Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins.

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1-40% of cases of pregnant women infected by ZIKV, suggesting that mothers' infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses' tissues.

Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1–40% of cases of pregnant women infected by ZIKV, suggesting that mothers’ infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses’ tissues.

Zika virus selectively kills aggressive human embryonal CNS tumor cells in vitro and in vivo

Zika virus (ZIKV) is largely known for causing brain abnormalities due to its ability to infect neural progenitor stem cells during early development. Here, we show that ZIKV is also capable of infecting and destroying stem-like cancer cells from aggressive human embryonal tumors of the central nervous system (CNS). When evaluating the oncolytic properties of Brazilian Zika virus strain (ZIKV(BR)) against human breast, prostate, colorectal, and embryonal CNS tumor cell lines, we verified a selective infection of CNS tumor cells followed by massive tumor cell death. ZIKV(BR) was more efficient in destroying embryonal CNS tumorspheres than normal stem cell neurospheres. A single intracerebroventricular injection of ZIKV(BR) in BALB/c nude mice bearing orthotopic human embryonal CNS tumor xenografts resulted in a significantly longer survival, decreased tumor burden, fewer metastasis, and complete remission in some animals. Tumor cells closely resembling neural stem cells at the molecular level with activated Wnt signaling were more susceptible to the oncolytic effects of ZIKV(BR). furthermore, modulation of Wnt signaling pathway significantly affected ZIKV(BR)-induced tumor cell death and viral shedding. Altogether, these preclinical findings indicate that ZIKV(BR) could be an efficient agent to treat aggressive forms of embryonal CNS tumors and could provide mechanistic insights regarding its oncolytic effects.

Zika virus selectively kills aggressive human embryonal CNS tumor cells in vitro and in vivo

Zika virus (ZIKV) is largely known for causing brain abnormalities due to its ability to infect neural progenitor stem cells during early development. Here, we show that ZIKV is also capable of infecting and destroying stem-like cancer cells from aggressive human embryonal tumors of the central nervous system (CNS). When evaluating the oncolytic properties of Brazilian Zika virus strain (ZIKV(BR)) against human breast, prostate, colorectal, and embryonal CNS tumor cell lines, we verified a selective infection of CNS tumor cells followed by massive tumor cell death. ZIKV(BR) was more efficient in destroying embryonal CNS tumorspheres than normal stem cell neurospheres. A single intracerebroventricular injection of ZIKV(BR) in BALB/c nude mice bearing orthotopic human embryonal CNS tumor xenografts resulted in a significantly longer survival, decreased tumor burden, fewer metastasis, and complete remission in some animals. Tumor cells closely resembling neural stem cells at the molecular level with activated Wnt signaling were more susceptible to the oncolytic effects of ZIKV(BR). furthermore, modulation of Wnt signaling pathway significantly affected ZIKV(BR)-induced tumor cell death and viral shedding. Altogether, these preclinical findings indicate that ZIKV(BR) could be an efficient agent to treat aggressive forms of embryonal CNS tumors and could provide mechanistic insights regarding its oncolytic effects.

Padronização das condições de análise da glicoproteína recombinante do vírus da raiva

A glicoproteína do vírus da raiva (RVGP) é o antígeno mais importante para a prevenção da raiva por meio de estratégias de vacinação. A criação de uma vacina recombinante contra a raiva tem sido objeto de muitas pesquisas. A vacina de subunidade tendo a RVGP como imunógeno necessita atender a muitos requisitos de segurança e eficácia. Pureza e imunogenicidade são dois desses requisitos que podem ser conseguidos por meio de protocolos eficientes de purificação, e garantidos por bons protocolos de análise. O objetivo deste trabalho foi padronizar as melhores condições analíticas de amostras de RVGP produzidas em diferentes sistemas recombinantes. Para isso, células S2 recombinantes (S2MtRVGP-His) foram cultivadas em frascos-T e a expressão da RVGP foi induzida pela adição de CuSO4. Células aderentes, BHK-21, que expressam RVGP após transdução do vírus recombinante Semliki Forest Virus (SFV), também foram utilizadas. As amostras de células que expressam GPV foram ressuspensas com um dos quatro tampões em estudo: TD (25 mM Tris - HCl, 137 mM de NaCl, 5 mM de KCl, 0.7 mM Na2PO4), TM (50 mM Tris - HCl, 500 mM de NaCl), T4 (25 mM Tris - HCl, 25 mM de NaCl, 5 mM de MgCl2) e TDMg (25 mM Tris - HCl, 65 mM de NaCl, 5 mM de MgCl2, 0.7 mM Na2PO4), cada um em quatro diferentes valores de pH (6.8, 7.2, 7.4 ou 8.0) e duas concentrações de detergentes DDM ou IGEPAL (0.2% ou 0.04%), resultando em 64 formulações para a lise celular e de solubilização da RVGP. Após incubação à 4º C ou à temperatura ambiente durante 30 ou 60 minutos, as amostras foram analisadas por Dot blotting. As membranas foram reveladas utilizando a técnica ECL. Essa padronização é de grande interesse, pois a realização de análises de RVGP em uma dessas condições pode fornecer resultados confiáveis e, consequentemente, auxiliar o estabelecimento de um bom protocolo de purificação para a RVGP.