Project 5: mAb Development Flaviviruses and Alphaviruses

SUMMARY Flaviviruses and alphaviruses are insect-transmitted RNA viruses that globally cause severe human syndromes, including acute and chronic musculoskeletal disease, hemorrhagic fever, hepatitis, and encephalitis. Flaviviruses and alphaviruses are pathogens with pandemic potential because of the geographical expansion of their vectors, urbanization and population density

increases, and their capacity for epidemic transmission. In Project 5 of the Flavivirus and Alphavirus ReVAMPP (FLARE) Center, we propose to use multiple orthogonal antibody discovery approaches to generate and validate best-in-class human monoclonal antibodies (mAbs) against prototype flaviviruses (West Nile virus [WNV] and dengue virus [DENV]) and

alphaviruses (chikungunya virus [CHIKV]). Using these mAbs, we aim to determine the principles that govern the design of optimal mAb combinations to elicit synergistic responses and create barriers to genetic resistance in vitro and in vivo. In collaboration with the Structure, Computational, and Protein Engineering Core C, we also will develop novel computational

methods to improve upon mAb neutralization potency and breadth. We will refine a high-efficiency screening platform to rapidly discover human mAbs against prototype flaviviruses and alphaviruses that then can be genetically modified to endow extended half-life properties, enabling them as vaccine-like treatment options. Identification of key protective and neutralizing

epitopes of mAbs (with Core C) also can inform immunogen design in Projects 1-3 through reverse vaccinology approaches. In Aim 1, we will perform structural and function synergy studies to determine the principles governing the selection of optimal mAb combination therapies against the alphavirus, CHIKV. In Aim 2, we will use innovative computational approaches (with Core C)

to functionally mature the paratope-epitope interactions of human mAbs against DENV to enhance potency and breadth. In Aim 3, we will perform a new discovery screening campaign to identify potently neutralizing anti-WNV mAbs that can be partnered with a computationally modified version of WNV-86 to enhance inhibitory potency and prevent neutralization escape. In

Aim 4, as a proof-of-concept, we will demonstrate the efficiency and applicability of our workflow by performing a ‘sprint’ to rapidly identify an optimal combination therapy of potently neutralizing mAbs against Mayaro virus, an emerging alphavirus with pandemic potential. Overall, experiments in Project 5 will refine our understanding of the correlates of mAb protection against

flaviviruses and alphaviruses to enable the design of a modular ‘ plug-and-play’ workflow that can respond to potential pandemics by rapidly generating optimized combinations of mAbs.