Effect of in vivo administration of anti-CTLA-4 monoclonal antibody and IL-12 on the induction of low-dose oral tolerance.

Oral tolerance has been characterized as an immunological hyporesponsiveness to fed antigen. Previous studies have suggested that high-dose oral tolerance involves the preferential interaction of B7 with CTLA-4 on the T cell. To determine whether similar mechanisms are involved in the induction of low-dose oral tolerance, mice were treated with anti-CTLA-4 monoclonal antibody (MoAb), with or without IL-12, at the time of feeding.