Transient expression of human interleukin-15 in <i>Nicotiana benthamiana</i>

A plant-based expression system provides a cost-effective, scalable, and safe alternative to traditional cell culture platforms. In this study, recombinant human interleukin-15 (IL-15) was transiently expressed in <i>Nicotiana benthamiana</i> plants using agroinfiltration. IL-15 is a cytokine with significant potential in cell engineering, immunotherapy, and cancer therapy. A codon-optimized IL-15 gene was cloned into a binary vector designed for plant expression and introduced into <i>Rhizobium radiobacter</i> (formerly <i>Agrobacterium tumefaciens</i>). The <i>R. radiobacter</i> for human IL-15 expression was infiltrated into <i>N. benthamiana</i> leaves. Following purification, receptor-binding assays confirmed that the plant-derived IL-15 could bind to the IL-15 receptor comparably to its mammalian-produced counterpart. This first report of IL-15 expression in plants highlights the promise of plant-based systems for biopharmaceutical production and lays the groundwork for further development of IL-15 for applications in cell engineering, clinical therapies, and the cultured meat industry.