Strategies for the Induction of Tolerance with Monoclonal Antibodies

The introduction in the organism of tissues expressing foreign genes—ranging from major histocompatibility antigens to the products of gene therapy—have in common their ability to elicit protective immune responses leading to their rejection. Different strategies have been proposed to overcome immune rejection. Monoclonal antibodies, targeting molecules involved in the molecular events required for T cell activation, offer the promise of resetting the immune system toward tolerance without compromising overall immune competence. The mechanisms leading to immune tolerance rely not only on the induction of regulatory T cells, but also on the elimination of aggressive clones, and the triggering of specific gene expression programs that contribute to self-defense of the target tissue.