Protection against dengue disease by synthetic nucleic acid antibody prophylaxis/immunotherapy.

Seleeke Flingai,Kate E Broderick,Janess M Mendoza,Ami Patel,Niranjan Y Sardesai,Sujan Shresta,David B Weiner,Emily M Plummer,Kar Muthumani

doi:10.1038/srep12616

Abstract

Dengue virus (DENV) is the most important mosquito-borne viral infection in humans. In recent years, the number of cases and outbreaks has dramatically increased worldwide. While vaccines are being developed, none are currently available that provide balanced protection against all DENV serotypes. Advances in human antibody isolation have uncovered DENV neutralizing antibodies (nAbs) that are capable of preventing infection from multiple serotypes. Yet delivering monoclonal antibodies using conventional methods is impractical due to high costs. Engineering novel methods of delivering monoclonal antibodies could tip the scale in the fight against DENV. Here we demonstrate that simple intramuscular delivery by electroporation of synthetic DNA plasmids engineered to express modified human nAbs against multiple DENV serotypes confers protection against DENV disease and prevents antibody-dependent enhancement (ADE) of disease in mice. This synthetic nucleic acid antibody prophylaxis/immunotherapy approach may have important applications in the fight against infectious disease.

Highlights

For delivering cross-reactive, neutralizing monoclonal antibodies into the circulation may provide rapid, complete protection against DENV-associated disease
Two optimized plasmids were constructed: pDVSF-3 WT, which encodes for the heavy and light chains of DV87.1, and pDVSF-3 LALA, which encodes for an Fc region-modified version of DV87.1 with abrogated Fcγ receptor (Fcγ R) binding by way of two leucine-to-alanine (LALA) mutations in the CH2 region[29] that have been shown to eliminate antibody-dependent enhancement[14]
The plasmids were transfected into human embryonic kidney (HEK) 293T cells, and secreted antibody levels in the supernatant were quantified after 48 hours by enzyme-linked immunosorbent assay (ELISA) (Fig. 1b)

Summary

Introduction

For delivering cross-reactive, neutralizing monoclonal antibodies into the circulation may provide rapid, complete protection against DENV-associated disease One such approach involves vector-mediated gene transfer of monoclonal antibodies. Several studies have demonstrated the effectiveness of this delivery strategy in protecting NHPs against SIV17, humanized mice against HIV18,19, and mice and ferrets against influenza[20,21,22] While these studies have employed intramuscular or intranasal administration of adeno-associated virus (AAV) vectors to produce protective antibodies, our interest in DNA plasmids has led us to explore whether such vectors can be used to deliver neutralizing monoclonal antibodies into the circulation. We describe an approach to delivering cross-reactive neutralizing antibodies against DENV into the circulation using DNA plasmid-mediated antibody gene transfer This synthetic DNA-encoded antibody approach (DMAb) produces biologically relevant levels of mAbs after a single intramuscular injection of antibody-encoding DNA. We demonstrate that intramuscular delivery of a DNA plasmid encoding an anti-DENV human IgG1 nAb, with an Fc region mutation that abrogates Fcγ R binding, protects mice from both virus-only infection and antibody-enhanced lethal infection

Methods

Results

Conclusion