RESUMO
@#[Abstract] In recent years, investigation on immune checkpoint inhibitors has made exciting progress in anti-tumor therapy. Through continuous exploration, there is a deeper understanding of intermolecular interaction patterns among PD-L1, PD-1, CD80, CTLA-4, etc. In addition to classically acting as a T cell inhibitory receptor, PD-L1 was found to be co-expressed with PD-1 or CD80 on the same cell and play a positive immunoregulatory function through cis-interaction, significantly affecting the interaction network between tumor cells and immune cells and the efficacy of immunotherapy, and bringing new changes to the understanding of the mechanisms of cancer immunotherapy. This review provides an in-depth analysis of the cis-PD-L1/PD-1 and cis-PD-L1/CD80 pathways and their interactions with a complex network of CTLA-4 and CD28 molecules, finally outlines the effects of blocking this cis-interaction pathway on T cell signaling, cytotoxic function, and the efficacy of anti-tumor immunotherapy.