One-step design of a stable variant of the malaria invasion protein RH5 for use as a vaccine immunogen.

摘要: Many promising vaccine candidates from pathogenic viruses, bacteria, and parasites are unstable cannot be produced cheaply for clinical use. For instance, Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is essential erythrocyte invasion, highly conserved among field isolates, elicits antibodies that neutralize in vitro protect an animal model, making it a leading malaria candidate. However, functional RH5 only expressible eukaryotic systems exhibits moderate temperature tolerance, limiting its usefulness hot low-income countries where prevails. Current approaches to immunogen stabilization involve iterative application of rational or semirational design, random mutagenesis, biochemical characterization. Typically, each round optimization yields minor improvement stability, multiple rounds required. In contrast, we developed one-step design strategy using phylogenetic analysis Rosetta atomistic calculations PfRH5 variants with improved packing surface polarity. To demonstrate the robustness this approach, tested three designs, all which showed stability relative wild type. The best, bearing 18 mutations PfRH5, expressed folded form bacteria at >1 mg per L culture, had 10–15 °C higher thermal tolerance than type, while also retaining ligand binding immunogenic properties indistinguishable proving value as future generation vaccines against blood stage. We envision efficient computational methodology will used enhance biophysical other recalcitrant emerging pathogens.