Figure 6. ZIKV triggers a broad antiviral response but no IFN upregulation and a minimal proinflammatory response in human testicular tissue.

(A) Levels of IFN-β and CXCL10 measured by flow cytometry–based multiplex assay in mock-infected and ZIKV-infected human testis explant supernatants. Each symbol represents a different donor. Bars represent median values. *P < 0.05 (Friedman-Dunn nonparametric comparison). (B) Correlation between secreted CXCL10 induction in ZIKV-infected versus mock-infected explants and ZIKV RNA level in culture supernatant on day 6 p.i. (Spearman’s nonparametric test). (C) Innate immune gene expression determined by RT-qPCR in testis explants from 6 donors (T1–T6) infected with ZIKV for 3, 6, and 9 days (d3, d6, d9). Heatmap shows log₂-transformed expression ratios between ZIKV-infected and time-matched mock-infected controls. Green indicates upregulation and red downregulation of mRNA compared with controls. Type I and II IFN mRNAs were below the quantification threshold (data not shown). (D) Viral loads in supernatants of the testis explants analyzed in C. (E) Examples of correlation between gene fold expression on day 9 and the level of infection on day 3 p.i. (Spearman’s nonparametric test). Other correlations are shown in Supplemental Figure 9.