Autoimmune thyroiditis in guinea pigs association with histocompatibility type

Adoptive transfer of experimental autoimmune thyroiditis (EAT) in guinea pigs: requirement for Ia-positive antigen-presenting cells for in vitro activation of effector T cells

Lymph node T cells from guinea pigs sensitized in vivo with guinea pig thyroglobulin (GPTG) could transfer experimental autoimmune thyroiditis (EAT) to normal syngeneic recipients after in vitro culture with GPTG or GPTG-pulsed peritoneal exudate cells (PEC). Although EAT effector T cells have been shown previously to be Ia negative at the time of transfer, the addition of specific anti-Ia serum to the cultures inhibited effector cell activation. The inhibitory effect of anti-Ia on effector-T-cell activation was shown to be due to inhibition of the function of antigen-presenting PEC rather than to an effect on the sensitized T cell. Moreover, only Ia-positive PEC could present antigen in this system and Ia matching between the PEC and the T cell was required for effective T-cell activation. GPTG-pulsed Strain 2 (EAT susceptible) and Strain 13 (EAT resistant) PEC could both present antigen to T cells from 2 X 13 F1 guinea pigs although Strain 2 PEC were more effective, suggesting that defective antigen presentation by macrophages may at least partially explain the relative resistance to EAT of Strain 13 guinea pigs. These results indicate that interaction between Ia-positive PEC and sensitized T cells in vitro is necessary for the development of active effector T cells that can transfer EAT.

Gene(s) at I-A subregion controls the autoimmune response to thyroglobulin in mice

Immunization of mice with thyroglobulin emulsified in Freund's complete adjuvant produces autoimmune thyroiditis, characterized by antibodies to thyroglobulin and infiltration of the thyroid with mononuclear cells. Some strains of mice are low and others are high responders to thyroglobulin. The immune response as reflected especially in the magnitude of the thyroid infiltration, is controlled by gene(s) within the H-2 locus. Previous attempts to map the Ir gene(s) for thyroglobulin (Ir-Tg) showed that it could be assigned to either the K or I-A subregion of H-2. An H-2 recombinant strain of mice, B10.MBR (H-2bq1), in which the H-2K is derived from the H-2b haplotype and which carries the I-Ak allele(s), was immunized with thyroglobulin. B10.MBR mice were high responders to thyroglobulin in contrast to C57BL/6 mice, which have both the H-2K and I-A from the H-2b haplotype and were low responders. This suggests that Ir-Tg, which controls the severity of autoimmune thyroiditis, maps within the I-A subregion, similar to gene(s) controlling the susceptibility to experimental myasthenia gravis.