Structure-Guided Design of an Anti-dengue Antibody Directed to a Non-immunodominant Epitope

Abstract

SUMMARY Dengue is the most common vector-borne viral disease, causing nearly 400 million infections yearly. Currently there are no approved therapies. Antibody epitopes that elicit weak humoral responses may not be accessible by conventional B cell panning methods. To demonstrate an alternative strategy to generating a therapeutic antibody, we employed a non-immunodominant, but functionally relevant, epitope in domain III of the E protein, and engineered by structure-guided methods an antibody directed to it. The resulting antibody, Ab513, exhibits high-affinity binding to, and broadly neutralizes, multiple genotypes within all four serotypes. To assess therapeutic relevance of Ab513, activity against important human clinical features of dengue was investigated. Ab513 mitigates thrombocytopenia in a humanized mouse model, resolves vascular leakage, reduces viremia to nearly undetectable levels, and protects mice in a maternal transfer model of lethal antibody-mediated enhancement. The results demonstrate that Ab513 may reduce the public health burden from dengue.

Rational Engineering and Characterization of an mAb that Neutralizes Zika Virus by Targeting a Mutationally Constrained Quaternary Epitope

“…Antibodies were expressed in Freestyle 293 cells by transient transfection with Polyethyleneimine (PEI) and purified by protein A chromatography(Robinson et al, 2015). The purified antibodies were quantified by IgG ELISA.…”

“…In between the different steps, plates were washed twice with PBST (PBS+0.05%Tween). Absorbance is read at 450nm using a plate reader (Robinson et al, 2015). The antibody affinity is obtained by measuring the mAb concentration that result in 50% maximal effective concentration of binding.…”

The mechanistic role of antibodies to dengue virus in protection and disease pathogenesis

“…Broadly neutralizing anti-EDIII monoclonal antibodies such as 1A1D-2 can also potently neutralize DENV-1, DENV-2, and DENV-3 at 37°C by inhibiting attachment of DENV to host cells [46]. Furthermore, using the structural framework of EDIII, Robinson et al developed a unique EDIII potent neutralizing antibody that binds to the epitope-paratope interface on EDIII of all DENV serotypes and potently neutralizes DENV by preventing viral fusion [47], reinforcing the notion that EDIII antibodies can be highly neutralizing. In addition, antibodies that target complex quaternary structures of DENV can be highly neutralizing.…”

ANALYSIS OF DOMAIN SPECIFICITY OF THE PROTECTIVE CHIMERIC ANTIBODY ch14D5a AGAINST GLYCOPROTEIN E OF TICK-BORNE ENCEPHALITIS VIRUS

“…Актуальность получения ре-комбинантных аналогов поверхностных белков различных флавивирусов определяется необходимостью разработки вакцин нового поколения (Chen, 2015;Rey et al, 2018), создания высокочувствительных тест-систем (Holbrook et al, 2004;Zidane et al, 2013), а также проведения струк-турных исследований (Rey et al, 1995;Wu et al, 2003;Volk et al, 2009). Рекомбинантные флавивирусные белки используются при изучении эпитопов, узнаваемых по-тенциально терапевтическими высоконейтрализующими и протективными антителами Robinson et al, 2015;Barba-Spaeth et al, 2016;Zhao et al, 2016;Wang et al, 2017).…”