Infected tumor cells secrete a PD-L1×CD3 bispecific that binds PD-L1 on target cells and CD3 on T cells, creating an immune synapse that triggers T‑cell cytotoxicity (perforin/granzyme) and concurrently blocks PD‑1/PD‑L1 signaling; thus PD‑L1+ cells are directly killed by redirected T cells.