Biological function study on surface antigen-related protein Tgsrs51 of Toxoplasma gondii

Objective Toxoplasma gondii is an obligate intracellular protozoan parasite that infects all warm-blooded animals，including humans.Currently，there is a lack of specific drugs for the treatment of toxoplasmosis，and traditional drug therapy faces issues such as significant toxic side effects and limited efficacy.Therefore，developing a safe and effective vaccine has become an important strategy for preventing and controlling the disease.Surface antigen-related sequence proteins（SRSs）of T. gondii play a crucial role in virulence，invasion and adhesion，and immune regulation of the parasite.Among them，SRS51 protein（TGME49_308840），as a member of the SRS family，has potential research value due to its unclear specific biological function.This study aims to explore the biological function and mechanism of action of Toxoplasma gondii SRS51 protein，providing a reference for the development of safe and effective T. gondii vaccines. Method With the Toxoplasma gondii type II Pru strain as the subject，CRISPR-Cas9 gene editing and seamless cloning techniques were employed to construct a Tgsrs51 gene-deleted strain（PruΔsrs51）.The biological function of the Toxoplasma SRS51 protein was systematically evaluated through plaque assay，cell invasion and proliferation assay，escape assay，in vitro bradyzoite conversion assay，and mouse virulence assay. Result After the deletion of the Tgsrs51 gene，the plaque area and number of T. gondii significantly decreased（P