NONINVOLVEMENT OF IL-4 AND IL-10 IN TOLERANCE INDUCTION TO EXPERIMENTAL AUTOIMMUNE-THYROIDITIS

The mechanisms of tolerance induced with deaggregated mouse thyroglobu lin (dMTg) in experimental autoimmune thyroiditis (EAT) is not yet wel l defined. As shown previously, the induction and maintenance of toler ance require CD4(+) T cells exerting active regulatory function to pre vent EAT induction, To examine whether Th2 cells are responsible for r esistance, we injected anti-IL-4 and anti-IL-10, separately or togethe r, into CBA (H2(k)) mice at the time of MTg pretreatment to study the role of IL-4 and IL-10 in tolerance induction, Our results show that t olerance can be well established without involving IL-4 or IL-10. To d etermine whether IL-4 was involved in tolerance induction in another E AT-susceptible strain, IL-4 knockout mice on B10.Q background were sim ilarly pretreated with dMTg and immunized. These IL-4 knockout mice ex hibited very good tolerance. The lack of response to EAT induction was not due to IL-4 deficiency, since immunized IL-4 knock-out control mi ce developed severe EAT. Moreover, resistance was strong in IL-4 knock -out mice also given anti-IL-10. The data in both susceptible stains s how that IL-4 and IL-10 play a small role in induced resistance to EAT . (C) 1998 Academic Press.