LAURA HELENA VEGA GONZALES GIL
@fiocruz.br
Virology
IAM-FIOCRUZ
Scopus Publications
Scopus Publications
José Valter Joaquim Silva Júnior, Andréa Nazaré Monteiro Rangel da Silva, Jefferson José da Silva Santos, and Laura Helena Vega Gonzales Gil
Springer US
Raiza P.S. Lucena, Alberto G. Silva-Junior, Laura H.V. Gil, Marli T. Cordeiro, César A.S. Andrade, and Maria D.L. Oliveira
Elsevier BV
Debora Regina Lopes dos Santos, Ricardo Durães-Carvalho, Noemi Rovaris Gardinali, Lais Ceschini Machado, Vanessa Salete de Paula, Gabriel da Luz Wallau, Jaqueline Mendes de Oliveira, Lindomar José Pena, Marcelo Alves Pinto, Laura Helena Vega Gonzalez Gil,et al.
Springer Science and Business Media LLC
AbstractHepatitis E virus (HEV) circulation in humans and swine has been extensively studied in South America over the last two decades. Nevertheless, only 2.1% of reported HEV strains are available as complete genome sequences. Therefore, many clinical, epidemiological, and evolutionary aspects of circulating HEV in the continent still need to be clarified. Here, we conducted a retrospective evolutionary analysis of one human case and six swine HEV strains previously reported in northeastern, southern, and southeastern Brazil. We obtained two complete and four nearly complete genomic sequences. Evolutionary analysis comparing the whole genomic and capsid gene sequences revealed high genetic variability. This included the circulation of at least one unrecognized unique South American subtype. Our results corroborate that sequencing the whole capsid gene could be used as an alternative for HEV subtype assignment in the absence of complete genomic sequences. Moreover, our results substantiate the evidence for zoonotic transmission by comparing a larger genomic fragment recovered from the sample of the autochthonous human hepatitis E case. Further studies should continuously investigate HEV genetic diversity and zoonotic transmission of HEV in South America.
Ana C. Puhl, Rafaela S. Fernandes, Andre S. Godoy, Laura H.V.G. Gil, Glaucius Oliva, and Sean Ekins
Elsevier BV
Marjorie C. L. C. Freire, Luis G. M. Basso, Luis F. S. Mendes, Nathalya C. M. R. Mesquita, Melina Mottin, Rafaela S. Fernandes, Lucca R. Policastro, Andre S. Godoy, Igor A. Santos, Uriel E. A. Ruiz,et al.
Scientific Reports Springer Science and Business Media LLC
AbstractChikungunya virus (CHIKV) is the causative agent of Chikungunya fever, an acute febrile and arthritogenic illness with no effective treatments available. The development of effective therapeutic strategies could be significantly accelerated with detailed knowledge of the molecular components behind CHIKV replication. However, drug discovery is hindered by our incomplete understanding of their main components. The RNA-dependent RNA-polymerase (nsP4-CHIKV) is considered the key enzyme of the CHIKV replication complex and a suitable target for antiviral therapy. Herein, the nsP4-CHIKV was extensively characterized through experimental and computational biophysical methods. In the search for new molecules against CHIKV, a compound designated LabMol-309 was identified as a strong ligand of the nsp4-CHIKV and mapped to bind to its active site. The antiviral activity of LabMol-309 was evaluated in cellular-based assays using a CHIKV replicon system and a reporter virus. In conclusion, this study highlights the biophysical features of nsP4-CHIKV and identifies a new compound as a promising antiviral agent against CHIKV infection.
Lucca R. Policastro, Isabela Dolci, Andre S. Godoy, José V. J. Silva Júnior, Uriel E. A. Ruiz, Igor A. Santos, Ana C. G. Jardim, Kirandeep Samby, Jeremy N. Burrows, Timothy N. C. Wells,et al.
MDPI AG
Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disabling disease that can cause long-term severe arthritis. Since the last large CHIKV outbreak in 2015, the reemergence of the virus represents a serious public health concern. The morbidity associated with viral infection emphasizes the need for the development of specific anti-CHIKV drugs. Herein, we describe the development and characterization of a CHIKV reporter replicon cell line and its use in replicon-based screenings. We tested 960 compounds from MMV/DNDi Open Box libraries and identified four candidates with interesting antiviral activities, which were confirmed in viral infection assays employing CHIKV-nanoluc and BHK-21 cells. The most noteworthy compound identified was itraconazole (ITZ), an orally available, safe, and cheap antifungal, that showed high selectivity indexes of >312 and >294 in both replicon-based and viral infection assays, respectively. The antiviral activity of this molecule has been described against positive-sense single stranded RNA viruses (+ssRNA) and was related to cholesterol metabolism that could affect the formation of the replication organelles. Although its precise mechanism of action against CHIKV still needs to be elucidated, our results demonstrate that ITZ is a potent inhibitor of the viral replication that could be repurposed as a broad-spectrum antiviral.
Laura H. V. G. Gil, Tereza Magalhaes, Beatriz S. A. S. Santos, Livia V. Oliveira, Edmilson F. Oliveira-Filho, João L. R. Cunha, Ana L. S. Fraiha, Brenda M. M. Rocha, Barbara C. Longo, Roselene Ecco,et al.
MDPI AG
Madariaga virus (MADV) is a member of the eastern equine encephalitis virus (EEEV) complex that circulates in Central and South America. It is a zoonotic, mosquito-borne pathogen, belonging to the family Togaviridae. Disturbances in the natural transmission cycle of this virus result in outbreaks in equines and humans, leading to high case fatality in the former and acute febrile illness or neurological disease in the latter. Although a considerable amount of knowledge exists on the eco-epidemiology of North American EEEV strains, little is known about MADV. In Brazil, the most recent isolations of MADV occurred in 2009 in the States of Paraíba and Ceará, northeast Brazil. Because of that, health authorities have recommended vaccination of animals in these regions. However, in 2019 an equine encephalitis outbreak was reported in a municipality in Ceará. Here, we present the isolation of MADV from two horses that died in this outbreak. The full-length genome of these viruses was sequenced, and phylogenetic analyses performed. Pathological findings from postmortem examination are also discussed. We conclude that MADV is actively circulating in northeast Brazil despite vaccination programs, and call attention to this arbovirus that likely represents an emerging pathogen in Latin America.
Matheus N. Weber, Ana C. S. Mosena, Letícia F. Baumbach, Mariana S. da Silva, Raíssa Canova, Débora R. L. dos Santos, Renata da F. Budaszewski, Livia V. de Oliveira, Michel M. Soane, Natália B. Saraiva,et al.
Springer Science and Business Media LLC
A Correction to this paper has been published: https://doi.org/10.1007/s42770-021-00504-4
Matheus N. Weber, Ana C. S. Mosena, Letícia F. Baumbach, Mariana S. da Silva, Raíssa Canova, Débora R. L. dos Santos, Renata da F. Budaszewski, Livia V. de Oliveira, Michel M. Soane, Natália B. Saraiva,et al.
Springer Science and Business Media LLC
Flaviviruses as West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Ilhéus virus (ILHV), and Rocio virus (ROCV) are previously reported in different Brazilian regions, but studies in Southern Brazil are still scarce. To improve the information regarding flaviviruses in Southern Brazil, horse serum samples were analyzed using RT-qPCR and a commercial ELISA-Ab against WNV followed by PRNT75. All 1000 samples analyzed by real-time RT-PCR resulted negative. The 465 subsampled samples were analyzed by a commercial ELISA-Ab against WNV, and the 18.5% (86/465) positive samples were further analyzed by PRNT75. In the PRNT75, 13/86 and 2/86 horses were positive for SLEV and WNV, respectively. It was observed that 5.8% (13/226) of the farms presented at least one positive animal for SLEV in PRNT75, whereas 0.9% (2/226) for WNV. Apart from the lower seroprevalences identified when compared to data previously reported in other Brazilian regions, our results suggest that public health professionals must be aware of the presence of these potential zoonotic pathogens.
Rafaela S. Fernandes, Marjorie C. L. C. Freire, Renata V. Bueno, Andre S. Godoy, Laura H. V. G. Gil, and Glaucius Oliva
MDPI AG
Single-stranded positive RNA ((+) ssRNA) viruses include several important human pathogens. Some members are responsible for large outbreaks, such as Zika virus, West Nile virus, SARS-CoV, and SARS-CoV-2, while others are endemic, causing an enormous global health burden. Since vaccines or specific treatments are not available for most viral infections, the discovery of direct-acting antivirals (DAA) is an urgent need. Still, the low-throughput nature of and biosafety concerns related to traditional antiviral assays hinders the discovery of new inhibitors. With the advances of reverse genetics, reporter replicon systems have become an alternative tool for the screening of DAAs. Herein, we review decades of the use of (+) ssRNA viruses replicon systems for the discovery of antiviral agents. We summarize different strategies used to develop those systems, as well as highlight some of the most promising inhibitors identified by the method. Despite the genetic alterations introduced, reporter replicons have been shown to be reliable systems for screening and identification of viral replication inhibitors and, therefore, an important tool for the discovery of new DAAs.
Estefani P. Simão, Dammyres B.S. Silva, Marli T. Cordeiro, Laura H.V. Gil, Cesar A.S. Andrade, and Maria D.L. Oliveira
Elsevier BV
Arboviruses have been emerging as a significant global health problem due to the recurrent epidemics. Arboviruses require the development of new diagnostic devices due to the nonspecific clinical manifestations. Herein, we report a biosensor based on cysteine (Cys), zinc oxide nanoparticles (ZnONp), and Concanavalin A (ConA) lectin to differentiate between arboviruses infections. ConA is capable of interacting with the saccharide components of the viral capsid. In this study, we evaluated the reproducibility, sensitivity, and specificity of the sensor for the virus of Dengue type 2 (DENV2), Zika (ZIKV), Chikungunya (CHIKV), and Yellow fever (YFV). Atomic force microscopy measurements confirmed the electrode surface modification and revealed a heterogeneous topography during the biorecognition process. Cyclic voltammetry (CV) and impedance spectroscopy (EIS) were used to characterize the biosensor. The blockage of the oxidation-reduction process is related to the formation of Cys-ZnONp-ConA system on the electroactive area and its subsequent interaction with viral glycoproteins. The sensor exhibited a linear response to different concentrations of the studied arboviruses. Our study demonstrates that ConA lectin recognizes the structural glycoproteins of the DENV2, ZIKV, CHIKV, and YFV. DENV2 is the most structurally similar to ZIKV. Our results have shown that the impedimetric response correlates with the structural glycoproteins, as follow: DENV2 (18.6 kΩ) > ZIKV (14.6 kΩ) > CHIKV (6.86 kΩ) > YFV (5.98 kΩ). The homologous structural regions contribute to ConA-arboviruses recognition. Our results demonstrate the use of the proposed system for the development of biosensors for arboviruses infections.
K.M. Guarines, R.P.G. Mendes, M.T. Cordeiro, M.P. Miagostovich, L.H.V.G. Gil, K.Y. Green, and L.J. Pena
FapUNIFESP (SciELO)
Norovirus (NoV) is the main cause of gastroenteritis outbreaks worldwide. Although NoV spreads mainly from person to person, it is estimated that a large proportion of NoV outbreaks are caused by foodborne transmission. Bivalve mollusks are one of the most important foods involved in NoV transmission to humans. Little is known about NoV prevalence in shellfish harvested and commercialized in Brazil. The aim of this study was to map, for the first time, the distribution of NoV contamination in oysters and mussels harvested and commercialized in the coast of Pernambuco state, northeast Brazil. A total of 380 mollusks (260 oysters and 120 mussels) were collected between February and August 2017 either directly from harvesting areas or obtained from beach vendors at 17 sites in Pernambuco. Samples were processed and tested for NoV contamination using a SYBR Green real-time PCR assay. All samples were negative for NoV GI or GII contamination, suggesting a low risk of NoV contamination from this food source during the study period. Additional surveys in different areas of the Brazilian coast are warranted to monitor the risk of NoV infection upon seafood consumption.
Renato AS Oliveira, Edmilson F de Oliveira-Filho, Ana IV Fernandes, Carlos AA Brito, Ernesto TA Marques, Marli C Tenório, and Laura HGV Gil
FapUNIFESP (SciELO)
BACKGROUND Dengue virus (DENV) has circulated in Brazil for over 30 years. During this time, one serotype has cyclically replaced the other, until recently, when all four distinct serotypes began to circulate together. Persistent circulation of DENV for long time periods makes sequential infections throughout a person’s life possible. After primary DENV infection, life-long immunity is developed for the infecting serotype. Since DENV and Zika virus (ZIKV) are antigenically similar, the possibility of cross-reactions has attracted attention and has been demonstrated in vitro. OBJECTIVE The aim of this study was to investigate whether immune-sera from DENV and ZIKV infected patients would cross-react in vitro with other Flaviviridae family members. METHODS Cross-reaction of the studied samples with yellow fever virus (YFV), West Nile virus (WNV), Rocio virus (ROCV), Saint Louis virus (SLEV) and Ilheus virus (ILHV) has been investigated by plaque reduction neutralisation test (PRNT) and the antibody-dependent enhancement (ADE) by flow-cytometry. FINDINGS Antibodies against ZIKV and DENV virus cross-reacted with other flaviviruses either neutralising or enhancing the infection. Thus, viral entrance into FcRFcɣRII-expressing cells were influenced by the cross-reactive antibodies. ZIKV or DENV immune sera enhanced cellular infection by WNV, ILHV, ROCV and SLEV. Finally, DENV immune sera presented higher neutralising activity for YFV and SLEV. While ZIKV immune sera neutralised WNV, ILHV and ROCV with high frequencies of positivity. MAIN CONCLUSIONS The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies.
Edmilson Ferreira de Oliveira-Filho, Debora RL dos Santos, Ricardo Durães-Carvalho, Adalúcia da Silva, Gustavo Barbosa de Lima, Antônio Fernando B Batista Filho, Lindomar J Pena, and Laura HVG Gil
FapUNIFESP (SciELO)
Hepatitis E virus (HEV), an emerging virus associated with acute hepatic disease, leads to thousands of deaths worldwide. HEV has already been reported in Brazil; however, there is a lack of epidemiological and molecular information on the genetic variability, taxonomy, and evolution of HEV. It is thus unclear whether hepatitis E is a neglected disease in Brazil or it has low relevance for public health in this country. Here, for the first time, we report the presence of HEV in Northeast Brazil. A total of 119 swine faecal samples were screened for the presence of HEV RNA using real-time polymerase chain reaction (RT-PCR) and further confirmed by conventional RT-PCR; among these, two samples were identified as positive. Molecular evolution analyses based on capsid sequences revealed that the samples had close proximities to HEV sequences belonging to genotype 3 and were genetically related to subtype 3f isolated in humans. Parsimony ancestral states analysis indicated gene flow events from HEV cross-species infection, suggesting an important role of pig hosts in viral spillover. HEV’s ability for zoonotic transmission by inter-species host switching as well as its possible adaptation to new animal species remain important issues for human health.
José V.J. Silva, Louisa F. Ludwig-Begall, Edmilson F. de Oliveira-Filho, Renato A.S. Oliveira, Ricardo Durães-Carvalho, Thaísa R.R. Lopes, Daisy E.A. Silva, and Laura H.V.G. Gil
Elsevier BV
Abstract
Chikungunya fever is a mosquito-borne viral illness characterized by a sudden onset of fever associated with joint pains. It was first described in the 1950s during a Chikungunya virus (CHIKV) outbreak in southern Tanzania and has since (re-) emerged and spread to several other geographical areas, reaching large populations and causing massive epidemics. In recent years, CHIKV has gained considerable attention due to its quick spread to the Caribbean and then in the Americas, with many cases reported between 2014 and 2017. CHIKV has further garnered attention due to the clinical diagnostic difficulties when Zika (ZIKV) and dengue (DENV) viruses are simultaneously present. In this review, topical CHIKV-related issues, such as epidemiology and transmission, are examined. The different manifestations of infection (acute, chronic and atypical) are described and a particular focus is placed upon the diagnostic handling in the case of ZIKV and DENV co-circulating. Natural and synthetic compounds under evaluation for treatment of chikungunya disease, including drugs already licensed for other purposes, are also discussed. Finally, previous and current vaccine strategies, as well as the control of the CHIKV transmission through an integrated vector management, are reviewed in some detail.
E. F. de Oliveira-Filho, R. A. S. Oliveira, D. R. A. Ferreira, P. O. Laroque, L. J. Pena, M. M. Valença-Montenegro, R. A. Mota, and L. H. V. G. Gil
Wiley
Mosquito-borne diseases such as dengue, yellow fever and, more recently, Chikungunya virus (CHIKV) and Zika virus (ZIKV) have a great impact in the public health. In addition, the presence of such viruses might have an impact on wild animal conservation as well as their possible role as animal reservoir. Here, we performed a serological survey searching for antibodies against a panel of flaviviruses [ZIKV, Dengue virus (DENV), Yellow Fever virus (YFV), West Nile virus (WNV), Saint Louis Encephalitis virus (SLEV), Ilheus virus (ILHV) and Rocio virus (ROCV)] using plaque reduction neutralization test (PRNT90 ) in both free-ranging and captive capuchin monkeys (Sapajus flavius and Sapajus libidinosus). Captive and free-living monkeys were sampled between June 2015 and January 2016 in the state of Pernambuco, including in the border with State of Paraíba, the epicentre of the ZIKV epidemics in Brazil. We have found neutralizing antibodies for ZIKV, DENV-1, DENV-2, DENV-3, DENV-4, YFV, ILHV and SLEV in both S. flavius and S. libidinosus samples. No positives samples were found for ROCV and WNV. Our results suggest that these flaviviruses might be circulating in capuchin monkey in the studied region. The possible presence of these viruses represents a risk for public health, as well as for animal conservation, especially for S. flavius which is a critically endangered species, facing high risk of extinction.
José V.J. Silva, Thaísa R.R. Lopes, Edmilson F. de Oliveira-Filho, Renato A.S. Oliveira, Ricardo Durães-Carvalho, and Laura H.V.G. Gil
Elsevier BV
Emerging and re-emerging viral infections transmitted by insect vectors (arthopode-borne viruses, arbovirus) are a serious threat to global public health. Among them, yellow fever (YFV), dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses are particularly important in tropical and subtropical regions. Although vector control is one of the most used prophylactic measures against arboviruses, it often faces obstacles, such as vector diversity, uncontrolled urbanization and increasing resistance to insecticides. In this context, vaccines may be the best control strategy for arboviral diseases. Here, we provide a general overview about licensed vaccines and the most advanced vaccine candidates against YFV, DENV, CHIKV and ZIKV. In particular, we highlight vaccine difficulties, the current status of the most advanced strategies and discuss how the molecular characteristics of each virus can influence the choice of the different vaccine formulations.
Tauyne Menegaldo Pinheiro, Mânlio Tasso de Oliveira Mota, Aripuanã Sakurada Aranha Watanabe, Joice Matos Biselli-Périco, Betânia Paiva Drumond, Milene Rocha Ribeiro, Danila Vedovello, João Pessoa Araújo, Paulo Filemon Paolucci Pimenta, Bárbara Aparecida Chaves,et al.
Public Library of Science (PLoS)
The dynamics of dengue virus (DENV) circulation depends on serotype, genotype and lineage replacement and turnover. In São José do Rio Preto, Brazil, we observed that the L6 lineage of DENV-1 (genotype V) remained the dominant circulating lineage even after the introduction of the L1 lineage. We investigated viral fitness and immunogenicity of the L1 and L6 lineages and which factors interfered with the dynamics of DENV epidemics. The results showed a more efficient replicative fitness of L1 over L6 in mosquitoes and in human and non-human primate cell lines. Infections by the L6 lineage were associated with reduced antigenicity, weak B and T cell stimulation and weak host immune system interactions, which were associated with higher viremia. Our data, therefore, demonstrate that reduced viral immunogenicity and consequent greater viremia determined the increased epidemiological fitness of DENV-1 L6 lineage in São José do Rio Preto.
Sabrina Ribeiro de Almeida Queiroz, José Valter Joaquim Silva Júnior, Andréa Nazaré Monteiro Rangel da Silva, Amanda Gomes de Oliveira Carvalho, Jefferson José da Silva Santos, and Laura Helena Vega Gonzales Gil
FapUNIFESP (SciELO)
INTRODUCTION
Pseudo-infectious yellow fever viral particles (YFV-PIVs) have been used to study vaccines and viral packaging. Here, we report the development of a packaging cell line, which expresses the YFV prM/E proteins.
METHODS
HEK293 cells were transfected with YFV prM/E and C (84 nt) genes to generate HEK293-YFV-PrM/E-opt. The cells were evaluated for their ability to express the heterologous proteins and to package the replicon repYFV-17D-LucIRES, generating YFV-PIVs.
RESULTS
The expression of prM/E proteins was confirmed, and the cell line trans-packaged the replicon for recovery of a reporter for the YFV-PIVs.
CONCLUSIONS
HEK293-YFV-prM/E-opt trans-packaging capacity demonstrates its possible biotechnology application.
Edmilson F. de Oliveira-Filho, Kennya G. S. Lopes, Deivson S. Cunha, Virginia S. Silva, Clara N. Barbosa, Daniel F. Brandespim, José Wilton Pinheiro Junior, Giovani R. Bertani, and Laura H. V. G. Gil
Springer Science and Business Media LLC
Anti-HEV antibodies were detected in animals from abattoir and in farms from northeast Brazil. Our results suggest that HEV is highly disseminated in the swine population and might present a great risk to animal handlers and for consumption of raw or undercooked meat and meat products in northeast Brazil.
Alessandra Vidotto, Ana T. S. Morais, Milene R. Ribeiro, Carolina C. Pacca, Ana C. B. Terzian, Laura H. V. G. Gil, Ronaldo Mohana-Borges, Philippe Gallay, and Mauricio L. Nogueira
American Chemical Society (ACS)
Yellow fever virus (YFV) replication is highly dependent on host cell factors. YFV NS4B is reported to be involved in viral replication and immune evasion. Here interactions between NS4B and human proteins were determined using a GST pull-down assay and analyzed using 1-DE and LC-MS/MS. We present a total of 207 proteins confirmed using Scaffold 3 Software. Cyclophilin A (CypA), a protein that has been shown to be necessary for the positive regulation of flavivirus replication, was identified as a possible NS4B partner. 59 proteins were found to be significantly increased when compared with a negative control, and CypA exhibited the greatest difference, with a 22-fold change. Fisher's exact test was significant for 58 proteins, and the p value of CypA was the most significant (0.000000019). The Ingenuity Systems software identified 16 pathways, and this analysis indicated sirolimus, an mTOR pathway inhibitor, as a potential inhibitor of CypA. Immunofluorescence and viral plaque assays showed a significant reduction in YFV replication using sirolimus and cyclosporine A (CsA) as inhibitors. Furthermore, YFV replication was strongly inhibited in cells treated with both inhibitors using reporter BHK-21-rep-YFV17D-LucNeoIres cells. Taken together, these data suggest that CypA-NS4B interaction regulates YFV replication. Finally, we present the first evidence that YFV inhibition may depend on NS4B-CypA interaction.
Renato Antonio dos Santos Oliveira, Marli Tenório Cordeiro, Patrícia Muniz Mendes Freire de Moura, Paulo Neves Bapti Baptista Filho, Ulisses de Mendonça Braga-Neto, Ernesto Torres de Azevedo Marques, and Laura Helena Vega Gonzales Gil
Elsevier BV
BACKGROUND
DENV infection can induce different clinical manifestations varying from mild forms to dengue fever (DF) or the severe hemorrhagic fever (DHF). Several factors are involved in the progression from DF to DHF. No marker is available to predict this progression. Such biomarker could allow a suitable medical care at the beginning of the infection, improving patient prognosis.
OBJECTIVES
The aim of this study was to compare the serum expression levels of acute phase proteins in a well-established cohort of dengue fever (DF) and dengue hemorrhagic fever (DHF) patients, in order to individuate a prognostic marker of diseases severity.
STUDY DESIGN
The serum levels of 36 cytokines, chemokines and acute phase proteins were determined in DF and DHF patients and compared to healthy volunteers using a multiplex protein array and near-infrared (NIR) fluorescence detection. Serum levels of IL-1ra, IL-23, MIF, sCD40 ligand, IP-10 and GRO-α were also determined by ELISA.
RESULTS
At the early stages of infection, GRO-α and IP-10 expression levels were different in DF compared to DHF patients. Besides, GRO-α was positively correlated with platelet counts and IP-10 was negatively correlated with total protein levels.
CONCLUSIONS
These findings suggest that high levels of GRO-α during acute DENV infection may be associated with a good prognosis, while high levels of IP-10 may be a warning sign of infection severity.
TELISSA C. KASSAR, TEREZA MAGALHÃES, JOSÉ V.J. S. JÚNIOR, AMANDA G.O. CARVALHO, ANDRÉA N.M.R. DA SILVA, SABRINA R.A. QUEIROZ, GIOVANI R. BERTANI, and LAURA H.V.G. GIL
FapUNIFESP (SciELO)
Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies. Here, we report the construction of a recombinant yellow fever virus (YFV) expressing Gaussia luciferase (GLuc) (YFV-GLuc). We show, through RT-PCR, sequencing and measurement of GLuc activity, that stability of the heterologous gene was maintained after six passages. Furthermore, a direct association between GLuc expression and viral replication was observed (r2=0.9967), indicating that measurement of GLuc activity may be used to assess viral replication in different applications. In addition, we evaluated the use of the recombinant virus in an antiviral assay with recombinant human alfa-2b interferon. A 60% inhibition of GLuc expression was observed in cells infected with YFV-GLuc and incubated with IFN alfa-2b. Previously tested on YFV inhibition by plaque assays indicated a similar fold-decrease in viral replication. These results are valuable as they show the stability of YFV-GLuc and one of several possible applications of this construct.
José Valter Joaquim Silva Júnior, Thaísa Regina Rocha Lopes, Edmilson Ferreira de Oliveira-Filho, Renato Antonio dos Santos Oliveira, and Laura Helena Vega Gonzales Gil
FapUNIFESP (SciELO)
Marli T. Cordeiro, Carlos A. A. Brito, Lindomar J. Pena, Priscila M. S. Castanha, Laura H. V. G. Gil, Kennya G. S. Lopes, Rafael Dhalia, Jucille A. Meneses, Ana C. Ishigami, Luisa M. Mello,et al.
Oxford University Press (OUP)
BACKGROUND
Usually, immunoglobulin M (IgM) serologic analysis is not sufficiently specific to confirm Zika virus (ZIKV) infection. However, since IgM does not cross the placenta, it may be a good marker of infection in neonates.
METHODS
We tested blood from 42 mothers and neonates with microcephaly and collected cerebrospinal fluid (CSF) specimens from 30 neonates. Molecular assays were performed for detection of ZIKV, dengue virus, and chikungunya virus; IgM enzyme-linked immunosorbent assays and plaque-reduction neutralization tests (PRNTs) were performed to detect ZIKV and dengue virus. No control neonates without microcephaly were evaluated.
RESULTS
Among neonates, all 42 tested positive for ZIKV IgM: 38 of 42 serum specimens (90.5%) were positive, whereas 30 of 30 CSF specimens (100%) were positive. ZIKV IgM-specific ELISA ratios, calculated as the mean optical density (OD) of the test sample when reacted on viral antigen divided by the mean OD of the negative control when reacted with viral antigen, were higher in CSF specimens (median, 14.9 [range, 9.3-16.4]) than in serum (median, 8.9 [range, 2.1-20.6]; P = .0003). All ZIKV IgM-positive results among the neonates were confirmed by the detection of neutralizing antibodies. Mother/neonate pairs with primary ZIKV infection had neutralizing antibodies to ZIKV only, and mother/neonate pairs with ZIKV virus infection secondary to infection with another flavivirus had high titers of neutralizing antibodies to ZIKV. Among secondary infections, median titers in serum were 2072 (range, 232-12 980) for mothers and 2730 (range, 398-12 980) for neonates (P < .0001), and the median titer in CSF was 93 (range, 40-578) among neonates (P < .0001).
CONCLUSIONS
Among neonates, detection of ZIKV IgM in serum is confirmatory of congenital ZIKV infection, and detection of ZIKV IgM in CSF is confirmatory of neurologic infection. Therefore, we recommend testing for ZIKV IgM in neonates suspected of having congenital ZIKV infection and performance of PRNTs in equivocal cases.