Abstract:

BACKGROUND: So far, inducible co-stimulator is the important costimulatory molecule family member. Inducible co-stimulator can promote the activation of T cells proliferation and secretion, regulate Th1/Th2 cell polarization dependence, enhance B cell function which depend on the T cells. So, blocking the inducible co-stimulator may result the inactivation and no reaction of cloning in T cells, thus inducing the immune escape of tumor on the body.
OBJECTIVE: To build a plasmid expression of inducible co-stimulator Ig, in order to observe the expression in rat body. 
METHODS: cDNA encoding the extracellular domain of human inducible co-stimulator was prepared. The encode of the domain was fused with the gene of immunoglobulin IgG constant fragment (Ig) of encoding mouse, in order to build the inducible co-stimulator Ig fusion gene and the secreted eukaryotic expression vector pcDNA3-inducible co-stimulator Ig. Enzyme digestion of the recombinant and sequencing was performed, and then the positive liposome coated pcDNA3-inducible co-stimulator Ig was transferred into the muscle tissue of mouse right thigh. Western blot was used to detect the level of inducible co-stimulator Ig.
RESULTS AND CONCLUSION: The sequencing confirmed that the size of target gene fragment pcDNA3- inducible co-stimulator Ig plasmid was exactly the same with the sequence of inducible co-stimulator published on Genebank, which indicated the successful of plasmid construction. After transferred into the mouse for 7 days, the liposome coated pcDNA3-inducible co-stimulator Ig was positively expressed in the mice serum, which showed that pcDNA3-inducible co-stimulator Ig could be expressed in the rat muscle cells. The results suggest that gene synthesis and recombinant technology can successfully construct the eukaryotic expression vector pcDNA3-inducible co-stimulator Ig.

Key words: transfection, neoplasms, inducible T-cell co-stimulator protein, plasmid