Biology subjects

Meganck, R. M.

Publications and source records attributed to Meganck, R. M..

2 recordsLinked to original sources

bioRxiv2023

Evolution of a Functionally Intact but Antigenically Distinct DENV Fusion Loop

A hallmark of Dengue virus (DENV) pathogenesis is the potential for antibody-dependent enhancement, which is associated with deadly DENV secondary infection, complicates the identification of correlates of protection, and negatively impacts the safety and efficacy of DENV vaccines. ADE is linked to antibodies targeting the fusion loop (FL) motif of the envelope protein, which is completely conserved in mosquito-borne flaviviruses and required for viral entry and fusion. In the current study, we utilized saturation mutagenesis and directed evolution to engineer a functional variant with a mutated FL (D2-FL) which is not neutralized by FL-targeting monoclonal antibodies. The FL mutations were combined with our previously evolved prM cleavage site to create a mature version of D2-FL (D2-FLM), which evades both prM- and FL-Abs but retains sensitivity to other type-specific and quaternary cross-reactive (CR) Abs. CR serum from heterotypic (DENV4) infected non-human primates (NHP) showed lower neutralization titers against D2-FL and D2-FLM than isogenic wildtype DENV2 while similar neutralization titers were observed in serum from homotypic (DENV2) infected NHP. We propose D2-FL and D2-FLM as valuable tools to delineate CR Ab subtypes in serum as well as an exciting platform for safer live attenuated DENV vaccines suitable for naive individuals and children.

microbiology↗

bioRxiv2021

Genetically Engineered DENV Produces Antigenically Distinct Mature Particles

Maturation of Dengue viruses (DENV) alters the structure, immunity and infectivity of the virion and highly mature particles represent the dominant form in vivo. The production of highly mature virions principally relies on the structure and function of the viral premature protein (prM) and its cleavage by the host protease furin. We developed a reliable clonal cell line which produces single-round mature DENVs without the need for DENV reverse genetics. More importantly, using protein engineering coupled with natural and directed evolution of the prM cleavage site, we engineered genetically stable mature DENVs without comprising viral yield and independent of cell, host, or passage. Using these complementary strategies to regulate maturation, we demonstrate that the resulting mature DENVs are antigenically distinct from their isogenic immature forms. Given the clinical importance of mature DENVs in immunity, our strategy provides a reliable strategy for the production of stable, high-titer mature candidate DENV live virus vaccines, genetically stabilized viruses for DENV maturation and immunity studies, and models for maturation-regulated experimental evolution in mammalian and invertebrate cells. Our data from directed-evolution across host species reveals distinct maturation-dependent selective pressures between mammalian and insect cells, which sheds light on the divergent evolutionary relationship of DENVs between its host and vector.

microbiology↗