Evolution of a cytokine using DNA family shuffling

Publisher Website
Google Scholar
Abstract
DNA shuffling of a family of over 20 human interferon-α (Hu-IFN-α) genes was used to derive variants with increased antiviral and antiproliferation activities in murine cells. A clone with 135,000-fold improved specific activity over Hu-IFN-α2a was obtained in the first cycle of shuffling. After a second cycle of selective shuffling, the most active clone was improved 285,000-fold relative to Hu-IFN-α2a and 185-fold relative to Hu-IFN-α1. Remarkably, the three most active clones were more active than the native murine IFN-αs. These chimeras are derived from up to five parental genes but contained no random point mutations. These results demonstrate that diverse cytokine gene families can be used as starting material to rapidly evolve cytokines that are more active, or have superior selectivity profiles, than native cytokine genes.