Mouse and Human Monoclonal Antibodies Protect against Infection by Multiple Genotypes of Japanese Encephalitis Virus

Abstract

Japanese encephalitis virus (JEV) remains a leading cause of viral encephalitis worldwide. Although JEV-specific antibodies have been described, an assessment of their ability to neutralize multiple genotypes of JEV has been limited. Here, we describe the development of a panel of mouse and human neutralizing monoclonal antibodies (MAbs) that inhibit infection in cell culture of four different JEV genotypes tested. Mechanism-of-action studies showed that many of these MAbs inhibited infection at a postattachment step, including blockade of virus fusion. Mapping studies using site-directed mutagenesis and hydrogen-deuterium exchange with mass spectrometry revealed that the lateral ridge on domain III of the envelope protein was a primary recognition epitope for our panel of strongly neutralizing MAbs. Therapeutic studies in mice demonstrated protection against lethality caused by genotype I and III strains when MAbs were administered as a single dose even 5 days after infection. This information may inform the development of vaccines and therapeutic antibodies as emerging strains and genotypic shifts become more prevalent.

Mechanism of differential Zika and dengue virus neutralization by a public antibody lineage targeting the DIII lateral ridge

“…Previous studies have shown that antibody-mediated immune responses against flaviviruses are protective (Nybakken et al, 2005;Sapparapu et al, 2016;Shrestha et al, 2010;Fernandez et al, 2018). The identification of the mechanisms of neutralization and key epitopes of potently neutralizing antibodies has implications for antibody-based therapies and vaccine development.…”

Basics of memory B‐cell responses: lessons from and for the real world

“…Passive transfer of minute quantities of immune serum from WNV‐convalescent mice into B‐cell‐deficient animals confers protection to homologous virus infection . Analysis of mouse monoclonal antibodies has revealed that the most potent neutralizing epitopes are located on the lateral ridge epitope of DIII (DIII‐lr) . Interestingly, these DIII‐lr‐specific antibodies are immunodominant in mice, whereas in humans, these specificities clearly exist but are overwhelmed by DII‐fl‐reactive cells and antibodies .…”

“…2 Analysis of mouse monoclonal antibodies has revealed that the most potent neutralizing epitopes are located on the lateral ridge epitope of DIII (DIIIlr). 45,[60][61][62][63] Interestingly, these DIII-lr-specific antibodies are immunodominant in mice, whereas in humans, these specificities clearly exist but are overwhelmed by DII-flreactive cells and antibodies. 38,45,46,64 The DIII-lr epitope is only weakly conserved across flavivirus species, so longlived plasma cell DIII-lr responses provide type-specific immunity with minimal ability to promote ADE.…”

Broad Dengue Neutralization in Mosquitoes Expressing an Engineered Antibody

“…Due to similarities within viral families, this research could have far-reaching consequences for rendering mosquitoes resistant to other arboviruses like ZIKV and CHIKV by using similar genetic engineering strategies to develop scFv-based transgenes. Multiple potent antibodies that effectively neutralize these various mosquito-borne viruses have also been identified in the last decade [57][58][59][60][61] . Although not all of these will confer robust viral resistance when expressed in vivo in mosquitoes, the availability of diverse, well-characterized antibodies of this sort, largely as a result of antibody therapeutic development efforts 58 , should allow for the identification of those that function within the desired context.…”