Cost-Effective Purification of Endotoxin-Free LIF, IL-2, and IL-33

Abstract

We describe a cost-effective Escherichia coli (E. coli)-based platform for producing endotoxin-free cytokines. As a proof of concept, we applied this protocol to purify four representative human and mouse cytokines - mouse leukemia inhibitory factor (mLIF), human interleukin-2 (hIL-2), and human and mouse interleukin-33 (hIL-33 and mIL-33) - and demonstrated their bioactivity to be equivalent to commercial counterparts for direct use in stem cell culture and immune cell activation, both in vitro and in vivo. Reagent costs for producing these proteins are approximately 5%-10% of commercial list prices. This platform is readily adaptable to other costly cytokines and growth factors, providing a scalable and affordable approach to accelerate research in cell biology, tissue engineering, and biomanufacturing.