An overview of dengue viral infection circulating in Pakistan

Background & objectives: Dengue virus (DENV) is an RNA virus that infects approximately 2.5 billion people around the world. The incidence of dengue fever has rapidly increased at an alarming rate in the last few years and has affected thousands of people in Pakistan. This review explores the prevalence, serotypes and pathogenesis of dengue virus circulating in Pakistan. Methods: A systematic review of observational studies published between 1994 and December 2019 was performed. All records of the confirmed outbreak of dengue fever in Pakistan were reviewed and articles containing no primary data were excluded. Results: Four identified serotypes of dengue virus (DENV 1-4) circulate in different regions of the world causing epidemics. The most prevalent serotype, which is still epidemic and dominant in Pakistan, is DENV-2. Many factors like over-population, rapid urbanization, travelling, lack of vector control in dengue endemic areas and inadequate health-care are responsible of dynamic and huge raise of dengue in Pakistan. Interpretation & conclusion: Currently there is no specific treatment for prevention of dengue virus. Recently some antiviral compounds were being tested to eradicate this disease. There is a need to develop an efficient and safe vaccine for all four serotypes to combat dengue viral infection globally and particularly in Pakistan.

In Silico Screening of Natural Products as Potential Inhibitors of SARS-CoV-2 Using Molecular Docking Simulation / 中国结合医学杂志

OBJECTIVE@#To explore potential natural products against severe acute respiratory syndrome coronavirus (SARS-CoV-2) via the study of structural and non-structural proteins of human coronaviruses.@*METHODS@#In this study, we performed an in-silico survey of 25 potential natural compounds acting against SARS-CoV-2. Molecular docking studies were carried out using compounds against 3-chymotrypsin-like protease (3CLPRO), papain-like protease (PLPRO), RNA-dependent RNA polymerase (RdRp), non-structural protein (nsp), human angiotensin converting enzyme 2 receptor (hACE2R), spike glycoprotein (S protein), abelson murine leukemia viral oncogene homolog 1 (ABL1), calcineurin-nuclear factor of activated T-cells (NFAT) and transmembrane protease serine 2.@*RESULTS@#Among the screened compounds, amentoflavone showed the best binding affinity with the 3CLPRO, RdRp, nsp13, nsp15, hACE2R. ABL1 and calcineurin-NFAT; berbamine with hACE2R and ABL1; cepharanthine with nsp10, nsp14, nsp16, S protein and ABL1; glucogallin with nsp15; and papyriflavonol A with PLPRO protein. Other good interacting compounds were juglanin, betulinic acid, betulonic acid, broussooflavan A, tomentin A, B and E, 7-methoxycryptopleurine, aloe emodin, quercetin, tanshinone I, tylophorine and furruginol, which also showed excellent binding affinity towards a number of target proteins. Most of these compounds showed better binding affinities towards the target proteins than the standard drugs used in this study.@*CONCLUSION@#Natural products or their derivatives may be one of the potential targets to fight against SARS-CoV-2.

Generation and immunogenicity evaluation of Senecavirus A virus-like particles / 生物工程学报

To develop Senecavirus A (SVA) virus-like particles (VLPs), a recombinant prokaryotic expression plasmid pET28a-SVA-VP031 was constructed to co-express SVA structural proteins VP0, VP3 and VP1, according to the genomic sequence of the field isolate CH-FJ-2017 after the recombinant proteins were expressed in E .coli system, and purified by Ni+ ion chromatographic method. The SVA VLPs self-assemble with a high yield in vitro buffer. A typical VLPs with an average diameter of 25-30 nm which is similar to native virions by using TEM detection. Animals immunized by SVA VLPs shown that the VLPs induced high titers neutralizing antibodies in Guinea pigs. This study indicated that the VLPs produced with co-expressing SVA structural proteins VP0, VP3 and VP1 in prokaryotic system is a promising candidate and laid an important foundation for the development of a novel SVA VLPs vaccine.

Development of a sandwich ELISA for detecting 3AB non-structural protein of foot-and-mouth disease virus / 生物工程学报

Antigenic purity is important for quality control of the foot-and-mouth (FMD) whole virus inactivated vaccine. The recommended method for evaluation the antigenic purity of FMD vaccine is to check the serum conversion to non-structural protein (NSP) 3AB antibody after 2 to 3 times inoculation of animals with inactivated vaccine. In this study, we developed a quantitative ELISA to detect the amount of residual 3AB in vaccine antigen, to provide a reference to evaluate the antigenic purity of FMD vaccine. Monoclonal antibody (Mab) of NSP 3A and HRP-conjugated Mab of NSP 3B were used to establish a sandwich ELISA to quantify the NSP 3AB in vaccine antigen of FMD. Purified NSP 3AB expressed in Escherichia coli was serially diluted and detected to draw the standard curve. The detectable limit was determined to be the lowest concentration of standard where the ratio of its OD value to OD blank well was not less than 2.0. Results: The OD value was linearly corelated with the concentration of 3AB protein within the range between 4.7 and 600 ng/mL. The correlation coefficient R² is greater than 0.99, and the lowest detectable limit is 4.7 ng/mL. The amount of 3AB protein in non-purified inactivated virus antigen was detected between 9.3 and 200 ng/mL depending on the 12 different virus strains, whereas the amount of 3AB in purified virus antigen was below the lowest detectable limit. The amount of 3AB in 9 batches of commercial FMD vaccine antigens was between 9.0 and 74 ng/mL, whereas it was below the detectable limit in other 24 batches of commercial vaccine antigens. Conclusion: the sandwich ELISA established in this study is specific and sensitive to detect the content of 3AB protein in vaccine antigen of FMD, which will be a useful method for evaluation of the antigenic purity and quality control of FMD inactivated vaccine.

Progress on TMPRSS2-ERG fusion gene product transcription regulation mechanism in prostate cancer cells / 中国临床药理学与治疗学

Prostate cancer is the most common malignant tumor in men in Europe and the United States, but the mechanism of prostate cancer occurrence and development is not completely clear. In prostate cancer, the TMPRSS2-ERG fusion gene has a high incidence, which promotes ERG overexpression and causes changes in target genes and signaling pathways, such as androgen receptors, spotted zinc finger structural proteins, Notch pathways. In-depth understanding of the transcriptional regulation mechanism of TMPRSS2-ERG fusion gene products in prostate cancer cells can provide new targets for drug action in the treatment of prostate 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.

Chikungunya infection: A potential re-emerging global threat

Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and under-developed countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

Chikungunya infection: A potential re-emerging global threat

Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and under-developed countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

A experiência brasileira na erradicação da febre aftosa e o emprego do sistema I-ELISA 3ABC/EITB para certificação sanitária de bovinos e bubalinos / The Brazilian experience in the eradication of foot-and-mouth disease and the use of I-ELISA 3ABC/EITB system for sanitary certification of bovine and buffaloes

A vacinação contra febre aftosa é ferramenta eficaz para erradicação e prevenção da doença, contudo, a presença de proteínas não capsidais (PNC) na vacina, produzidas durante a multiplicação viral, tem sido o principal problema, visto que sua presença dificulta as ações de vigilância, cuja busca se baseia na detecção de anticorpos contra essas proteínas para diferenciar animal vacinado de infectado. Por esse motivo, o Ministério da Agricultura, Pecuária e Abastecimento publicou em 2008 a Instrução Normativa nº 50 (IN 50), que incluiu no controle da qualidade da vacina a pesquisa de anticorpos contra as PNC, para avaliar a retirada dessas proteínas. Considerando a interferência vacinal, objetivou-se avaliar a frequência de bovinos reagentes às PNC, analisada pelo sistema I-ELISA 3ABC/EITB, no Laboratório de Viroses de Bovídeos do Instituto Biológico de São Paulo, no período de 2002 a 2012. Dos 34.705 bovinos examinados, observou-se que a proporção de reagentes às PNC aumentou com a idade, evidenciando aumento da frequência de reagentes em animais que receberam maior número de vacinações, indicando interferência da vacinação na resposta às proteínas. Quando comparados antes e após a publicação da IN 50, observa-se diminuição da reatividade, com redução, em 2010, de quase a metade em relação a 2007, e ainda maior quando comparado com o período 2002 a 2006. Isso demonstra a efetividade da purificação da vacina em resposta ao cumprimento da IN 50, embora permaneça alguma sororreatividade em bovinos com múltiplas vacinações. O sistema I-ELISA 3ABC/EITB demonstrou ser uma ótima ferramenta para impedir a movimentação de possíveis portadores do vírus oriundos de rebanhos vacinados, desde que seja considerado todo o contexto sanitário e epidemiológico.(AU)

Vaccination against foot-and-mouth disease is an effective tool for eradication and prevention of this disease. However, the presence of non-capsidal proteins (NCP) in the vaccine, produced during viral replication, has been the main problem, since their presence hamper the vigilance as its relies on the detection of antibodies against NCP to differentiate vaccinated from infected animals. Therefore, the Brazilian Ministry of Agriculture, Livestock and Supply published the Normative Instruction 50 (IN 50) that included the detection of antibodies against the NCP to evaluate the removal of these proteins. Considering the vaccine interference, this paper aimed to evaluate the frequency of reagents to NCP, analyzed by I-ELISA 3ABC/EITB system in the Laboratory of Bovine Viruses (LVB), Biological Institute (IB), São Paulo, SP, Brazil, from 2002 to 2012. Of the 34,705 cattle examined, it was observed that the proportion of reagents to NCP increased with age, indicating increased frequency of reagents in animals that received more vaccines, showing interference of proteins in response to vaccination. When compared before and after the publication of IN 50, there was decreased reactivity, with reduction in 2010, of nearly half compared to 2007, and even higher when compared with 2002 to 2006. This shows the effectiveness of the purification of the vaccine in response to the implementation of IN 50, although it remains some seroreactivity in cattle with multiple vaccinations. The I-ELISA 3ABC/EITB system proved to be a great tool to prevent the movement of possible carriers of the virus derived from vaccinated herds, provided that all sanitary and epidemiological context are taken in consideration.(AU)

Significance of cerebrospinal fluid matrix metalloproteinase-9, interleukin-6, and tumor necrosis factor-alpha protein in children with viral encephalitis / 中华实用儿科临床杂志

Objective To explore the significance of changes of matrix metalloproteinase-9 (MMP-9),interleukin-6 (IL-6),and tumor necrosis factor-alpha (TNF-oα) protein level in the cerebrospinal fluid (CSF) of children with viral encephalitis (VE).Methods The concentration of neuron-specific enolase (NSE),structural proteins 100B (S100B),and MMP-9,IL-6,TNF-α in the CSF of VE children were detected by an enzyme linked immunosorbent assay,and the correlations of them were analyzed.Results NSE,S100B,MMP-9,IL-6,TNF-α protein expression could be found significantly higher than those in the control group,and there were significant differences according to statistics expression trends(all P ＜0.05).The NSE protein expression was significantly positive related with S100B in the VE group (r =0.467,P =0.009),and the concentration was markedly negative related with the duration of viral encephalitis (r =-0.472,P =0.008).MMP-9,IL-6 protein expression were significantly positive related with NSE,S100B respectively (r =0.698,P =0.00 ; r =0.559,P =0.00 ; r =0.812,P =0.00 ; r =0.664,P =0.00).TNF-α protein expression was positive related with CSF S100B(r =0.363,P =0.049),but there was no correlation between TNF-α and NSE (r =0.245,P =0.193).Conclusions The neurons and the neuroglial cells are damaged in the viral encephalitis children.MMP-9,IL-6,TNF-α protein may participate in the pathological damage process of nerve cells in VE children in different degrees.

The function of helper plasmids from HEP-Flury strain rabies virus on encapsidating the full-length genome of CTN strain / 中华流行病学杂志

Objective To identify the helper plasmids from HEP-Flury strain rabies virus that could encapsidate the full-length genome of CTN strain. Methods Four overlapped fragments covering the full-length genome of rabies virus CTN strain were cloned into expression vector. A recombinant full-length genome plasmid (pCTN-GFP) contained the full-length genome of the CTN strain expect for ψ gene which was replaced by GFP gene was then constructed using restriction enzyme cleavage and ligation in vitro. In order to obtain the recombinant rabies virus CTN-GFP, the pCTN-GFP was transfected with helper plasmids carrying N, P, L gene of HEP-Flury strain. Results The four gene fragments of the genome were amplified and cloned into the expression vector. The recombinant genome cDNA plasmid pCTN-GFP was constructed and subjected to restriction endonuclease digestions. After sequenced to assure no absence and mutations compared with their parental viruses, it was ready for virus rescue. After the transfection of both pCTN-GFP and the helper plasmids from HEP-Flury strain into BHK-21 cells, the recombinant rabies virus CTN-GFP was rescued and confirmed by fluorescence analysis and RT-PCR, which demonstrated that the CTN-GFP was recovered from cloned cDNA. Conclusion The proteins of HEP-Flury strain rabies virus could encapsidate and transcribe the CTN strain rabies virus RNA genome.

Proteomic Analyses of the Shrimp White Spot Syndrome Virus / 中国病毒学·英文版

White spot syndrome virus (WSSV), a unique member within the virus family Nimaviridae, is the most notorious aquatic virus infecting shrimp and other crustaceans and has caused enormous economic losses in the shrimp farming industry worldwide. Therefore, a comprehensive understanding of WSSV morphogenesis, structural proteins, and replication is essential for developing prevention measures of this serious parasite. The viral genome is approximately 300kb and contains more than 180 open reading frames (ORF). However, most of proteins encoded by these ORF have not been characterized. Due to the importance of WSSV structural proteins in the composition of the virion structure, infection process and interaction with host cells, knowledge of structural proteins is essential to understanding WSSV entry and infection as well as for exploring effective prevention measures. This review article summarizes mainly current investigations on WSSV structural proteins including the relative quantities, localization, function and protein-protein interactions. Traditional proteomic studies of 1D or 2D gel electrophoresis separations and mass spectrometry (MS) followed by database searches have identified a total of 39 structural proteins. Shotgun proteomics and iTRAQ were initiated to identify more structural proteins. To date, it is estimated that WSSV is assembled by at least 59 structural proteins, among them 35 are defined as the envelope fraction (including tegument proteins) and 9 as nucleocapsid proteins. Furthermore, the interaction within several major structural proteins has also been investigated. This identitification and characterization of WSSV protein components should help in the understanding of the viral assembly process and elucidate the roles of several major structural proteins.

Bioinformatic Analysis of Structural Proteins of Paramyxovirus Tianjin Strain / 中国病毒学·英文版

The amino acid sequences of the NP,P, M, F,HN and L proteins of the paramyxovirus Tianjin strain were analyzed by using the bioinformatics methods. Phylogenetic analysis based on 6 structural proteins among the Tianjin strain and 25 paramyxoviruses showed that the Tianjin strain belonged to the genus Respirovirus, in the subfamily Paramyxovirinae, and was most closely related to Sendal virus (SeV). Phylogenetic analysis with 14 known SeVs showed that Tianjin strain represented a new evolutionary lineage. Similarities comparisons indicated that Tianjin strain P protein was poorly conserved, sharing only 78.7%-91.9% amino acid identity with the known SeVs, while the L protein was the most conserved, having 96.0%-98.0% amino acid identity with the known SeVs. Alignments of amino acid sequences of 6 structural proteins clearly showed that Tianjin strain possessed many unique amino acid substitutions in their protein sequences, 15 in NP, 29 in P, 6 in M, 13 in F, 18 in HN, and 29 in L. These results revealed that Tianjin strain was most likely a new genotype of SeV. The presence of unique amino acid substitutions suggests that Tianjin strain maybe has a significant difference in biological, pathological, immunological, or epidemiological characteristics from the known SeVs.

Research progresses on genomics and proteomic of Chlamydia spp / 基础医学与临床

Following genomes from various strains of Chlamydia spp being sequenced,it was found that there were only tiny changes in their gene components,the infected host variety and pathogenisis process were very different.The genomes from Chlamydia trachomatis,C.muridarum,C.pneumoniae,Chlamydophila caviae were studied in detail,which revealed the relationship of chlamydial genomes and multiple members causes.The discovery of polymorphic membrane protein gene family,type Ⅲ secretion gene and peptidoglycan coding gene showed the great research success in the field.After the complete nucleotide acids of various species and strains of Chlamydia spp were sequenced many proteins were further identified,involving the outer membrane protein,major outer membrane protein,hot shock protein and polymorphic membrane protein with different functions and structures.Fully understanding the properties of these proteins is in favor of studying mechanisms of pathogenisis and immunity of Chlamydia as well as high-effective gene engineering vaccine against chlamydiosis.

Expression of the Structural Proteins of Japanese Encephalitis Virus

Japanese encephalitis virus (JEV) is one of the most important human pathogens, which causes the permanent neuropsychiatric sequelae and even fatal diseases with high mortality and morbidity, especially among children. In this study, we expressed the structural proteins (C, prM, and E) of JEV using a Sindbis virus-based heterologous gene expression vector, the pSinRep5. We designed two expression vectors (pSinRep5/JEV C-E and pSinRep5/JEV C-NS1), which encode the precise coding sequence of JEV C-E and JEV C-NS1 proteins, respectively. These cloned JEV structural protein genes were designed to express under the Sindbis virus subgenomic promoter. Upon the transfection and expression of the pSinRep5/JEV C-E or pSinRep5/JEV C-NS1 plasmid, the transfected cells expressed approximately 55 kDa JEV E prtiens. As designed, the JEV NS1 proteins were expressed only in the SinRep5/JEV C-NS1 RNAtransfected cells. In addition, we found in the pSinRep5/JEV C-NS1-transfected cells that the viral proteins were predominantly localized around the perinuclear membranes. On the other hand, cytoplasmic staining was mainly observed in the pSinRep5/JEV C-E RNA-transfected cells in the absence of NS1 protein. Thus, our system will provide a useful tool to dissect intracellular membrane localization signals located in the JEV structural proteins without handling the infectious JEV viral particles and to characterize viral morphogenesis of this pathogen.