Production, Characterization and Applications for Toxoplasma gondii-Specific Polyclonal Chicken Egg Yolk Immunoglobulins

Abstract

Background Toxoplasma gondii may cause abortions, ocular and neurological disorders in warm-blood hosts. Immunized mammals are a wide source of hyperimmune sera used in different approaches, including diagnosis and the study of host-parasite interactions. Unfortunately, mammalian antibodies present limitations for its production, such as the necessity for animal bleeding, low yield, interference with rheumatoid factor, complement activation and affinity to Fc mammalian receptors. IgY antibodies avoid those limitations; therefore they could be an alternative to be applied in T. gondii model.Methodology/Principal FindingsIn this study we immunized hens with soluble tachyzoite antigens of T. gondii (STAg) and purified egg yolk antibodies (IgY) by an inexpensive and simple method, with high yield and purity degree. IgY anti-STAg antibodies presented high avidity and were able to recognize a broad range of parasite antigens, although some marked differences were observed in reactivity profile between antibodies produced in immunized hens and mice. Interestingly, IgY antibodies against Neospora caninum and Eimeria spp. did not react to STAg. We also show that IgY antibodies were suitable to detect T. gondii forms in paraffin-embedded sections and culture cell monolayers.Conclusions/SignificanceDue to its cost-effectiveness, high production yield and varied range of possible applications, polyclonal IgY antibodies are useful tools for studies involving T. gondii.

IgY-Technology Applied to Studies of Toxoplasma gondii Infection

“…NaS or AmS precipitation provides fractions with low protein content compared to original yolk, but with a high specific activity [26]. Salt-based yolk antibody precipitation is promising to be a more efficient and useful purification method for the large-scale IgY from egg yolk preparation [16,27].…”

“…Optionally, organic solvents (chloroform) have been used as a mean to remove yolk lipid content at the initial step of IgY isolation [1,14]. The water-dilution method is a widespread procedure for the yolk lipid removal, which provides IgY-enriched water-soluble fraction [14][15][16].…”

“…Gel filtration by Sephacryl S300 and Sephadex G50 or G75 provides a high-purity IgY separation but further protein concentration procedures for separated antibody samples are desired [16,36,37]. On the other hand, the ion-exchange chromatography is a widespread method to separate proteins from mixtures and it is also used for immunoglobulins isolation.…”

“…IgY-based ELISA does not demand expressive modifications from the most common procedures and reagents used to carry out this protocol [16,51]. Egg yolk IgY can be labeled with horseradish peroxidase for use in immunoenzymatic assays [52].…”

“…The results indicated differences between the specificities of egg yolk IgY antibodies and rabbit IgG serum antibodies, although both animal species had been immunized with identical antigen preparations. Ferreira Junior et al [16] have produced comparative mice IgG and chicken IgY against soluble antigens from tachyzoites of T. gondii. They purified yolk antibodies by water dilution method, sodium sulfate precipitation, and molecular weight exclusion chromatography.…”