Characterizing the Specificity and Cross-Reactivity Profile of the B Cell Response to Dengue Virus Serotype 2

Abstract

Dengue is a Flavivirus transmitted by Aedes mosquitoes, which causes significant disease burden worldwide (Michlmayr et al., 2021). Dengue disease can vary in severity from asymptomatic to potentially deadly dengue hemorrhagic fever/dengue shock syndrome. There are four serotypes of dengue virus, which share antigenic similarities to each other, and to other viruses in the Flavivirus genus (Michlmayr et al., 2021; Rathore et al., 2020). The goal of this study was to characterize the specificity and cross-reactivity profile of the B cell response to dengue virus serotype 2 virus-like particles (DENV-2 VLPs). We hypothesized that immunization of rabbits with DENV-2 VLP would generate both dengue serotype-2 specific, and cross-reactive antibodies to other dengue serotypes as well as other viruses in the flavivirus genus. Immunization and B cell isolation work was performed by a commercial vendor, and B cell supernatants were provided to Takeda. We screened this series of B cell supernatants from DENV-2 VLP-immunized rabbits using a Luminex®-based indirect immunoassay, in which antigens from DENV serotypes 1-4 and other flaviviruses were coupled to magnetic microspheres to enable detection of antibodies of interest. A subset of monoclonal antibodies was selected for further characterization based on the diversity and uniqueness of their antigen binding profiles, assay cut-off criteria, antibody binding strength, and virus neutralization potential. Our results indicated that immunization of rabbits with DENV-2 VLP generated both dengue serotype-specific and serotype cross-reactive antibodies and revealed a distinctive recognition pattern to a range of flavivirus antigens. Through this work, we identified a final panel of 14 monoclonal antibodies that will serve as tools for investigation into the roles for shared and unique epitope-specificities in the anti-dengue antibody response.