IL-10 kinetics in thyroiditis-prone BB/Wor rats

Cytokines modulate the course of autoimmunity, but their role in the evolut ion of spontaneous disease is unclear This study compared the cytokine kine tics of T cell cultures from thyroiditis (LT)-prone NB line BB/Wor rats wit h those of Wistar (Wis) rat controls following activation with the thyroid- specific antigen thyroglobulin (Tg) or Concanavalin A (Con A). Design: T ce ll enhanced splenocytes from 60 day old Wis and NB rats were activated with 0.5 mug/ml rat thyroglobulin (Tg) or Con A in the presence of homologous i rradiated splenocytes as antigen presenting cells (APC's). In addition, the effect of APC's was determined in a crisscross experiment which examined N B T cell responses to Con A in the presence of Wis APC's. ELISA and RT-PCR were used to examine IL-2, IL-4, LL-IO, TNF alpha, IFN gamma, IL-10 concent rations and mRNA expression in the supernatant and cells from parallel cult ures harvested at specific intervals. Frozen thyroids from 60 day old NB, W is and Fisher rats were examined for the presence of IL-10 by immunohistoch emistry. T cell proliferation was measured by H-3 thymidine uptake. Results : Following activation with either Tg or Con A, IL-10 concentrations exceed ed IFN gamma in NB rat cultures, but IFN gamma exceeded IL-10 in Wis cultur es. Wis splenocytes significantly enhanced NB T cell proliferation and cyto kine responses to Con A. Thyroids from 60 day NB rats contained IL-10, but no IFN gamma. There was no IL-10 in thyroids from Wistar or Fisher rats. Co nclusion: Splenocyte responses in LT-prone BB/Wor rats favor IL-10 producti on. Future investigations will examine the source of intrathyroidal IL-10 a nd its role in LT.