Serological Evidence of Japanese Encephalitis Virus Circulation in Asian Children From Dengue-Endemic Countries

Nealon, Joshua; Taurel, Anne Frieda; Yoksan, Sutee; Moureau, Annick; Bonaparte, Matt; Quang, Luong Chan; Capeding, María Rosario; Prayitno, Ari; Hadinegoro, Sri Rezeki; Chansinghakul, Danaya; Bouckenooghe, Alain

doi:10.1093/infdis/jiy513

Cited by 17 publications

(18 citation statements)

References 29 publications

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“…Both CD8+ and CD4+ T cells have been shown to play an important role in protection against DENV, JEV and Zika virus (5,(9)(10)(11)(12). Individuals who were naturally exposed to JEV were shown to have antibody and T cell responses, that showed high cross-reactivity with DENV (5,13). In our previous studies we showed that T cell responses of 20-30% of individuals who were naturally infected with DENV were cross-reactive with JEV (14).…”

Section: Introductionmentioning

confidence: 95%

“…This would be important especially in order to understand how sequential infection with different flaviviruses or immune responses induced by vaccination against JEV, would subsequently influence the disease outcome when naturally infected or vaccinated with DENV. It was recently shown that infection with JEV was far commoner than previously thought in DENV endemic countries and interpretation of natural infection with JEV was difficult especially following secondary dengue infections, due to the presence of more cross-reactive heterotypic antibodies (13). Therefore, as an initial step it would be important to identify T cell epitopes that are specific to JEV and do not cross-react with DENV in order to identify individuals who have had natural JEV infection, and also to further investigate T cell responses to JEV, independent of DENV-specific T cell responses.…”

Section: Introductionmentioning

confidence: 99%

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Identification of Immune Responses to Japanese Encephalitis Virus Specific T Cell Epitopes

Pushpakumara

Jeewandara

Wijesinghe

et al. 2020

Front. Public Health

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Background: Due to the similarity between the dengue (DENV) and the Japanese encephalitis virus (JEV) there is potential for immune cross-reaction. We sought to identify T cell epitopes that are specific to JEV and do not cross react with DENV.Methodology: 20mer peptides were synthesized from regions which showed >90% conservation. Using IFNγ cultured ELISpot assays, we investigated JEV-specific T cell responses in DENV − and JEV − non-immune individuals (DENV − JEV − = 21), JEV seronegative and had not received the JE vaccine, but who were DENV seropositive (DENV + JEV − = 22), JEV + (seropositive for JEV and had received the JE vaccine), but seronegative for DENV (DENV − JEV + = 23). We further assessed the responses to these peptides by undertaking ex vivo IFNγ assays and flow cytometry.Results: None of DENV − JEV − individuals responded to any of the 20 JEV-specific peptides. High frequency of responses was seen to 6/20 peptides by individuals who were JEV + but DENV − , where over 75% of the individuals responded to at least one peptide. P34 was the most immunogenic peptide, recognized by 20/23 (86.9%) individuals who were DENV − JEV + , followed by peptide 3 and peptide 7 recognized by 19/23 (82.6%). Peptide 34 from the NS2a region, showed <25% homology with any flaviviruses, and <20% homology with any DENV serotype. Peptide 20 and 32, which were also from the non-structural protein regions, showed <25% homology with DENV. Ex vivo responses to these peptides were less frequent, with only 40% of individuals responding to peptide 34 and 16-28% to other peptides, probably as 5/6 peptides were recognized by CD4+ T cells.Discussion: We identified six highly conserved, T cell epitopes which are highly specific for JEV, in the Sri Lankan population. Since both JEV and DENV co-circulate in the same regions and since both JE and dengue vaccines are likely to be co-administered in the same geographical regions in future, these JEV-specific T cell epitopes would be useful to study JEV-specific T cell responses, in order to further understand how DENV and JEV-specific cellular immune responses influence each other.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Identification of Immune Responses to Japanese Encephalitis Virus Specific T Cell Epitopes

Pushpakumara

Jeewandara

Wijesinghe

et al. 2020

Front. Public Health

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“…Four studies reported on the seroprevalence of JE in the country (13)(14)(15)(16)(17). These studies included baseline serologic assessments performed in clinical trials on vaccines for flavivirus (i.e., JE and dengue).…”

Section: Seroprevalence Studiesmentioning

confidence: 99%

Epidemiology of Japanese encephalitis in the Philippines prior to routine immunization

Lopez

Raguindin

Aldaba

et al. 2021

International Journal of Infectious Diseases

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This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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“…Vietnam is located in the tropics of Southeast Asia, and several mosquito-borne diseases are endemic, including Japanese encephalitis [ 1 ], dengue fever [ 2 ], and Zika [ 3 ]. Culex species are considered to be important vectors of Japanese encephalitis virus (JEV), including Culex quinquefasciatus Say (Diptera: Culicidae) [ 4 ], but other mosquito genera may also serve as competent vectors of the virus [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

Essential Oils of Zingiber Species from Vietnam: Chemical Compositions and Biological Activities

Hương

Chung

Hương

et al. 2020

Plants

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Mosquito-borne diseases are a large problem in Vietnam as elsewhere. Due to environmental concerns regarding the use of synthetic insecticides as well as developing insecticidal resistance, there is a need for environmentally-benign alternative mosquito control agents. In addition, resistance of pathogenic microorganisms to antibiotics is an increasing problem. As part of a program to identify essential oils as alternative larvicidal and antimicrobial agents, the leaf, stem, and rhizome essential oils of several Zingiber species, obtained from wild-growing specimens in northern Vietnam, were acquired by hydrodistillation and investigated using gas chromatography. The mosquito larvicidal activities of the essential oils were assessed against Culex quinquefasciatus, Aedes albopictus, and Ae. aegypti, and for antibacterial activity against a selection of Gram-positive and Gram-negative bacteria, and for activity against Candida albicans. Zingiber essential oils rich in α-pinene and β-pinene showed the best larvicidal activity. Zingiber nudicarpum rhizome essential oil showed excellent antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, with minimum inhibitory concentrations (MIC) of 2, 8, and 1 μg/mL, respectively. However, the major components, α-pinene and β-pinene, cannot explain the antibacterial activities obtained.

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Serological Evidence of Japanese Encephalitis Virus Circulation in Asian Children From Dengue-Endemic Countries

Cited by 17 publications

References 29 publications

Identification of Immune Responses to Japanese Encephalitis Virus Specific T Cell Epitopes

Identification of Immune Responses to Japanese Encephalitis Virus Specific T Cell Epitopes

Epidemiology of Japanese encephalitis in the Philippines prior to routine immunization

Essential Oils of Zingiber Species from Vietnam: Chemical Compositions and Biological Activities

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