RESUMO
Molecular surveillance is vital for monitoring arboviruses, often employing genus-specific quantitative reverse-transcription polymerase chain reaction (RT-qPCR). Despite this, an overlooked chikungunya fever outbreak occurred in Yunnan province, China, in 2019 and false negatives are commonly encountered during alphaviruses screening practice, highlighting the need for improved detection methods. In this study, we developed an improved alphaviruses-specific RT-qPCR capable of detecting chikungunya virus, eastern equine encephalitis virus, western equine encephalitis virus, Venezuelan equine encephalitis virus, Sindbis virus, Mayaro virus, and Ross River virus with high sensitivity and specificity. The assay identified three chikungunya virus-positive cases out of 188 sera retrospectively. Later genetic characterization suggested that imported cases from neighboring countries may be responsible for the neglected chikungunya fever outbreak of 2019 in Yunnan. Our findings underscore the value of improved alphaviruses-specific RT-qPCR in bolstering alphaviruses surveillance and informing preventive strategies.
Assuntos
Infecções por Alphavirus , Alphavirus , Vírus Chikungunya , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Humanos , Alphavirus/genética , Alphavirus/isolamento & purificação , Infecções por Alphavirus/diagnóstico , Infecções por Alphavirus/virologia , Infecções por Alphavirus/prevenção & controle , Infecções por Alphavirus/epidemiologia , China/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Vírus Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Estudos Retrospectivos , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/prevenção & controle , Febre de Chikungunya/virologia , Febre de Chikungunya/epidemiologia , Vírus da Encefalite Equina do Leste/genética , Surtos de Doenças/prevenção & controle , Sindbis virus/genética , Vírus da Encefalite Equina do Oeste/genética , Ross River virus/genética , Ross River virus/isolamento & purificação , Vírus da Encefalite Equina Venezuelana/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , RNA Viral/genéticaRESUMO
Japanese encephalitis virus (JEV), a member of the Flaviviridae family and a flavivirus, is known to induce acute encephalitis. Vimentin protein has been identified as a potential receptor for JEV, engaging in interactions with the viral membrane protein. The Fc fragment, an integral constituent of immunoglobulins, plays a crucial role in antigen recognition by dendritic cells (DCs) or phagocytes, leading to subsequent antigen presentation, cytotoxicity, or phagocytosis. In this study, we fused the receptor of JEV vimentin with the Fc fragment of IgG and expressed the resulting vimentin-Fc fusion protein in Escherichia coli. Pull-down experiments demonstrated the binding ability of the vimentin-Fc fusion protein to JEV virion in vitro. Additionally, we conducted inhibition assays at the cellular level, revealing the ability of vimentin-Fc protein suppressing JEV replication, it may be a promising passive immunotherapy agent for JEV. These findings pave the way for potential therapeutic strategies against JEV.