Interacción in silico de las moléculas Agatisflavona, Amentoflavona y Punicalina con la Importina α 1 humana / In silico interaction of Agathisflavone, Amentoflavone and Punicalin molecules with human Importin α1

RESUMEN Varios virus con genoma de ARN en fases iniciales de la infección realizan la translocación de proteínas al interior del núcleo de la célula hospedera mediante la vía de las importinas α1. Este transporte es fundamental para el éxito de la replicación viral y se ha convertido en un blanco para la búsqueda y desarrollo de nuevos antivirales. El objetivo de este estudio fue determinar y caracterizar interacciones entre la Agatisflavona, Amentoflavona, Punicalina con el sitio mayor de unión de las Importinas α1 humanas mediante el análisis in silico del acoplamiento molecular y simulaciones de dinámica molecular. Las pruebas de acoplamiento molecular se realizaron entre estos fitoconstituyentes y la estructura de la importina α1 humana. Las afinidades de interacción fueron detectadas con la Agatisflavona, Amentoflavona y Punicalina (ΔG b = -8,8, -9,1 y -8,8 kcal.mol-1 respectivamente), con afinidades de interacción específicamente a los dominios ARM2-ARM5 (sitio mayor de unión) de las importinas α1. Las simulaciones de dinámica molecular revelaron interacciones significativamente favorables (P<0,001) con los ligandos Agatisflavona y Amentoflavona (ΔG b = -18,60±0,35 y -22,55±2,41 kcal.mol-1) mientras que la Punicalina registró mayores valores de energía de interacción (ΔG b = -5,33±1,72 kcal.mol-1). Los hallazgos obtenidos en este estudio computacional sugieren que las moléculas Agatisflavona y Amentoflavona presentan interacciones favorables con el sitio mayor de unión de las Importinas α1, en comparación a lo registrado con la Punicalina, sin embargo, se recomienda realizar ensayos in vitro a modo de confirmar estas observaciones.

ABSTRACT Several RNA-viruses during early stages of infection perform the translocation of proteins into the nucleus of host cell by the importin α1 pathway. This transport is essential for viral replication success and has become a target to search and development new antivirals. The objective of this study was to determine and characterize interactions between Agathisflavone, Amentoflavone and Punicalin with the major binding site of human importins α1 by in silico analysis of molecular docking and molecular dynamics simulations. Molecular docking tests were performed between these phytoconstituents and the structure of human importin α1. Interaction's affinity was detected with the Agathisflavone, Amentoflavone and Punicalin (ΔG b = -8.8, -9.1 and -8.8 kcal.mol-1 respectively), with binding affinity to ARM 2-ARM 5 domains (major binding site) of importins α1. Molecular dynamics simulations revealed significantly favorable interactions (P<0.001) with the ligands Agatisflavone and Amentoflavone (ΔG b = -18.60 ± 0.35 and -22.55 ± 2.41 kcal.mol-1) meanwhile Punicalin showed higher values of interaction free energy (ΔG b = -5.33 ± 1.72 kcal.mol-1). The findings obtained suggest that Agathisflavone and Amentoflavone could favorably interact to the major binding site of Importins α1 compared to that registered with Punicalin, however, it is recommended to perform in vitro assays to confirm these observations.

Caracterización y fisiopatología del Sars-Cov-2, Revisión de la literatura actual / Characterization and pathophysiology of sars-cov-2, actual literature review

RESUMEN La enfermedad por coronavirus 2019 (COVID-19) es causada por un nuevo betacoronavirus conocido como síndrome respiratorio agudo severo coronavirus-2 (SARS-CoV-2). Para el 22 de junio del 2021, el número de casos confirmados en todo el mundo había superado los 178 millones, con más de 3 millones de muertes. La fisiopatología de la COVID-19 a partir de la infección por SARS-CoV-2 no está del todo dilucidada. En el presente artículo se exponen los hallazgos encontrados después de la búsqueda en la literatura científica realizada en la base de datos PubMed entre octubre de 2020 y abril de 2021 en la cual se incluyeron 71 artículos, con el objetivo de la revisión fisiopatológica completa, detallada y actualizada del SARS-CoV-2, abordando temas como la caracterización y ciclo de vida del virus, el mecanismo de transmisión, la cinética viral y la respuesta inmune, junto con la dinámica fisiopatológica de la infección. MÉD.UIS.2021;34(2): 61-75.

ABSTRACT Coronavirus disease 2019 (COVID-19) is caused by a new betacoronavirus named as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). On June 22nd, 2021, the number of confirmed cases worldwide exceeded 178 million, resulting in more than 3 million deaths. The pathophysiology of COVID-19 from the infection of SARS-CoV-2 is not entirely elucidated. This review presents the findings after the research in the scientific literature carried out in the PubMed database between October 2020 and April 2021, in which 71 articles were included, with the aim of a complete, detailed and updated pathophysiological review of SARS-CoV-2, addressing issues such as the characterization and life cycle of the virus, the transmission mechanism, viral kinetics and immune response, along with the pathophysiological dynamics of the infection. MÉD.UIS.2021;34(2): 61-75.

Research advances in hepatitis B virus and ubiquitination of related proteins / 临床肝胆病杂志

Protein ubiquitination is widely observed in cells and is a modification after protein translation. Hepatitis B virus (HBV) and ubiquitination of related proteins have attracted more and more attention. This article reviews HBV and the ubiquitination of related proteins, so as to provide a reference for further research on the regulation of HBV replication and the ubiquitination of related proteins, as well as new ideas and methods for curing chronic HBV infection.

Vacunas para SARS-CoV-2: diferentes estrategias de los desarrollos en curso / Vaccines for SARS-CoV-2: different strategies of ongoing developments

El objetivo de este artículo es proporcionar una guía que sirva para la interpretación y seguimiento de los esfuerzos que se están desarrollando en todo el mundo con el objetivo de obtener una vacuna que pueda generar inmunidad contra el nuevo coronavirus SARS-CoV-2 de 2019, el agente causante de la enfermedad por coronavirus denominada COVID-19. Cinco meses después de haber sido detectada la enfermedad, ya hay 102 vacunas en distintos estadios de desarrollo, registradas por la Organización Mundial de la Salud (OMS), correspondientes a 8 plataformas vacunales con diferentes estrategias, y todos los días aparecen nuevas. Esto representará un enorme desafío de organismos internacionales, para la evaluación, comparación y selección de aquellas que cumplan con los criterios regulatorios indispensables de seguridad y eficacia y que, por otro lado, puedan ser producidas en cantidades suficientes para abastecer la demanda mundial. (AU)

The objective of this article is to provide a guide to help the interpretation and monitoring the efforts that are being carried out worldwide to obtain a vaccine that will be able to generate immunity against the new 2019 SARS-CoV-2 coronavirus, the viral agent causes the disease named COVID-19. Five months after the disease was detected, there are already 102 vaccines at different stages of development, registered by World Health Organization (WHO), corresponding to 8 vaccination platforms base on different strategies, and every day new ones appear. This will represent a huge challenge for international organizations, to evaluate, compare and selects those that will meet the essential regulatory criteria of safety and efficacy and that, would be able to be produced in enough quantities to supply the worldwide demand. Key words: SARS-Cov-2 vaccine, vaccine platform, COVID-19 strategy, attenuated virus, viral vector, viral proteins, viral DNA, viral RNA, nucleic acids, viral like particles, WHO. (AU)

Clinical impact & pathogenic mechanisms of human parvovirus B19: A multiorgan disease inflictor incognito

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.

Revisión sistemática: estrategias virales para la inducción de cáncer "virus de Epstein-Barr: latencia y mecanismos asociados a la oncogénesis viral" / Viral strategies for cancer induction "Epstein-Barr virus: latency and mechanisms associated with viral oncogenesis"

Resumen La infección crónica con virus oncogénicos es responsable de aproximadamente el 20% de todos los cánceres reportados en humanos, este proceso de oncogénesis viral presenta una naturaleza compleja, multietapa y multifactorial. Un ejemplo de ello es el Virus de Epstein- Barr (EBV), un herpesvirus que infecta de manera latente a más del 90% de la población. Aunque la infección a menudo cursa de manera asintomática, el EBV es capaz de modificar su expresión genómica estableciendo diferentes fases de latencia, alterando así el metabolismo de sus células blanco, como son los linfocitos B y las células epiteliales, proceso que resulta determinante en la aparición y desarrollo de diferentes patologías que van desde la mononucleosis infecciosa hasta procesos oncológicos como el linfoma de Burkitt, el cáncer gástrico o el cáncer nasofaríngeo.

Abstract Chronic infection with oncogenic viruses is responsible for approximately 20% of all cancers worldwide in humans, this viral transformation represents a complex, multistage and multifactorial process. An example is the Epstein-Barr virus (EBV), a herpesvirus that latently infects over 90% of the population. Although the infection often courses asymptomatically, EBV is able to modify its genomic expression by establishing different latency phases, thus altering the B lymphocytes and epithelial cells metabolism, a determinant process in the appearance and development of different pathologies ranging from infectious mononucleosis to oncological processes such as Burkitt's lymphoma, gastric cancer and nasopharyngeal cancer.

Characterisation of a rare, reassortant human G10P[14] rotavirus strain detected in Honduras

BACKGROUND Although first detected in animals, the rare rotavirus strain G10P[14] has been sporadically detected in humans in Slovenia, Thailand, United Kingdom and Australia among other countries. Earlier studies suggest that the strains found in humans resulted from interspecies transmission and reassortment between human and bovine rotavirus strains. OBJECTIVES In this study, a G10P[14] rotavirus genotype detected in a human stool sample in Honduras during the 2010-2011 rotavirus season, from an unvaccinated 30-month old boy who reported at the hospital with severe diarrhea and vomiting, was characterised to determine the possible evolutionary origin of the rare strain. METHODS For the sample detected as G10P[14], 10% suspension was prepared and used for RNA extraction and sequence independent amplification. The amplicons were sequenced by next-generation sequencing using the Illumina MiSeq 150 paired end method. The sequence reads were analysed using CLC Genomics Workbench 6.0 and phylogenetic trees were constructed using PhyML version 3.0. FINDINGS The next generation sequencing and phylogenetic analyses of the 11-segmented genome of the G10P[14] strain allowed classification as G10-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3. Six of the genes (VP1, VP2, VP3, VP6, NSP2 and NSP4) were DS-1-like. NSP1 and NSP5 were AU-1-like and NSP3 was T6, which suggests that multiple reassortment events occurred in the evolution of the strain. The phylogenetic analyses and genetic distance calculations showed that the VP7, VP4, VP6, VP1, VP3, NSP1, NSP3 and NSP4 genes clustered predominantly with bovine strains. NSP2 and VP2 genes were most closely related to simian and human strains, respectively, and NSP5 was most closely related to a rhesus strain. MAIN CONCLUSIONS The genetic characterisation of the G10P[14] strain from Honduras suggests that its genome resulted from multiple reassortment events which were possibly mediated through interspecies transmissions.

Factores solubles con actividad antiviral: en búsqueda de nuevos blancos terapéuticos para la infección por el VIH-1 / Soluble factors with antiviral activity: searching for new therapeutic targets to HIV-1 infection / Fatores solúveis com atividade antiviral: em busca de novos alvos terapêuticos para a infecção pelo HIV-1

Los mecanismos innatos antivirales han resultado de gran interés debido a su uso potencial para la prevención y tratamiento de la infección por el VIH. En particular, los factores solubles antivirales han sido objeto de múltiples investigaciones por su capacidad de inhibir diferentes pasos del ciclo replicativo viral y de potenciar la respuesta inmune del hospedero. Entre estos factores solubles se destacan TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 y SLPI, que actúan directamente sobre la partícula viral o la célula, o promueven la producción de moléculas involucradas en la respuesta inmune contra el virus. Algunos de ellos se han correlacionado con un bajo riesgo de adquirir la infección por el VIH o con una lenta progresión a sida. La exploración de los mecanismos antivirales de estas proteínas es requisito para el desarrollo de nuevas alternativas terapéuticas.

Antiviral innate mechanisms have a potential use in developing preventive and therapeutic strategies against HIV. Specifically, antiviral soluble factors have been evaluated in multiple investigations, based on their capacity to inhibit different steps of the viral cycle, and to increase the host immune response. Among these factors, TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 and SLPI are of particular interest, as they can act directly on the viral particle or the cell, or promote the production of molecules related to the viral immune response. Some of these factors have been associated with a low risk of HIV infection or slow progression to AIDS. Evaluation of mechanisms exhibited by antiviral proteins is a requirement for developing new therapeutic alternatives.

Os mecanismos inatos antivirais resultaram de grande interesse devido a seu uso potencial para a prevenção e tratamento da infecção pelo HIV. Em particular, os fatores solúveis antivirais foram objeto de múltiplas pesquisas por sua capacidade de inibir diferentes passos do ciclo replicativo viral e de potenciar a resposta imune do hospedeiro. Entre estes fatores solúveis se destacam TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 e SLPI, que atuam diretamente sobre a partícula viral ou a célula, ou promovem a produção de moléculas envolvidas na resposta imune contra o vírus. Alguns deles se correlacionaram com um baixo risco de adquirir a infecção pelo HIV ou com uma lenta progressão a aids. A exploração dos mecanismos antivirais destas proteínas é requisito para o desenvolvimento de novas alternativas terapêuticas.

MOLECULAR VARIABILITY OF THREE GENES OF POTATO VEIN YELLOW VIRUS INFECTING Solanum tuberosum, USING SINGLE STRAND CONFORMATIONAL POLYMORPHISM / Variabilidad molecular de tres genes del virus del amarillamiento de las venas de la hoja de la papa que infecta Solanum tuberosum, mediante la técnica de polimorfismo conformacional de cadena sencilla

Potato yellow vein virus (PYVV), a virus with tripartite RNA (ss+) genome is classified as member of the genus Crinivirus within the family Closteoviridae. PYVV is the causal agent of potato yellow vein disease (PYVD) with yield loss between 25 %-50 % in field. Single strand conformational polymorphism (SSCP) has been reported to estimate variability in different viruses' species. In this study, the molecular variability of PYVV analyzed by SSCP patterns of three genes: major capsid protein (CP), minor capsid protein (CPm), and heat shock protein (Hsp70) obtained from 60 virus isolates from potato plants expressing PYVD. Leaves collected in Nariño, Colombia from 30 Solanum tuberosum Phureja Group (PhG) and 30 from the Andigena Group (AG). Genes amplified by RT-PCR and the purified PCR products used for SSCP. Three SSCP patterns detected for the CP gene, 12 for CPm and 12 for Hsp70. The pattern C was the most frequent for the Hsp70 gene and the pattern IV (33.3 %) for CPm gene in the Andigena Group. The pattern 1 for CP gene was present in 93.3 % of both host groups, indicating low number of variants compared to the CPm and Hsp70 genes. This is the first attempt to estimate intra e inter PYVV variability by the use of a simple molecular method considering three genes in a large group of potato samples affected by PYVD. SSCP technique was useful to evaluate the viral variability.

Potato yellow vein virus o virus del amarillamiento de venas de la hoja de la papa (PYVV) es un virus RNA tripartito (ss+) de la familia Closteroviridae género Crinivirus que causa la enfermedad de amarillamiento de nervaduras de la hoja de papa (PYVD) reduciendo la productividad, entre el 25 % y 50 %. La técnica de polimorfismo conformacional de cadena sencilla (SSCP) ha sido usada para estimar la variabilidad en diferentes especies de virus. En el presente trabajo se analizó la variabilidad molecular de 60 aislados de PYVV a partir de la comparación de tres genes: el gen de la proteína mayor de la cápside (CP), proteína menor de la cápside (CPm) y la proteína de choque térmico (Hsp70). Los aislados se obtuvieron de dos grupos de Solanum tuberosum: 30 del Grupo Phureja (GPh) y 30 del Grupo Andígena (GA), provenientes del departamento de Nariño, Colombia. Los genes se amplificaron por RT-PCR y los productos purificados se emplearon para SSCP en geles de poliacrilamida. Se detectaron tres perfiles de SSCP para el gen CP, 12 para el CPm y 12 para el Hsp70. Para el GA el perfil más frecuente del gen Hsp70 fue el perfil C (66,6 %) y para el gen CPm fue el IV (33,3 %). Para el gen CP, el patrón uno se encontró en el 93,3 % de los aislados, indicando menor variabilidad. Esta es la primera estimación de variabilidad de PYVV en diferentes genes y a través de una técnica molecular simple.

Hepatitis B virus preS2 activates human acyl protein thioesterase 1 promoter / 重庆医学

Objective To investigate the trans‐regulative effect of hepatitis B virus (HBV) preS2 on the promoter of human acyl protein thioesterase 1 (APT1) gene .Methods The promoter sequence of human APT1 gene was identified applying the soft‐ware of bioinformatics .The APT1 promoter and HBV preS2 gene were amplified with PCR and cloned into pGL3 and pcDNA3 .1 (-) plasmids to construct the luciferase reporter gene plasmid of human APT1 gene promoter pGL3‐APT1 and the preS2 eukary‐otic expression plasmid pcDNA3 .1(-)‐preS2 ,respectively .The effect of the preS2 on the human APT1 gene promoter was exam‐ined by cotransfecting hepatocellular carcinoma cell HepG2 with pGL3‐APT1 and pcDNA3 .1(-)‐preS2 and measuring luciferase activities of the HepG2 cells .The statistical data were analyzed with independent‐samples t test .Results Both plasmids of pGL3‐APT1 and pcDNA3 .1(-)‐preS2 were confirmed by DNA sequencing to be accurately constructed as design .The luciferase activity of the pGL3‐APT1 was 1 .2 times (P<0 .01) that of the positive control plasmid pGL3‐Control .And the luciferase activity of the HepG2 cells cotransfected with pcDNA3 .1(-)‐preS2 and pGL3‐APT1 was 2 .6 times (P<0 .01) that of the HepG2 cells cotrans‐fected with the plasmid without preS2 gene pcDNA3 .1(-) and pGL3‐APT1 .Conclusion The human APT1 promoter cloned in the study has high promoter activity ;HBV preS2 activates human APT1 promoter .

The molecular epidemiology of a local dengue fever outbreak in Shenzhen / 中华传染病杂志

Objective To determine the pathogen of a local dengue fever outbreak in Shenzhen city in 2010,and to analyze the molecular characteristics of the epidemic dengue virus strain as well as explore the possible origin.Methods The serum samples collected from the suspect dengue fever cases were detected for IgM, IgG by enzyme-linked immunosorbent assay ( ELISA ),immunochromatography and dengue virus nucleic acid by real-time polymerase chain reaction (PCR).Serum samples from patients with early stage dengue fever were used to isolate virus with C6/36 and BHK-21 cell lines.The type of isolated virus strain was determined by RT-semi-nested-PCR and realtime PCR.E gene of isolated virus strain was amplified by RT-PCR and sequenced.Homology and phylogenetic tree of E gene of Shenzhen dengue virus with the strains isolated from other areas were constructed.Results IgM,IgG and RNA of type 1 dengue virus were detected in serum samples from dengue fever suspected patients.Type 1 dengue virus named DEV1-SZ1029 was successfully isolated from the serum sample.The homology of nucleotide sequence of E gene of SZ1029 strain with standard type 1 dengue virus HAWAII 45,Fj231/04,GD14/97 and GD05/99 were 94.8％,99.6％,97.7％ and 98.5 ％,respectively.The phylogenetic tree indicated that SZ1029 had the greatest similarity with the D1/Malaysia/36000/05 strain,SG(EHI)DED142808 strain and Fj231/04 strain and they lied in the same branch of the phylogenetic tree.The isolated dengue virus type 1 belonged to genetype Ⅰ with GZ/80,Taiwan87,All patients lived in a certain construction site in Shenzhen and had no recent travel history outside the area in one month before infection.Conclusions The virological,serological and molecular features all identify that the local dengue fever outbreak in Shenzhen in 2010 is caused by type 1 dengue virus and SZ1029 strain may be transferred from Southeast Asian region,and there may be a plague focus in Shenzhen.

Evaluation of immunogenic potential of 75kDa and 56kDa proteins of newcastle disease virus (NDV).

The R2B strain of virus of new castle disease virus (NDV) was propagated in 9-11 day old embryonated chicken eggs via allantoic cavity route and after seven serial passages virus was purified from allantoic fluid. Purified virus was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis which yielded six major polypeptides ranging from 38-200 kDa. Protein fractions, corresponding to 75 and 56kDa, resembling haemagglutinin-neuraminidase (HN) and fusion (F) proteins were used to ascertain their immunization potential. Immunization of viral proteins was compared with the whole virus vaccine. Among different group of birds, highest haemagglutination inhibition (HI) and enzyme linked immunosorbent assay (ELISA) titers were obtained in birds immunized with whole virus vaccine followed by viral proteins, 75 and 56kDa in combination which was comparable with birds immunized with 56kDa protein alone. Despite lower values of HI and ELISA titers elicited by viral subunits in immunized birds, when challenged with virulent NDV strain, protection accorded by viral proteins in combination (75 +56kDa) or 56kDa alone was comparable with whole virus vaccine.

Bioinformatics analysis of the structure and function of enterovirus 71 VP1 gene and protein / 中华传染病杂志

Objective To understand the structures and functions of enterovirus 71 (EV71)VP1 gene and its encoded protein using bioinformatics method, so as to direct studies of its biological function. Methods VP1 gene and its encoded protein of EV71 2008-GZCH07 strain and other representative EV71 strains were analyzed by online analysis at bioinformatics websites and software packages. Multi-sequence homological alignment and phylogenetic analysis were performed.Physicochemical characteristics, secondary structure, homology modeling of tertiary structure,enzymological characteristics, antigenic epitope of VP1 gene encoded protein were predicted. Results The homology of EV71 2008-GZCH07 strain was highest (97% and 98%) with ZJ001 strain, and lowest with human coxsackievirus A16. The homology of EV71 2008-GZCH07 strain and EV71 types A,B,C was 86%-98%. Phylogenetic analysis demonstrated that 2008-GZCH07 stain was close to ZJ001 and BJ08-Z025-5 stains, which belonged to C4 subtype. In VP1 encoded proteins of EV71 types A,B,C, the relationship between 2008-GZCH07 and EV71-B, EV71-C was closer than EV71-A.The whole length of VP1 gene was 510 bp, with open reading frame (ORF) located at 116-510 bp region,and it encoded 132 amino acids with isoelectric point of 4.39.The protein was rich of a-helix and random coilon without transmembrane regions, and contained 5 high hydrophobic regions and belonged to extracellular protein. The homology modeling of tertiary structure showed that the region was on the surface of protein and formed a binding loop. There was 5 antigen epitopes. And 7 key catalytic sites were located at or close to the loop. Conclusions EV71-VP1 encoded protein contains many phosphorylation sites, with many biological function sites and antigenic epitope regions, which might be a potential target antigen for immunodiagnosis, anti-schistosome drug and vaccine development, and would be basis of further study of diagnosis, treatment and prevention of EV71 infection.

Study on glycoprotein gene sequences of nine rabies virus isolates in Henan Province / 中华传染病杂志

Objective To understand the nucleotide and amino acid differences of glycoprotein gene (G gene) between isolated rabies viruses in Henan Province and rabies vaccine strains used for human and animals. Methods G gene sequences of nine rabies viruses isolated from dogs in Xinyang city of Henan Province in December 2006 were amplified by reverse transcriptase (RT)-heminestedpolymerase chain reaction (PCR), and then were cloned and sequenced. The phylogenetic trees were constructed for analyzing the genetic characteristics of these rabies viruses. Results The homology of G gene among the nine isolates from Henan Province was 97.6% - 98.9% at nucleotide level and 99.2%-99.8% at amino acid level. The similarities between these isolates and CTN vaccine strain were 85.6%-93.0% and 91.9%-92.9% at nucleotide and amino acid level, respectively, which were higher than those between these isolates and other vaccine strains (80.4% - 83.3% and 87.7% - 92.5% at nucleotide and amino acid level, respectively). The nine isolates had several amino acid substitutions when compared to other genotype 1 rabies virus strains. Conclusions The nine rabies viruses strains isolated from Henan Province all belong to genotype 1. CTN may be an effective vaccine for preventing rabies in Henan Province.

Expression of Hepatitis B Virus X Protein in Hepatocytes Suppresses CD8+ T Cell Activity

BACKGROUND: CD8+ T cells contribute to the clearance of Hepatitis B virus (HBV) infection and an insufficient CD8+ T cell response may be one of the major factors leading to chronic HBV infection. Since the HBx antigen of HBV can up-regulate cellular expression of several immunomodulatory molecules, we hypothesized that HBx expression in hepatocytes might affect CD8+ T cell activity. METHODS: We analyzed the activation and apoptosis of CD8+ T cells co-cultured with primary hepatocytes rendered capable of expressing HBx by recombinant baculovirus infection. RESULTS: Expression of HBx in hepatocytes induced low production of interferon-gamma and apoptosis of CD8+ T cells, with no effect on CD8 T cell proliferation. However, transcriptional levels of H-2K, ICAM-1 and PD-1 ligand did not correlate with HBx expression in hepatocytes. CONCLUSION: Our results suggest that HBx may inhibit CD8+ T cell response by regulation of interferon-gamma production and apoptosis.

Expression and purification of JC virus VP2 fusion protein and preparation of its polyclonal antibody / 中华传染病杂志

Objective To obtain the antigen and antibody of JC virus(JCV)VP2.Methods The JCV VP2 gene were amplified from a cerebrospinal fluid sample by polymerase chain reaction (PCR)and confirmed by sequencing.Then,the gene was cloned into plasmid pET32a(+)to construct recombinant prokaryotic expression vector pET-32a(+)-VP2.The recombinant plasmid was transformed into the competent E.coli BL21.Induced with isopropyl-β-D-1-1 thiogalactopyranoside (IPTG),E.coli BL21 were subsequently crushed by ultrasound.The gene expression in the supernatant was analyzed by Western blot.Thereafter,the expressed protein was purified by isoeleetric point method.The polyclonal antibody against JCV VP2 protein was obtained from the BALB/c mouse immunized with the purified protein.Results The VP2 fusion protein was expressed in the E.coli BL21.The recombinant fusion protein was expressed by IPTG induetion with relative molecular mass of 58.5×10~3.Sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDSPAGE)analysis showed that the expression level was highter after 6-10 h of IPTG induction.The recombinant protein had good antigenicity which was confirmed by BALB/c mice immunized with the protein.Conclusions The successful expression and purification of VP2 fusion protein and the antibody will be valuable for the study on the biological function of VP2 and JCV epidemiologieal investigation.

The Nucleocytoplasmic Transport of Viral Proteins / 中国病毒学·英文版

Molecules can enter the nucleus by passive diffusion or active transport mechanisms, depending on their size. Small molecules up to size of 50-60 kDa or less than 10 nm in diameter can diffuse passively through the nuclear pore complex (NPC), while most proteins are transported by energy driven transport mechanisms. Active transport of viral proteins is mediated by nuclear localization signals (NLS), which were first identified in Simian Virus 40 large T antigen and had subsequently been identified in a large number of viral proteins. Usually they contain short stretches of lysine or arginine residues. These signals are recognized by the importin super-family (importin α and β) proteins that mediate the transport across the nuclear envelope through Ran-GTP. In contrast, only one class of the leucine-rich nuclear export signal (NES) on viral proteins is known at present. Chromosome region maintenance 1 (CRM1) protein mediates nuclear export of hundreds of viral proteins through the recognition of the leucine-rich NES.

Construction and Expression of Recombinant Plasmid Encoding prME Protein Derived from Japanese Encephalitis Virus and Granulocyte-macrophage Colony-stimulating Factor of BALB/c Murine / 中国医科大学学报

Objective Construction and expression of recombinant plasmid fusing encoding prME protein derived from Japanese encephalitis virus （JEV） and GM-CSF of BALB/c mouse. Methods GM-CSF gene was ampli/ied by nested-RT-PCR from BALB/c spleen cells. JEV prME protein gene was eluted by the digestion with restrict/on endonucleases BamH I/EcoR I from pJME piasmid. Genetic fusion of prME protein and GM-CSF are subcloned info pcDNA3.1 （＋） eukaryotic vector, and named as pJME/GM-CSF.The recombinant was confirmed by restriction enzymes digestion and DNA sequencing, and then transfected into China hamster ovary （CHO） cells by Lipofectamine2000. pJME/ GM-CSF expression in CHO cells was examined by Western blot. Results We observed 2001 bp and 2472 bp DNA fragments when pJME/GM-CSF was digested with BamHI/EcoRI and BamHI/NotI respectively as expected. The estimated molecular weight of the fusion protein was 85kD. Conclusion The recombinant pJME/GM-CSF was constructed and transfected into CHO cells successfully with pJME/GMCSF stably expressed.

Effects of hepatitis B virus X protein on the induction of cytochrome P450 3A4 in HepG2 cells / 中华传染病杂志

Objective To investigate the effect of hepatitis B virus X protein (HBx) on the induction of eytochrome P450 (CYP) 3A4 by 1α, 25-(OH)2D3 in HepG2 cells in vitro. Methods HepG2 cells were transiently transfected with plasmid pEGFP-N1 (control) or co-transfected with recombinant HBx eukaryotic expression plasmid pcDNA3-X and pEGFP-N1. All HepG2 cells were divided into four groups: control group (without transfection), plasmid pEGFP-N1 transfection group, plasmid pEGFP-N1 transfection plus 1α ,25-(OH)2D3 group, plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α ,25-(OH)2D3 group. The expression of CYP3A4 in HepG2 cell was induced by 0.35 μ mol/L 1α ,25-(OH)2D3 for 72 h, and mRNA levels and protein levels of CYP3A4 in the cells were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay and Western-blot assay, respectively. The comparison between groups was done by F test. Results CYP3A4 mRNA level in plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α ,25-(OH)2D3 group was 1.52 folds of control group, while that in plasmid pEGFP-N1 transfection plus 1α, 25-(OH)2D3 group was 3.97 folds (F= 4.72, P<0. 05). Similarly, intracellular CYP3A4 protein expression in plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α , 25-(OH)2D3 group increased to 2.1 folds of control group, while that in plasmid pEGFP-N1 transfection plus 1α,25-(OH)2D3 group increased to 5.9 folds (F=4.68, P<0.05). Conclusion HBx interferes with the induction of CYP3A4 by 1α , 25-(OH)2D3 in HepG2 cell line, which suggests that HBx has suppressive effect on the expression of CYP3A4.

Effects of small interfering RNA targeting hepatitis B virus X protein on mitochondrial function in healthy liver cell line steadily expressed X gene / 中华传染病杂志

Objective To construct and identify recombinant expression plasmid of small interfering RNA (siRNA)targeting hepatitis B virus X protein(HBx), and observe its effect on mitoehondrial function in healthy liver cell line steadily expressed HBx gene (HL-7702/HBx). Methods Two siRNA sequences containing short hairpin structure, which target on the total length HBx gene, were synthesized and cloned into the vector psiRNA-Hh1GFPzeo to eonstruct recombinant expression plasmids pX1 and pX2. Non-specific recombinant pScr plasmid served as control. After siRNA transfected into HL-7702/HBx cells line by liposome, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were performed to identify the suppressive effect on HBx expression. Levels of intraeellular reactive oxygen species (ROS) and mitochondrial membrane potential (△ m) were determined by flow cytometry. The experimental results were compared by analysis of variance. Results Successful constructions of pX1 and pX2 were confirmed by restriction enzyme digestion and sequencing. The expressions of HBx mRNA and protein after 48 h of transfection into HL-7702/HBx cells in control group were 0.65± 0.12 and 0.62± 0.09, respectively, which were both higher than those (0.33±0.10 and 0.19±0.08, respectively) in group pX1 (t=4.73, P<0.05; t=7.53, P<0.05) and those (0.48±0.10 and 0.37±0.11, respectively) in group pX2 (t=2.39, P<0.05;t=4.43,P<0.05). But the inhibition of group pX1 was stronger than that of pX2 (t=2.28,P<0.05). Levels of ROS and △ m after RNA interference were 5.00±0.38 and 33.86±0.50, respectively, while those in control group were 72. 10±0. 55 and 3. 57±0.26, respectively (ROS: t=276.22, P<0.05; △ m: t=107.15, P<0.05). Conclusions siRNA targeting HBx can efficiently and specifically suppress the HBx expression in HL-7702/HBx cells, and decrease the level of ROS and increase the level of △ m, thus relieve cellular oxidative stress.