Expression of Plasmid Encoded GRA4 Gene of Toxoplasma gondii RH Strain in CHO Eukaryotic Cells

Background: Toxoplasmosis is a common infection all around the world. During pregnancy; it may lead to congenital disorders or abortion in human and animals. Severe damage of toxoplasmosis indicates to require effective vaccine. One of dense granules antigen is GRA4 that secrete from tachyzoite and bradyzoite. GRA4 genome is unique without intron and is one of the major immunogenic proteins from Toxoplasma gondii. Methods: We confirmed the cloning of GRA4 gene into pcDNA3 by restriction enzyme and PCR of GRA4 gene with pcGRA4 plasmids as template. Then with using calcium- phosphate method we transfected the pcGRA4 into CHO (Chinesehamster ovary) cells. The yielded protein was separated by SDS-PAGE and moved by electroblotting to nitrocellulose paper. Results: Result of SDS-PAGE analysis showed the appearance of band approximately 42 kDa which was absent in the negative control, that was able to identify toxoplasmosis antibody IgM+ serum in western blot analysis. Conclusion: pcGRA4 plasmid is able to synthesis of antigenic protein in CHO cells. The ability of pcGRA4 for induction of protective immune response against toxoplasmosis will be evaluated in mouse model.