Objective:To establish an animal model of Graves’disease by immunizing syngeneic BALB/c mice with hTSHR-ac-tivated splenocytes. Methods:The female BALB/c mice(6～8 weeks) were randomly divided into 2 groups(group a and group b)

which were immunized with recombinant plasmid pcDNA3.1/hTSHR and blank plasmid pcDNA3.1(+) respectively for 3 times at 3-week intervals.The animals were sacrificed at 18th week and their splenocytes were isolated.Other two groups of female syn- geneic BALB/c mice(6~8 weeks) were divided randomly into experimental and control groups

which received splenocytes from group a and group b respectively. Four weeks later

the thyroid glands were removed for histological examination and the sera were determined for Total T4

TSH and TRAb measurements. Results:The thyroid tissues under light microscope displayed dif- fuse hypercellularity with the follicular epithelia being tall cuboidal cells and reduced colloid in 44% of experimental mice with irregular apical poles protruding into the follicular space; there was minimal immune cell in the interstitium with hyper- aemia and edema. Electron microscope examination revealed that the follicular epithelia contained numerous mitochondria and rough endoplasmic reticula

and many long microvilli existed in the luminal surface.The serum level of TT4 in experimental mice was higher than that in control(7.13±1.02 vs 6.43±0.57 μg/dL) (P<0.05).The serum level of TSH in experimental mice was lower than that in control(0.070±0.032 vs 0.098±0.020 μIU/ml) (P<0.05).Hyperthyroidism probably appeared in 4 mice and subclinical hyperthyroidism in 1 mouse. Conclusion:We have effectively induced an animal model which mimics some char- acteristics of human Graves’disease via splenocytes from the animals immunized with recombinant plasmid pcDNA3.1/hTSHR.