[Murine model of Graves disease induced by thyroid-stimulating hormone receptor gene transfected via liposome].

Objective: To compare the efficacy of different expression vectors, target genes, and immunization procedures in transfecting mice via liposome to construct murine model of Graves disease.

Methods: We linked pCDNA3.1(+) and pUBC to full-length human TSHR and TSHR A subunit cDNA to yield four plasmids, which were later injected intramascularly or subcutaneously into female Balb/c mice via liposome. The blood anti-TSHR antibody (TRAb) were determined and the body weight were measured after each immunization. Serum thyroid hormone levels were measured after the animals were sacrificed.

Results: In mice immunized with pUBC, no significant variance with control in weight nor serum TRAb concentration was observed. Weight gain in pCDNA3.1(+) group was significantlyly slower than controls (p<0.05), and serum TRAb concentration was also significantly elevated. In pCDNA group, animals immunized with TSHR A subunit (TSHRA subgroup) as the target gene revealed even significantly slower weight gain (p<0.001) and even faster TRAb elevation than those immunized with full length TSHR. Significantly higher FT4 (p=0.023) was observed in TSHRA and TSHR subgroups, which was reversely correlated to weight gain, but no significant difference (p>0.05) in FT3 was observed. Weight gain and TRAb concentration mainly varied in the later period of immunization.

Conclusions: Immunization with pCDNA3.1(+) and TSHR A subunit gene together with higher immunization frequency increases the chance of model induction. Furthermore, FT4 is a better indicator for assessing the thyroid function in this model.