Project description:To investigate the cellular pathologies in human NPCs after ZIKV infection, we performed global transcriptome profiling of the FD, FV, and H&S organoids at 3 and 6 dpi. We found 105 upregulated genes in the FD NPCs, 60 genes in the FV NPCs, and 168 genes in the H&S NPCs, with at least 1.5-fold differences found between ZIKV-infected groups and the control groups at 6 dpi. Among them, 28 genes overlapped in all three regional NPCs. These 28 common genes exclusively referred to the pathways associated with immune responses to viral infection, which could be clustered to the ISG family.
Project description:In this study, proteomic analysis on ZIKV-infected primary human fetal neural progenitor cells (NPCs) revealed that virus infection altered levels of cellular proteins involved in NPC proliferation, differentiation and migration.
Project description:Zika virus (ZIKV) infection causes microcephaly and has been linked to other brain abnormalities. How ZIKV impairs brain development and function remains elusive. Here we systematically profiled transcriptomes of human neural progenitor cells (hNPCs) and astrocytes exposed to Asian ZIKVC, African ZIKVM, and Dengue virus (DENV). DENV causes distinct gene expression changes; and ZIKV has a broader impact on the expression of gene involved in DNA replication and repair. While overall expression profiles are similar, ZIKVC, but not ZIKVM, induces upregulation of viral response genes. Upon ZIKV infection, astrocytes exhibit more prominent transcriptome changes than hNPCs, particularly enriching genes related to inflammatory response and cytokine production pathways. Our analyses reveal cell-type- and strain-specific molecular signatures associated with ZIKV infection, and identify astrocytes as a major direct target of ZIKV. Further investigation of ZIKV-host interactions based our transcriptomic datasets may help to illuminate neural virulence determinants of ZIKV in patients. Gene Expression Analyses of the cells infected with different flaviviruses
Project description:Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that causes severe outbreaks in human populations. ZIKV infection leads to the accumulation of small non-coding viral RNAs (known as sfRNAs) that are crucial for evasion of antiviral responses and for viral pathogenesis. However, the mechanistic understanding of how sfRNAs function remains incomplete. Here, we use recombinant ZIKVs and ribosome profiling of infected human cells to show that sfRNAs block translation of antiviral genes. Mechanistically, we demonstrate that specific RNA structures present in sfRNAs trigger PKR activation, which instead of limiting viral replication, enhances viral particle production. Although ZIKV infection induces mRNA expression of antiviral genes, translation efficiency of type I interferon and interferon stimulated genes were significantly downregulated by PKR activation. Our results reveal a novel viral adaptation mechanism mediated by sfRNAs, where ZIKV increases its fitness by repurposing the antiviral role of PKR into a proviral factor.
Project description:Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that causes severe outbreaks in human populations. ZIKV infection leads to the accumulation of small non-coding viral RNAs (known as sfRNAs) that are crucial for evasion of antiviral responses and for viral pathogenesis. However, the mechanistic understanding of how sfRNAs function remains incomplete. Here, we use recombinant ZIKVs and ribosome profiling of infected human cells to show that sfRNAs block translation of antiviral genes. Mechanistically, we demonstrate that specific RNA structures present in sfRNAs trigger PKR activation, which instead of limiting viral replication, enhances viral particle production. Although ZIKV infection induces mRNA expression of antiviral genes, translation efficiency of type I interferon and interferon stimulated genes were significantly downregulated by PKR activation. Our results reveal a novel viral adaptation mechanism mediated by sfRNAs, where ZIKV increases its fitness by repurposing the antiviral role of PKR into a proviral factor.
Project description:The re-emergence of Zika virus (ZIKV) in the Western Hemisphere has resulted in global public health crisis since 2015. ZIKV preferentially infects and targets human neural progenitor cells (hNPCs) and causes fetal microcephaly upon maternal infection. hNPCs not only play critical roles during fetal brain development, but also persist in adult brain throughout life. Yet the mechanism of innate antiviral immunity in hNPCs remains largely unknown. Here, we show that ZIKV infection triggers the abundant production of virus-derived small interfering RNAs in hNPCs, but not in the more differentiated progenies or somatic cells. Ablation of key RNAi machinery components significantly enhances ZIKV replication in hNPCs. Furthermore, enoxacin, a broad-spectrum antibiotic that is known as an RNAi enhancer, exerts potent anti-ZIKV activity in hNPCs and other RNAi-competent cells. Strikingly, enoxacin treatment completely prevents ZIKV infection and circumvents ZIKV-induced microcephalic phenotypes in brain organoid models that recapitulate human fetal brain development. Our findings highlight the physiological importance of RNAi-mediated antiviral immunity during the early stage of human brain development, uncovering a novel strategy to combat human congenital viral infections through enhancing RNAi.
Project description:Congenital Zika syndrome (CZS), caused by Zika virus (ZIKV) infection, has been associated to impairment of early brain development, particularly related to neural progenitor cells (NPCs) survival and growth. In this work we report in a high-throughput manner (RNA-Seq) the differences in the transcriptomes of hiPSCs(human induced pluripotent stem cells)-derived NPCs from 3 pairs of discordant twins for Congenital Zika syndrome (CZS). We found significant differences in the expression levels of genes relevant to the regulation of neural development between the NPCs from CZS-affected and non-affected twins, suggesting that epigenetic differences may contribute to the different susceptibilities of NPCs to ZIKV infection.
Project description:Induction of long-lived antibody responses during infection or vaccination is often essential for subsequent protection, but the relative contributions of T follicular helper (Tfh) cells and T helper 1 (Th1) cells for induction of antigen specific antibody responses to viruses are unclear. Here, we establish an acute Zika virus (ZIKV) infection model in immunocompetent mice, and show that ZIKV infection elicits robust Th1-like Tfh cell and protective antibody responses. While these Th1-like Tfh cells share phenotypic and transcriptomic profiles with both Tfh and Th1 cells, they also have unique surface markers and gene expression characteristics, and are dependent on T-bet for their development. Th1-like Tfh cells, but not Th1 cells, are essential for class switching of ZIKV-specific IgG2c antibodies and maintenance of long-term neutralizing antibody responses. Our study suggests that specific modulation of the Th1-like Tfh cell response during infection or vaccination may augment the induction of antiviral antibody response to ZIKV and other viruses.
Project description:Zika virus (ZIKV) is unique among mosquito-borne flaviviruses in its ability to be sexually transmitted. The testes have been implicated as sites of long-term ZIKV replication, and our previous studies have identified Sertoli cells (SC), the nurse cells of the seminiferous epithelium that govern spermatogenesis, as major targets of ZIKV infection. To improve our understanding of the host-ZIKV interaction within human testicular cells, we analyzed ZIKV-induced proteome changes in SC and mixed seminiferous tubule cells (STC) using high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS). We found that ZIKV infection in SC and STC induced distinct IFN-stimulated proteins and impacted pathways and functional networks associated with innate antiviral defense. IFN signaling was the most significantly enriched pathway and MX1 was the most abundant IFN-stimulated protein in both SC and STC. Increased levels of MX1 at later time points of infection coincided with diminished propagation of ZIKV in SC, whereas silencing of MX1 and IFIT1 enhanced peak ZIKV titers in SC. Furthermore, although downstream IFN-I signaling was found to be functional and restricted ZIKV replication in SC, in comparison to A549 cells, SC exhibited dampened expression of IFN-I/III-stimulated genes despite higher levels of virus progeny and IFN-I/III transcripts. Together, this study highlights the IFN-I/III response as a driver of the antiviral state that limits ZIKV infection in SC and suggests that delayed and reduced robustness of innate antiviral defense in SC may contribute to ZIKV persistence in the testes.
Project description:Although dendritic cells (DCs) are among the human cell population best equipped for cell-intrinsic antiviral immune defense, they seem highly susceptible to infection with Zika Virus (ZIKV). Using highly-purified mDC isolated from individuals with naturally-acquired acute infection, we here show that ZIKV induces profound perturbations of transcriptional signatures relative to uninfected patients. Interestingly, we noted a remarkable downregulation of antiviral Interferon-stimulated genes and innate immune sensors, suggesting that ZIKV can actively suppress Interferon-dependent immune responses. In contrast, several host factors known to support ZIKV infection were strongly upregulated during natural ZIKV infection; these transcripts included AXL, the main entry receptor for ZIKV, SOCS3, a negative regulator of ISG expression, and IDO-1, a recognized inducer of regulatory T cell responses. Thus, during in vivo infection, ZIKV can transform the transcriptome of dendritic cells in favor of the virus to render these cells highly conducive to ZIKV infection.