ZIKV Envelope Domain-Specific Antibodies: Production, Purification and Characterization.

Sami Akhras,Fabian Elgner,Marie-Luise Herrlein,Eberhard Hildt,Thomas Holzhauser

doi:10.3390/v11080748

Sami Akhras, Fabian Elgner + Show 3 more

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https://doi.org/10.3390/v11080748

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Abstract

Infection with Zika virus (ZIKV) came first to public attention after it was found to be associated with congenital microcephaly during the outbreak in Brazil (2015–2016). Diagnosis of ZIKV suffers from extensive cross-reactivity with other Flaviviruses, which are circulating in many ZIKV epidemic areas. Due to the fatal outcome of ZIKV infection during pregnancy, detailed knowledge about neutralizing and non-neutralizing epitopes is crucial for the development of robust detection systems of protective antibodies. Therefore, additional information about ZIKV immunogenicity and antibody response is required. In this project, we report the production, purification and characterization of six different polyclonal antibodies against ZIKV envelope (E) protein. The produced antibodies bind to isolated ZIKV E protein as well as to the surface of ZIKV particles, interestingly without being potently neutralizing. Surface plasmon resonance measurement showed that these antibodies bind with high affinity to ZIKV E protein. Epitope mapping revealed that the epitopes are distributed among the three ZIKV E domains with seven binding sites. These identified binding sites overlap only partially with the previously described epitopes recognized by neutralizing antibodies, which is in accordance with their lack of potent neutralizing activity. Additionally, these antibodies showed neither cross-reactivity nor potent neutralizing activity against West Nile virus, a related flavivirus. The gained set of data helps to extend our understanding about the distribution of neutralizing and non-/weak-neutralizing epitopes in ZIKV E protein, and provides a rationale for ZIKV vaccine design and development of robust detection assays for neutralizing antibodies.

Highlights

Zika virus (ZIKV) is a mosquito-borne virus, which was first isolated in 1947 from a rhesus monkey in the Zika forest in Uganda [1]
In order to gain more information about distribution pattern of neutralizing and non-/weakneutralizing epitopes in the ZIKV E protein, we present in this work the design, production, and purification of different ZIKV E protein domains, which we used for immunization and production of E-specific polyclonal antibodies
The results showed that all hyper-immune sera contain ZIKV E-specific antibodies, and that these antibodies are directed to the corresponding domains of the E protein: Sera K89/K90 showed reactivity to ZIKV E protein, K87/K88 showed reactivity to ZIKV ED1+2 protein, and K45/K48 showed reactivity to ZIKV ED3 protein (Figure 2c)

Summary

Introduction

Zika virus (ZIKV) is a mosquito-borne virus, which was first isolated in 1947 from a rhesus monkey in the Zika forest in Uganda [1]. The first described infection of humans with ZIKV was in Nigeria in 1954 [2]. Before the first reported outbreak, which occurred in Yap Island in Micronesia (2007) [3], only 14 cases of human infection with ZIKV were documented. The outbreak in Yap Island was followed by a larger epidemic in French Polynesia in the South Pacific in 2013–2014 [4]. ZIKV started to attract international attention after being linked to some neurological complications in humans such as congenital microcephaly and the Guillain–Barré syndrome (GBS) [5,6,7]. During the ZIKV outbreak in Brazil (2015–2016) [8], the WHO declared the outbreak as a public health emergency of international concern (PHEIC, February 2016). ZIKV belongs to the genus Flavivirus of the family Flaviviridae and Viruses 2019, 11, 748; doi:10.3390/v11080748 www.mdpi.com/journal/viruses

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