells, may play a role in H. pylori-induced inflammation, due to triggering responses that ultimately lead to the recruitment of polymorphs, including neutrophils. The so-called innate or unconventional T cells, that include two conserved T cell subsets expressing invariant antigen-specific receptors, the CD1d-restricted natural killer T cells which are activated by glycolipids, and the mucosal-associated invariant T cells which play a role in defense against orally acquired pathogens in the intestinal mucosa, have only begun to receive attention. A greater knowledge of the range of T cell responses induced by H. pylori is required for a deeper understanding of the pathogenesis of this bacterium and its ability to perpetuate chronic infection, and could reveal new strategies for therapeutic exploitation.

Egg yolk-derived immunoglobulin (IgY) against Porphyromonas gingivalis 40-kDa outer membrane protein inhibits coaggregation activity

The anaerobic bacterium Porphyromonas gingivalis, a major pathogen in periodontitis, aggregates with a number of oral bacteria to form dental plaque, which is important for its colonization. We previously cloned the gene coding the 40-kDa outer membrane protein (OMP) of P. gingivalis 381 and produced large amounts of the recombinant (r) protein. Affinity-purified rabbit antiserum against r40-kDa OMP effectively inhibited the coaggregation activity of P. gingivalis to oral bacteria, thus 40-kDa OMP was thought to be an important coaggregation factor of P. gingivalis. Further, since it is conserved among many P. gingivalis strains, this coaggregation factor may be an effective target for passive immunotherapy against P. gingivalis infection. Recently, passive immunization approaches using a specific antibody produced from hen egg yolk (IgY) have been developed for oral infectious diseases, and shown to be convenient and economic. In the present study, we immunized hens intramuscularly with r40-kDa OMP and obtained highly purified IgY from the egg yolks. The purified IgY specifically recognized r40-kDa OMP and also reacted with a functional coaggregation-associated domain peptide of 40-kDa OMP. Our results demonstrated that a ratio of purified IgY as low as 2.5 microg/150 microl significantly inhibited the coaggregation of P. gingivalis with Streptococcus gordonii, which was verified by a visual coaggregation assay and radioactivity-based quantitative micro-coaggregation assay. We concluded anti-r40-kDa OMP IgY may be useful for passive immunization against periodontal diseases caused by P. gingivalis infection.

Preparation of egg yolk immunoglubin against recombinant vacuolating cytotoxin A-Helicobacter pylori adhesin A in Helicobacter pylori

AIM: To prepare a highly specific and efficient egg yolk immunoglubin (IgY) against recombinant vacuolating cytotoxin A-Helicobacter pylori adhesin A (VacA-HpaA) from the yolk of hen's eggs.

METHODS: Recombinant bacteria of pQE30-VacA-HpaA-DH5α was cultured in large numbers to get VacA-HpaA fusion protein. The recombinant protein was purified by Ni2+-NTA column chromatography and used to immunize the hens. The VacA-HpaA IgY was extracted from the yolk of hen's eggs by water-dilution methods. In order to evaluate the relationship between IgY titer and immune time, the titer of IgY was detected by enzyme-linked immunosorbent assay (ELISA). IgY was purified and concentrated by deposition technique with ammonium sulfate. The purity of IgY was analyzed by SDS-PAGE, and protein content of IgY was checked by Bradford method. The specificities of VacA-HpaA IgY to the antigens of VacA and HpaA were identified by Western blotting.

RESULTS: The recombinant protein was mainly expressed as inclusion body. The content of fusion protein was 0.72 g/L. VacA-HpaA IgY from eggs' yolk of hens immunized with the fusion protein could react with the fusion protein. The titer of VacA-HpaA IgY was increased with the immune time. After purification and concentration, the purity of VacA-HpaA IgY was about 60%; the titer was 1∶128 000; And the concentration of IgY was 22 g/L. Western blot exhibited the protein bands with molecular weight of 27 000 and 30 `000. The titer of VacA-HpaA IgY to VacA and HpaA were 1∶3200 and 1∶6400 (P < 0.01).

CONCLUSION: VacA-HpaA-IgY with high concentration, purity, and specificity is successfully prepared.

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori infection

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.

Bovine anti-Helicobacter pylori antibodies neutralize inhibitory effects of SS1 and NCTC11637 antigens on proliferation of Hela cells

AIM: To investigate the inhibitory effects of SS1 and NCTC11637 antigens on the proliferation of Hela cells, and to observe the neutralization of bovine anti-Helicobacter pylori antibodies against SS1 and NCTC11637.

METHODS: The cows were immunized with sonicated Helicobacter pylori (H. pylori) antigen. After the scheduled immunization was completed, the immunization was strengthened with an interval of 1-2 month.The bovine serum was prepared when the ratio in agar-double diffusion was 1:32. The bovine milk was collected at the same time. The serum proteins (81.4g/L) were isolated and purified by saturated ammonium sulfate (500, 330, 330 g/L) and DEAE-32. The obtained proteins were identified by SDS-PAGE. Bovine anti-H. pylori IgGs were incubated with SS1 or NCTC11637, respectively, at 37 ℃ for 2 h, and then added into the solutions including Hela cells. The proliferation of Hela cells was determined by cell growth curve. MTT assay was adopted to evaluate the inhibitory effects of SS1 and NCTC11637 antigens on the proliferation of Hela cells.

RESULTS: The bacterial protein of SS1 and NCTC11637 inhibited the proliferation of Hela cells in a concentration-dependent manner (SS1: r = 0.9 594; NCTC11637: r = 0.9 371), and the cells manifested apoptotic or lysed features. For the same effect, a higher concentration of SS1 was needed. After treatment with bovine anti-H. pylori IgG, the inhibitory effects of SS1 and NCTC11637 on Hela cells were neutralized, and their inhibition rates were negatively related with the concentration of bovine anti-H. pylori IgG (SS1: r = -0.9 936; NCTC11637: r = -0.9 627).

CONCLUSION: SS1 and NCTC11637 can inhibit the proliferation of Hela cells, and bovine anti-H. pylori antibodies can neutralize the inhibiting action in a concentration-dependent manner.

Prevention and treatment of Helicobacter pylori infection with adhesin conservatory region vaccine: an animal model study

AIM: To investigate the effects of Helicobacter pylori (H. pylori) adhesin conservatory region vaccine in the prevention and treatment of H. pylori infection in a mouse model.

METHODS: The study was divided into two parts. In the first part, the specific germ free C57BL/6 mice were orally immunized with vaccine (100 mg) plus cholera toxin (CT) (2 mg), vaccine (100 mg), CT(2 mg), or PBS once a week for four weeks. Two weeks after the last immunization, all animals were challenged by live H. pylori, and were sacrificed 4 weeks after the challenge. In the second part, H. pylori infected mice were treated in the same way as in the first part. Four weeks after the last treatment, all animals were sacrificed, and the stomach biopsies were collected to detect H. pylori by the semi-quantitative bacterial culture assay.

RESULTS: The prophylactic rate from H. pylori infection was 61.5% (16/26) in the mice immunized with vaccine plus CT. The eradication rate of the vaccine plus CT group was 38.5% (10/26). No protective or therapeutic effect was observed in all other 3 groups. The H. pylori colony density in the vaccine plus CT group was significantly lower than those inother three groups in the second part of experiment (P<0.05).

CONCLUSION: The vaccine consisting of adhesin conservatory region and adjuvant is not only effective in the prevention, but also in the treatment of H. pylori infection.