An attenuated Zika virus NS4B protein mutant is a potent inducer of antiviral immune responses

Guangyu Li; Awadalkareem Adam; Huanle Luo; Chao Shan; Zengguo Cao; Camila R Fontes-Garfias; Vanessa V Sarathy; Cody Teleki; Evandro R Winkelmann; Yuejin Liang; Jiaren Sun; Nigel Bourne; Alan D T Barrett; Pei-Yong Shi; Tian Wang

doi:10.1038/s41541-019-0143-3

An attenuated Zika virus NS4B protein mutant is a potent inducer of antiviral immune responses

NPJ Vaccines. 2019 Nov 28:4:48. doi: 10.1038/s41541-019-0143-3. eCollection 2019.

Authors

Guangyu Li¹, Awadalkareem Adam¹, Huanle Luo¹, Chao Shan², Zengguo Cao², Camila R Fontes-Garfias², Vanessa V Sarathy^{3

4}, Cody Teleki¹, Evandro R Winkelmann¹, Yuejin Liang¹, Jiaren Sun¹, Nigel Bourne^{1

4

5}, Alan D T Barrett^{1

3

4}, Pei-Yong Shi^{2

4

6}, Tian Wang^{1

3

4}

Affiliations

¹ 1Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA.
² 2Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA.
³ 3Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA.
⁴ 4Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA.
⁵ 5Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555 USA.
⁶ 6Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555 USA.

Abstract

Live attenuated vaccines (LAVs) are one of the most important strategies to control flavivirus diseases. The flavivirus nonstructural (NS) 4B proteins are a critical component of both the virus replication complex and evasion of host innate immunity. Here we have used site-directed mutagenesis of residues in the highly conserved N-terminal and central hydrophobic regions of Zika virus (ZIKV) NS4B protein to identify candidate attenuating mutations. Three single-site mutants were generated, of which the NS4B-C100S mutant was more attenuated than the other two mutants (NS4B-C100A and NS4B-P36A) in two immunocompromised mouse models of fatal ZIKV disease. The ZIKV NS4B-C100S mutant triggered stronger type 1 interferons and interleukin-6 production, and higher ZIKV-specific CD4⁺ and CD8⁺ T-cell responses, but induced similar titers of neutralization antibodies compared with the parent wild-type ZIKV strain and a previously reported candidate ZIKV LAV with a 10-nucleotide deletion in 3'-UTR (ZIKV-3'UTR-Δ10). Vaccination with ZIKV NS4B-C100S protected mice from subsequent WT ZIKV challenge. Furthermore, either passive immunization with ZIKV NS4B-C100S immune sera or active immunization with ZIKV NS4B-C100S followed by the depletion of T cells affords full protection from lethal WT ZIKV challenge. In summary, our results suggest that the ZIKV NS4B-C100S mutant may serve as a candidate ZIKV LAV due to its attenuated phenotype and high immunogenicity.

Keywords: Biotechnology; Diseases; Immunology; Live attenuated vaccines; Microbiology.

Abstract

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