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.

Egg Yolk Antibody for Passive Immunization: Status, Challenges, and Prospects.

The immunoglobulin Y (IgY) derived from hyperimmune egg yolk is a promising passive immune agent to combat microbial infections in humans and livestock. Numerous studies have been performed to develop specific egg yolk IgY for pathogen control, but with limited success. To date, the efficacy of commercial IgY products, which are all delivered through an oral route, has not been approved or endorsed by any regulatory authorities. Several challenging issues of the IgY-based passive immunization, which were not fully recognized and holistically discussed in previous publications, have impeded the development of effective egg yolk IgY products for humans and animals. This review summarizes major challenges of this technology, including in vivo stability, purification, heterologous immunogenicity, and repertoire diversity of egg yolk IgY. To tackle these challenges, potential solutions, such as encapsulation technologies to stabilize IgY, are discussed. Exploration of this technology to combat the COVID-19 pandemic is also updated in this review.

An IgY Effectively Prevents Goslings from Virulent GAstV Infection.

Goose astrovirus (GAstV) leads to viscera and joints urate deposition in 1- to 20-day-old goslings, with a mortality rate of up to 50%, posing a severe threat to entire colonies; however, there is no efficient prevention and control method for GAstV infection. This study describes a prophylactic anti-GAstV strategy based on the specific immunoglobulin Y (IgY) from egg yolk. The specific IgY was produced by 22-week-old laying hens intramuscularly immunized with the inactivated GAstV three consecutive times, with 2-week intervals. The egg yolk was collected weekly after the immunization and the anti-GAstV IgY titer was monitored using an agar gel immune diffusion assay (AGID). The results revealed that the AGID titer began to increase on day 7, reached a peak on day 49, and remained at a high level until day 77 after the first immunization. The specific IgY was prepared from the combinations of egg yolk from day 49 to day 77 through PEG-6000 precipitation. Animal experiments were conducted to evaluate the effects of prevention and treatment. The result of the minimum prophylactic dose of the IgY showed that the protection rate was 90.9% when 2.5 mg was administrated. Results of the prevention and the treatment experiments showed prevention and cure rates of over 80% when yolk antibody was administered in the early stages of the GAstV infection. These results suggested that the specific IgY obtained from immunized hens with the inactivated GAstV could be a novel strategy for preventing and treating GAstV infection.

Trends in industrialization and commercialization of IgY technology.

IgY technology refers to the strategic production process involved in generating avian immunoglobulin (IgY) against target antigens in a much more cost-effective manner with broad applications in the fields of diagnostics, prophylaxis, and therapeutics for both human and veterinary medicine. Over the past decade, promising progress in this research area has been evident from the steep increase in the number of registered manufacturing companies involved in the production of IgY products, the number of patents, and the notable number of clinical trials underway. Hence, it is crucial to conduct a prospective analysis of the commercialization and marketing potential of IgY-based commercial products for large-scale applications. This review revealed that the number of IgY patent applications increased steeply after 2010, with the highest of 77 patents filed in 2021. In addition, 73 industries are reportedly involved in marketing IgY products, out of which 27 were promoting biotherapeutics for human and veterinary medicine and 46 were in the diagnostic field. IgY antibodies are being used as primary and secondary antibodies, with approximately 3729 and 846 products, respectively. Biotherapeutic product consumption has notably increased as a food supplement and as a topical application in human and veterinary medicine, which are under different clinical phases of development to reach the market with around 80 and 56 products, respectively. In contrast, the number of IgY products as parenteral administrations and licensed drugs is not well developed given the lack of technical standards established for IgY registration and industrialization, as well as the restriction of the nature of polyclonal antibodies. However, recent ongoing research on functional IgY fragments indicates a promising area for IgY applications in the near future. Therefore, retrospective analysis with speculations is mandatory for IgY technology maturation toward industrialization and commercialization.

Dietary supplementation of sulfur amino acids improves intestinal immunity to Eimeria in broilers treated with anti-interleukin-10 antibody.

Oral antibody to interleukin-10 (anti-IL-10) enhances the intestinal immune defense against Eimeria. The sulfur amino acids methionine and cysteine (M+C) play essential roles in inducing and maintaining protective immune responses during intestinal infections. Hence, increased dietary M+C may support the anti-IL-10-induced intestinal immunity to Eimeria. Broilers (n = 640) were arranged in a 2 × 2 × 2 factorial design with 2 levels of each of the 3 main factors: dietary standardized ileal digestible (SID) M+C levels (0.6% or 0.8%), dietary anti-IL-10 supplementation (with or without), and coccidiosis challenge (control or challenge). Briefly, the broilers were supplied with either 0.6% or 0.8% SID M+C, each with or without anti-IL-10 (300 µg/kg), from d 10 to 21. On d 14, broilers from each diet were gavaged with either PBS or Eimeria. The resulting Eimeria infection induced fecal oocyst shedding and intestinal lesions. Broilers fed 0.8% SID M+C (main effects, P ≤ 0.05) had decreased feed-to-gain ratio, increased duodenum and cecum luminal anti-Eimeria IgA titers, and decreased fecal oocyst counts, when compared to 0.6% SID M+C. The supplementation of anti-IL-10 (main effects, P ≤ 0.05) increased cecum luminal total IgA concentration and decreased cecum lesions. Interactions (P ≤ 0.05) were detected for growth performance and cecum luminal IFN-γ. Briefly, the highest body weight gain and feed intake were reached in PBS-gavaged broilers fed 0.8% SID M+C with no anti-IL-10 and in Eimeria-challenged broilers fed 0.8% SID M+C with anti-IL-10. In Eimeria-infected broilers, anti-IL-10 increased intestinal luminal IFN-γ and body weight gain only at 0.8% SID M+C. Collectively, anti-IL-10 increased intestinal luminal IFN-γ levels, decreased cecum lesions and restored growth only when fed with adequate amounts of sulfur amino acids. Our findings underscore the importance of providing sufficient essential nutrients to support the anti-IL-10 induced immunity against coccidiosis.

Specific anti-SARS-CoV-2 S1 IgY-scFv is a promising tool for recognition of the virus.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread globally, a series of vaccines, antibodies and drugs have been developed to combat coronavirus disease 2019 (COVID-19). High specific antibodies are powerful tool for the development of immunoassay and providing passive immunotherapy against SARS-CoV-2 and expected with large scale production. SARS-CoV-2 S1 protein was expressed in E. coli BL21 and purified by immobilized metal affinity chromatography, as antigen used to immunize hens, the specific IgY antibodies were extracted form egg yolk by PEG-6000 precipitation, and the titer of anti-S1 IgY antibody reached 1:10,000. IgY single chain variable fragment antibody (IgY-scFv) was generated by using phage display technology and the IgY-scFv showed high binding sensitivity and capacity to S1 protein of SARS-CoV-2, and the minimum detectable antigen S1 protein concentration was 6 ng/µL. The docking study showed that the multiple epitopes on the IgY-scFv interacted with multiple residues on SARS-CoV-2 S1 RBD to form hydrogen bonds. This preliminary study suggests that IgY and IgY-scFv are suitable candidates for the development of immunoassay and passive immunotherapy for COVID-19 to humans and animals.

Ex Vivo Evaluation of Egg Yolk IgY Degradation in Chicken Gastrointestinal Tract.

Egg yolk antibody (immunoglobulin Y, IgY), due to its unique features (e.g., cost-effectiveness for mass production), is emerging as a promising passive immune agent and alternative to antibiotics to combat infectious diseases, particularly in livestock. Oral administration of egg yolk IgY is the most common and convenient route that has been extensively investigated for controlling enteric pathogens. However, the in vivo stability of egg yolk IgY in the gastrointestinal (GI) tract, a critical issue for the success of this approach, still has not been clearly elucidated. Our recent study showed instability of orally administered egg yolk IgY in chicken GI tract, as demonstrated by both in vivo and ex vivo evidence. To better understand the magnitude and dynamics of instability of egg yolk IgY in vivo, in this study, we conducted comprehensive ex vivo analyses by spiking hyperimmune egg yolk IgY in fresh GI contents collected from five broilers at each sampling age (2, 4, or 6 weeks). The pH in gizzard slightly increased with age from 2.4 to 3.0, while the pH in the small intestine was around 5.8. ELISA analysis indicated that a short time of treatment (30 or 60 min) of IgY with the gizzard contents from the chickens at 2, 4, and 6 weeks of age greatly reduced specific IgY titer by over 8, 6, and 5 log2 units, respectively, when compared with saline control. However, small intestine content only had a mild effect on egg yolk IgY, leading to 1 log2 unit of reduction in IgY titer upon 30 min of treatment. Consistent with these findings, SDS-PAGE and immunoblotting analyses provided direct evidence demonstrating that egg yolk IgY could be drastically degraded to undetectable level in gizzard content upon as short as 5 min of treatment; however, the IgY was only slightly degraded in small intestine content. Immunoblotting also showed that treatment of IgY with HCl (pH 3.0) for 60 min did not affect its integrity at all, further supporting the enzymatic degradation of IgY in gizzard. Collectively, egg yolk IgY could be substantially degraded in chicken gizzard, highly warranting the development of effective approaches, such as encapsulation, for the controlled release and protection of orally administered egg yolk IgY in livestock.

Passive Immunization of Chickens with Anti-Enterobactin Egg Yolk Powder for Campylobacter Control.

Enterobactin (Ent) is a highly conserved and important siderophore for the growth of many Gram-negative bacterial pathogens. Therefore, targeting Ent for developing innovative intervention strategies has attracted substantial research interest in recent years. Recently, we developed a novel Ent conjugate vaccine that has been demonstrated to be effective for controlling Gram-negative pathogens using both in vitro and in vivosystems. In particular, active immunization of chickens with the Ent conjugate vaccine elicited strong immune responses and significantly reduced intestinal colonization of Campylobacter jejuni, the leading foodborne bacterial pathogen. Given that hyperimmune egg yolk immunoglobulin Y (IgY) has been increasingly recognized as a promising and practical non-antibiotic approach for passive immune protection against pathogens in livestock, in this study, we assessed the efficacy of oral administration of broiler chickens with the anti-Ent hyperimmune egg yolk powder to control C. jejuni colonization in the intestine. However, supplementation of feed with 2% (w/w) of anti-Ent egg yolk powder failed to reduce C. jejuni colonization when compared to the control group. Consistent with this finding, the ELISA titers of the specific IgY in cecum, ileum, duodenum, gizzard, and serum contents were similar between the two groups throughout the trial. Chicken intestinal microbiota also did not change in response to the egg yolk powder treatment. Subsequently, to examine ex vivo stability of the egg yolk IgY, the chicken gizzard and duodenum contents from two independent sources were spiked with the egg yolk antibodies, incubated at 42 °C for different lengths of time, and subjected to ELISA analysis. The specific IgY titers were dramatically decreased in gizzard contents (up to 2048-fold) but were not changed in duodenum contents. Collectively, oral administration of broiler chickens with the anti-Ent egg yolk powder failed to confer protection against intestinal colonization of C. jejuni, which was due to instability of the IgY in gizzard contents as demonstrated by both in vivo and ex vivo evidence.

Evaluation of the Immunogenic Response of a Novel Enterobactin Conjugate Vaccine in Chickens for the Production of Enterobactin-Specific Egg Yolk Antibodies.

Passive immunization with specific egg yolk antibodies (immunoglobulin Y, IgY) is emerging as a promising alternative to antibiotics to control bacterial infections. Recently, we developed a novel conjugate vaccine that could trigger a strong immune response in rabbits directed against enterobactin (Ent), a highly conserved siderophore molecule utilized by different Gram-negative pathogens. However, induction of Ent-specific antibodies appeared to be affected by the choice of animal host and vaccination regimen. It is still unknown if the Ent conjugate vaccine can trigger a specific immune response in layers for the purpose of production of anti-Ent egg yolk IgY. In this study, three chicken vaccination trials with different regimens were performed to determine conditions for efficient production of anti-Ent egg yolk IgY. Purified Ent was conjugated to three carrier proteins, keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA) and CmeC (a subunit vaccine candidate), respectively. Intramuscular immunization of Barred Rock layers with KLH-Ent conjugate four times induced strong immune response against whole conjugate vaccine but the titer of Ent-specific IgY did not change in yolk with only a 4 fold increase detected in serum. In the second trial, three different Ent conjugate vaccines were evaluated in Rhode Island Red pullets with four subcutaneous injections. The KLH-Ent or CmeC-Ent conjugate consistently induced high level of Ent-specific IgY in both serum (up to 2,048 fold) and yolk (up to 1,024 fold) in each individual chicken. However, the Ent-specific immune response was only temporarily and moderately induced using a BSA-Ent vaccination. In the third trial, ten White Leghorn layers were subcutaneously immunized three times with KLH-Ent, leading to consistent and strong immune response against both whole conjugate and the Ent molecule in each chicken; the mean titer of Ent-specific IgY increased approximately 32 and 256 fold in serum and yolk, respectively. Consistent with its potent binding to various Ent derivatives, the Ent-specific egg yolk IgY also inhibited in vitro growth of a representative Escherichia coli strain. Together, this study demonstrated that the novel Ent conjugate vaccine could induce strong, specific, and robust immune response in chickens. The Ent-specific hyperimmune egg yolk IgY has potential for passive immune intervention against Gram-negative infections.

Chicken Egg Yolk Antibody (IgY) Protects Mice Against Enterotoxigenic Escherichia coli Infection Through Improving Intestinal Health and Immune Response.

Chicken egg yolk antibody (IgY), considered as a potential substitute for antibiotics, has been used for preventing pathogens infection in food, human and animals. This study investigated effects of IgY on growth, adhesion inhibitory and morphology of enterotoxigenic Escherichia coli (ETEC) K88 in vitro, and evaluated the protective effects of IgY on intestinal health and immune response of mice infected with ETEC in vivo. Sixty pathogen-free C57BL/6J (4-6 weeks of age) mice were divided into six treatments: control (neither IgY nor ETEC infection), ETEC infection, ETEC-infected mice treated with 250 µL of high-dose (32 mg/mL), medium-dose (16 mg/mL) or low-dose (8 mg/mL) anti-ETEC IgY, or ETEC-infected mice treated with 250 µL of non-specific IgY (16 mg/mL). Anti-ETEC IgY inhibited ETEC growth, reduced adherence of ETEC to intestinal epithelial cells J2 and damaged the morphology and integrity of ETEC cell. Oral administration of anti-ETEC IgY effectively ameliorated ETEC-induced clinical signs, reduced ETEC colonization and intestinal permeability, alleviated inflammatory response through reducing the production and expression of proinflammatory cytokines, improved intestinal morphology, and inhibited excessive activation of the mucosal immune response of challenged mice. The overall protective effects of high-dose and medium-dose anti-ETEC IgY against ETEC infection were more effective. These results suggest that anti-ETEC IgY may function as a promising novel prophylactic agent against enteric pathogens infection.

Production and characteristics of a novel chicken egg yolk antibody (IgY) against periodontitis-associated pathogens.

Periodontitis is a bacterial biofilm-induced oral disease, mostly caused by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis). Oral administration of chicken egg yolk antibody (IgY) is a promising nutritional strategy to control pathogen infections. The objective of this study was to produce an A. actinomycetemcomitans- and P. gingivalis-specific IgY and evaluate its effects on bacterial agglutination and biofilm formation. Thirty laying hens were immunized with a complex of lysate containing typical molecular weights of membrane proteins of A. actinomycetemcomitans and P. gingivalis. IgY was isolated by polyethylene glycol 6000 and ammonium sulfate and purified by dialysis. The results of enzyme-linked immunosorbent assay showed that the obtained IgY were specific to both A. actinomycetemcomitans and P. gingivalis. In addition, immunoelectron microscopy scanning and crystal violet staining showed that the IgY could bind to cell wall of the pathogens and efficiently accelerate agglutination and inhibit biofilm formation. Furthermore, the activity of the IgY remained stable at different temperature, pH, and storage period. This is the first report that a novel two-in-one IgY was produced to modulate the agglutination and biofilm formation of A. actinomycetemcomitans and P. gingivalis, suggesting the potential of IgY to control periodontitis caused by oral pathogens.

Rainbow trout fillet biopreservation by edible chitosan-based coating containing egg yolk antibody (IgY) and lycopene.

The aim of the study was to investigate the effect of the extracted egg yolk antibody along with lycopene on the chemical quality of the rainbow trout fillet during 16 days of refrigeration storage. Chickens were immunized against Pseudomonas fluorescens (P. fluorescens), Shewanella putrefaciens (S. putrefaciens) and total spoilage bacteria and their eggs were collected for the isolation of egg yolk antibodies. Then fish fillets were immersed in chitosan-based coating solutions, containing lycopene and extracted antibodies, and analyzed for lipid oxidation changes (peroxide, thiobarbituric acid, free fatty acid and fatty acid profile), physico-chemical properties (pH and water holding capacity), and sensory evaluation, during 16 days of refrigeration storage. Results showed that chitosan solutions with lycopene or IgY could significantly (p < 0.05) increase the oxidative stability of lipids in fish fillets; although, combinational use of lycopene and IgY showed a higher effect on delaying the rate of lipid oxidation. Significant differences were also observed between treatments contained combination of chitosan, antibody and lycopene with the control group, regarding pH and WHC. Saturated fatty acids increased in all treatments, although the changes in the treatments containing lycopene and antibody were significantly (p < 0.05) lower than the control group. Hence the addition of egg yolk antibody and lycopene in coating solution are good bio-preservatives for seafood products as it improves sensory attributes and prevents lipid oxidation.

Intact anti-LPS IgY is found in the blood after intragastric administration in mice.

Severe burn injury and cirrhosis often cause the translocation of bacterial endotoxins into blood, leading to systemic damage and even death. Our previous studies have shown that anti-lipopolysaccharide egg yolk antibody (anti-LPS IgY) can neutralize bacterial endotoxins in vitro and in vivo effectively, thereby reducing endotoxin damage. Whether anti-LPS IgY can be absorbed into the blood through the intestinal barrier and neutralize endotoxins in circulation remains unclear. In this study, we used in vivo small animal imaging techniques, protein purification, molecular biology, and mass spectrometry to show that intragastrically administered anti-LPS IgY is detected in the blood of mice as an intact molecule and has the capacity to bind to LPS. Immunohistochemical analysis confirmed that anti-LPS IgY is associated with the intestinal mucosa of mice. However, the route of absorption of this large protein molecule was not determined. This study suggests that anti-LPS IgY can be absorbed into the circulation, with the same molecular mass as purified anti-LPS IgY as a macromolecular protein, suggesting a new strategy for the prevention of damage caused by endotoxins.

Effect of IgY on Periodontitis and Halitosis Induced by Fusobacterium nucleatum.

Fusobacterium nucleatum is a morbific agent in periodontitis and halitosis. Egg yolk antibody (IgY) was obtained from egg yolks from chickens stimulated with F. nucleatum. This study was to assess the effectiveness of IgY on periodontitis and halitosis caused by F. nucleatum in vitro and in vivo. The growth of F. nucleatum was inhibited (p <0. 05) by different concentrations of IgY in vitro and the results of a Halimeter show volatile sulfur compounds (VSCs) were reduced to 904 ± 57 ppb at a concentration 40 mg/ml of IgY. The changes of fatty acids of F. nucleatum were determined using GC-MS. The scores for odor index of rat saliva were decreased. The major constituent of volatile organic compounds (VOCs) including short-chain acids decreased 46.2% in 10 mg/ml IgY, ammonia decreased 70% in 40 mg/ml IgY, while aldehydes and olefine ketones were almost unchanged. The ELISA assay revealed that IL-6 and TNF-α were decreased after 4 weeks' IgY treatment. Morphometric (X-ray) and histological analyses (HE) showed that IgY reduced alveolar bone loss and collagen fibers became orderly in rat models. As a result, IgY may have the potential to treat periodontitis and halitosis.

Extraction of specific egg yolk antibodies and application in chitosan coating: effect on microbial and sensory properties of rainbow trout fillet during chilled storage.

BACKGROUND: This study investigated the effect of chitosan coating enriched with extracted egg yolk antibodies on microbial and sensory quality of rainbow trout fillet during refrigeration (4 ± 1 °C). Firstly, bacterial antigen suspensions (total psychrophilic bacteria, Pseudomonas fluorescens and Shewanella putrefaciens) were injected into the breast muscles of chickens. Eggs of immunized chickens were then collected to isolate immunoglobulin from egg yolks (IgY). Fresh fish fillets were coated by chitosan solution containing different types of IgY separately, at two concentrations (60 and 90 mg mL-1 ), refrigerated for 16 days and analysed for total viable count, psychrotrophic, Pseudomonas spp., P. fluorescens and S. putrefaciens count as well as sensorial properties. RESULTS: The tested microbial values increased in all samples during the storage period; however, CH + IgY treated samples could significantly retard microbial growth compared to control. The shelf life of CH + IgY-P samples was extended for about 4 days, while it was extended for about 8 days in CH + IgY-S and CH + IgY-T samples, when they were compared to control (p < 0.05). Higher scores for sensory attributes were also observed in CH + IgY treated samples, especially in CH + IgY-S samples until the end of storage period. CONCLUSIONS: Accordingly, use of chitosan coating containing IgY increases the microbial and sensory quality of fish flesh at 4 °C. Therefore, given the consumer interest in natural additives, chitosan coating containing IgY can be a promising candidate. © 2018 Society of Chemical Industry.

Anti-lipopolysaccharide egg yolk antibodies enhance the phagocytosis of mammalian phagocytes.

Macrophages play crucial roles in combatting infectious diseases by promoting inflammation and phagocytosis. The decline of macrophage phagocytic function will bring many serious consequences, including weakened pathogen clearance. As an avian antibody, immunoglobulin Y (IgY) has been widely used in preventing and treating infectious diseases, but whether it can enhance the phagocytic ability of mammalian macrophages in order to clear pathogens is still unknown. In this study, mouse peritoneal macrophages and THP-1 cells were cultured with anti-lipopolysaccharide (LPS) IgY in vivo or in vitro, respectively. Morphological observation, ELISA, fluorescence immunoassays and flow cytometry were used to study whether IgY could enhance phagocytosis of mammalian macrophages. It was found that without anti-LPS IgY, mouse peritoneal macrophages showed adherent growth with no differentiation and little pseudopod extension; but with anti-LPS IgY, peritoneal macrophages presented more significant characteristics in adherent growth, extension deformation and protruding pseudopods. With flow cytometry, the macrophages from mice injected with anti-LPS IgY exhibited a significantly higher percentage of phagocytosis and index (90.83±2.59% and 4.45±0.13 respectively) compared with phosphate buffered saline (PBS) groups (64.32±1.5%, and 2.36±0.11) and non-immunized groups (65.94%±1.4%, and 2.4±0.15). With phorbol-12-myristate-13-acetate (PMA)-induced THP-1 cells, similar results were found; the percentage and index were significantly higher, with larger body and more pseudopods, for THP-1 cells that were co-incubated with anti-LPS IgY (79.83±0.38% and 2.64±0.03), compared with cells that were co-incubated with PBS (68.07±0.52%, and 1.88±0.03) or non-immunized IgY (74.89±1.14% and 2.30±0.02). The results showed that anti-LPS IgY was effective in promoting the growth of macrophages, pseudopod extension and stronger phagocytic capacity. Our study indicated that anti-LPS IgY could enhance the phagocytic capacity of mammalian macrophages to internalize pathogens more effectively with larger body and more pseudopods. This may be important to encourage IgY to be used to prevent and treat infectious diseases.

Advances in structure, function and application of egg yolk antibody in human and animal diseases / 中国人兽共患病学报

Egg yolk immunoglobulin(IgY),also called egg yolk antibody,is a specific antibody secreted by birds after stimulation with certain antigens.For that it exhibits good resistance to heat,acid and proteinase-mediated degradation,its early-stage products were developed as food or food additives,and they have gained great social and economic benefits in both food safety and ecological agriculture fields.Due to the specific antibodies contained in these products,the products can help to resist pathogen infection.Therefore egg yolk antibody shows great value for development and application in the prevention and treat ment of animal and human diseases,and also shows great potential in human health care area.This review focuses on the development and applications of IgY biologics related with antiviral,antibacterial,antiparasitic and antitumor activities.

Preparation of egg yolk antibodies against human isomaltase and determination of their biological activities / 医学研究生学报

Objective Antibody drugs are one of the hot topics in biomedical research.This study aims to develop egg yolk antibodies (IgYs) against human isomaltase and determine their biological activities.Methods The purified recombinant isomaltase protein was used as an antigen to immunize egg-laying hens in combination with complete Freund adjuvant (CFA).Anti-isomahase IgYs were extracted by water dilution-sodium sulfate extraction assay and further analyzed for their purity,specificity,titer and stability by SDS-PAGE,Western blot and ELISA respectively,and their inhibitory effect on human alpha-glycosidase enzymes was evaluated by the PNPG method.Results Anti-isomaltase IgYs were obtained,with a titer of 1 ∶ 12800,capable of specifically binding human isomaltase,and with a good thermal stability,acid/alkali stability and pepsin resistance.Conclusion Anti-human isomaltase IgYs were successfully prepared,which may provide an experimental ground for further investigation of oral antihyperglycemic agents for type Ⅱ diabetes mellitus.

Purification of chicken IgY by binding capture using elastin-like polypeptide-tagged immunoglobulin-binding domain of streptococcal protein G.

Chicken egg yolk immunoglobulin (IgY) is a superior alternative to mammalian immunoglobulin, but its practical application is limited due to the complex purification procedure. In this study, the C2 domain of streptococcal protein G (SPG) with the binding affinity for chicken IgY was expressed in E. coli as an elastin-like polypeptide (ELP) fusion protein, and purified to a high purity by inverse transition cycling (ITC). Binding experiments showed that chicken IgY could bind to and eluted off the ELP-C2 fusion protein in pH-, temperature- and/or time-dependent manners. By using the ELP-C2 protein, a simple chicken IgY purification method was developed, and its purification performance was compared with that of ammonium sulfate precipitation and ethanol fractionation. Quantitative SDS-PAGE analysis showed that the ELP-C2 binding capture method provided a chicken IgY purity of 96.3% and a recovery of 64%, both of which were significantly higher than that of the two traditional methods The ELP-C2 binding capture method could be accomplished within 3h, in contrast to 30.3h for ammonium sulfate precipitation or 4.3h for ethanol fractionation. These data suggest that the ELP-C2 binding capture was a simple, efficient and cost-effective method for purification of chicken IgY.