Expression and in vitro function of anti-CTLA-4 human antibody expressed in plants

Abstract Biosimilars produced in plant systems encompass a range of molecules, including antibodies, vaccines, enzymes, receptors, and other therapeutic molecules. In the present study, we aimed to express the immune checkpoint-inhibitor anti-CTLA-4 antibody, Ipilimumab, in Nicotiana tabacum plant. We generated transgenic tobacco plants using Agrobacterium -mediated transformation and purified an anti-CTLA-4 monoclonal antibody (mAb P CTLA-4) using protein A affinity chromatography. This purified mAb P CTLA-4 showed specific binding activity to CTLA-4-positive human tonsil tissues, as confirmed by immunoblot, indirect ELISA, and immunohistochemistry analyses. Our study confirmed that mAb P CTLA-4 effectively targeted CTLA-4 in human tonsil tissues. These findings suggest that our plant-derived anti-CTLA-4 antibody retains its original functionality, underscoring the promising potential of plant-based therapeutic expression systems for producing high-value medicinal biosimilars.