Antibody Responses to Zika Virus Infections in Environments of Flavivirus Endemicity

Abstract

Zika virus (ZIKV) infections occur in areas where dengue virus (DENV), West Nile virus (WNV), yellow fever virus (YFV), and other viruses of the genus Flavivirus cocirculate. The envelope (E) proteins of these closely related flaviviruses induce specific long-term immunity, yet subsequent infections are associated with cross-reactive antibody responses that may enhance disease susceptibility and severity. To gain a better understanding of ZIKV infections against a background of similar viral diseases, we examined serological immune responses to ZIKV, WNV, DENV, and YFV infections of humans and nonhuman primates (NHPs). Using printed microarrays, we detected very specific antibody responses to primary infections with probes of recombinant E proteins from 15 species and lineages of flaviviruses pathogenic to humans, while high cross-reactivity between ZIKV and DENV was observed with 11 printed native viruses. Notably, antibodies from human primary ZIKV or secondary DENV infections that occurred in areas where flavivirus is endemic broadly recognized E proteins from many flaviviruses, especially DENV, indicating a strong influence of infection history on immune responses. A predictive algorithm was used to tentatively identify previous encounters with specific flaviviruses based on serum antibody interactions with the multispecies panel of E proteins. These results illustrate the potential impact of exposure to related viruses on the outcome of ZIKV infection and offer considerations for development of vaccines and diagnostics.

Human Antibody Responses to Emerging Mayaro Virus and Cocirculating Alphavirus Infections Examined by Using Structural Proteins from Nine New and Old World Lineages

“…1; see Table S1 and Fig. S1 in the supplemental material) for inclusion in the microarray by previously described methods (29). Arthritogenic CHIKV (three genotypes: Asian, ECSA, and WAf), MAYV, ONNV, and RRV and encephalitogenic VEEV, EEEV, and WEEV were all represented in the microarray.…”

“…Soluble and insoluble proteins were separated by centrifugation (15,000 ϫ g, 10 min) and analyzed by SDS-PAGE (Bio-Rad, Hercules, CA), followed by Coomassie staining and Western blot analysis with a mouse anti-polyhistidine monoclonal antibody (clone HIS-1; Sigma-Aldrich) detected with horseradish peroxidase-conjugated goat anti-mouse antibody (Bio-Rad). All expressed proteins were present in inclusion bodies and purified as previously described, with some modifications (29,63). Briefly, insoluble protein pellets were washed twice with a buffer consisting of 50 mM Tris-HCl (pH 7.4), 1 M urea, and 1% Triton X-100 and then washed once with 50 mM Tris-HCl (pH 7.4) with centrifugation at 15,000 ϫ g for 10 min between washing steps.…”

“…Multiplexed surveillance assays that include both endemic and nonendemic viruses will be important for monitoring disease outbreaks and spread to new geographic regions. Further, the ability to expand this multiplex assay by the addition of new antigens that are synthesized from sequence data will provide a means to rapidly incorporate assays for new pathogens into disease surveillance matrices (29)(30)(31)61).…”

“…In the absence of viremia, enzyme-linked immunosorbent assays (ELISAs) and plaque reduction neutralization tests can be used to detect virus-specific antibodies, but these methods are not amenable to high-throughput analysis, and live-virus assays may require biosafety level 3 laboratory containment. Alternatively, serological assays that employ individually expressed viral proteins often yield species-specific signals with fewer cross-reactive antibody interactions than those that use whole viruses (29,30). Further, assays based on protein microarrays are easily scaled to process large numbers of specimens against expandable antigen panels (29)(30)(31)).…”

“…Alternatively, serological assays that employ individually expressed viral proteins often yield species-specific signals with fewer cross-reactive antibody interactions than those that use whole viruses (29,30). Further, assays based on protein microarrays are easily scaled to process large numbers of specimens against expandable antigen panels (29)(30)(31)). An examination of the alphavirus proteome suggests several possible antigens that could be included in a microarray for analysis of antibody responses.…”