Forty-five female DDYK mice were divided into three groups and immunized with different preparations of human thyroglobulin (HTg). Group 1 mice were immunized subcutaneously in the back with. HTg emulsified with FCA. Group 2 mice were immunized subcutaneously in the back with HTg dissolved in PBS. Group 3 mice were immunized with HTg dissolved in PBS and FCA separately in the right (HTg) and left (FCA) of the back.
After the fourth immunization (45 days after the first immunization), antisera as well as thyroid glands were obtained, and titers of anti-HTg, anti-T3, anti-T4 and the presence of lesions of autoimmune thyroiditis were examined.
In group 1 mice, titers of anti-HTg and anti-T4 antibodies were significantly higher than those of the other two groups, whereas titers of anti-T3 antibodies were significantly lower than those of the other two groups. In group 1 mice, a significant correlation between titers of anti-T3 and anti-T4 antibodies was observed, whereas in group 2 and group 3 mice, no such correlation was observed.
The incidence of lesions of autoimmune thyroiditis was significantly higher in group 2 and group 3 mice than in group 1 mice. Thus emulsification of HTg with FCA had inhibitory effects on the induction of experimental thyroiditis in mice immunized with HTg.
These results indicate the possibility that FCA has a modulatory effect both quantitatively and qualitatively on the immune response against HTg in mice.
