immunosuppressive agent An agent that suppresses immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-cells or by inhibiting the activation of helper cells. In addition, an immunosuppressive agent is a role played by a compound which is exhibited by a capability to diminish the extent and/or voracity of an immune response. CHEBI:35705 chebi_ontology immunosuppressant immunosuppressive agents inmunosupresor immunomodulator