Biology subjects

Tanuri, A.

Publications and source records attributed to Tanuri, A..

13 recordsLinked to original sources

bioRxiv2025

Microcephaly-like phenotype triggered by novel reassortant and prototypic Oropouche Virus strains in brain organoids

Oropouche virus (OROV) is an emerging arbovirus currently spreading across South America, with increasing reports of neurological manifestations, severe systemic disease, and congenital abnormalities. Although traditionally associated with mild febrile illness, the recent geographic expansion and surge in OROV outbreaks have prompted attention to its neurotropic potential. Here, we investigated the impact of OROV infection on human neural development using neural stem cells (NSCs) and brain organoids derived from induced pluripotent stem cells. Recent OROV isolates exhibiting genomic reassortment and associated with increased neurological manifestations were compared with a prototypical strain for the ability to infect NSCs, early-stage organoids, and more mature cortical-like tissues. OROV infected NSCs efficiently, leading to widespread cell death, depletion of proliferative progenitors, and disruption of neuroepithelial organization. Transcriptomic profiling of infected NSCs revealed a robust reduction of antiviral response genes and an enrichment of pathways related to viral replication, apoptosis, and the inhibition of stem cell maintenance and neuronal differentiation. These molecular signatures aligned with the phenotypic collapse of progenitor pools and cortical structure observed in organoids. OROV antigens were detected in both astrocytes and neurons, with associated structural degeneration. Although a substantial overlap in differentially expressed genes was observed between the two viral strains, some strain-specific transcriptional responses were detected. However, these modest differences did not translate into distinct cytopathogenic effects between the two viral strains. These phenotypes, including the reduced growth of infected organoids, resemble those previously described with Zika virus in the same cellular models, supporting the hypothesis that OROV may impair brain development. Together, these results reveal a previously unrecognized neuroteratogenic potential of OROV strains and provide mechanistic insight into the potential of OROV to induce microcephaly-like phenotypes, highlighting its relevance as a significant threat to maternal-fetal health.

neuroscience↗

bioRxiv2023

Lessons from a multilaboratorial task force for diagnosis of a fatal toxoplasmosis outbreak in captive primates in Brazil

As exemplified by the Coronavirus Disease 2019 (COVID-19) pandemic, infectious diseases may emerge and spread rapidly, often causing serious economic losses and public health concerns. In fact, disease outbreaks have become increasingly common, especially those of zoonotic origin. The Brazilian Ministry of Health is responsible for national epizootic surveillance. However, the systems focus primarily on diseases affecting humans has led to the neglect of other zoonotic diseases. In this report, we present an integrated investigation of an outbreak that occurred during the first year of the COVID-19 pandemic among captive neotropical primates housed at a primatology center in Brazil. After presenting a range of non-specific clinical signs, including fever, prostration, inappetence, and abdominal pain, ten primates from five different species died within approximately four days. Despite the state of health emergency due to the pandemic, a network of volunteer researchers was established to investigate the outbreak. A wide range of high-resolution techniques was used for different pathogens, including SARS-CoV-2 (RTq-PCR, ELISA and IHC), Toxoplasma gondii (IHC and IFA) and Escherichia coli (IFA), as well as a portable Metagenomic Sequencing utilizing Nanopore Technology. Within a span of four days after necropsies, we successfully identified T. gondii as the causative agent of this outbreak. This case highlights some of the obstacles faced with the current Brazilian surveillance system, which is still limited. A cross-platform interdisciplinary investigation could be a possible model for future epizootic investigations in non-human animals. Author summaryThe Brazilian epizootic surveillance system, under the regulation of the Ministry of Health, has been established to address a national list of compulsory notifiable diseases. However, focusing mainly on the risks to humans causes other zoonoses to be neglected. Here we present an outbreak that occurred during the first year of the COVID-19 pandemic that affected eleven neotropical primates (NP) belonging to six different species. Within four days of exhibiting a range of non-specific clinical signs, including fever, prostration, inappetence, and abdominal pain, ten NPs died. Despite testing negative for pathogens included in the national surveillance policy, a collaborative group of researchers investigated the outbreak in detail. Using integrated diagnostic techniques, we identified Toxoplasma gondii as the causative agent four days after necropsy. Toxoplasmosis causes devastating acute death outbreaks in neotropical primates and is currently absent in the national guidelines. This unified effort proved the effectiveness of a multidisciplinary collaborative surveillance network in facilitating precise diagnoses.

microbiology↗

bioRxiv2022

Polycomb Repressive Complex 1 subunit Cbx4 positively regulates effector responses in CD8 T cells

CD8 T cell differentiation is controlled by the crosstalk of various transcription factors and epigenetic modulators. Uncovering the different players in regulating this process is fundamental to improving immunotherapy and designing novel therapeutic approaches. Here, we show that Polycomb Repressive Complex (PRC)1 subunit Chromobox (Cbx)4 favors differentiation to effector CD8 T cells. Cbx4 deficiency in CD8 T cells induced transcriptional signature and phenotype of memory cells, increasing the formation of memory population during acute viral infection. It has been previously shown that besides chromodomain-mediated binding to H3K27me3, Cbx4 function as a SUMO E3 ligase in a SUMO interacting motifs (SIM)-dependent way. The overexpression of Cbx4 mutants in distinct domains showed that this protein regulates CTL differentiation primarily in a SIM-dependent way and partially through its chromodomain. Our data revealed a novel role of a Polycomb group protein Cbx4 controlling CD8 T lymphocyte differentiation and indicates the SUMOylation process as a key molecular mechanism connected to chromatin modification in this process. SummaryUnderstanding the epigenetic control of CTL differentiation is critical for the manipulation of these cells in immunotherapy protocols. This article demonstrates a novel role for Cbx4, a Polycomb-group protein, in supporting CD8 T cell commitment to an effector cell phenotype.

immunology↗

bioRxiv2021

Copper imbalance linked to oxidative stress and cell death during Zika virus infection in human astrocytes

The Zika virus (ZIKV) caused neurological abnormalities in more than 3500 Brazilian newborns between 2015 and 2020. Data have pointed to oxidative stress in astrocytes as well as to dysregulations in neural cell proliferation and cell cycle as important events accounting for the cell death and neurological complications observed in Congenital Zika Syndrome. Copper imbalance has been shown to induce similar alterations in other pathologies, and disturbances in copper homeostasis have already been described in viral infections. For this reason, we investigated copper homeostasis imbalance as a factor that could contribute to the cytotoxic effects of ZIKV infection in iPSC-derived human astrocytes. Our results show that ZIKV infection leads to a downregulation of one of the transporters mediating copper release, ATP7B protein. We also observed the activation of mechanisms that counteract high copper levels, including the synthesis of copper chaperones and the reduction of the copper importer protein CTR1. Finally, we show that chelator-mediated copper sequestration in ZIKV-infected astrocytes reduces the levels of reactive oxygen species and improves cell viability, but does not change the overall percentage of infected cells. In summary, our results show that copper homeostasis imbalance plays a role in the pathology of ZIKV in astrocytes, indicating that it may also be a factor accounting for the developmental abnormalities in the central nervous system following viral infection. Evaluating micronutrient levels and the use of copper chelators in pregnant women susceptible to ZIKV infection may be promising strategies to manage novel cases of congenital ZIKV syndrome.

neuroscience↗

bioRxiv2021

Zika virus infection during development impairs the formation of corpus callosum by disturbing axon guidance and growth of callosal neurons.

Congenital Zika Syndrome (CZS) is a set of birth defects caused by Zika virus (ZIKV) infection during pregnancy. Microcephaly is its main feature, but other brain abnormalities are found in CZS patients, such as ventriculomegaly, brain calcifications, and dysgenesis of the corpus callosum. Many studies have focused on microcephaly, but it remains unknown how ZIKV infection leads to callosal malformation. To tackle this issue, we infected mouse embryos in utero with a Brazilian ZIKV isolate and found that they are born with a reduction in callosal area and density of callosal neurons. ZIKV infection also causes a density reduction of PH3+ cells, intermediate progenitor cells and SATB2+ neurons. Moreover, axonal tracing revealed that callosal axons are reduced and misrouted. Also, ZIKV infected cultures show a reduction of callosal axon length. GFAP labelling showed that in utero infection compromises glial cells responsible for midline axon guidance. The RNA-Seq data from infected brains identified downregulation of axon guidance and axonogenesis related genes. In sum, we showed that ZIKV infection impairs critical steps of corpus callosum formation by disrupting not only neurogenesis but also axon guidance and growth across the midline. Summary StatementZika virus infection during development impairs the formation of corpus callosum by disturbing axon guidance and growth of callosal neurons.

neuroscience↗

bioRxiv2021

Immunogenicity of trimetric spike protein associated to Poly(I:C) plus Alum

The SARS-CoV-2 pandemic has had a social and economic impact worldwide, and vaccination is an efficient strategy for diminishing those damages. New adjuvant formulations are required for the high vaccine demands, especially adjuvant formulations that induce a Th1 phenotype. Herein we assess a vaccination strategy using a combination of Alum and polyinosinic:polycytidylic acid (Poly(I:C)) adjuvants plus the SARS-CoV-2 spike protein in a prefusion trimeric conformation by an intradermal (ID) route. We found high levels of IgG anti-spike antibodies in the serum by enzyme linked immunosorbent assay (ELISA) and high neutralizing titers against SARS-CoV-2 in vitro by neutralization assay, after one or two boosts. By evaluating the production of IgG subtypes, as expected, we found that formulations containing Poly(I:C) induced IgG2a whereas Alum did not. The combination of these two adjuvants induced high levels of both IgG1 and IgG2a. In addition, cellular immune responses of CD4+ and CD8+ T cells producing interferon-gamma were equivalent, demonstrating that the Alum + Poly(I:C) combination supported a Th1 profile. Based on the high neutralizing titers, we evaluated B cells in the germinal centers, which are specific for receptor-binding domain (RBD) and spike, and observed that more positive B cells were induced upon the Alum + Poly(I:C) combination. Moreover, these B cells produced antibodies against both RBD and non-RBD sites. We also studied the impact of this vaccination preparation (spike protein with Alum + Poly(I:C)) in the lungs of mice challenged with inactivated SARS-CoV-2 virus. We found a production of IgG, but not IgA, and a reduction in neutrophil recruitment in the bronchoalveolar lavage fluid (BALF) of mice, suggesting that our immunization scheme reduced lung inflammation. Altogether, our data suggest that Alum and Poly(I:C) together is a possible adjuvant combination for vaccines against SARS-CoV-2 by the intradermal route.

immunology↗

bioRxiv2020

Ultrastructural analysis of SARS-CoV-2 interactions with the host cell via high resolution scanning electron microscopy

SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Here, we investigated the interaction of this new coronavirus with Vero cells using high resolution scanning electron microscopy. Surface morphology, the interior of infected cells and the distribution of viral particles in both environments were observed 2 and 48 hours after infection. We showed areas of viral processing, details of vacuole contents, and viral interactions with the cell surface. Intercellular connections were also approached, and viral particles were adhered to these extensions suggesting direct cell-to-cell transmission of SARS-CoV-2. HighlightsWe used high resolution scanning electron microscopy to investigate Vero cells infected with SARS-CoV-2 at 2 and 48 hours post-infection. The central conclusions of this work include: O_LIInfected cells display polarization of their cytosol forming a restricted viroplasm-like zone dedicated to virus production and morphogenesis. C_LIO_LIThis is the first demonstration of SARS-CoV-2 attachment by scanning electron microscopy. C_LIO_LIThis is the first scanning electron microscopy images of the interior of SARS-CoV-2 infected cells and exploration of their vacuole contents. C_LIO_LIPerspective-viewing of bordering vesicles in close association with vacuoles. C_LIO_LIObservation of membrane ruffles and structures suggestive of exocytosis on the surface of infected cells. C_LIO_LIThe first demonstration of viral surfing in cell-to-cell communication on SARS-CoV-2 infection. C_LI

microbiology↗

bioRxiv2019

The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by Zika virus

The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak was described in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water supplies of NE compared to other regions of Brazil. Experimentally, we described that STX doubled the amount of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.\n\nAuthor summaryThe uncontrolled spreading of cyanobacteria in drinking water reservoirs has been the cause of serious public health problems worldwide. Toxin-producing cyanobacterial blooms commonly occur during drought periods in the northeast (NE) region of Brazil. During Zika Virus (ZIKV) outbreak in 2015-16, Brazilian NE showed disproportionately higher microcephaly incidence. Here, we test the hypothesis that the cyanotoxin saxitoxin (STX) may act as a co-insult for ZIKV. Water quality surveillance data showed increased cyanobacteria population and higher STX amount in NE region during 2014-2018. In vitro, we observed that neural progenitor cell death was doubled after STX exposure to ZIKV-infected brain organoids. In vivo, chronic ingestion of STX during gestational period potentiated ZIKV-derived brain abnormalities in newborn mice. Our study provides new insights that may explain the discrepancies among Brazilian regions regarding CZS severity. Moreover, the data highlight the importance of cyanobacteria and cyanotoxin freshwater monitoring for future arbovirus outbreaks.

neuroscience↗

bioRxiv2019

The potential role of collagens in congenital Zika syndrome: A systems biology approach

Zika virus (ZIKV) infection during pregnancy could cause a set of severe abnormalities in the fetus known as congenital Zika syndrome (CZS). Experiments using animal models and in vitro systems significantly contributed to our understanding of the physiopathology of ZIKV infection. However, the molecular basis of CZS is not yet studied in humans. Here, we used a systems biology approach to integrate transcriptomic, proteomic and genomic data from post-mortem brains of neonates with CZS. We observed that collagen genes were greatly reduced in CZS brains at both the RNA and protein levels and that neonates with CZS have several polymorphisms in collagen genes associated with osteogenesis imperfect and arthrogryposis. These findings were validated using immunohistochemistry and collagen staining of ZIKV infected and non-infected samples. Additionally, it was found that cell adhesion genes that are essential for neurite outgrowth and axon guidance were up-regulated and thereby confirmed the neuronal migration defects observed. This work provided new insights into the underlying mechanisms of CZS and revealed host genes associated with CZS susceptibility.

systems biology↗

bioRxiv2019

Emergence of the Zika virus Asian lineage in Angola

Research In ContextO_ST_ABSEvidence before this studyC_ST_ABSWe searched PubMed without language restrictions using the keywords Zika and Africa for papers published to October 2018. We also checked available Situation Report publications from WHO for evidence of Zika virus (ZIKV) or congenital Zika disease in Africa. ZIKV African lineage has been detected within Africa since the mid 20th century, yet evidence for spread of the ZIKV Asian lineage within Africa is limited. Two countries in Africa (Cabo Verde and Angola) have reported ZIKV cases that are believed to be caused by a newly introduced Asian lineage virus. Sequence data are critical for confirming and understanding the spread of ZIKV Asian lineage within Africa, but these data are currently limited to a single 193bp fragment of the ZIKV NS1 gene from Angola. In addition, whilst epidemiological data on ZIKV and suspected microcephaly cases have been reported in detail from Cabo Verde, data from Angola are extremely limited.\n\nAdded value of this studyWe provide a detailed report of detected ZIKV acute cases and suspected microcephaly cases in Angola. We sequence ZIKV genomes from three acutely infected cases. These represent the first three Asian lineage genomes available from Africa, one of which was acquired from a baby with confirmed microcephaly. Analysis of these sequences suggests that ZIKV may have been introduced to Angola between July 2015 and June 2016, after which it likely circulated for at least one year. This provides the first genetic confirmation of autochthonous ZIKV Asian lineage transmission within Africa. We suggest that the virus was more likely introduced to Angola directly from Brazil, rather than from Cabo Verde. Our analyses from Angola, only the second African country to report presence of the Asian virus lineage, therefore improve our understanding of the extent and clinical impact of ZIKV Asian lineage in the continent.\n\nImplications of all the available evidenceThe circulation of ZIKV Asian lineage within parts of sub-Saharan Africa is concerning given the potential for continued viral spread across much of the continent. Available evidence suggests that ZIKV has circulated and caused cases of microcephaly in Cabo Verde and in Angola. Detecting additional ZIKV transmission using only clinical data on suspected microcephaly or clusters of mild illness may be challenging in countries where systems for reporting birth defects are limited and infectious disease burden is high. Further spread of the ZIKV Asian lineage would likely not be detected unless molecular surveillance systems for ZIKV are implemented to routinely monitor ZIKV transmission in Africa. Implementation of such a surveillance system is especially important in countries that are linked by high human mobility to areas that have experienced recent or ongoing outbreaks of ZIKV.\n\nAbstractO_ST_ABSBackgroundC_ST_ABSZika virus (ZIKV) infections and suspected microcephaly cases have been recently reported in Angola, but no data are available on the origins, epidemiology, and diversity of the virus.\n\nMethodsSerum samples from 54 suspected ZIKV cases, 76 suspected microcephaly cases, and 24 mothers of infants with suspected microcephaly were received by the Angolan Ministry of Health. Computed tomographic brain imaging and serological assays (PRNT) were conducted on one microcephalic infant. All sera were tested for ZIKV by RT-qPCR. 349 samples from HIV+ patients and 336 samples from patients suspected of chikungunya virus or dengue virus infection were also tested. Portable sequencing was used to generate Angolan ZIKV genome sequences, including from a ZIKV+ neonate with microcephaly born in Portugal to an Angolan resident. Genetic and mobility data were analysed to investigate the date of introduction and geographic origin of ZIKV in Angola.\n\nFindingsFour autochthonous cases were ZIKV positive via RT-qPCR, with all positive samples collected between December 2016 and June 2017. Viral genomes were generated for two of these cases, and from the neonate with microcephaly identified in Portugal. Genetic analyses and other data indicate that ZIKV was introduced to Angola from Brazil between July 2015 and June 2016. This introduction likely initiated local ZIKV circulation in Angola that continued until June 2017. The scanned microcephaly case showed brain abnormalities consistent with congenital Zika syndrome and serological evidence for maternal ZIKV infection.\n\nInterpretationOur analyses confirm the autochthonous transmission of the ZIKV Asian lineage in continental Africa. Conducting ZIKV surveillance throughout Africa is critical in the light of presented evidence for autochthonous ZIKV transmission in Angola, and associated microcephaly cases.\n\nFundingRoyal Society, Wellcome Trust, CNPq, CAPES, ERC, Oxford Martin School, Global Challenges Research Fund, Africa Oxford, and John Fell Fund.

epidemiology↗

bioRxiv2018

Reactivation of latent HIV-1 in vitro using an alcoholic extract from Euphorbia umbellata (Euphorbiaceae) latex.

Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and contains in its latex a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract able to increase HIV transcription and reactivate HIV from latency models. This activity was mediated by NF-kB activation followed by nuclear translocation and binding to HIV LTR promoter. In addition, E. umbellate latex extract induced the production of pro inflammatory cytokines together with IL21 in in vitro human PBMC cultures. Our latex extract activates latent HIV in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. These results strongly indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapy to promote HIV cure and eradication.

microbiology↗

bioRxiv2018

Yellow fever virus is susceptible to sofosbuvir both in vitro and in vivo

Yellow fever virus (YFV) is a member of the Flaviviridae family, that causes major mortality. In Brazil, YFV activity increased in the last years. It has been registered that sylvatic, instead of urban, yellow fever (YF) leads our contemporary public health concern. Low vaccinal coverage leaves the human population near the jangle vulnerable to the outbreak, making it necessary to identify therapeutic options. Repurposing of clinically approved antiviral drugs represents an alternative for such identification. Other Flaviviruses, such Zika (ZIKV) and dengue (DENV) viruses, are susceptible to Sofosbuvir, a clinically approved drug against hepatitis C virus (HCV). Moreover, sofosbuvir has a safety record on critically ill hepatic patients, making it an attractive option. Our data show that YFV RNA polymerase uses conserved amino acid resides for nucleotide binding to dock sofosbuvir. This drug inhibited YFV replication in different lineages of human hepatoma cells, Huh-7 and HepG2, with EC50 value of 4.8 {micro}M. Sofosbuvir protected YFV-infected neonatal Swiss mice from mortality and weight loss. Our pre-clinical results indicate that sofosbuvir could represent an option against YFV.

microbiology↗

bioRxiv2017

Sofosbuvir protects Zika virus-infected mice from mortality, preventing short- and long-term sequela

Zika virus (ZIKV) caused significant public health concern, because of its association with congenital malformations, neurological disorders in adults and, more recently, with deaths. Considering the necessity to mitigate the cases ZIKV-associated diseases, antiviral interventions against this virus are an urgent necessity. Sofosbuvir, a drug in clinical use against Hepatitis C Virus (HCV), is among the FDA-approved substances endowed with anti-ZIKV activity. In this work, we further investigated the in vivo activity of sofosbuvir against ZIKV. Neonatal Swiss mice were infected with ZIKV (2 x 107 PFU) and treated with sofosbuvir at 20 mg/kg/day, a concentration compatible with pre-clinical development of this drug. We found that sofosbuvir reduced acute levels of ZIKV from 60 to 90 % in different anatomical compartments, such as in blood plasma, spleen, kidney and brain. Early treatment with sofosbuvir doubled the percentage and time of survival of ZIKV-infected animals, despite the aggressive virus challenge assayed and also prevented the acute neuromotor impairment triggered by the virus. On the long-term behavior analysis of ZIKV-associated sequelae, sofosbuvir prevented loss of hippocampal- and amygdala-dependent memory. Our results point out that sofosbuvir inhibits ZIKV replication in vivo, which is consistent with the prospective necessity of antiviral drugs to treat ZIKV-infected individuals.

microbiology↗