Immunogenicity of NS4b dengue 3 virus mimotope presented to the immune system as multiple antigen peptide system

The availability of random peptide libraries displayed on bacteriophage (RPL) has provided a powerful tool for selecting sequences that mimic binding properties of natural antigen epitopes (mimotopes). These mimotopes can be used for vaccine design, drug development, and diagnostic assays. Several mimotopes have been shown to induce production of antibodies against the natural antigen. We have previously identified four dengue virus mimotopes from a phage-displayed peptide library using antidengue 3 human sera. Three of them showed similarity in their amino acid sequences with the NS4b proteins of dengue. Few studies have examined the role of NS4b proteins in the antibody response to dengue virus infection. A multiple antigen peptide (MAP) system was chemically synthesized containing this mimotope (NS4b MAP), and BALB/c mice were immunized to evaluate its immunogenicity. Antipeptide responses were induced and recognised DENV-3 infected cells as determined by immunofluorescence. The high levels of the IgG2a subtype against NS4bMAP suggest the induction of a Th1-like response. Our findings suggest that the NS4b mimotope might be a useful tool for the development of multiepitope diagnostic assays, dengue virus vaccine design, and pathogenesis studies

Epidemiological studies on dengue virus type 3 in Playa municipality, Havana, Cuba, 2001–2002

SummaryObjectivesRecognizing the uniqueness of secondary dengue virus (DENV)-1/3 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases at an interval of 24 years, we sought to estimate DENV infections as well as the ratios between mild disease and DHF/DSS by DENV infection sequence in Playa District (Havana, Cuba) during the 2001–2002 outbreak of dengue virus type 3 (DENV-3).MethodsA retrospective seroepidemiological study was conducted in 2003 in Playa District. Blood samples were collected from a 1% random sample of residents and were studied for the prevalence of dengue neutralizing antibodies.ResultsDENV-3 was found to have infected 7.2% (95% confidence interval (95% CI) 6.0–8.4%) of susceptible individuals (the entire cohort), the majority of whom experienced silent infections. Virtually every individual who had a secondary infection in the sequence DENV-1 then DENV-3 became ill, with a ratio of severe to mild cases of 1:35 (95% CI 1:67–1:23). Secondary infections in the sequence DENV-2/3 were less pathogenic than DENV-1/3. Mild disease accompanying secondary DENV2/3 occurred at a ratio of 1:4.49 infections (95% CI 1:5.77–1:3.42) secondary infections.ConclusionsThe results obtained highlight the role of the infecting serotype and also the sequence of the viral infection in the clinical outcome of a dengue infection

Dengue 3 Epidemic, Havana, 2001

In June 2001, dengue transmission was detected in Havana, Cuba; 12,889 cases were reported. Dengue 3, the etiologic agent of the epidemic, caused the dengue hemorrhagic fever only in adults, with 78 cases and 3 deaths. After intensive vector control efforts, no new cases have been detected

Diagnostic performance of anti-Zika virus IgM, IgAM and IgG ELISAs during co-circulation of Zika, dengue, and chikungunya viruses in Brazil and Venezuela

BACKGROUND: Serological diagnosis of Zika virus (ZIKV) infection is challenging because of the antibody cross-reactivity among flaviviruses. At the same time, the role of Nucleic Acid Testing (NAT) is limited by the low proportion of symptomatic infections and the low average viral load. Here, we compared the diagnostic performance of commercially available IgM, IgAM, and IgG ELISAs in sequential samples during the ZIKV and chikungunya (CHIKV) epidemics and co-circulation of dengue virus (DENV) in Brazil and Venezuela. METHODOLOGY/PRINCIPAL FINDINGS: Acute (day of illness 1-5) and follow-up (day of illness ≥ 6) blood samples were collected from nine hundred and seven symptomatic patients enrolled in a prospective multicenter study of symptomatic patients recruited between June 2012 and August 2016. Acute samples were tested by RT-PCR for ZIKV, DENV, and CHIKV. Acute and follow-up samples were tested for IgM, IgAM, and IgG antibodies to ZIKV using commercially available ELISAs. Among follow-up samples with a RT-PCR confirmed ZIKV infection, anti-ZIKV IgAM sensitivity was 93.5% (43/48), while IgM and IgG exhibited sensitivities of 30.3% (10/35) and 72% (18/25), respectively. An additional 24% (26/109) of ZIKV infections were detected via IgAM seroconversion in ZIKV/DENV/CHIKV RT-PCR negative patients. The specificity of anti-ZIKV IgM was estimated at 93% and that of IgAM at 85%. CONCLUSIONS/SIGNIFICANCE: Our findings exemplify the challenges of the assessment of test performance for ZIKV serological tests in the real-world setting, during co-circulation of DENV, ZIKV, and CHIKV. However, we can also demonstrate that the IgAM immunoassay exhibits superior sensitivity to detect ZIKV RT-PCR confirmed infections compared to IgG and IgM immunoassays. The IgAM assay also proves to be promising for detection of anti-ZIKV seroconversions in sequential samples, both in ZIKV PCR-positive as well as PCR-negative patients, making this a candidate assay for serological monitoring of pregnant women in future ZIKV outbreaks

Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium

Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio

Cinética y capacidad neutralizante de los anticuerpos homólogos y heterólogos contra serotipos de virus dengue en relación con el intervalo entre las infecciones, la secuencia de infección, duración de la viremia y la amplificación dependiente de anticuerpos en infecciones primarias y secundarias

Para sustentar el papel de la infección secundaria en la etiopatogenia del Dengue y Dengue Hemorrágico en epidemias por Dengue 2 y 3 y la influencia de la secuencia de infección e intervalo de tiempo sobre la sensibilización , evaluamos la presencia de anticuerpos específicos contra serotipos, la cinética de anticuerpos neutralizantes en sueros inmunes a Dengue 1 colectados 4 y 20 años después de la primoinfección, la amplificación dependiente de anticuerpos después de 20 años, la capacidad neutralizante de sueros contra 7 cepas de Dengue 3 y la cinética de anticuerpos neutralizantes en relación con la viremia en infectados con virus dengue 3. Se confirma que la infección secundaria fue el factor de riesgo más importante en las epidemias de 1997 y 2001-2002 después de 20-24 años de la primoinfección, donde los serotipos en las secuencias de infección fueron importantes. Los anticuerpos homotípicos a Dengue 1 se incrementaron con la infección secundaria después de 20 años de la primoinfección, sugiriendo que ganan afinidad y pierden actividad heterotípica con el tiempo, mientras los heterotípicos disminuyeron o se mantuvieron bajos. Los mayores títulos de anticuerpos neutralizantes se encontraron frente a la cepa de Dengue 3 aislada al final de la epidemia 2001-2002. La duración de la viremia en la infección primaria en la epidemia 2001-2002 fue mayor que en la secundaria, no detectándose en los primeros anticuerpos neutralizantes durante la fase aguda, mientras que en la infección secundaria los niveles se elevaron después del quinto día, coincidiendo con la caída de la viremia

Cinética y capacidad neutralizante de los anticuerpos homólogos y heterólogos contra serotipos de virus dengue en relación con el intervalo entre las infecciones, la secuencia de infección, duración de la viremia y la amplificación dependiente de anticuerpos en infecciones primarias y secundarias

Para sustentar el papel de la infección secundaria en la etiopatogenia del Dengue y Dengue Hemorrágico en epidemias por Dengue 2 y 3 y la influencia de la secuencia de infección e intervalo de tiempo sobre la sensibilización , evaluamos la presencia de anticuerpos específicos contra serotipos, la cinética de anticuerpos neutralizantes en sueros inmunes a Dengue 1 colectados 4 y 20 años después de la primoinfección, la amplificación dependiente de anticuerpos después de 20 años, la capacidad neutralizante de sueros contra 7 cepas de Dengue 3 y la cinética de anticuerpos neutralizantes en relación con la viremia en infectados con virus dengue 3. Se confirma que la infección secundaria fue el factor de riesgo más importante en las epidemias de 1997 y 2001-2002 después de 20-24 años de la primoinfección, donde los serotipos en las secuencias de infección fueron importantes. Los anticuerpos homotípicos a Dengue 1 se incrementaron con la infección secundaria después de 20 años de la primoinfección, sugiriendo que ganan afinidad y pierden actividad heterotípica con el tiempo, mientras los heterotípicos disminuyeron o se mantuvieron bajos. Los mayores títulos de anticuerpos neutralizantes se encontraron frente a la cepa de Dengue 3 aislada al final de la epidemia 2001-2002. La duración de la viremia en la infección primaria en la epidemia 2001-2002 fue mayor que en la secundaria, no detectándose en los primeros anticuerpos neutralizantes durante la fase aguda, mientras que en la infección secundaria los niveles se elevaron después del quinto día, coincidiendo con la caída de la viremia

Law and Ethics: Controversial Advertisements Related to Body Image

Our creative project focuses on the body image controversies that exist in public relations and advertising. We looked into different controversial advertisements and gave the public the opportunity to voice their opinion to supplement our research into the meso level culture and normalities.Advertisin

Comparison of Rapid Centrifugation Assay with Conventional Tissue Culture Method for Isolation of Dengue 2 Virus in C6/36-HT Cells

A rapid centrifugation assay was compared with conventional tube cell culture for dengue virus isolation in both sera and autopsy samples from dengue and dengue hemorrhagic fever/dengue shock syndrome fatal cases. The rapid centrifugation assay allowed isolation of virus from 16.6% more samples than the conventional method, and it shortened the time for dengue virus detection. Finally, it allowed the isolation of dengue 2 virus in 42.8% of tissue samples from five fatal cases. Our results suggest that the rapid centrifugation assay may be useful for detection of dengue virus in clinical specimens