Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells

The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3'UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3'UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3'UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3'UTRs with possible implications in virulence and viral transmission.Fil: Filomatori, Claudia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Carballeda, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Villordo, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Aguirre, Sebastian. Cedars Sinai Medical Center; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pallarés, Horacio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Maestre, Ana M.. Cedars Sinai Medical Center; Estados UnidosFil: Sánchez Vargas, Irma. State University of Colorado - Fort Collins; Estados UnidosFil: Blair, Carol D.. State University of Colorado - Fort Collins; Estados UnidosFil: Fabri, Cintia. Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio I. Maiztegui"; ArgentinaFil: Morales, Maria A.. Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio I. Maiztegui"; ArgentinaFil: Fernandez Sesma, Ana. Cedars Sinai Medical Center; Estados UnidosFil: Gamarnik, Andrea Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

ASPECTOS EMOCIONAIS DE PORTADORES DE OSTEOARTROSE QUE FREQUENTAM UM PROGRAMA DE REABILITAÇÃO FISIOTERAPÊUTICA EM GRUPO

The emotional profile of a group physiotherapeutic rehabilitation program was analyzed in patients with Osteoarthrosis (OA). The sample consisted of 25 patients aged 18 years or older, both sexes, diagnosed with OA. Personal and anthropometric data were collected, and questionnaires were evaluated evaluating pain, quality of life, anxiety, depression, stress levels and self-esteem of the patients. The mean age was 61.24 ± 11.32. The means in the HAD questionnaire were, for anxiety 13.90 ± 2.18, and depression 14.66 ± 1.52. The LIPP ranged from 40% to 60% in stage II and III of stressor symptoms, in the SF-36 questionnaire the emotional aspect was 34.65 ± 40.22 and in Rosenberg the self-confidence had a mean of 16.32 ± 2.98 and self-depreciation with 14.56 ± 4.05. This study showed that the symptoms of anxiety and depression are present in the aging process along with OA. Therefore, it becomes indispensable to the evaluation and appropriate treatment of the emotional profile of these patients.Analisou-se o perfil emocional, de um programa de reabilitação fisioterapêutica em grupo, em pacientes com Osteoartrose (OA).  A amostra integrou 25 pacientes com idade maior ou igual a 18 anos, ambos os sexos, diagnosticados com OA. Foram coletados dados pessoais e antropométricos, e aplicados questionários avaliando dor, qualidade de vida, ansiedade, depressão, níveis de estresse e autoestima dos pacientes. A média da idade foi 61,24 ± 11,32. As médias no questionário HAD foram, para ansiedade 13,90 ± 2,18, e depressão 14,66 ± 1,52. O LIPP variou entre 40% a 60% na fase II e III de sintomas estressores, no questionário SF-36 no aspecto emocional a média foi 34,65 ± 40,22 e no Rosenberg a autoconfiança teve média 16,32 ± 2,98 e auto depreciação com 14,56 ± 4,05. Este estudo mostrou que os sintomas de ansiedade e depressão estão presentes no processo do envelhecimento juntamente com a OA. Diante disso, torna-se indispensável à avaliação e o tratamento adequado do perfil emocional desses pacientes

Genomic epidemiology unveils the dynamics and spatial corridor behind the Yellow Fever virus outbreak in Southern Brazil

Despite the considerable morbidity and mortality of yellow fever virus (YFV) infections in Brazil, our understanding of disease outbreaks is hampered by limited viral genomic data. Here, through a combination of phylogenetic and epidemiological models, we reconstructed the recent transmission history of YFV within different epidemic seasons in Brazil. A suitability index based on the highly domesticated Aedes aegypti was able to capture the seasonality of reported human infections. Spatial modeling revealed spatial hotspots with both past reporting and low vaccination coverage, which coincided with many of the largest urban centers in the Southeast. Phylodynamic analysis unraveled the circulation of three distinct lineages and provided proof of the directionality of a known spatial corridor that connects the endemic North with the extra-Amazonian basin. This study illustrates that genomics linked with eco-epidemiology can provide new insights into the landscape of YFV transmission, augmenting traditional approaches to infectious disease surveillance and control

Zika Virus Subgenomic Flavivirus RNA Generation Requires Cooperativity between Duplicated RNA Structures That Are Essential for Productive Infection in Human Cells

ACKNOWLEDGMENTSA.V.G., M.M.G.L.L., and L.D.B. are members of the Argentinean Council of Investigation (CONICET). H.M.P. and G.S.C.N. were granted CONICET fellowshipsInternational audienceFlaviviruses are important emerging and reemerging human pathogens. Understanding the molecular mechanisms for viral replication and evasion of host antiviral responses is relevant to development of control strategies. Flavivirus infections produce viral noncoding RNAs, known as sfRNAs, involved in viral replication and pathogenesis. In this study, we dissected molecular determinants for Zika virus sfRNA generation in the two natural hosts, human cells and mosquitoes. We found that two RNA structures of the viral 3′ UTR operate in a cooperative manner to produce two species of sfRNAs and that the deletion of these elements has a profoundly different impact on viral replication in the two hosts. Generation of at least one sfRNA was necessary for efficient Zika virus infection of Aedes aegypti mosquitoes. Moreover, recombinant viruses with different 3′ UTR arrangements revealed an essential role of sfRNAs for productive infection in human cells. In summary, we define molecular requirements for Zika virus sfRNA accumulation and provide new ideas of how flavivirus RNA structures have evolved to succeed in different hosts

Production of sfRNAs in Zika virus infections.

<p>(<b>A</b>) Northern blot hybridization showing the accumulation sfRNA in C6/36 and A549 cells infected with a Zika isolate from Argentina (INEVH). (<b>B</b>) RNA structure model predicted for the ZIKV 3’UTR. Conserved SLI, SLII, pseudo-dumbbell (ψ-DB) and DB structures are indicated. Pseudoknots are indicated with red lines. Location and size of the two sfRNAs identified in infected cells are shown (sfRNA1 and sfRNA2). (<b>C and D</b>) Northern blots showing the pattern of sfRNAs in Raji, A549 and C6/36 cells infected with ZIKV from different origins (Cambodia, Senegal and Puerto Rico) as indicated on the top.</p

Comparative analysis of predicted RNA structures of the 3’UTR of mosquito-borne flaviviruses (MBFV).

<p>(<b>A</b>) Conserved stem loops of selected viruses from each subgroup of MBFV are shown in red. Predicted H-type pseudoknots are indicated with red dashed lines and pseudoknots including nucleotides present in the three-way junction are shown in black dashed lines. Information obtained from crystallographic studies using MVEV and ZIKV RNAs was included [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006265#ppat.1006265.ref025" target="_blank">25</a>,<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006265#ppat.1006265.ref039" target="_blank">39</a>]. Group-specific RNA structures are indicated in grey. The distance tree was drawn using the neighbor joining method of all complete genome sequences for each virus available in GenBank. (<b>B</b>) Representation of the complete 3’UTR structure of different MBFVs showing the conserved elements involved in Xrn1 stalling. Conserved stem loop (SL) and dumbbell (DB) structures are shown in red and blue, respectively. Arc plots of RNA structures corresponding to the conserved xrRNA1, xrRNA2, xrRNA3 and xrRNA4 are shown for DENV1 to 4, ZIKV, WNV, MVEV, SLEV and BAGV. The conserved 3’SL structure is shown in dark blue.</p

Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells - Fig 1

<p>Different patterns of sfRNA produced during dengue virus host adaptation (<b>A</b>) Schematic representation of DENV 3’UTR diversification during host switch. Variants in viral populations obtained in mosquito or human cells are represented by circles. The size and color of circles represent the frequency and number of mutations of variants, respectively. The distance between variants is also shown by a fan dendrogram. (<b>B</b>) Genomic and subgenomic DENV RNAs produced in infections using viruses generated in human (DENV-H) or mosquito (DENV-M) cells. Cells were infected at MOI of 1 with DENV-H or DENV-M. Northern blots using a mix of radiolabeled probes that recognize the viral 3’UTR, capsid and NS5 (left), only the 3’UTR (middle) or only the 3’SL (right) are shown. The species of sfRNAs detected are indicated on the right. (<b>C</b>) Northern blot showing sfRNAs produced during the process of DENV adaptation to human cells. Specific probes complementary to the viral 3’UTR were used to hybridize RNA isolated from A549 cells infected with the indicated viruses. P5H, P10H and P15H indicate viral stocks passaged 5, 10 and 15 times in human cells, respectively. (<b>D</b>) Northern blot showing sfRNAs produced during the process of DENV adaptation to mosquito cells. Specific probes complementary to the viral 3’UTR were used to hybridize RNA isolated from C6/36 cells infected with the indicated viruses.</p

Mapping the sfRNAs generated in DENV infected human and mosquito cells.

<p>(<b>A</b>) Secondary structure of DENV 3’UTR indicating the location and size of sfRNAs identified by sequencing analysis. Below, plots representing relative amounts of sfRNA species produced using human or mosquito infected cells. The amount of each sfRNA was estimated by ImageJ-quantitation and expressed as the mean +/- SD of the relative percentage from total sfRNAs (n = 3). (<b>B</b>) Northern blot hybridization using specific probes complementary to the viral 3’UTR employing RNA extracted at 30 and 50 hpi from C6/36 or A549 cells infected with either DENV-M or DENV-H stocks, as indicated. (<b>C</b>) DENV sfRNAs produced in infected <i>Ae</i>. <i>albopictus</i> and <i>Ae</i>. <i>aegypi</i> mosquitos. Northern blot hybridization using RNA extracted from mosquitos infected with DENV-M or DENV-H. A probe complementary to the viral 3’SL was used for detection.</p

Mosquito adapted DENV variant exhibit an exacerbated antiviral response in human cells.

<p>Time course analysis of antiviral response in dendritic cells (DCs). DCs of three independent donors were infected with PT or MS3 virus, and at 3, 12, and 24 hpi IFNβ (<b>A</b>) or ISG15 (<b>B</b>) mRNA were determined by real time PCR. (<b>C</b>) The levels of IP-10 in the supernatant of infected cells was assessed by ELISA at 3, 12, 24, 48 and 72 hpi. Data are the means and standard deviations of three replicates from a representative donor.</p

Dissecting the molecular determinants for sfRNA accumulation during DENV host change.

<p>(<b>A</b>) Schematic representation of mosquito-selected viral variants with mutations and deletions within the viral 3’UTR. DENV variants were found with deletions, variant S1 and S2, or point mutations variants S3 to S6. The location of the mutations is indicated. (<b>B</b>) Replication of parental (PT) and recombinant viruses carrying the mutations identified. Immunofluorescence of cells infected PT and the mutants S1 to S6 as indicated at the top. Viral RNA detection using specific radiolabeled probes complementary to capsid and NS5 coding sequences is shown at 72hpi of A549 cells (bottom). (<b>C</b>) Northern blot hybridization for sfRNA detection using transfected cells with each DENV mutant as indicated on the top. <b>(D)</b> The structure of xrRNA2 is necessary for accumulation of short sfRNA species. Schematic representation of changes in the xrRNA2 structure of mutant S6 and restored R6, and Northern blot shown the accumulated sfRNAs in each case. <b>(E)</b> Point mutations within xrRNA2 are sufficient for the switch of sfRNA pattern produced during DENV infections. Schematic representation of mutation abrogating PK formation (M-PKII) is shown on the left and Northern blot comparing the accumulation of sfRNAs detected in infected cells with M-PKII or a virus with a complete deletion of xrRNA2 (ΔSLII).</p