Progress on research of chicken IgY antibody-FcRY receptor combination and transfer

IgY Antibodies from Birds: A Review on Affinity and Avidity

IgY antibodies are found in the blood and yolk of eggs. Several studies show the feasibility of utilising IgY for immunotherapy and immunodiagnosis. These antibodies have been studied because they fulfil the current needs for reducing, replacing, and improving the use of animals. Affinity and avidity represent the strength of the antigen-antibody interaction and directly influence antibody action. The aim of this review was to examine the factors that influence the affinity and avidity of IgY antibodies and the methodologies used to determine these variables. In birds, there are few studies on the maturation of antibody affinity and avidity, and these studies suggest that the use of an adjuvant-type of antigen, the animal lineage, the number of immunisations, and the time interfered with the affinity and avidity of IgY antibodies. Regarding the methodologies, most studies use chaotropic agents to determine the avidity index. Studies involving the solution phase and equilibrium titration reactions are also described. These results demonstrate the need for the standardisation of methodologies for the determination of affinity and avidity so that further studies can be performed to optimise the production of high avidity IgY antibodies.

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.

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.

Comparative Yolk Proteomic Analysis of Fertilized Low and High Cholesterol Eggs during Embryonic Development

Simple Summary

Cholesterol exists in each cell of the living organism and plays a significant role in cellular functions. Several reports have demonstrated that high yolk cholesterol concentration affected embryo mortality, hatchability, and performance. The present results showed that high-cholesterol egg yolks had increased protein intensities and egg and yolk weight relative to low-cholesterol egg yolks. The differentially expressed yolk proteins were primarily involved in lipid transport, lipid localization, nutrient reservoir function, and embryo protection during embryonic development.

Abstract

The yolk is the principal part of the egg that contains vitamins, minerals, lipids, and proteins which are essential for embryo development and hatching. The egg yolk contains significant amounts of lipoproteins, triacylglycerides, and cholesterol, whose dynamics are indistinct during embryogenesis. The effects of cholesterol on the yolk protein abundance, intensity, and function are ill-defined during embryonic development. Using two-dimensional gel electrophoresis, eggs with respective high and low cholesterol protein abundance were investigated after 0, 2, 6, and 13 days of embryogenesis and further analyzed by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. The results revealed that the vitellogenin proteins are the most abundant egg yolk protein that showed proximity and a high degree of variation in isoelectric point and molecular weight. The results demonstrated increased expression of vitellogenin-1 and vitellogenin-3 at two days and vitellogenin-2 protein at 13 days of embryogenesis in both egg types. The ovoinhibitor, immunoglobulin lambda light chain precursor, Ig-gamma (clone-36 chicken), and beta-2-glycoprotein-1 precursor proteins were significantly expressed in high cholesterol eggs while haptoglobin protein PIT-54 and vitelline membrane outer layer proteins intensities were significant in low cholesterol eggs at two days of embryogenesis. The high cholesterol eggs showed a modest increase in egg weight, yolk weight, albumen height, yolk color, and egg strength relative to the low cholesterol eggs. The gene ontology enrichment analysis revealed that the differentially expressed proteins such as vitellogenin proteins were involved in lipid transport and lipid localization biological processes and showed nutrient reservoir activity function. The ovotransferrin regulated the biological processes of plasminogen activation and extracellular matrix disassembly and characterized the anchored component of the plasma membrane. The ovoinhibitor protein was involved in response to mineralocorticoid and corticosterone biological processes whereas the vitellin membrane outer layer protein constituted the extracellular exosome, extracellular organelle, and membrane-bounded vesicle cellular components. Collectively, our study revealed yolk protein abundance, molecular function, cellular components, and biological processes and concluded that yolk protein intensities were significantly altered by cholesterol concentration.

Proteomic analysis of fertilized egg yolk proteins during embryonic development

Egg yolk is an important source of nutrients for embryo development. In this study, the egg yolk protein composition at 0, 10, and 18 D of incubation was analyzed by 2-dimensional gel electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. A significant difference in the abundance of 42 protein spots representing 12 proteins were identified (P < 0.05). The 2-DE gel image analysis exhibited that the molecular weight (MW) of 29 protein spots was lower than their theoretical value, in which 14 vitellogenin (VTG) fragments were lower than the theoretical value. There were 13 protein spots showed a higher MW including 5 ovotransferrins with MW of 87.2 kDa. The gene ontology enrichment analysis suggested that biological process of the differentially expressed proteins were mainly involved in lipid transport and lipid localization at 10 and 18 D of incubation. The molecular function of the differentially expressed proteins was involved in nutrient reservoir activity, lipid transporter activity, and antigen binding at 10 D of incubation. At 18 D of incubation, the differentially expressed proteins mainly participated in nutrient reservoir activity and substrate-specific transporter activity. The high abundance of VTGs at 10 D of incubation might participate in lipid localization and lipid transportation to facilitate the yolk nutrient transport to embryo. The low expression of ovotransferrins at 10 D of incubation indicated the chondrogenesis of embryo.