A bivalent Epstein-Barr virus vaccine induces neutralizing antibodies that block infection and confer immunity in humanized mice

Abstract

Epstein-Barr virus (EBV) is the major cause of infectious mononucleosis and is associated with several human cancers and, more recently, multiple sclerosis. Despite its prevalence and health impact, there are currently no vaccines or treatments. Four viral glycoproteins (gp), gp350 and gH/gL/gp42, mediate entry into the major sites of viral replication, B cells, and epithelial cells. Here, we designed a nanoparticle vaccine displaying these proteins and showed that it elicits potent neutralizing antibodies that protect against infection in vivo. We designed single-chain gH/gL and gH/gL/gp42 proteins that were each fused to bacterial ferritin to form a self-assembling nanoparticle. Structural analysis revealed that single-chain gH/gL and gH/gL/gp42 adopted a similar conformation to the wild-type proteins, and the protein spikes were observed by electron microscopy. Single-chain gH/gL or gH/gL/gp42 nanoparticle vaccines were constructed to ensure product homogeneity needed for clinical development. These vaccines elicited neutralizing antibodies in mice, ferrets, and nonhuman primates that inhibited EBV entry into both B cells and epithelial cells. When mixed with a previously reported gp350 nanoparticle vaccine, gp350D 123 , no immune competition was observed. To confirm its efficacy in vivo, humanized mice were challenged with EBV after passive transfer of IgG from mice vaccinated with control, gH/gL/gp42+gp350D 123 , or gH/gL+gp350D 123 nanoparticles. Although all control animals were infected, only one mouse in each vaccine group that received immune IgG had detectable transient viremia. Furthermore, no EBV lymphomas were detected in immune animals. This bivalent EBV nanoparticle vaccine represents a promising candidate to prevent EBV infection and EBV-related malignancies in humans.

Protective anti-gB neutralizing antibodies targeting two vulnerable sites for EBV-cell membrane fusion

“…The epitopes of 3A3 and 3A5 defined in this study represent the major immunogenic sites specific for EBV gB in human sera. This study highlights the importance of the neutralizing antigenic sites at gB D-II and D-IV together with those at gp350 and gHgL recognized by neutralizing antibodies ( 18 , 24 , 32 , 35 ) for the rational design of successful anti-EBV vaccines and therapeutics.…”

“…Given that EBV elicits broad antibody responses against its glycoproteins in humans, the gB epitopes recognized by 3A3 and 3A5 could be exploited in combination with the other antigenic sites on gp350 and gHgL recognized by the neutralizing mAbs 72A1, AMMO1, 769B10, and 1D8 ( 18 , 24 , 32 ) for the design of potent vaccines. The recent exciting studies reported the design of nanoparticles displaying gp350 and/or gHgL, which elicited potent neutralizing antibodies against EBV infection ( 32 , 35 ). Carefully designed approaches that combine multiple EBV immunogens and properly expose these neutralizing antigenic sites could be further explored to induce broader and stronger immunity against EBV infection.…”

Designing a multi-epitope vaccine against coxsackievirus B based on immunoinformatics approaches

“…However, since the vaccines are based on human HLA, functional evaluation is actually difficult to be carried out using routine experimental animals. Even though there are humanized mice, it is still recognized that testing the vaccine in such a model would be difficult ( 104 , 105 ). Nonetheless, it is possible to determine in vitro if the antibodies generated were neutralizing and to determine the cytolytic potential of the T cells ( 106 , 107 ).…”

A Lymph Node Targeted Adjuvant and Engineered Subunit Vaccine Promotes Potent Immunity to Epstein-Barr Virus in HLA-expressing Mice

“…Long-term persistence of cellular and humoral immunity may provide more robust protection against EBV-associated diseases. It is also important to emphasize that while vaccine formulations based on EBV glycoproteins (gp350, gH/gL and gH/gL/gp42) have shown some protection against EBV infection in humanized mice 51 , it is unlikely that the antibodies directed to these glycoproteins alone can offer protection against latent EBV infection. In contrast, previous studies have clearly demonstrated that adoptive immunotherapy with latent antigenspeci c T cells can reverse the outgrowth of EBV malignancies and offer clinical bene t to patients with progressive MS 41,52−54 .…”