Generation and Characterisation of Peptide-Based IgY Antibodies Against SRS29B Protein of Toxoplasma gondii.

Toxoplasmosis, a worldwide zoonotic infection caused by the protozoan parasite Toxoplasma gondii, has the potential to cause severe illness in both humans and animals. In this study, we describe the production and characterisation of IgY polyclonal antibodies capable of specifically recognising the SRS29B surface protein from Toxoplasma gondii tachyzoites lysates. To this end, a series of bioinformatics tools were employed to predict potential SRS29B B-cell epitopes, including Antheprot, IEDB, BCPREDS, ABCpred and Bepipred. Four peptides were synthesised to generate IgY antibodies. The production of specific antibodies against the SRS29B peptide constructs was confirmed in experimental animals using ELISA and MABA assays. This outcome demonstrated a correlation between the predictive analysis and the response obtained in chickens. Antibodies targeting the peptide constructs containing the SRS29B sequences (217-229 aa, 238-253 aa and 259-274 aa) recognised molecules present in the tachyzoite lysates of T. gondii, as confirmed by western blot analysis. This specific recognition was further supported by the inhibition of tachyzoite protein recognition upon exposure to homologous peptides. These findings suggest that three selected peptide constructs are suitable for the development of an antigen-capture assay to facilitate the detection of T. gondii in raw milk as well as for diagnosing acute toxoplasmosis.