Atezolizumab and granzyme B as immunotoxin against PD-L1 antigen; an insilico study

CD274 gene encodes programmed death-ligand 1 (PD-L1) protein, also known as B7 homolog 1 (B7-H1), which is a crucial hallmark for highly proliferation cells including cancer cells. PD-1 and PD-L1 interaction is assumed as a negative regulator for immune response which can inhibit the T cell growth and cytokine secretion and supports tumor cells evasion from immune system. therefore, PD-L1 could be assumed as a candidate target for immune-therapy. The predicted structure of PD-L1 indicates (Gly4Ser) 3 linker-based chains links. In that line, different simulation softwares applied to explore the structure of granzyme B (GrB), a serine protease in cytotoxic lymphocytes granules as an apoptosis mediator, was attached to its specific antibody structure (atezolizumab) via an adaptor sequence. Evaluation of accuracy, energy minimization and characterization of biological properties of the final processed structure were performed and our computational outcomes indicated that the employed method for structure prediction has been successfully managed to design the immunotoxin structure. It is necessary to mention that, the precise and accurate design of the immune-therapeutic agents against cancer cells can be confirmed by employment of in-silico approaches. Consequently, based on this approach we could introduce a capable immunotoxin which specifically targeting PD-L1 in an accurate orientation and initiates cancer cell destruction by its toxin domain.