Life Sciences & Biotechnology
Title : | High resolution structural analyses of broadly neutralizing human antibodies against dengue virus |
Area of research : | Life Sciences & Biotechnology |
Principal Investigator : | Dr. Vidya MangalaPrasad, Indian Institute Of Science, Bangalore, Karnataka |
Timeline Start Year : | 2022 |
Timeline End Year : | 2025 |
Contact info : | vmprasad@iisc.ac.in |
Equipments : | "CO2 incubator
Liquid nitrogen transfer/storage dewar(s)
Computing desktop workstation" |
Details
Executive Summary : | Dengue virus (DENV) is a mosquito-borne flavivirus that causes dengue fever, dengue hemorrhagic fever and shock syndrome. Its symptoms can range from fever, joint pain, body aches to vomiting and bleeding that can be fatal. DENV accounts for nearly 100 million symptomatic infections annually across the world with India contributing to ~34% of cases {Bhatt et.al., Nature, 2013}. Presence of multiple DENV serotypes with varying antigenicity along with antibody dependent enhancement (ADE) of secondary DENV infections pose a multitude of challenges to develop therapeutic strategies that are effective against all serotypes. In this study, the main objective is to structurally characterize the epitope and binding characteristics of a new class of broadly neutralizing human antibodies (human bnAbs) that have strong neutralization activity against all 4 DENV serotypes without cross-reactivity to other flaviviruses. Although the broad neutralization potency of these bnAbs is proven {Durham et.al., eLife, 2019}, its target epitope on the virus surface and mechanism of neutralization is unknown. Three bnAbs, in particular, will be studied in interaction with DENV to elucidate their epitopes and binding characteristics. Two of these human bnAbs bind and neutralize DENV irrespective of its maturation state. Considering that circulating populations of DENV in nature are a mixture of mature as well as immature forms of the virion and their respective structures present vastly different conformations of the viral surface proteins; it is of particular significance to unravel how these antibodies recognize structural features on the virion. For these studies, DENV serotype 2 will be propagated and purified in my lab as it is one of the widely used strains of the virus. Using single particle cryo-electron microscopy (cryo-EM), high resolution, near-atomic structures of mature and immature DENV in complex with these new class of human bnAbs will be determined. Using the determined high resolution structures of DENV-bnAb complexes, spatial location of the binding epitopes along with involved amino acids can be elucidated. The structures will also reveal the approach and binding characteristics of the different bnAbs. These results will, thus, aid to identify and characterize the quaternary epitope of these bnAbs, which in turn may help to deduce their mechanisms of action. Collectively, these studies will not only help to characterize bnAbs that could be used to develop monoclonal antibody therapies against DENV but also aid in characterizing a novel vulnerable site on DENV that could be exploited for immunogen design. |
Total Budget (INR): | 59,02,193 |
Organizations involved