Structural and biophysical studies of dengue virus neutralization and infection enhancment by monoclonal antibodies. (360G-Wellcome-080721_Z_06_Z)

Structural and biophysical studies of dengue virus neutralization and infection enhancement by monoclonal antibodies The mechanisms of antibody-dependant neutralization and enhancement of dengue virus infection by monoclonal antibodies are very poorly understood. Mechanisms for neutralization have been proposed based on antibodies either blocking virus attachment to receptor and/or inhibition of conformational change required for viral fusion, whereas it has been postulated that the mechanism of enhancement is dependent on weak antibody binding that is insufficient to neutralize. A structural analysis of the interaction of the envelope protein of dengue virus with various antibodies of different neutralization activity, antigen specificity and avidity, is important to be able to correlate structural and biophysical data with function. This is fundamental if one is to gain an understanding of the fundamental basis for antibody neutralization and enhancement, and will impact on the design of future vaccines for dengue. The goal is a structural characterization of the interaction between the envelope glycoprotein (E) of dengue virus with functionally well characterized antibodies, in order to tease out if there are generic mechanisms for neutralization and enhancement. 1. Determine the structure of complexes of domain III of E with antibodies of known serological properties. 2. Determine the structure of complexes of full length E with antibodies of known serological properties. 3. To biophysically characterize the interaction of these antibodies with E using techniques, such as SPR and AUC. The effects of pH on antibody binding will be examined as well as the effects of binding to potential receptors. 4. To determine the structure of virus-Fab complexes either by cryo-electron microscopy or crystallography.