Immunoinformatic analysis of some dense granule antigens of Toxoplasma gondii: Potential implications for vaccine development

This study utilized an extensive in silico strategy to first identify and characterize six recently studied, virulent dense granule antigens (GRAs) of T. gondii , including GRA15, GRA60, GRA76, GRA83, GRA-α, and GRA-β", and to subsequently assess their immunogenic B- and T-cell epitopes. Based on a series of bioinformatics web servers, we predicted the physicochemical, antigenic and structural properties of the proteins, as well as subcellular characteristics with an emphasis on predicted signal peptides and transmembrane domains. All GRAs were predicted to be hydrophilic, thermotolerant, antigenic and non-allergenic, with GRA-α and GRA-β also showing particularly good predicted solubility properties. Using a multi-server approach, the B-cell epitopes were assessed and screened for antigenicity and solubility. Also, major histocompatibility complex (MHC)-binding T-cell epitopes were additionally screened antigenicity/immunogenicity, allergenicity, toxicity, and IFN-γ induction. The predicted cytotoxic T-lymphocyte (CTL) epitopes were found to possess high global population coverage at 88.02 %. This study provides only a foundational epitope identification platform using computer-based method that is instrumental in reframing the future experimental design of multi-epitope vaccines for toxoplasmosis. • Dense granule antigens are among immunogenic secretory proteins of T. gondii . • Six novel GRAs were evaluated in silico using immunoinformatics tools. • Data retrieved can be used for GRA-based multi-epitope vaccines.