Production of IgY polyclonal antibody against diphtheria toxin and evaluation of its neutralization effect by Vero cell assay

Application of two novel anionic peroxidases from Raphanus sativus L. var niger roots in labeling antibodies and developing an enzyme-linked immunosorbent assay

HRP, or horseradish peroxidase, is a reporter enzyme with extensive use in biotechnological applications. We previously reported the purification and characterization of two anionic peroxidases from Raphanus sativus L. var niger (black radish) roots. Here, we evaluated the applicability of these two novel peroxidases as alternatives to traditional horseradish peroxidase (HRP). The two novel peroxidases (BRP-A and BRP-B) and HRP were conjugated to IgY polyclonal antibodies by chemical methods based on the use of sodium periodate and cyanuric chloride. Moreover, the applicability of BRP-A and BRP-B in immunoassays was investigated by comparing the signal generated by these novel peroxidases in ELISA with HRP conjugates. Additionally, the limit of detection (LOD) was calculated for BRP-A, BRP-B, and HRP conjugates. Finally, the thermal stability of peroxidase antibody conjugates at 37 °C and 4 °C was compared. The peroxidase antibody conjugates prepared by the periodate method generated a much stronger signal than those prepared by the cyanuric chloride method. The signal obtained by BRP-A and BRP-B conjugates was much lower compared to the commercial HRP enzyme. The limit of detection was found to be 385.71, 213.75, and 43.6 ng per well for BRP-A, BRP-B, and HRP conjugates prepared by the periodate method, respectively. However, for conjugates prepared by the cyanuric chloride method, the limit of detection could only be estimated for HRP since BRP-A and BRP-B had an extremely low signal-to-noise ratio. All peroxidase conjugates had comparable thermal stability at 37 °C and 4 °C.

Development of polyclonal chicken egg yolk immunoglobulin Y (IgY) antibodies targeting SARS-CoV-2 multi-epitope antigen

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is the primary cause of the Coronavirus disease 2019 (COVID-19) pandemic, which affects millions of people worldwide with high levels of infectivity and mortality. However, the antibodies developed for COVID-19 research and diagnostics are still limited. Therefore, in this study, we developed polyclonal immunoglobulin (IgY) antibodies from chicken egg yolk targeting multi-epitope antigen of SARS-CoV-2. After immunizing hens with a SARS-CoV-2 multi-epitope peptide, IgY antibodies were isolated from chicken eggs and further characterized using SDS-PAGE and ELISA. The results showed that the IgY antibodies were successfully isolated from egg yolks. The sandwich ELISA results demonstrated that the isolated IgYs could bind to SARS-CoV-2 antigens, both the multi-epitope peptide and the trimeric Spike. Furthermore, the developed polyclonal antibodies could recognize SARS-CoV-2 in human nasopharyngeal swab samples, even at the lowest concentration (dilution at 1:10000). Thus, it can be concluded that the developed polyclonal IgYs were successfully produced and have the potential to be applied in the development of COVID-19 diagnostics.

Passive protection of chicken egg yolk immunoglobulin (IgY) against Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus)

IgY is an immunoglobulin primarily found in the serum and egg yolk of birds, amphibians, and reptiles. Recent years, IgY is considered to have a good application prospect in the immunodiagnostics and passive immunotherapy of aquatic diseases. In this study, we prepared a specific IgY against Streptococcus agalactiae in tilapia after immunizing the hens for 4 times. The result of ELISA detection showed that the IgY titers in water-soluble fraction (WSF) after 6 weeks of immunization reached 1:51200 and last for 4 weeks. Western blot (WB) analysis data showed that the specific IgY could recognize the target band, the specific IgY showed a concentration-dependent inhibitory effect on the growth of S. agalactiae, altered cell wall structure and aggluted of S. agalactiae. The quantitative reverse transcription PCR (qRT-PCR) analysis data suggested that the specific IgY downregulated the expression of pro-inflammatory factors (IL-8, TNF-α), upregulated the anti-inflammatory factors (IL-10, TGF-β). In addition, the histopathological results showed that the specific IgY significantly decreased the pathological manifestations, dramatically improved the survival rates of tilapia in injection, feeding, and immersion experiments. Collectively, our findings demonstrated that the broad potential of specific IgY for the prevention and treatment of S. agalactiae infection in tilapia.

Production, characterization and therapeutic efficacy of egg yolk antibodies specific to Nosema ceranae

Nosema disease, caused by Nosema ceranae, one of the single-celled fungal microsporidian parasites, is one of the most important and common diseases of adult honey bees. Since fumagillin, which has been used for decades in the control of Nosema disease in honey bees (Apis mellifera), poses a toxic threat and its efficacy against N. ceranae is uncertain, there is an urgent need to develop alternative prophylactic and curative strategies for the treatment of this disease. The main aim of this study was to investigate the therapeutic potential of specific egg yolk immunoglobulins (IgY) on Nosema disease. For this purpose, the presence of N. ceranae was determined by microscopic and PCR methods in honey bees collected from Nosema suspicious colonies by conducting a field survey. Layered Ataks chickens, divided into four groups each containing 20 animals, were vaccinated with live and inactivated vaccines prepared from field isolates of N. ceranae. Eggs were collected weekly for 10 weeks following the last vaccination. IgY extraction was performed using the PEG precipitation method from egg yolks collected from each group, and the purity of the antibodies was determined by SDS-PAGE and Western Blot. The presence of N. ceranae-specific IgYs was investigated by Western Blot and indirect ELISA methods. It was determined that specific IgYs showed high therapeutic efficacy on Nosema disease in naturally infected bee colonies. In addition, honey bees collected from infected colonies were brought to the laboratory and placed in cages with 30 bees each, and the effectiveness of IgYs was investigated under controlled conditions. It was detected that specific IgY reduced the Nosema spore load and the number of infected bees significantly in both the field and experimental study groups treated for seven days. It was concluded that chicken IgYs, an innovative and eco-friendly method, had a significant potential for use as an alternative to antifungal drugs.

IgY Antibodies as Biotherapeutics in Biomedicine

Since the discovery of antibodies by Emil Von Behring and Shibasaburo Kitasato during the 19th century, their potential for use as biotechnological reagents has been exploited in different fields, such as basic and applied research, diagnosis, and the treatment of multiple diseases. Antibodies are relatively easy to obtain from any species with an adaptive immune system, but birds are animals characterized by relatively easy care and maintenance. In addition, the antibodies they produce can be purified from the egg yolk, allowing a system for obtaining them without performing invasive practices, which favors the three “rs” of animal care in experimentation, i.e., replacing, reducing, and refining. In this work, we carry out a brief descriptive review of the most outstanding characteristics of so-called “IgY technology” and the use of IgY antibodies from birds for basic experimentation, diagnosis, and treatment of human beings and animals.