Quantitative proteomic analysis of the Toxoplasma gondii cytoskeleton and bioinformatic identification of highly antigenic proteins.

The Toxoplasma gondii cytoskeleton is a highly organized structure essential for parasite motility, replication, and host cell invasion. To identify its components, a highly enriched fraction of tachyzoite cytoskeletons was obtained and quantitatively analyzed by mass spectrometry. We identified 623 proteins classified into 18 functional groups, including 30 IMC proteins, 34 cytoskeleton proteins, and 14 uncharacterized proteins. A comprehensive bioinformatic analysis was conducted to assess protein abundance (fmol), antigenicity, accessibility, interactome, and homology, with the aim of identifying immunogenic targets. Among the top vaccine candidates were -GRA12, IMC1, ROP8, and -IMC4, with ROP8 emerging as the most promising based on epitope prediction. Data are available via ProteomeXchange with identifier PXD063409. SIGNIFICANCE: Toxoplasma gondii represents one of the most virulent and successful parasites in human and veterinary pathogenesis. Since T. gondii is a highly dynamic parasite that depends on its cytoskeleton to invade and disseminate through tissues, knowledge of its cytoskeleton composition is essential for understanding the biological mechanisms involved in parasite-host interactions and for the design of pharmaceutical and vaccination strategies. Quantitative proteomic analysis of the T. gondii cytoskeleton provided new and extensive information on its composition and, through bioinformatics approaches, allowed us to suggest several candidate molecules for future immunoprotective design.