ABSTRACT
ObjectiveTo investigate the antiviral effect of Menispermi Rhizoma total alkaloids and its relationship with the type Ⅰ interferon （IFN-Ⅰ） signaling pathway. MethodThe effects of Menispermi Rhizoma total alkaloids on the intracellular replication of influenza A virus （H1N1）， vesicular stomatitis virus （VSV）， and cerebral myocarditis virus （EMCV） were detected by fluorescent inverted microscope， flow cytometry， Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and Western blot. A mouse model infected with H1N1 was constructed， and the mice were divided into a control group， H1N1 model group， Menispermi Rhizoma total alkaloids groups （10， 20， 30 mg·kg-1）， and oseltamivir group （40 mg·kg-1）， so as to study the effects on the weight and survival rate of infected mice. Real-time PCR was used to detect the activation effect of Menispermi Rhizoma total alkaloids on the IFN-Ⅰ pathway in cells， and the relationship between the antiviral effect of Menispermi Rhizoma total alkaloids in IFNAR1 knockout A549 cells （IFNAR1-/--A549） and IFN-Ⅰ pathway was detected. ResultCompared with the control group， the virus proliferated significantly in the model group （P<0.01）. Compared with the model group， Menispermi Rhizoma total alkaloids could significantly inhibit the replication of H1N1， VSV， and EMCV in vitro （P<0.01）， inhibit the weight loss of the mice infected with the H1N1 in vivo， and improve the survival rate of mice （P<0.05）. In addition， Menispermi Rhizoma total alkaloids activated the IFN-I pathway and relied on this pathway to exert the function of antiviral infection. ConclusionMenispermi Rhizoma total alkaloids exert antiviral effects in vivo and in vitro by activating the IFN-Ⅰ pathway.
ABSTRACT
The enrichment of therapeutic protein production yield in mammalian cell cultures by modulating mRNA stability is a fairly new strategy in biotechnological applications. Here, we describe the application of 3'-untranslated region (3'UTR) from RNA viral genome to modulate mRNA stability.The data obtained showed that the use of the 3 'UTR sequence of the encephalomyocarditis virus (EMCV 3'UTR) downstream of the target gene was not able to significantly modulate the free energy density indicators of the RNA. However, the sequence influenced the stability of the mRNA (and, therefore, the amount of protein production) in a cell type and time-dependent manner, indicating a central role of mRNA-stabilizing binding sites/cellular factors in this process. Our data might be of interest for the biotechnology community to improve recombinant protein production in mammalian cell cultures and RNA-based therapy/vaccination approaches.
El enriquecimiento de la producción terapéutica de proteínas en cultivos de células de mamíferos mediante la modulación de la estabilidad del ARNm es una estrategia nueva en aplicaciones biotecnológicas. Se describe la aplicación de la región 3'-no traducida (3'UTR) del genoma viral ARN para modular la estabilidad del ARNm. Los datos obtenidos mostraron que el uso de la secuencia 3'UTR del virus de la encefalomiocarditis (EMCV 3'UTR) aguas abajo del gen objetivo no pudo modular significativamente los indicadores de densidad de energía libre del ARN. Sin embargo, la secuencia influyó en la estabilidad del ARNm (y, por lo tanto, en la cantidad de producción de proteínas) dependiente de la célula y del tiempo, lo que indica un papel central de los sitios de unión estabilizadores de ARNm/factores celulares en este proceso. Nuestros datos podrían ser de interés para la comunidad biotecnológica para mejorar la producción de proteínas recombinantes en cultivos de células de mamíferos y en enfoques de terapia/vacunación basados en ARN.
Subject(s)
Biological Products , Recombinant Proteins/biosynthesis , Untranslated Regions , Green Fluorescent Proteins/metabolism , Encephalomyocarditis virus/metabolism , Biotechnology , Genome, Viral , Cell Culture Techniques , RNA Stability , Encephalomyocarditis virus/geneticsABSTRACT
Objective To establish a TaqMan real-time PCR assay for the detection of encephalo-myocarditis virus ( EMCV) .Methods Based on the conservative region of 3D gene of EMCV published in GenBank , a pair of primers and one TaqMan probe were designed and synthesized .Then a TaqMan real-time PCR assay was set up and the reactive system was optimized .The sensitivity and specificity of the assay was evaluated respectively .The TaqMan real-time PCR assay was then carried out to detect 98 randomly selected swine serum samples and the results were compared with those by using ELISA .Results The Ct value of the templates had a good linear relationship with the log starting quantity , with a correlation coefficient of 0.995.The TaqMan real-time PCR assay was only specific for EMCV and its sensitivity was 100 times higher than that of the ordinary PCR .The coincidence rate between the established assay and the ELISA assay was 98.0%in the detection of 98 blood samples.Conclusion The TaqMan real-time PCR assay for the detec-tion of EMCV was successfully established with advantages of high sensitivity and good specificity .It could be used for detection of EMCV and quantitative analysis .
ABSTRACT
Ethanol extracts of eighteen Bignoniaceae species have been evaluated by the MTT assay for cytotoxicity in Vero cells and for antiviral activity against Human herpes virus type 1, Vaccinia virus and murine Encephalomyocarditis virus. Among such species, seven are reported to be of traditional medicinal use No cytotoxicity was observed for most of the extracts up to the concentration of 500 μg/mL. Fourteen (50 percent) of the 28 extracts assayed have disclosed antiviral activity with EC50 values in the range of 4.6+0.3 to 377.2+17.7 μg/mL. Only two species, Arrabidaea samydoides and Callichlamys latifolia, have shown activity against all the three viruses. The extracts were chemically characterized by their TLC and HPLC-DAD profiles. Mangiferin is the major constituent of A. samydoides but the isolated compound has been less active than the crude extract. This is the first report on the antiviral evaluation of the eighteen Bignoniaceae species assayed.
Extratos etanólicos de dezoito espécies vegetais pertencentes à família Bignoniaceae, das quais sete são descritas como de uso medicinal, foram avaliados, pelo ensaio colorimétrico do MTT, para atividades citotóxica, em células Vero, e antiviral, frente aos vírus herpes simplex-tipo 1, vaccinia e encefalomiocardite murina. A maior parte dos extratos não apresentou citotoxicidade até a concentração de 500 μg/mL. Dos 28 extratos testados quatorze (50 por cento) apresentaram atividade antiviral com valores de CE50 na faixa de 4,6+03 a 377,2+17,7 μg/mL. Somente duas espécies, Arrabidaea samydoides e Callichlamys latifolia, foram ativas frente aos três vírus. Os extratos foram caracterizados pelos seus perfís cromatográficos em CCD e CLAE-FR. Análises por CLAE-FR mostraram que a mangiferina é o constituinte majoritário em A. samydoides mas a substância isolada foi menos ativa do que o extrato bruto. Esta é a primeira vez que se relata a atividade antiviral de extratos das dezoito espécies avaliadas.
ABSTRACT
In order to survey the prevalence of encephalomyocarditis virus (EMCV) infection in pigs in Hebei Province from 2006 to 2008,a total of 1306 swine serum from 31 farms in 10 regions in Hebei were tested for antibodies against EMCV nonstructural protein 2C by ELISA.Positive rates of antibodies in different regions and different age groups were analyzed.The results showed that antibodies against EMCV 2C were found in 176 out of 1306 serum samples collected from Hebei Province and the total positive rate was 13.48%.Seroprevalence of EMCV infection appeared in six out of ten surveyed regions and the highest positive rate was 26%.There was significant difference of seroprevalence in EMCV infection between breeder sows and other swine species.This survey indicated that EMCV infection has occurred in pig farms in most regions of Hebei Province and EMCV-carried breeder sows were one of the crucial causes for EMCV infection and prevalence.
ABSTRACT
Objective:To express the EMCV 3AB gene by prokaryotic expression systerm,and prepare monoclonal antibodies against it. Method: NSP 3AB gene of Encephalomyocarditis virus (EMCV) was amplified and cloned into a prokaryotic expression vector pGEX-6P-1 and a recombinant protein 3AB with high antigenicity was expressed in E.coli. Balb / c mice were immunized by purified recombinant 3AB protein of inclusion-body, and the splenocytes of the immunized mice were fused with murine myeloma cells to produce hybridoma cell line. Results: After subcloning by 3 times, one strain of hybridoma cell line steadily secreting antibodies of 3AB protein was obtained, named 2D12. The McAb belongs to IgG1/?. The McAb and was confirmed by indirect immunofluorescent assay (IFA) and Western blot. Conclusion: These results can provide a potential value for structural and functional studies of EMCV-3AB and early diagnosis of Encephalomyocarditis virus infection.