[The immune system: new therapeutic targets].

Control of the immune reaction can become a major goal, particularly in patients with autoimmune diseases or who express alloreactivity after organ transplantation. The most important side effect of this control is an immunodeficiency, a consequence of the wide spectrum of activity of the treatment. Thus, in order to limit the infectious risks, it would appear reasonable to try to develop new more selective strategies. A better definition of the cellular and molecular mechanisms implicated in the initiation and effector phases of autoimmune diseases authorizes the development of new therapeutic approaches able to target precise points of the immune system. There are a large number of potential targets, mainly directed at orientating the cytokinic response toward an antiinflammatory profile, neutralizating proinflammatory cytokines or their receptors, inducing regulatory lymphocytes in order to normalize the state of T and B cell tolerance, and modulating cellular cooperation and lymphocytic homing by blocking adhesion molecules. Some of these new approaches have already been validated in autoimmune diseases, others will follow soon.