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Student Thesis Defense: Stephan Kudlacek (Kuhlman lab)
July 2, 2020 @ 12:30 pm - 1:30 pm
This event will be broadcast via Zoom. Links will be provided to UNC affiliated email addresses only or through written consent of defending student. Contact event organizer, Holly Shepherd, for the Zoom link.
Abstract: Dengue virus is a highly prevalent, multi-serotype, arbovirus whose infections present a worldwide public health burden. While current vaccine measures, have contributed to controlling the spread of this virus, development is still required to create a vaccine capable of providing complete and safe protection against dengue. Analysis of antibodies produced from dengue immune individuals have revealed that quaternary structural epitopes present on envelope (E) protein dimers are critical targets of antibodies capable of providing protection against dengue infection. We use molecular modeling to identify mutations capable of stabilizing the dengue virus 2 E protein homodimer for stable presentation of quaternary epitopes. These mutations improve the DENV2 E dimer affinity (Kd) at 37˚C from 12µM to <100pM and improve the total protein stability by up to +18.2˚C. Interestingly, a stable dimer variant crystallizes in the same dimer conformation observed when bound to a DENV quaternary epitope broadly neutralizing antibody. DENV neutralizing quaternary epitope antibodies have improved binding to these stable dimers compared to WT, indicating stable presentation of quaternary epitopes at body temperature. Furthermore, immunizing mice with these stable dimers results in elicitation of DENV E dimer specific quaternary epitope antibodies. This work provides further insight into the requirements needed to elicit quaternary epitope antibodies to aid in the development of effective DENV subunit vaccines.