Proteomic identification of a Toxoplasma gondii sporozoite-specific antigen using HDAC3 inhibitor-treated tachyzoites as surrogate

ABSTRACT: The apicomplexan parasite Toxoplasma gondii has a complex life cycle involving multiple host species. Access to sexual stages and sporozoite-containing oocysts, essential for the parasite’s environmental transmission, is limited and requires animal experiments with cats. In vitro alternatives and resource-efficient methods are needed to improve our understanding of these crucial stages. Several molecular factors and transcriptional switches have been identified in recent years that are responsible for differentiation. Their genetic depletion or drug-induced inhibition, targeting the histone deacetylase HDAC3 in tachyzoites, leads to the expression of non-tachyzoite genes, including genes of sexual stages and the oocyst. This opens up the possibility of studying aspects of these stages in vitro. Here, we applied this concept and show that apicidin, a commercially available HDAC3 inhibitor, could be used to identify the hitherto unknown antigen of the sporozoite-specific monoclonal antibody G1/19 in tachyzoites. Using mass spectrometry of immunoprecipitated G1/19 target protein from apicidin-treated cultures, we identified it as SporoSAG. In addition, for the much less abundant sporozoite-specific protein LEA860, apicidin treatment was still sufficient to induce a detectable protein level in immunofluorescence microscopy. We discuss further use cases for apicidin-treated tachyzoites as surrogates for sexual stages and oocysts and address the limitations of this approach. Collectively, the paucity of material of sexual stages and oocysts from T. gondii can be overcome to some extent without the need for cat-derived material.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human) Toxoplasma Gondii

SUBMITTER: Joerg Doellinger  

LAB HEAD: Peter Lasch

PROVIDER: PXD055279 | Pride | 2025-05-07

REPOSITORIES: Pride