Résumé
T lymphocytes play a central role in the immune response. Coming from the bone marrow, they are attracted by the thymus where they are educated, they mature and differentiate into two main subsets: helper T-cells and suppressor/cytotoxicity T-cells. T lymphocytes are involved in the immune response at different levels. As "conductor" of the whole lymphoid system, they are able to recognize foreign antigens and to induce the activation and the regulation of other T-cells and also B cells by the way of many soluble factors named lymphokines. As effector cells of cell-mediated immune responses, they are able to provoke delayed type hypersensitivity reactions and to specifically kill target cells (anti-viral cytotoxicity, for instance). The in vitro effect of some antibiotics on T-cells has been investigated. Clearly, a lot of them are able to modulate T-cell functions.