Induction of autoimmunity by immunization of mice with human thyrotropin receptor.

The development of autoimmunity was investigated after repeated immunizations with human thyrotropin receptor (hTSH-R) of five congenic strains of female and male mice. After each immunization, free T3 levels and antibodies to hTSH-R and to six peptides of the hTSH-R were assayed. Our results showed that H-2s and H-2q female mice developed features of autoimmunity such as antibody responses to hTSH-R and to hTSH-R peptides, transient variations in the levels of free T3 thyroid hormone, and lymphocytic infiltrations in their thyroid glands. Concerning the antibody responses to hTSH-R peptides, we found that peptide P1 (352-366) contained a major B cell epitope. Furthermore, strain-specific B cell epitope was exemplified by peptide 92 (12-30) and two male- and female-specific B cell epitopes were located in peptides 91 (32-46) and 93 (316-330), respectively. These features appeared rather related to hyperthyroidism.