Production of MAG1 Antigen of Toxoplasma gondii in Escherichia coli

Introduction: toxoplasmosis is a parasitic infection caused by the protozoan toxoplasma gondii; it leads to serious medical problems in congenitally-infected and immunocompromised individuals, while it is quite harmless in immunocompetent individuals. toxoplasma tissue cyst matrix protein (mag1) induces early humoral and cell-mediated immune responses. previous studies suggested recombinant mag1 as a promising antigen for serodiagnosis of toxoplasma infection. methods: a dna fragment encoding mag1, comprising amino acids 50 to 207, was amplified from t. gondii rh strain and cloned in prokaryotic expression plasmid pet-15b(+). recombinant mag1 was expressed in escherichia coli, and highly purified in a single step by immobilized metal ion affinity chromatography. results: the cloned dna fragment was sequenced and showed 100% similarity with the published sequences available in genbank database. the results indicated proper antigenicity of recombinant mag1 . in western blot analysis, purified protein showed a much stronger reactivity with sera from patients with acute toxoplasma infection, compared to sera from chronic infection. conclusion: mag1 protein, alone or in combination with other acute-phase markers might be useful in discriminating acute/reactivated toxoplasma infections from chronic forms.