Suppressor T cells, antigen-presenting cells and the role of I-J restriction in oral tolerance to ovalbumin.

Suppressor T cells (Ts) and antigen-presenting cell (APC) activity are both important for the induction of systemic tolerance after feeding protein antigens to mice. In this report, we have examined further the nature of the inter-relationship between Ts and APC in oral tolerance to ovalbumin (OVA). We found previously that oral tolerance to OVA could prevented by treating mice with oestradiol, and we now report that oestradiol enhances the ability of spleen APC to present OVA to T cells. In parallel, mice treated with oestradiol do not generate the Ts activity normally found after feeding OVA. Treatment of mice with anti-I-J antiserum prevents the induction of both tolerance and Ts activity after feeding OVA, but the suppressor effector cells generated by feeding OVA can not be depleted in vitro by treatment with anti-I-J antibody plus complement. In vivo administration of monoclonal anti-I-A antibody had no effect on oral tolerance to OVA. Our results show that induction of oral tolerance to OVA is an I-J-restricted phenomenon and we propose that this reflects an interaction between specific Ts cells and a population of I-J+ cells which we suggest are APC.