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Enhancement of Zika virus pathogenesis by preexisting antiflavivirus immunity

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Science  14 Apr 2017:
Vol. 356, Issue 6334, pp. 175-180
DOI: 10.1126/science.aal4365
  • Fig. 1 ZIKV binding and enhancement of infection by DENV- and WNV-immune plasma.

    (A and B) Plasma samples from seropositive DENV-infected (n = 141), seropositive WNV-infected (n = 146), or seronegative control (n = 15) donors were evaluated for reactivity to ZIKV E protein by ELISA (A) or enhancement of ZIKV infection of K562 cells (B). Calculations of area under the curve (AUC) based on serially diluted plasma measurements are shown. Black bars, geometric means. (C and D) Scatterplots showing the relationship between ZIKV binding and enhancement of ZIKV infection for DENV-immune (C) and WNV-immune (D) plasma. Each point represents one donor. Significance was analyzed by nonparametric unpaired Mann-Whitney U tests for (A) and (B) and by nonparametric Spearman’s rank correlation for (C) and (D) (r, correlation coefficient). **P < 0.01; ****P < 0.0001.

  • Fig. 2 Enhancement of ZIKV infection through IgG engagement of Fcγ receptors.

    (A) IgG purified from plasma pooled (n = 15 per group) from control, DENV-, or WNV-infected donors was evaluated for enhancement of ZIKV infection in K562 cells. (B) Pooled plasma samples from control, DENV-, or WNV-infected donors were evaluated for enhancement of ZIKV infection in K562 cells before and after IgG purification. (C to E) Purified IgG from control, DENV-, or WNV-seropositive donors was tested for enhancement of ZIKV infection in K562 cells in the presence or absence of Fcɣ receptor binding inhibitor (FcɣR BI) (C), antibodies (α) against CD32 (D), or antibodies against CD16 (E). (F) Plasma IgG from control, DENV-, or WNV-seropositive donors was incubated in the presence or absence of PNGase F before evaluation of ZIKV infection enhancement in K562 cells. The same control, DENV, and WNV IgG samples are shown in (A), (C), (D), and (E). All graphs show means ± SD.

  • Fig. 3 In vivo enhancement of ZIKV infection by DENV- and WNV-convalescent plasma.

    (A) 20 μl of PBS or plasma from control, DENV-, or WNV-infected donors was administered intraperitoneally to Stat2−/− mice 2 hours before intradermal inoculation with 5 × 103 plaque-forming units of ZIKV strain PRVABC59. The Kaplan-Meier survival curve is shown; significance was determined using the Mantel-Cox log-rank test and adjusted for multiple comparisons using the Bonferroni correction. Mice were monitored for (B) weight loss and (C) clinical score using a 6-point system (n = 5 per group), with a score of 7 awarded to deceased animals. Significance was determined using Student’s t test and adjusted for multiple comparisons using the Bonferroni correction. In symptom score comparisons, the day with the highest average score per group was used. Daily body temperature measurements were taken from mice receiving PBS (D) or control (E), DENV- (F), or WNV-immune plasma (G). Statistically significant differences were calculated by comparing day 3 (the day of the highest total average temperature) and day 0 for each group. *P < 0.05; **P < 0.01; ***P < 0.001. (B) and (C), means ± SEM; (D) to (G), means ± SD.

  • Fig. 4 In vivo ADE correlates with amplified ZIKV replication.

    (A) Blood viral titers of mice treated with PBS or control, DENV-, or WNV-positive donor plasma were assessed by real-time polymerase chain reaction (PCR) on days 3 and 6 postinfection. Viral titers were quantified by a plaque assay on spinal cords (B) and testes (C) isolated on day 6 postinfection from ZIKV-infected Stat2−/− mice treated with PBS or a low dose of control, DENV-, or WNV-positive donor plasma. Paraffin-embedded spinal cords (D) and testes (E), taken on day 6 postinfection from ZIKV-infected Stat2−/− mice treated with PBS or a low dose of control, DENV-, or WNV-positive donor plasma sections, were stained for ZIKV (green) and nuclear DAPI (4′,6-diamidino-2-phenylindole; blue). Representative images are shown at 10× magnification; scale bars, 50 μm. Brains (F), ovaries (G), and eyes (H) were also evaluated for viral loads on day 6. *P < 0.05; **P < 0.01. Means ± SEM. PFU, plaque-forming unit.

Supplementary Materials

  • Enhancement of Zika virus pathogenesis by preexisting antiflavivirus immunity

    Susana V. Bardina, Paul Bunduc, Shashank Tripathi, James Duehr, Justin J. Frere, Julia A. Brown, Raffael Nachbagauer, Gregory A. Foster, David Krysztof, Domenico Tortorella, Susan L. Stramer, Adolfo García-Sastre, Florian Krammer, Jean K. Lim

    Materials/Methods, Supplementary Text, Tables, Figures, and/or References

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    • Materials and Methods
    • Figs. S1 to S12
    • Table S1
    • References
    Correction (12 April 2017): In the section "ZIKV infection of Stat2-/- mice," the amount of virus used was incorrectly stated as 1 × 105 PFU; the correct amount is 5 × 103 PFU. The PDF has been corrected.
    The original version is accessible here.

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