Designed chimeric nanoparticle displaying viral fusion apparatus elicit potent neutralizing antibody against Epstein-Barr virus infection
Epstein-Barr virus (EBV) ubiquitously infects global population and leads to a variety malignancies and autoimmune diseases. It establishes its lytic-latency life cycle relying on the tropism transition between B cell and epithelial cell, during which its critical glycoprotein gB and gHgL act as the fusion apparatus mediating viral recognition and membrane fusion in either cell type. Thus. simultaneous targeting to fusion apparatus would be ideal strategy to construct potent EBV prophylactic vaccine. In this study, we designed chimeric nanoparticle multivalently displaying gB and gHgL with even gp42 upon the nanoparticle surface, inducing significantly robust neutralizing antibody generation in both murine and non-human primate models. As we further identify the comparable immunization potency between chimeric nanoparticle and whole live virion and preponderance of gB in neutralizing antibody elicitation, we used single-B cell sequencing to dissect the B cell response to chimeric nanoparticle immunization in mouse and isolate a gB-specific neutralizing antibody Fab5 targeting novel vulnerable site. These findings offers insight to advanced vaccine design for EBV and other herpesviruses. Overall design: The mice were immunized with gB/gHgL-chimeric nanoparticle and the total B cell were isolated by MACS. Then fluorescence labeled-gB or gHgL was used to further isolate gB or gHgL-specific B cells. These antigen-specific cells were sorted by FACS and suspended for single-B cell sequencing after constructing  whole transcriptome and VDJ library.