1. Department of Chemistry, University of California, Irvine, California 92617, United States
2. Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
3. Vaccine Research and Development Center, Department of Physiology & Biophysics, University of California, Irvine, California 92617, United States
4. School of Medicine, Institute for Immunology, University of California, Irvine, California 92617, United States