Production of PD-L1 immune checkpoint inhibitor in nicotiana benthamiana

Abstract

Immune checkpoint antibodies disrupt the binding of receptor-ligand pairs which regulate immune response in cancer treatment. PD-1/PD-L1 pathway has become one target of the cancer immunotherapy approaches. Atezolizumab, the first FDA-approved antibody to PD-L1 in the treatment of metastatic urothelial, non-small cell lung, small cell lung, and hepatocellular cancers, is expressed in Chinese Hamster Ovary (CHO) cell lines with several limitations, i.e., high costs of production, limited-capacity yields, and pathogen risks. To overcome these drawbacks, the transient expression in Nicotiana benthamiana leaves, which provide expandable scalability and inexpensive costs, was investigated by co-infiltration of Agrobacterium tumefaciens GV3101 cultures harboring Atezolizumab heavy chain and light chain in the genes of interest sites. The transient expression of Atezolizumab produced up to 86.76 micrograms/gram of fresh leaf weight after agroinfiltrated with OD 600 nm = 0.4 and 1:1 heavy chain to light chain ratio, then harvested on 6 days post-infiltration. The plant-produced anti-PD-L1 was assessed for physicochemical and functional properties compared to commercially available Tecentriq® from CHO cells, which showed similar binding efficacies to PD-L1 receptors. In conclusion, this research provides plants with an alternative cost-effective platform for producing functional monoclonal antibodies for cancer therapy.