Use of Envelope Domain III Protein for the Detection of IgG Type Antibodies Specific to Zika Virus by Indirect ELISA

Abstract

Zika virus (ZIKV) diagnostics are crucial for proper antenatal and postnatal care and also for surveillance and serosurvey studies. Since the viremia during ZIKV infection is fleeting, serological testing is highly valuable to inform diagnosis. However, current serology tests using whole virus antigens frequently suffer from cross reactivity issues, delays, and technical complexity, especially in low and middle income countries (LMICs) and endemic countries. Here, we describe an indirect ELISA to detect specific IgG antibodies using the ZIKV envelope domain III (EDIII) protein expressed in Drosophila S2 cells as an immunogen. Using a total of 367 clinical samples, we showed that the EDIII-ELISA was able to detect IgG antibodies against ZIKV with high sensitivity of 100.0% and specificity of 94.7% when compared to plaque reduction neutralization tests (PRNTs) as the gold standard and using 0.208 as the cut-off OD value. These results show the usefulness of the recombinant envelope domain III as an alternative to standard whole virus proteins for ZIKV diagnostics as it improves the sensitivity and specificity of IgG ELISA assay when used as an immunogen. This method should, therefore, be extended to serological diagnostic techniques for other members of the flavivirus genus and for use in IgM diagnostic testing.

Global seroprevalence of Zika virus in asymptomatic individuals: A systematic review

“…This method has shown higher specificity compared to other ELISAs, but should undergo further validation [ 41 ]. Additionally, some studies have used the envelope protein domain III (EDIII), which is highly diverse among flaviviruses and can improve sensitivity and specificity of the assays [ 61 ]. Nevertheless, neutralization tests continue to be considered the “gold standard” and provide better specificity, but the potential for cross-reactivity persists in flavivirus-endemic areas.…”

Multiplex Serology for Sensitive and Specific Flavivirus IgG Detection: Addition of Envelope Protein Domain III to NS1 Increases Sensitivity for Tick-Borne Encephalitis Virus IgG Detection

“…Previous studies have shown that ZIKV rEDIII is a useful antigen to discriminate between ZIKV and DENV infections [ 39 , 40 , 61 ]. We, however, observed clear reactivity (but less than that for the homologous antigen–antisera combination) of ZIKV sera with the rEDIII of the four DENV serotypes but not vice versa ( Figure 6 a,b).…”

“…Here, we have sought to expand our NS1 IgG orthoflavivirus array for the specific and sensitive detection of TBEV IgG elicited by either natural infection or vaccination. To this end, we explored the added value of the reported high sensitivity and specificity of domain III of the E protein (EDIII) [ 39 , 40 , 41 ]. We could successfully show that the addition of flavivirus EDIII next to the routinely used antigen NS1 increases the sensitivity for TBEV IgG detection.…”

Production of Recombinant Zika Virus Envelope Protein by Airlift Bioreactor as a New Subunit Vaccine Platform

“…In addition, paired testing of acute phase and convalescence samples to show seroconversion compared to the standard Plaque Reduction Neutralization Tests (PRNT) is therefore a common procedure that can significantly increase the sensitivity to validate this assay. Envelope domain III has also been shown to be highly sensitive and specific for ZIKV diagnosis [ 62 ], while other domains, like NS1, have been used for ZIKV diagnosis [ 63 , 64 ] and some sensitive biosensors platforms have been developed also for ZIKV diagnosis [ 65 ].…”