| In vitro study | Ipilimumab (anti-CTLA-4) is a human IgG1k monoclonal antibody that binds to the extracellular region of human CTLA-4 with high affinity and is an inhibitor of the function of this complex. Ipilimumab can cause T cell activation and proliferation, lymphocyte infiltration, leading to tumor cell death. The enhancement of effector T cell function and the suppression of CD4 Treg cells and CD8 suppressor cells are the key to the therapeutic effect of ipilimumab. Ipilimumab enhances proliferation of ATC (activated T cells), BiAb-mediated tumor-specific cytotoxicity and cytokine synthesis, while attenuating Treg activity with a IL-10 reduction in release. Co-administration of Ipilimumab and nivolumab can enhance effector and memory T cell responses without inappropriately activating naive T cells. |