Immunoglobulin Y Research Articles

Egg yolk immunoglobulin Y as a promising tool to detect immune complexes in neurocysticercosis serum samples.

Neurocysticercosis (NCC) is a neglected tropical disease and its diagnosis is still a challenge due to non-specific manifestations. Neuroimaging techniques are used in the diagnosis of NCC, however, due to the high cost of these methods and the advantages presented in the use of immunological tests, such as ease of performance and satisfactory results, immunoassays are commonly used to detect antibodies against Taenia sp. antigens. The aim of the present study was to produce, characterize and apply specific polyclonal immunoglobulin Y (IgY) anti-Taenia crassiceps extracted from egg yolk of hens immunized with T. crassiceps metacestodes. Indirect enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence tests were performed for characterization of IgY antibodies. Diagnostic performance was verified by ELISA for immune complex detection testing 90 serum samples. Values of sensitivity, specificity, positive and negative likelihood ratios (LR+/LR-) and area under the curve (AUC) were calculated and presented the following results: sensitivity 83.3%, specificity 96.7%, AUC 0.966, LR+ 25.0 and LR- 0.17. Results of this pioneering and innovative study demonstrate that anti-T. crassiceps IgY antibodies present potential applicability and can be used as an efficient tool in human NCC serodiagnosis.

Polymorphisms and Associations of the NRAMP-1 and iNOS Genes on Newcastle Disease and Salmonella enteritidis Resistances in SenSi-1 Agrinak Chickens

NRAMP-1 and iNOS genes were reported to be associated with a defense mechanism against bacteria and virus infections. This study aimed to identify NRAMP-1 and iNOS genes polymorphisms and their associations with the defense mechanisms against Salmonella enteritidis and Newcastle Disease (ND) in SenSi-1 Agrinak chicken. The present study used a total number of 172 SenSi-1 Agrinak chicken. Identifications of NRAMP-1 and iNOS genes polymorphisms were performed by PCR-RFLP method. NRAMP-1 and iNOS genotypes were associated with immunoglobulin Y (IgY) concentration, specific antibodies against S. enteritidis and ND using General Linear Model (GLM). Immunity characteristics were further grouped into high, medium, and low categories. NRAMP-1|SacI exon 11 and iNOS|AluI intron 24 in SenSi-1 Agrinak chickens were polymorphic. TC genotype has a higher immune response to infectious agents compared to TT and CC genotypes. The frequency of C allele was higher than the T allele in the concentration of immunoglobulin Y (IgY), antibodies titers against S enteritidis and ND. The TC genotype of NRAMP-1 gene was significantly associated with ND antibody titers, and the TT genotype of iNOS was significantly associated with S. enteritidis specific antibody. NRAMP-1 and iNOS genes can be used as potential candidate genes for immune traits in SenSi-1 Agrinak chickens.

Yolkin Isolated from Hen Egg Yolk as a Natural Immunoregulator, Activating Innate Immune Response in BMDM Macrophages.

One of the goals of biomedical sciences is to search and identify natural compounds that are safe, have no side effects, and possess immunostimulatory activity. It has been proven that medicines of natural origin can be effective agents, supporting the therapy of many diseases, not only in the weakened immune system of the body but also in the prevention of many diseases in healthy people. It has been shown that yolkin, a polypeptide complex isolated from hen egg yolk as a fraction accompanying immunoglobulin Y (IgY), possesses potential biological activity. However, the mechanism of its action has not been explained. The objective of this investigation was to examine the molecular mechanisms of innate immune response, activated in response to yolkin, in murine bone marrow-derived macrophages (BMDM). It was shown that yolkin induced phosphorylation of extracellular signal-kinases (ERK1/2) and c-Jun N-terminal kinase (JNK) and upregulated expression and production of type I interferons, TNF-α (tumor necrosis factor α), and nitric oxide (NO), in BMDM cells. Using pharmacological inhibitors of ERK 1/2 and JNK kinases, we revealed that the JNK signaling cascade is required for yolkin-induced inducible NOS expression and upregulation of NO production in mouse macrophages. Using the TLR4-deficient BMDM cell line, we established that yolkin can activate macrophages in a TLR4-dependent manner. It was also shown that NO, TNF-α, and type I IFNs (α/β) produced by BMDM cells in response to yolkin triggered antiviral activity. These data indicate that yolkin affects the regulation of the immune system and antiviral response; therefore, it can be used as an effective immunostimulator of the innate immunity or as a supplement of the conventional therapy of immunodeficiency.

The Impact of Probiotics and Egg Yolk IgY on Behavior and Blood Parameters in a Broiler Immune Stress Model.

Feed additives are used frequently in variable combinations to maximize broiler productivity and consumer safety. Therefore, we evaluated the efficiency of feed additives used in four different diets: a basal diet, a probiotic (PRO-PAC®) supplement diet, an egg yolk purified immunoglobulin Y (IgY) supplemented diet, and a combination of IgY and PRO-PAC® supplement (n = 15 for each group). We assessed the improvement of behavioral and hematological parameters of Ross broilers before and after an immune stress challenge using lipopolysaccharide (LPS). Behavioral as well as physiological parameters were analyzed. The standing frequency was the highest (P < 0.05) in broilers supplemented with a combination of probiotics and IgY. Likewise, latency approach score to a novel object improved (P < 0.01) in the combination group at week-3. After intraperitoneal injection of LPS, this combination group achieved the best gait score at week-3, followed by week-5, compared to birds fed the basal diet. The heterophil/lymphocyte (H/L) ratio, heterophil differential count, and eosinophil differential count in the basal diet group that was challenged with LPS were significantly increased (P < 0.01, P < 0.001, P < 0.05, respectively) compared to the combination groups. Therefore, we concluded that the combination of IgY and probiotics can significantly improve the behavior and the underlying physiological parameters of Ross broilers. Consequently, this combination can improve the broilers′ health, welfare and produce a safe meat free from harmful chemical residues.

Purification of animal immunoglobulin G (IgG) using peptoid affinity ligands.

The availability of highly pure animal antibodies is critical in the production of diagnostic tools and biosensors. The peptoid PL16, previously isolated from an ensemble of peptoid variants of the IgG-binding peptide HWRGWV, was utilized in this work as affinity ligand on WorkBeads resin for the purification of immunoglobulin G (IgG) from a variety of mammalian sources and chicken immunoglobulin Y (IgY). The chromatographic protocol initially optimized for murine serum and ascites was subsequently employed for processing rabbit, goat and sheep, donkey, llama, and chicken sera. The PL16-WorkBeads resin proved able to recover all antibody targets with values of yield between 50 and 90%, and purity consistently above 90%. Notably, PL16 not only binds a broader spectrum of animal immunoglobulins than the reference ligands Protein A and G, but it also binds equally well with all their subclasses. Unlike the protein ligands, in fact, PL16 afforded excellent values of yield and purity of mammalian polyclonal IgG, namely murine (47 and 94%), rabbit (66.5 and 91.7%), caprine IgG (63 and 91-95%), donkey, and llama (93 and 97%), as well as chicken IgY (42 and 92%). Of notice, it is also the ability of PL16 to target monomeric IgG without binding aggregated IgG; when challenged with a mixture of monomeric and aggregated murine IgG, PL16 eluted <3% of fed aggregates, against 11-13% eluted by Protein A and G. Collectively, these results prove the potential of the proposed peptoid ligand for large-scale purification of animal immunoglobulins.

The potency of Immunoglobulin Y anti Porphyromonas gingivalis to inhibit the adherence ability of Porphyromonas gingivalis on enterocytes

Background: Pophyromonas gingivalis (P. gingivalis) bacteria are the main type of bacterium that cause chronic periodontitis. Immunoglobulin Y (IgY) is a type of immunoglobulin found in poultry, such as chickens and birds. IgY can be used as an alternative method of preventing the accumulation of plaque that causes chronic periodontitis. Purpose: To determine the ability of IgY anti P. gingivalis to inhibit adherence of P. gingivalis. Methods: The samples were divided into eight groups, each group containing 10 ml of IgY anti P. gingivalis and 50 ml of enterocyte cells. The control group contained 50 ml of IgY anti P. gingivalis, and 50 ml of enterocyte cells. Serial dilution was carried out to the first seven groups, with the first group containing 90 ml phosphate-buffered saline (PBS) and 10 ml IgY anti P. gingivalis, and the second to seventh groups containing 50 ml PBS before adding 50 ml of enterocyte cells and 50 ml of bacterial suspension per group. The number of bacteria was calculated as an adherence index value using a light microscope. Results: This study shows that IgY anti P. gingivalis significantly reduces the adherence index value of P. gingivalis. Conclusion: IgY anti P. gingivalis has potency to inhibit the adherence of P. gingivalis.

The protective efficacy of specific egg yolk immunoglobulin Y(IgY) against Riemerella Anatipestifer infections

Riemerella anatipestifer (RA) is the significant pathogen of septicemia and duck infectious serositis, diseases which can result in high mortality for ducklings. However, these diseases are difficult to treat because of the bacteria’s broad resistance to multiple drugs. The purpose of this study was to produce a specific egg yolk immunoglobulin Y (IgY) targeted to RA, and to evaluate the protective efficacy of this IgY against RA infection. An RA-inactivated vaccine was produced via centrifugation and formalin treatment, using the most predominant serotype 2 wild-type strains in terms of worldwide prevalence. Anti-RA IgY was produced by immunizing Beijing Red No.1 hens with the inactivated vaccine. Enzyme-linked immunosorbent assays showed that the titer levels of anti-RA IgY antibodies increased significantly after exposure. Specific IgY isolated and purified from yolks effectively inhibited the growth of RA in the antibacterial activity assay, which revealed an 80 % reduction of bacteria populations. Animal experiments showed that duckling survival rates were able to reach up to 100 % after the ducklings were treated with 10 mg intramuscular injections of anti-RA IgY from 1 to 12 h after infection. However, the survival rates of ducklings treated with 30 mg of nonspecific IgY at 1 h after infection were 0%. Additionally, ducklings injected once with anti-RA IgY received complete protection in the first week, but the efficacy of this protection almost entirely disappeared after two weeks. The results suggested that specific anti-RA IgY has the potential to improve the degree of protection and responsiveness of ducklings to RA infections and provide them with passive immunity to RA. With further study, this is expected to become a new method for controlling RA infections.

Evaluation of a receptor gene responsible for maternal blood IgY transfer into egg yolks using bursectomized IgY-depleted chickens

In avian species, maternal immunoglobulin Y (IgY) is transferred from the blood to the yolks of maturing oocytes; however, the mechanism underlying this transfer is unknown. To gain insight into the mechanisms of maternal IgY transfer into egg yolks, IgY-depleted chickens were generated by removing the bursa of Fabricius (bursectomy) during egg incubation, and their egg production and IgY transport ability into egg yolks were determined. After hatching, blood IgY concentrations of the bursectomized chickens decreased gradually until sexual maturity, whereas those of IgA remained low from an early stage of growth (from at least 2 wk of age). Chickens identified as depleted in IgY through screening of blood IgY and IgA concentrations were raised to sexual maturity. At 20 wk of age, both blood and egg yolk IgY concentrations in the IgY-depleted group were 600-fold lower than those of the control group, whereas egg production did not differ between the groups. Intravenously injected, digoxigenin-labeled IgY uptake into the egg yolk was approximately 2-fold higher in the IgY-depleted chickens than in the controls, suggesting that IgY depletion may enhance IgY uptake in maturing oocytes. DNA microarray analysis of the germinal disc, including the oocyte nucleus, revealed that the expression levels of 73 genes were upregulated more than 1.5-fold in the IgY-depleted group, although we could not identify a convincing candidate gene for the IgY receptor. In conclusion, we successfully raised IgY-depleted chickens presenting a marked reduction in egg yolk IgY. The enhanced uptake of injected IgY into the egg yolks of the IgY-depleted chickens supports the existence of a selective IgY transport mechanism in maturing oocytes and ovarian follicles in avian species.

Exogenous GM1 Ganglioside Attenuates Ketamine-Induced Neurocognitive Impairment in the Developing Rat Brain

A prolonged exposure to ketamine triggers significant neurodegeneration and long-term neurocognitive deficits in the developing brain. Monosialotetrahexosylganglioside (GM1) can limit the neuronal damage from necrosis and apoptosis in neurodegenerative conditions. We aimed to assess whether GM1 can prevent ketamine-induced developmental neurotoxicity. Postnatal day 7 (P7) rat pups received 5 doses of intraperitoneal ketamine (20 mg/kg per dose) at 90-minute intervals for 6 hours. Cognitive functions, determined by using Morris water maze (MWM) including escape latency (at P32-36) and platform crossing (at P37), were compared among the ketamine-exposed pups treated with or without exogenous GM1 (30 mg/kg; n = 12/group). The effect of GM1 on apoptosis in hippocampus was determined by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining and activated caspase 3 measurement. The hippocampal expression of brain-derived neurotrophic factor (BDNF), along with the phosphorylation of protein kinase B (AKT) and extracellular signal-related kinases 1 and 2 (ERK1/2), was detected by western blotting (n = 6/group). Anti-BDNF antibody (2 μg per rat) administered before GM1 treatment was applied to determine the neuroprotective mechanisms of GM1. The rats receiving ketamine exposure experinced cognitive impairment in MWM test compared to the control rats, indicated by prolonged escape latency at P34 (P = .006), P35 (P = .002), and P36 (P = .005). However, in GM1-pretreated rats, ketamine exposure did not induce prolonged escape latency. The exogenous GM1 increased the platform-crossing times at P37 (3.00 ± 2.22 times vs 5.40 ± 1.53 times, mean ± standard deviation; P = .041) and reduced the hippocampal TUNEL-positive cells and cleaved-caspase 3 expression in ketamine-exposed young rats. Ketamine decreased BDNF expression and phosphorylation of AKT and ERK in the hippocampus, whereas exogenous GM1 blocked these ketamine-caused effects. However, for the ketamine-exposed rat pups receiving exogenous GM1, compared to immunoglobulin Y (IgY) isotype control, the BDNF-neutralizing antibody treatment counteracted the exogenous GM1-induced improvement of the escape latency at P36 (41.32 ± 12.37 seconds vs 25.14 ± 8.97 seconds, mean ± standard deviation; P = .036), platform-crossing times at P37 (2.16 ± 1.12 times vs 3.92 ± 1.97 times, mean ± standard deviation; P < .036), apoptotic activity, as well as AKT and ERK1/2 phosphorylation in the hippocampus of ketamine-challenged young rats. Our data suggest that the exogenous GM1 acts on BDNF signaling pathway to ameliorate the cognitive impairment and hippocampal apoptosis induced by ketamine in young rats. Our study may indicate a potential use of GM1 in preventing the cognitive deficits induced by ketamine in the young per se.

An easy and simple separation method for Fc and Fab fragments from chicken immunoglobulin Y (IgY)

Antigen-binding (Fab) and crystallizable (Fc) fragments are the active components of yolk immunoglobulin (IgY), which have been widely used in the pharmaceutical field. However, the common purification methods for the Fab and Fc fragments use combinations of multi-columns are complex and time-consuming. The objective of this study was to improve the separation efficiency of the Fab and Fc fragments from the hydrolyzed IgY and increase the purity of the isolated Fab and Fc fragments. Natural IgY was hydrolyzed using papain for 6 hr and then treated with 45% saturated ammonium sulfate to remove small molecular-weight-peptides. The fraction containing Fab and Fc fragments was loaded on a DEAE-Sepharose ion exchange column and the Fab fraction was washed out first with 10 mM Tris-HCl buffer (pH 7.6). Then, the Fc fraction bound to the DEAE Sepharose was eluted with 10 mM Tris-HCl buffer (pH 7.6) containing 0.21 M NaCl. The purity of the two fragments was 88.7% and 90.1%, respectively. The results of Western blotting and MS analyses indicated that this method purified Fab and Fc fractions with high purity. This method is easy and simple compared with other methods, and the active fragments separated can be easily used.

In vivo immunoprotective comparison between recombinant protein and DNA vaccine of Eimeria tenella surface antigen 4

Eimeria tenella, belonging to protozoon, is the causative agent of cecal coccidiosis in chicken and causes enormous impacts for poultry industry. The surface antigens of apicomplexan parasites function as attachment and invasion in host-parasite interaction. Meanwhile, host immune response is triggered as a result of parasitic invasion. Immunogenicity and potency as a vaccinal candidate antigen of E. tenella surface antigen 4 (EtSAG4) have been unknown. Therefore, a gene segment of E. tenella EtSAG4 was amplified and transplanted to pET28a prokaryotic vector for recombinant protein expression. Similarly, pEGFP-N1 eukaryotic vectors with EtSAG4 gene segment (pEGFP-N1-EtSAG4) amplified in 293 T cells as DNA vaccines. Reverse transcription-polymerase chain reaction (RT-PCR) assay and western blot analysis were used to demonstrate successful expressions of EtSAG4 in Escherichia coli or 293 T cells. Subsequently, animal experiments (72 cobb broilers) were performed to evaluate immunoprotective between recombinant protein and DNA vaccine of E. tenella EtSAG4 using different immunizing doses (50 or 100 μg), respectively. Serum from chickens infected with E. tenella identified recombinant EtSAG4 (rEtSAG4) protein. Chickens vaccinated with either rEtSAG4 protein or pEGFP-N1-EtSAG4 plasmids both shown a significant increase in concentration of IFN-γ (p < 0.05) compared with control groups indicating production of cell-mediated immunity. Besides, pEGFP-N1-EtSAG4 plasmids motivated more intense immune responses for immunoglobulin Y (IgY) and interleukin 17 (IL-17) (p < 0.05) contrast to control groups. However, there was no increase in concentration of interleukin 10 (IL-10) and interleukin 4 (IL-4) for both rEtSAG4 protein and pEGFP-N1-EtSAG4 plasmids. Chickens vaccinated with rEtSAG4 protein or pEGFP-N1-EtSAG4 plasmids both show higher weight, lower oocyst output and mean lesion scores compared with infection control groups. The highest anticoccidial index (ACI) value of immunized groups was 168.24 from EGFP-N1-EtSAG4 plasmids (100 μg) group. Generally, EGFP-N1-EtSAG4 plasmids as DNA vaccines provided a more effective immunoprotective for chickens against E. tenalla than that of rEtSAG4 protein as subunit vaccines. EtSAG4 is a promising candidate antigen gene for development of coccidiosis vaccine.

High selective purification of IgY from quail egg: Process design and quantification of deep eutectic solvent based ultrasound assisted liquid phase microextraction coupled with preparative chromatography

The present research investigates on task-specific deep eutectic solvents (TDES) based aqueous two-phase extraction and purification of immunoglobulins by chromatography from quail egg. The synthesis of TDES was accomplished with quaternary ammonium salt as hydrogen bond acceptor (HBA) and glycerol as hydrogen bond donor (HBD). Aqueous two-phase (ATPS) formation of TDESs with various salts was established and phase partitioning ability was evaluated using standard bovine immunoglobulin. Ultrasound-assisted liquid-liquid microextraction (UA-LLME) was performed with ATPS of better partitioning ability for quail egg yolk. Optimization of influential variables with response surface methodology was accomplished and maximum yield was achieved for 85% (v/v) of NADES for feed of 18 μg/ml of egg yolk isolate with ultrasound temperature of 35 °C and 12 min contact time respectively. The quantification of recovery was accomplished by gel filtration process with the determination of retention time, volume and resolution of separation using marker protein. Ultrapure immunoglobulin-Y (IgY) is achieved with anion exchange chromatography and yield was calculated. The results revealed that the selective concentration of immunoglobulin-Y from quail egg yolk could be performed using environment-friendly TDES based UA-LLME coupled with chromatography.

IgY antibody and human neurocysticercosis: a novel approach on immunodiagnosis using Taenia crassiceps hydrophobic antigens.

Human neurocysticercosis (NCC) is a worldwide neglected disease caused by Taenia solium metacestode and responsible for various complications and neurological disorders. This study aimed to evaluate the use of specific immunoglobulin Y (IgY) produced by laying hens immunized with a hydrophobic fraction of Taenia crassiceps metacestodes (hFTc) in NCC diagnosis. Egg yolk IgY antibodies were fractionated, purified and characterized. Enzyme-linked immunosorbent assay (ELISA) was carried out to evaluate the production kinetics and avidity maturation of anti-hFTc IgY antibodies throughout the IgY obtention process. Antigen recognition tests were carried out by Western blotting and immunofluorescence antibody test using purified and specific anti-hFTc IgY antibodies for detection of parasitic antigens of T. crassiceps and T. solium metacestodes. Sandwich ELISA was performed to detect circulating immune complexes formed by IgG and parasitic antigens in human sera. The results showed high diagnostic values (93.2% sensitivity and 94.3% specificity) for immune complexes detection in human sera with confirmed NCC. In conclusion, specific IgY antibodies produced from immunized hens with hFTc antigens were efficient to detect T. solium immune complexes in human sera, being an innovative and potential tool for NCC immunodiagnosis.

Anti-Ascaris suum immunoglobulin Y as a novel biotechnological tool for the diagnosis of human ascariasis.

Human ascariasis is a neglected tropical disease of great relevance to public health and is considered the most frequent helminthiasis in poor regions. Accurately diagnosing this parasite has been challenging due to limitations of current diagnostic methods. Immunoglobulin Y (IgY) technology is a very effective alternative for the production of highly specific and profitable antibodies. This study aimed to produce and apply anti-Ascaris suum IgY antibodies in the immunodiagnosis of human ascariasis. Five immunizations comprising total saline extract from A. suum adult life forms were given at 14-day intervals to Gallus gallus domesticus hens of the Isa Brown line. Eggs and blood samples were collected weekly and fortnightly, respectively, to monitor the production of antibodies. The specificity of antibodies was confirmed by dot-blot, kinetic enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence antibody tests. The application for disease diagnosis was performed through the detection of immune complexes in human serum samples by sandwich ELISA. Peaks of IgY anti-A. suum production occurred at weeks 6 and 8. IgY showed high avidity levels after the second dose of immunization, ranging from 64% to 93%, with a mean avidity index of 78.30%. Purified IgY recognized 12 bands of proteins from A. suum saline extract. Eggs, the uterine portion and cuticles of A. suum female adult are reactive in immunofluorescence. The detection of immune complexes showed diagnostic values of 80% sensitivity and 90% specificity. In conclusion, specific IgY have been shown to be a potential immunodiagnostic tool with promising future applications in human ascariasis.

Clinical efficacy of oral immunoglobulin Y in infant rotavirus enteritis: Systematic review and meta-analysis.

Background:Rotavirus (RV) can cause vomiting and diarrhea in infants and children, and could be treated clinically with immunoglobulin Y (IgY), which is an immunoglobulin extracted from chicken yolk. There is no systematic evaluation of immunoglobulin in the treatment of rotavirus enteritis. Therefore, we systematically evaluated rotavirus enteritis with oral immunoglobulin Y therapy using meta-analysis.Methods:We conducted a systematic search in CNKI, WANFANG DATA, VIP, PubMed, and the Cochrane Library databases (up to April 30, 2018). Using Revman 5.3 software for meta-analysis.Results:A total of 2626 subjects with rotavirus diarrhea from 17 randomized clinical trials were included in the meta-analysis. Of these, 1347 subjects received oral immunoglobulin Y and 1279 subjects received conventional treatment. The results of the meta-analysis indicated that the total number of effective cases and effective rates of immunoglobulin Y in treatment of rotavirus enteritis in infants and children was statistically different from that in the control group (odds ratio [OR] = 3.87, 95% confidence interval [CI] (3.17, 4.74), P < .00001) and (OR = 3.63, 95% CI [2.75, 4.80], P < .00001).Conclusions:Immunoglobulin Y is effective in the treatment of infantile rotavirus enteritis. Oral immunoglobulin Y can be widely used in the treatment of rotavirus enteritis in clinic.

Effects of heat stress on growth performance, selected physiological and immunological parameters, caecal microflora, and meat quality in two broiler strains.

ObjectiveThis study was conducted to investigate the effects of normal and heat stress environments on growth performance and, selected physiological and immunological parameters, caecal microflora and meat quality in Cobb 500 and Ross 308 broilers.MethodsOne-hundred-and-twenty male broiler chicks from each strain (one-day-old) were randomly assigned in groups of 10 to 24 battery cages. Ambient temperature on day (d) 1 was set at 32°C and gradually reduced to 23°C on d 21. From d 22 to 35, equal numbers of birds from each strain were exposed to a temperature of either 23°C throughout (normal) or 34°C for 6 h (heat stress).ResultsFrom d 1 to 21, strain had no effect (p>0.05) on feed intake (FI), body weight gain (BWG), or the feed conversion ratio (FCR). Except for creatine kinase, no strain×temperature interactions were observed for all the parameters measured. Regardless of strain, heat exposure significantly (p<0.05) reduced FI and BWG (d 22 to 35 and 1 to 35), immunoglobulin Y (IgY) and IgM, while increased FCR (d 22 to 35 and 1 to 35) and serum levels of glucose and acute phase proteins (APPs). Regardless of temperature, the Ross 308 birds had significantly (p<0.05) lower IgA and higher finisher and overall BWG compared to Cobb 500.ConclusionThe present study suggests that the detrimental effects of heat stress are consistent across commercial broiler strains because there were no significant strain×temperature interactions for growth performance, serum APPs and immunoglobulin responses, meat quality, and ceacal microflora population.

The activity of polyclonal IgY derived from Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in inhibiting colonization of Fusobacterium nucleatum and Streptococcus sanguinis

Background: Fusobacterium nucleatum (F. nucleatum) and Streptococcus sanguinis (S. sanguinis) play a role in dental plaque formation which leads to periodontitis. Immunoglobulin Y (IgY) is present in both serum and egg yolk and can bind to the surface components of bacteria. F. nucleatum and S. sanguinis feature the same type of IV pili as Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans). Saliva binding protein (SsaB) in S. sanguinis is a FimA homolog. FimA constitutes a surface element of Porphyromonas gingivalis (P. gingivalis). F. nucleatum and P. gingivalis possess the same outer membrane protein (OMP) molecular mass. Purpose: The study aimed to determine the activity of A. actinomycetemcomitans and P. gingivalis polyclonal IgY present in serum and egg yolk that can inhibit colonization of F. nucleatum and S. sanguinis. Methods: IgY samples were diluted with phosphate buffer saline (PBS). Several holes were made in the nutrient medium with 10 μl antigen (F. nucleatum/S. sanguinis) being inserted into the center hole. 10 μl PBS, 1:1, 1:2, 1:4, 1:8, 1:16 A. actinomycetemcomitans or P. gingivalis polyclonal IgY were subsequently introduced into the surrounding holes. The results of incubation at 37°C were observed after 24-48 hours. Kruskal Wallis and MannWhitney tests were administered to analyse the data. Results: A. actinomycetemcomitans and P. gingivalis polyclonal IgY groups in serum showed a precipitation line at dilution ratios of 1:1 and 1:2, whereas in egg yolk this occurred only at a 1:1 dilution ratio with F. nucleatum and S. sanguinis bacteria in this study. No significant differences were evident between each dilution (p&gt;0.05) and none existed between serum and egg yolk (p&gt;0.05). Conclusion: IgY polyclonal of A. actinomycetemcomitans and P. gingivalis in both serum and egg yolk initiate activities that can inhibit colonization of F. nucleatum and S. sanguinis.

Reducing Campylobacter jejuni colonization in broiler chickens by in-feed supplementation with hyperimmune egg yolk antibodies

Campylobacter infections sourced mainly to poultry products, are the most important bacterial foodborne zoonoses worldwide. No effective measures to control these infections in broiler production exist to date. Here, we used passive immunization with hyperimmune egg yolks to confer broad protection of broilers against Campylobacter infection. Two novel vaccines, a bacterin of thirteen Campylobacter jejuni (C. jejuni) and C. coli strains and a subunit vaccine of six immunodominant Campylobacter antigens, were used for the immunization of layers, resulting in high and prolonged levels of specific immunoglobulin Y (IgY) in the hens’ yolks. In the first in vivo trial, yolks (sham, bacterin or subunit vaccine derived) were administered prophylactically in the broiler feed. Both the bacterin- and subunit vaccine-induced IgY significantly reduced the number of Campylobacter-colonized broilers. In the second in vivo trial, the yolks were administered therapeutically during three days before euthanasia. The bacterin IgY resulted in a significant decrease in C. jejuni counts per infected bird. The hyperimmune yolks showed strong reactivity to a broad representation of C. jejuni and C. coli clonal complexes. These results indicate that passive immunization with hyperimmune yolks, especially bacterin derived, offers possibilities to control Campylobacter colonization in poultry.

Highly specific and sensitive anti-Strongyloides venezuelensis IgY antibodies applied to the human strongyloidiasis immunodiagnosis

Due to the epidemiological problem of the neglected condition of human strongyloidiasis, rapid and effective diagnosis is extremely important, with the development of new diagnostic tools being essential to reduce infections and chronic cases. Avian immunoglobulin Y (IgY) technology is an alternative for antibody production that has high specificity and profitability. This study aimed to produce and fractionate IgY antibodies from the egg yolks of hens that were immunized with the total antigenic extracts of Strongyloides venezuelensis infectious filariform larvae (iL3) and parthenogenetic females (pF). IgY antibodies were then evaluated by their recognition of antigenic proteins, evolutive helminth forms, and serological diagnosis of human strongyloidiasis by the detection of immune complexes in serum samples. Egg yolks were fractionated to obtain IgY antibodies by thiophilic interaction chromatography. Immune complex detection in serum samples showed diagnostic values for anti-iL3 IgY and anti-pF IgY antibodies at 95.56% and 88.89% sensitivity and 95.56% and 91.11% specificity, respectively. Therefore, IgY technology is a promising tool for the detection of blood circulating Strongyloides antigens, with possible application as a serological diagnostic method.

Efficient Production of Human Norovirus-Specific IgY in Egg Yolks by Vaccination of Hens with a Recombinant Vesicular Stomatitis Virus Expressing VP1 Protein.

Human norovirus (HuNoV) is responsible for more than 95% of outbreaks of acute nonbacterial gastroenteritis worldwide. Despite major efforts, there are no vaccines or effective therapeutic interventions against this virus. Chicken immunoglobulin Y (IgY)-based passive immunization has been shown to be an effective strategy to prevent and treat many enteric viral diseases. Here, we developed a highly efficient bioreactor to generate high titers of HuNoV-specific IgY in chicken yolks using a recombinant vesicular stomatitis virus expressing HuNoV capsid protein (rVSV-VP1) as an antigen. We first demonstrated that HuNoV VP1 protein was highly expressed in chicken cells infected by rVSV-VP1. Subsequently, we found that White Leghorn hens immunized intramuscularly with rVSV-VP1 triggered a high level of HuNoV-specific yolk IgY antibodies. The purified yolk IgY was efficiently recognized by HuNoV virus-like particles (VLPs). Importantly, HuNoV-specific IgY efficiently blocked the binding of HuNoV VLPs to all three types (A, B, and O) of histo-blood group antigens (HBGAs), the attachment factors for HuNoV. In addition, the receptor blocking activity of IgY remained stable at temperature below 70 °C and at pH ranging from 4 to 9. Thus, immunization of hens with VSV-VP1 could be a cost-effective and practical strategy for large-scale production of anti-HuNoV IgY antibodies for potential use as prophylactic and therapeutic treatment against HuNoV infection.