A Systematic Review of Apical and Basal Complex Roles in Toxoplasma gondii Invasion and Egress

Toxoplasma gondii is an obligate intracellular protozoan parasite of major medical and veterinary importance worldwide. Successful infection depends on its ability to actively invade host cells, replicate intracellularly, and egress to infect new cells. These processes involve complex molecular coordination among specialized organelles that ensure parasite survival and propagation. In the past decade, numerous experimental studies employing advanced molecular and high-resolution microscopy techniques have revealed new insights into the structural and functional dynamics of T. gondii, highlighting the need to systematically review and integrate these findings. This systematic review aims to identify, synthesize, and analyze experimental studies related to the molecular mechanisms of T. gondii infection, including host cell invasion, intracellular replication, and egress. Relevant literature published between 2015 and 2025 was retrieved from the Scopus and PubMed database using specific keywords. Articles were screened based on predefined inclusion and exclusion criteria, and the selection process followed the PRISMA guideline. From an initial 44 articles, 14 met the eligibility criteria after title and abstract screening, and 10 experimental studies were included for full-text analysis. Methodological quality and risk of bias of the included studies were evaluated using the Quality Assessment Tool for In Vitro Studies (QUIN) and visualized using the robvis tool. The systematic synthesis of these findings provides an integrated understanding of the molecular basis of T. gondii invasion and egress.