ALVINA CLARA FELIX
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
18 resultados
Resultados de Busca
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conferenceObject DENGUE IN SOUTHEASTERN BRAZIL: A LARGE OUTBREAK FOLLOWED BY A THREE-YEAR LOW INCIDENCE PERIOD. OBSERVATIONS FROM A PROSPECTIVE COHORT STUDY(2018) LUNA, Expedito; FIGUEIREDO, Gerusa; LEVI, Jose; CAMPOS, Sergio; FIGUEIREDO, Walter; COSTA, Angela; FELIX, Alvina; SOUZA, Nathalia; PANNUTI, Claudio- A human inferred germline antibody binds to an immunodominant epitope and neutralizes Zika virus(2017) MAGNANI, Diogo M.; SILVEIRA, Cassia G. T.; ROSEN, Brandon C.; RICCIARDI, Michael J.; PEDRENO-LOPEZ, Nuria; GUTMAN, Martin J.; BAILEY, Varian K.; MAXWELL, Helen S.; DOMINGUES, Aline; GONZALEZ-NIETO, Lucas; AVELINO-SILVA, Vivian I.; TRINDADE, Mateus; NOGUEIRA, Juliana; OLIVEIRA, Consuelo S.; MAESTRI, Alvino; FELIX, Alvina Clara; LEVI, Jose Eduardo; NOGUEIRA, Mauricio L.; MARTINS, Mauricio A.; MARTINEZ-NAVIO, Jose M.; FUCHS, Sebastian P.; WHITEHEAD, Stephen S.; BURTON, Dennis R.; DESROSIERS, Ronald C.; KALLAS, Esper G.; WATKINS, David I.The isolation of neutralizing monoclonal antibodies (nmAbs) against the Zika virus (ZIKV) might lead to novel preventative strategies for infections in at-risk individuals, primarily pregnant women. Here we describe the characterization of human mAbs from the plasmablasts of an acutely infected patient. One of the 18 mAbs had the unusual feature of binding to and neutralizing ZIKV despite not appearing to have been diversified by affinity maturation. This mAb neutralized ZIKV (Neut(50) similar to 2 mu g/ml) but did not react with any of the four dengue virus serotypes. Except for the expected junctional diversity created by the joining of the V-(D)-J genes, there was no deviation from immunoglobulin germline genes. This is a rare example of a human mAb with neutralizing activity in the absence of detectable somatic hypermutation. Importantly, binding of this mAb to ZIKV was specifically inhibited by human plasma from ZIKV-exposed individuals, suggesting that it may be of value in a diagnostic setting.
conferenceObject ZIKA VIRUS INFECTION IN A COHORT STUDY TO ASSESS THE INCIDENCE OF DENGUE, STATE OF SAO PAULO, BRAZIL, 2015, 2016(2017) FIGUEIREDO, Gerusa M.; LUNA, Expedito J.; CARDOSO, Maria Regina; LEVI, Jose E.; FELIX, Alvina C.; SOUZA, Nathalia C. C.; SOUZA, Ana C.; CAMPOS, Sergio R. Campos R.; FIGUEIREDO, Walter M.; COSTA, Angela A.; PANNUTI, Claudio S.- Cross reactivity of commercial anti-dengue immunoassays in patients with acute Zika virus infection(2017) FELIX, Alvina Clara; SOUZA, Nathalia C. Santiago; FIGUEIREDO, Walter M.; COSTA, Angela A.; INENAMI, Marta; SILVA, Rosangela M. G. da; LEVI, Jose Eduardo; PANNUTI, Claudio Sergio; ROMANO, Camila MaltaSeveral countries have local transmission of multiple arboviruses, in particular, dengue and Zika viruses, which have recently spread through many American countries. Cross reactivity among Flaviviruses is high and present a challenge for accurate identification of the infecting agent. Thus, we evaluated the level of cross reactivity of anti-dengue IgM/G Enzyme-Linked Immunosorbent Assays (ELISA) from three manufacturers against 122 serum samples obtained at two time-points from 61 patients with non-dengue confirmed Zika virus infection. All anti-dengue ELISAs cross reacted with serum from patients with acute Zika infection at some level and a worrisome number of seroconversion for dengue IgG and IgM was observed. These findings may impact the interpretation of currently standard criteria for dengue diagnosis in endemic regions.
- MAIT cells are activated in acute Dengue virus infection and after in vitro Zika virus infection(2018) PAQUIN-PROULX, Dominic; AVELINO-SILVA, Vivian I.; SANTOS, Bianca A. N.; BARSOTTI, Nathalia Silveira; SIROMA, Fabiana; RAMOS, Jessica Fernandes; TONACIO, Adriana Coracini; SONG, Alice; MAESTRI, Alvino; CERQUEIRA, Natalia Barros; FELIX, Alvina Clara; LEVI, Jose Eduardo; GREENSPUN, Benjamin C.; ROUGVIE, Miguel de Mulder; ROSENBERG, Michael G.; NIXON, Douglas F.; KALLAS, Esper G.Dengue virus (DENV) and Zika virus (ZIKV) are members of the Flaviviridae and are pre-dominantly transmitted via mosquito bites. Both viruses are responsible for a growing number of infections in tropical and subtropical regions. DENV infection can cause lethargy with severe morbidity and dengue shock syndrome leading to death in some cases. ZIKV is now linked with Guillain-Barre A syndrome and fetal malformations including microcephaly and developmental disorders (congenital Zika syndrome). The protective and pathogenic roles played by the immune response in these infections is unknown. Mucosal-associated invariant T (MAIT) cells are a population of innate T cells with potent anti-bacterial activity. MAIT cells have also been postulated to play a role in the immune response to viral infections. In this study, we evaluated MAIT cell frequency, phenotype, and function in samples from subjects with acute and convalescent DENV infection. We found that in acute DENV infection, MAIT cells had elevated co-expression of the activation markers CD38 and HLA-DR and had a poor IFN gamma response following bacterial stimulation. Furthermore, we found that MAIT cells can produce IFN gamma in response to in vitro infection with ZIKV. This MAIT cell response was independent of MR1, but dependent on IL-12 and IL-18. Our results suggest that MAIT cells may play an important role in the immune response to Flavivirus infections.
conferenceObject A COHORT STUDY TO DETERMINE THE INCIDENCE OF ZIKA VIRUS INFECTION AMONG NEWBORNS, SANTOS, BRAZIL, 2016-2017(2017) LUNA, Expedito J.; ROMANO, Camila M.; ARAUJO, Evaldo S.; LEVI, Jose E.; OLIVEIRA, Olimpia N.; FERNANDES, Luis R.; FELIX, Alvina C.; SOUZA, Nathalia S.; FERNANDES, Joao H.; CAMPOS, Sergio R.; FRAGOSO, Danielli B.; PANNUTI, Claudio S.- Data on dengue incidence in South-eastern Brazil, 2014-2018(2020) LUNA, Expedito; FIGUEIREDO, Gerusa; LEVI, Jose; CAMPOS, Sergio; FELIX, Alvina; SOUZA, Nathalia; FIGUEIREDO, Walter; COSTA, Angela; CARDOSO, Maria; PANNUTI, ClaudioData from the routine surveillance systems have been extensively used to estimate the incidence of dengue. However, routine surveillance data frequently underestimate the diseases' incidence. Underreporting of dengue cases is related to the varying spectrum of its clinical presentation, with a large proportion of mild and asymptomatic infections, to its unspecific signs and symptoms, to the limitations of access to health care, and to the performance of the surveillance system itself [1-3]. In order to obtain accurate figures on dengue incidence, a cohort of children and adolescents was set up and followed during four years. The incidence of reported cases was used as a reference for the sample size calculation, which was stratified by age groups. A two-stage procedure was used to select the participants: census tracts were randomly selected, and within each one, a pre-determined number of children of each age group was randomly selected. The parents or legal guardians of the participating children and adolescents provided a written informed consent. In the first home visit, they responded to a questionnaire containing data on socio-demographic characteristics, housing, access to water, sewage, and garbage collection. Also, during the first visit a blood sample of the participating child/adolescent was collected for dengue baseline serology. Beginning in the week after the enrolment, the parent or legal guardian that was designated in the first visit received weekly phone calls for fever surveillance. If the child/adolescent had fever during the week, a nurse was dispatched to the family's home to collect more detailed data on the fever episode and collect a blood sample for dengue diagnosis (IgG, IgM, NS1 and PCR). If the dengue diagnosis was confirmed, a medical appointment was scheduled, and another blood sample for confirmatory tests was collected. It was also agreed that in every anniversary of their participation, they would receive another visit for a blood collection for dengue serology, regardless if they had a fever episode or a confirmed dengue diagnosis during the previous year. This article contains the description of the cohort's dataset. It is associated with the article published in Acta Tropica, under the title ""A cohort study to assess the incidence of dengue, Brazil, 2014-2018"" [4]. The associated article focused on the seroprevalence and incidence of dengue, and explored some associations between both outcomes and some explanatory variables. (C) 2020 The Authors.
- Evaluation of serological cross-reactivity between yellow fever and other flaviviruses(2019) SOUZA, Nathalia Caroline Santiago e; FELIX, Alvina Clara; PAULA, Anderson Vicente de; LEVI, Jose Eduardo; PANNUTI, Claudio Sergio; ROMANO, Camila MaltaObjectives: This study was performed to determine whether neutralizing antibodies against yellow fever virus (YFV) generated by YFV vaccine could interfere in the specificity of dengue virus (DENV) and Zika virus (ZIKV) IgG ELISA tests. Methods: Seventy-nine pairs of serum samples (pre- and post-vaccination), collected during the years 1997-1998 from children with no history of yellow fever disease who had been vaccinated against YFV, were tested. The seroconversion post-vaccination was evaluated through plaque reduction neutralization test (PRNT), and four different commercial ELISA kits were used for the detection of DENV and ZIKV IgG antibodies. Results: A cross-reactivity rate of 3.9% with DENV IgG antibodies was found only with the Dengue Virus IgG Dx Select kit (Focus Diagnostics). Conclusions: As several countries have local transmission of multiple arboviruses, the absence of cross-reactivity or minimum cross-reactivity of YFV neutralizing antibodies with DENV and ZIKV antigens is a relevant finding, since the interpretation of sero-epidemiological investigations would be seriously impacted in many regions where YFV vaccination is mandatory. (C) 2019 The Authors.
- Rapid viral metagenomics using SMART-9N amplification and nanopore sequencing(2023) CLARO, I. M.; RAMUNDO, M. S.; COLETTI, T. M.; SILVA, C. A. M. da; VALENCA, I. N.; CANDIDO, D. S.; SALES, F. C. S.; MANULI, E. R.; JESUS, J. G. de; PAULA, A. de; FELIX, A. C.; ANDRADE, P. D. S.; PINHO, M. C.; SOUZA, W. M.; AMORIM, M. R.; PROENCA-MODENA, J. L.; KALLAS, E. G.; LEVI, J. E.; FARIA, N. R.; SABINO, E. C.; LOMAN, N. J.; QUICK, J.Emerging and re-emerging viruses are a global health concern. Genome sequencing as an approach for monitoring circulating viruses is currently hampered by complex and expensive methods. Untargeted, metagenomic nanopore sequencing can provide genomic information to identify pathogens, prepare for or even prevent outbreaks. SMART (Switching Mechanism at the 5′ end of RNA Template) is a popular approach for RNA-Seq but most current methods rely on oligo-dT priming to target polyadenylated mRNA molecules. We have developed two random primed SMART-Seq approaches, a sequencing agnostic approach ‘SMART-9N’ and a version compatible rapid adapters available from Oxford Nanopore Technologies ‘Rapid SMART-9N’. The methods were developed using viral isolates, clinical samples, and compared to a gold-standard amplicon-based method. From a Zika virus isolate the SMART-9N approach recovered 10kb of the 10.8kb RNA genome in a single nanopore read. We also obtained full genome coverage at a high depth coverage using the Rapid SMART-9N, which takes only 10 minutes and costs up to 45% less than other methods. We found the limits of detection of these methods to be 6 focus forming units (FFU)/mL with 99.02% and 87.58% genome coverage for SMART-9N and Rapid SMART-9N respectively. Yellow fever virus plasma samples and SARS-CoV-2 nasopharyngeal samples previously confirmed by RT-qPCR with a broad range of Ct-values were selected for validation. Both methods produced greater genome coverage when compared to the multiplex PCR approach and we obtained the longest single read of this study (18.5 kb) with a SARS-CoV-2 clinical sample, 60% of the virus genome using the Rapid SMART-9N method. This work demonstrates that SMART-9N and Rapid SMART-9N are sensitive, low input, and long-read compatible alternatives for RNA virus detection and genome sequencing and Rapid SMART-9N improves the cost, time, and complexity of laboratory work.
- Low prevalence after the first Zika virus epidemic wave in Southeastern Brazil(2018) LUNA, E.; ROMANO, C.; ARAUJO, E.; FELIX, A. C.; NAKASONE, O.; CAMPOS, S.; FERNANDES, L.; LEVI, J. E.; SANTIAGO, N.; FERNANDES, J.; FRAGOSO, D.; KALLAS, E.; PANNUTI, C.