SAG-related sequence SRS57, Toxoplasma gondii (SAG3)

Toxoplasma gondii is an obligatory intracellular coccidia parasite that has the largest zoonotic association globally and can cause miscarriage, stillbirth and neonatal complications in livestock, particularly sheep, goats and pigs. One third of the world's population is considered at risk of infection. Researches found that different strains of Toxoplasma gondii are known to induce different cytokine responses, and therefore their pathogenesis is also different. The surface antigen of Toxoplasma gondii is the key molecule in the immunodiagnosis and immunoprophylaxis of Toxoplasma gondii. The attachment of T. gondii to target cells is mediated by recognition of cellular heparan sulfate proteoglycan (HSPG). SAG3 is important for Toxoplasma's invasion of host cells; it is the first glycosaminoglycan-binding protein associated with Toxoplasma, and SAG3-HSPG interactions are involved in parasite attachment to target cells.