Recombinant lipidated Zika virus envelope protein domain III elicits durable neutralizing antibody responses against Zika virus in mice

Abstract

Background: The emergence of Zika virus (ZV) in tropical and subtropical areas of the world has created an urgent need for vaccines against ZV. However, approved vaccines that prevent ZV infection are not available. To develop an effective vaccine against ZV infection, a lipidated form of ZV envelope protein domain III that possesses an intrinsic adjuvant property was rationally designed. Our goal was to examine the immunogenicity of recombinant lipidated ZV envelope protein domain III (rLZE3) and evaluate its potential as a vaccine candidate against ZV.Methods: Recombinant ZV envelope protein domain III (rZE3) and rLZE3 were prepared with an Escherichia colibased system. Dendritic cell surface marker expression and cytokine production upon stimulation were analyzed to evaluate the function of rLZE3. Neutralizing antibody capacities were evaluated using focus reduction neutralization tests after immunization. To investigate the protective immunity in immunized mice, serum samples collected from immunized mice were adoptively transferred into AG129 mice, and then viremia levels and survival times were examined after ZV challenge.Results: rLZE3 alone but not rZE3 alone efficiently activated dendritic cells in vitro and was taken up by dendritic cells in vivo. Immunization of C57BL/6 mice with rLZE3 alone (without exogenous adjuvant) could induce ZVspecific neutralizing antibody responses. Furthermore, serum samples obtained from rLZE3-immunized mice provided protection as indicated by a reduction in viremia levels and prolongation of survival times after ZV challenge. Conclusion: These results indicate that rLZE3 is an excellent vaccine candidate and has great potential that should be evaluated in further preclinical studies.

A Polypeptide of Tumor-Associated Antigen L6 with Intrinsic Adjuvant Activity Enhances Antitumor Immunity

“…Our previous studies showed that recombinant lipidated proteins containing domain 3 of the envelope protein of dengue virus can enhance both antibody titers and neutralizing antibody titers [ 38 , 39 ]. Similar effects were observed with lipidated domain 3 of the envelope protein of the Zika virus [ 40 ]. We previously identified the B cell epitope of TAL6 that can induce ADCC to kill cancer cells [ 21 ].…”

Intranasal Vaccination With Recombinant Antigen-FLIPr Fusion Protein Alone Induces Long-Lasting Systemic Antibody Responses and Broad T Cell Responses

“…Construction of the pOVA, pOVA-FLIPr and pZEIII expression vectors has been described previously ( 40 , 48 ). The DNA sequence of ZEIII-FLIPr was synthesized (Purigo Biotechnology Co., Taipei, Taiwan) using E. coli codon usage according to the amino acid sequences of Zika virus PRVABC59 (accession number AMC13911) and FLIPr (accession number BAB57318).…”

“…The production and purification of rOVA, rOVA-FLIPr, and rZEIII was described previously ( 40 , 48 ). For the expression of rZEIII-FLIPr, pZEIII-FLIPr was transformed into E. coli BL21 (DE3) (Lucigen, Middleton, WI).…”

“…Cells were harvested and then disrupted in a French press (Constant Systems, Daventry, UK) at 27 Kpsi in homogenization buffer [20 mM Tris (pH 8.0), 50 mM sucrose, 500 mM NaCl and 10% glycerol]. The cell lysate was clarified by centrifugation (80,000×g for 40 min) as previously described ( 48 ). The majority of rZEIII-FLIPr was present in the inclusion bodies.…”

“…Antigen-specific IgG and IgA titers in the indicated samples were determined by titration as previously described with some modifications ( 48 ). Serum samples were prepared in 3-fold serial dilutions (starting at the indicated dilution) and then added to antigen-coated 96-well plates.…”