Displaying publications 1 - 20 of 129 in total

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  1. Fulltext Doubly Spliced RNA of Hepatitis B Virus Suppresses Viral Transcription via TATA-Binding Protein and Induces Stress Granule Assembly
    Tsai KN, Chong CL, Chou YC, Huang CC, Wang YL, Wang SW, et al.
    J Virol, 2015 Nov;89(22):11406-19.
    PMID: 26339052 DOI: 10.1128/JVI.00949-15
    The risk of liver cancer in patients infected with the hepatitis B virus (HBV) and their clinical response to interferon alpha therapy vary based on the HBV genotype. The mechanisms underlying these differences in HBV pathogenesis remain unclear. In HepG2 cells transfected with a mutant HBV(G2335A) expression plasmid that does not transcribe the 2.2-kb doubly spliced RNA (2.2DS-RNA) expressed by wild-type HBV genotype A, the level of HBV pregenomic RNA (pgRNA) was higher than that in cells transfected with an HBV genotype A expression plasmid. By using cotransfection with HBV genotype D and 2.2DS-RNA expression plasmids, we found that a reduction of pgRNA was observed in the cells even in the presence of small amounts of the 2.2DS-RNA plasmid. Moreover, ectopic expression of 2.2DS-RNA in the HBV-producing cell line 1.3ES2 reduced the expression of pgRNA. Further analysis showed that exogenously transcribed 2.2DS-RNA inhibited a reconstituted transcription in vitro. In Huh7 cells ectopically expressing 2.2DS-RNA, RNA immunoprecipitation revealed that 2.2DS-RNA interacted with the TATA-binding protein (TBP) and that nucleotides 432 to 832 of 2.2DS-RNA were required for efficient TBP binding. Immunofluorescence experiments showed that 2.2DS-RNA colocalized with cytoplasmic TBP and the stress granule components, G3BP and poly(A)-binding protein 1 (PABP1), in Huh7 cells. In conclusion, our study reveals that 2.2DS-RNA acts as a repressor of HBV transcription through an interaction with TBP that induces stress granule formation. The expression of 2.2DS-RNA may be one of the viral factors involved in viral replication, which may underlie differences in clinical outcomes of liver disease and responses to interferon alpha therapy between patients infected with different HBV genotypes.
    Matched MeSH terms: RNA, Viral/genetics
  2. Fulltext Antiretroviral drug resistance and HIV-1 subtypes among treatment-naive prisoners in Kelantan, Malaysia
    Ariffin TA, Mohamad S, Yusuf WN, Shueb RH
    J Infect Dev Ctries, 2014 Aug;8(8):1063-7.
    PMID: 25116676 DOI: 10.3855/jidc.4095
    INTRODUCTION: The widespread use of highly active antiretroviral therapy (HAART) and continuous reports of HIV-1 strains developing resistance to these drugs is rather alarming, as transmission of resistant viruses to newly infected persons is possible. This study aimed to determine HIV-1 subtypes and the prevalence of primary mutations associated with antiretroviral (ARV) resistance among treatment-naive prisoners on the east coast of Malaysia.
    METHODOLOGY: Viral RNA was extracted from plasma samples of 21 treatment-naive prisoners. Protease (PR) and reverse transcriptase (RT) regions were amplified and sequenced. Stanford HIV database algorithms were used for interpretation of resistance, and phylogenetic analysis was performed for subtype assignment.
    RESULTS: In the PR gene, no antiviral resistance-associated mutation was detected. For RT-associated mutations, K103N was the most prevalent in sequenced samples (14.3%). Genetic subtyping on the pol gene revealed that the majority of the prisoners were infected with subtype CRF33_01B (52.4%).
    CONCLUSION: Continuous surveillance of newly infected individuals is required to help strategize the best antiviral treatment for these patients.
    Matched MeSH terms: RNA, Viral/genetics
  3. Fulltext Molecular epidemiology of enterovirus 71 infection in the central region of Taiwan from 2002 to 2012
    Wu WH, Kuo TC, Lin YT, Huang SW, Liu HF, Wang J, et al.
    PLoS One, 2013;8(12):e83711.
    PMID: 24391812 DOI: 10.1371/journal.pone.0083711
    Enterovirus 71 (EV71), a causative agent of hand, foot, and mouth disease can be classified into three genotypes and many subtypes. The objectives of this study were to conduct a molecular epidemiological study of EV71 in the central region of Taiwan from 2002-2012 and to test the hypothesis that whether the alternative appearance of different EV71 subtypes in Taiwan is due to transmission from neighboring countries or from re-emergence of pre-existing local strains. We selected 174 EV71 isolates and used reverse transcription-polymerase chain reaction to amplify their VP1 region for DNA sequencing. Phylogenetic analyses were conducted using Neighbor-Joining, Maximum Likelihood and Bayesian methods. We found that the major subtypes of EV71 in Taiwan were B4 for 2002 epidemic, C4 for 2004-2005 epidemic, B5 for 2008-2009 epidemic, C4 for 2010 epidemic and B5 for 2011-2012 epidemic. Phylogenetic analysis demonstrated that the 2002 and 2008 epidemics were associated with EV71 from Malaysia and Singapore; while both 2010 and 2011-2012 epidemics originated from different regions of mainland China including Shanghai, Henan, Xiamen and Gong-Dong. Furthermore, minor strains have been identified in each epidemic and some of them were correlated with the subsequent outbreaks. Therefore, the EV71 infection in Taiwan may originate from pre-existing minor strains or from other regions in Asia including mainland China. In addition, 101 EV71 isolates were selected for the detection of new recombinant strains using the nucleotide sequences spanning the VP1-2A-2B region. No new recombinant strain was found. Analysis of clinical manifestations showed that patients infected with C4 had significantly higher rates of pharyngeal vesicles or ulcers than patients infected with B5. This is the first study demonstrating that different EV 71 genotypes may have different clinical manifestations and the association of EV71 infections between Taiwan and mainland China.
    Matched MeSH terms: RNA, Viral/genetics
  4. Fulltext Methods and matrices: approaches to identifying miRNAs for nasopharyngeal carcinoma
    Plieskatt JL, Rinaldi G, Feng Y, Levine PH, Easley S, Martinez E, et al.
    J Transl Med, 2014;12:3.
    PMID: 24393330 DOI: 10.1186/1479-5876-12-3
    Nasopharyngeal carcinoma (NPC) is a solid tumor of the head and neck. Multimodal therapy is highly effective when NPC is detected early. However, due to the location of the tumor and the absence of clinical signs, early detection is difficult, making a biomarker for the early detection of NPC a priority. The dysregulation of small non-coding RNAs (miRNAs) during carcinogenesis is the focus of much current biomarker research. Herein, we examine several miRNA discovery methods using two sample matrices to identify circulating miRNAs (c-miRNAs) associated with NPC.
    Matched MeSH terms: RNA, Viral/genetics
  5. Fulltext Serotype-specific host responses in rhesus macaques after primary dengue challenge
    Hickey AC, Koster JA, Thalmann CM, Hardcastle K, Tio PH, Cardosa MJ, et al.
    Am J Trop Med Hyg, 2013 Dec;89(6):1043-57.
    PMID: 24062475 DOI: 10.4269/ajtmh.13-0145
    Dengue virus (DENV) is considered to be the most important arthropod-borne viral disease and causes more than 100 million human infections annually. To further characterize primary DENV infection in vivo, rhesus macaques were infected with DENV-1, DENV-2, DENV-3, or DENV-4 and clinical parameters, as well as specificity and longevity of serologic responses, were assessed. Overt clinical symptoms were not present after infection. However, abnormalities in blood biochemical parameters consistent with heart, kidney, and liver damage were observed, and changes in plasma fibrinogen, D-dimers, and protein C indicated systemic activation of the blood coagulation pathway. Significant homotypic and heterotypic serum immunoglobulins were present in all animals, and IgG persisted for at least 390 days. Serum neutralizing antibody responses were highly serotype specific by day 120. However, some heterotypic neutralizing activity was noted in infected animals. Identification of serotype-specific host responses may help elucidate mechanisms that mediate severe DENV disease after reinfection.
    Matched MeSH terms: RNA, Viral/genetics
  6. Molecular diversity of HIV-1 and surveillance of transmitted drug resistance variants among treatment Naïve patients, 5 years after active introduction of HAART in Kuala Lumpur, Malaysia
    Ong LY, Razak SN, Lee YM, Sri La Sri Ponnampalavanar S, Syed Omar SF, Azwa RI, et al.
    J Med Virol, 2014 Jan;86(1):38-44.
    PMID: 24127302 DOI: 10.1002/jmv.23772
    Expansion of antiretroviral treatment programs have led to the growing concern for the development of antiretroviral drug resistance. The aims were to assess the prevalence of drug resistant HIV-1 variants and to identify circulating subtypes among HAART-naïve patients. Plasma specimens from N = 100 HIV+ HAART-naïve adult were collected between March 2008 and August 2010 and viral RNA were extracted for nested PCR and sequenced. PR-RT sequences were protein aligned and checked for transmitted drug resistance mutations. Phylogenetic reconstruction and recombination analysis were performed to determine the genotypes. Based on the WHO consensus guidelines, none of the recruited patients had any transmitted drug resistance mutations. When analyzed against the Stanford guidelines, 35% of patients had at least one reported mutation that may reduce drug susceptibility to PI (24%), NRTI (5%), and NNRTI (14%). The commonly detected mutation that may affect current first line therapy was V179D (3%), which may lead to reduced susceptibility to NNRTI. The predominant circulating HIV-1 genotypes were CRF01_AE (51%) and CRF33_01B (17%). The prevalence of unique recombinant forms (URF) was 7%; five distinct recombinant structures involving CRF01_AE and subtype B' were observed, among them a cluster of three isolates that could form a novel circulating recombinant form (CRF) candidate. Transmitted drug resistance prevalence among HAART-naïve patients was low in this cohort of patients in Kuala Lumpur despite introduction of HAART 5 years ago. Owing to the high genetic diversity, continued molecular surveillance can identify the persistent emergence of HIV-1 URF and novel CRF with significant epidemiological impact.
    Matched MeSH terms: RNA, Viral/genetics
  7. Fulltext Emergence of Japanese encephalitis virus genotype V in the Republic of Korea
    Takhampunya R, Kim HC, Tippayachai B, Kengluecha A, Klein TA, Lee WJ, et al.
    Virol J, 2011;8:449.
    PMID: 21943222 DOI: 10.1186/1743-422X-8-449
    Japanese encephalitis virus (JEV) genotype V reemerged in Asia (China) in 2009 after a 57-year hiatus from the continent, thereby emphasizing a need to increase regional surveillance efforts. Genotypic characterization was performed on 19 JEV-positive mosquito pools (18 pools of Culex tritaeniorhynchus and 1 pool of Cx. bitaeniorhynchus) from a total of 64 positive pools collected from geographically different locations throughout the Republic of Korea (ROK) during 2008 and 2010.
    Matched MeSH terms: RNA, Viral/genetics*
  8. Fulltext Role of exosomes as a proinflammatory mediator in the development of EBV-associated lymphoma
    Higuchi H, Yamakawa N, Imadome KI, Yahata T, Kotaki R, Ogata J, et al.
    Blood, 2018 06 07;131(23):2552-2567.
    PMID: 29685921 DOI: 10.1182/blood-2017-07-794529
    Epstein-Barr virus (EBV) causes various diseases in the elderly, including B-cell lymphoma such as Hodgkin's lymphoma and diffuse large B-cell lymphoma. Here, we show that EBV acts in trans on noninfected macrophages in the tumor through exosome secretion and augments the development of lymphomas. In a humanized mouse model, the different formation of lymphoproliferative disease (LPD) between 2 EBV strains (Akata and B95-8) was evident. Furthermore, injection of Akata-derived exosomes affected LPD severity, possibly through the regulation of macrophage phenotype in vivo. Exosomes collected from Akata-lymphoblastoid cell lines reportedly contain EBV-derived noncoding RNAs such as BamHI fragment A rightward transcript (BART) micro-RNAs (miRNAs) and EBV-encoded RNA. We focused on the exosome-mediated delivery of BART miRNAs. In vitro, BART miRNAs could induce the immune regulatory phenotype in macrophages characterized by the gene expressions of interleukin 10, tumor necrosis factor-α, and arginase 1, suggesting the immune regulatory role of BART miRNAs. The expression level of an EBV-encoded miRNA was strongly linked to the clinical outcomes in elderly patients with diffuse large B-cell lymphoma. These results implicate BART miRNAs as 1 of the factors regulating the severity of lymphoproliferative disease and as a diagnostic marker for EBV+ B-cell lymphoma.
    Matched MeSH terms: RNA, Viral/genetics*
  9. Alteration in lymphocyte responses, cytokine and chemokine profiles in chickens infected with genotype VII and VIII velogenic Newcastle disease virus
    Rasoli M, Yeap SK, Tan SW, Moeini H, Ideris A, Bejo MH, et al.
    Comp Immunol Microbiol Infect Dis, 2014 Jan;37(1):11-21.
    PMID: 24225159 DOI: 10.1016/j.cimid.2013.10.003
    Newcastle disease (ND) is a highly contagious avian disease and one of the major causes of economic losses in the poultry industry. The emergence of virulent NDV genotypes and repeated outbreaks of NDV in vaccinated chickens have raised the need for fundamental studies on the virus-host interactions. In this study, the profiles of B and T lymphocytes and macrophages and differential expression of 26 immune-related genes in the spleen of specific-pathogen-free (SPF) chickens, infected with either the velogenic genotype VII NDV strain IBS002 or the genotype VIII NDV strain AF2240, were evaluated. A significant reduction in T lymphocyte population and an increase in the infiltration of IgM+ B cells and KUL01+ macrophages were detected in the infected spleens at 1, 3 and 4 days post-infection (dpi) (P<0.05). The gene expression profiles showed an up-regulation of CCLi3, CXCLi1, CXCLi2 (IL-8), IFN-γ, IL-12α, IL-18, IL-1β, IL-6, iNOS, TLR7, MHCI, IL-17F and TNFSF13B (P<0.05). However, these two genotypes showed different cytokine expression patterns and viral load. IBS002 showed higher viral load than AF2240 in spleen at 3 and 4dpi and caused a more rapid up-regulation of CXCLi2, IFN-γ, IL-12α, IL-18, IL-1β, iNOS and IL-10 at 3dpi. Meanwhile, the expression levels of CCLI3, CXCLi1, IFN-γ, IL-12α, IL-1β and iNOS genes were significantly higher in AF2240 at 4dpi. In addition, the expression levels of IL-10 were significantly higher in the IBS002-infected chickens at 3 and 4dpi. Hence, infection with velogenic genotype VII and VIII NDV induced different viral load and production of cytokines and chemokines associated with inflammatory reactions.
    Matched MeSH terms: RNA, Viral/genetics
  10. Short communication: low prevalence of genotypic drug resistance mutations among antiretroviral-naive HIV type 1 patients in Malaysia
    Tee KK, Kamarulzaman A, Ng KP
    AIDS Res Hum Retroviruses, 2006 Feb;22(2):121-4.
    PMID: 16478392
    To assess the prevalence of mutations associated with drug resistance in antiretroviral-naive patients in Kuala Lumpur, Malaysia, genotypic resistance testing was conducted among drug-naive HIV-1 patients attending the University Malaya Medical Center (UMMC) between July 2003 and June 2004. Reverse transcriptase (RT) and protease genes of plasma virions were sequenced from 100 individuals. The majority of the patients were recently diagnosed. Codons 20-255 of the RT and 1-96 of the protease gene were examined for major and minor mutations associated with antiretroviral resistance reported by the International AIDS Society- USA (IAS-USA) Drug Resistance Mutations Group. The prevalence of patients with at least one major mutation conferring drug resistance was 1%, with only one patient having a Y181C amino acid substitution in the RT gene that confers high-level resistance to nevirapine and delavirdine. Minor mutations were detected in high prevalence in the protease gene. Amino acid substitutions I13V, E35D, and M36I were associated with CRF01_AE while L63P, V77I, and I93L were associated with subtype B. Baseline prevalence of major mutations associated with resistance to antiretroviral drugs was low among antiretroviral-naive HIV-1 patients, suggesting that routine drug resistance testing may be unnecessary for all individuals newly diagnosed with HIV or all patients beginning antiretroviral therapy.
    Matched MeSH terms: RNA, Viral/genetics
  11. Unusual, neurological and severe dengue manifestations during the outbreak in Sri Lanka, 2017
    Ngwe Tun MM, Muthugala R, Nabeshima T, Rajamanthri L, Jayawardana D, Attanayake S, et al.
    J Clin Virol, 2020 04;125:104304.
    PMID: 32145478 DOI: 10.1016/j.jcv.2020.104304
    BACKGROUND: Sri Lanka experienced its largest dengue outbreak in 2017 with more than 185,000 dengue cases including at least 250 fatalities.

    OBJECTIVES: Our study aimed to characterize the clinical, immunological and virological features of confirmed dengue patients in Sri Lanka during the outbreak in 2017 when unusual manifestations of severe dengue were observed.

    STUDY DESIGN: Sera from 295 patients who were admitted to Teaching Hospital Kandy, Kandy, Sri Lanka between March 2017- January 2018 were subjected to NS1 antigen, IgM and IgG ELISAs, virus isolation, conventional and real time RT-PCR and next generation sequencing.

    RESULTS: Primary and secondary infections were detected in 48.5 % and 51.5 % of the study population, respectively. Two hundred twenty five DENV strains were isolated (219 DENV-2, one DENV-3, two DENV-4, two mixed infections of DENV-2 and -3 and one mixed infection of DENV-2 and -4). Unusual and severe manifestations such as encephalitis, encephalopathy, liver failure, kidney failure, myocarditis, Guillain-Barré syndrome and multi-organ failure were noted in 44 dengue patients with 11 deaths. The viraemia levels in patients with primary infection and unusual manifestations were significantly higher compared to those in patients with secondary infection. A new clade of DENV-2 Cosmopolitan genotype strains was observed with the strains closely related to those from China, Malaysia, Indonesia, Singapore and Taiwan.

    CONCLUSIONS: The new clade of DENV-2 cosmopolitan genotype observed in Sri Lanka in 2017 caused an unprecedented, severe dengue outbreak. The emergence of DENV-3 and DENV-4 in the 2017 outbreak might cause future outbreaks in Sri Lanka.

    Matched MeSH terms: RNA, Viral/genetics
  12. Maternal hepatitis C (HCV) infection and Anti-D immunoglobulin therapy: study testing antibodies, RNA and Genotype of HCV in Baghdad
    Al-Kubaisy W, Daud S, Al-Kubaisi MW, Al-Kubaisi OW, Abdullah NN
    J Matern Fetal Neonatal Med, 2019 Oct;32(20):3464-3469.
    PMID: 29656685 DOI: 10.1080/14767058.2018.1465557
    Introduction: Hepatitis C virus (HCV) infection is a serious health problem. It is a major contributor to end-stage liver disease. Worldwide, 1-8% of all pregnant women were infected. Women with viral hepatitis may be at an increased risk of pregnancy complications. There are several obstetrics intervention acts as risk factors, which are specific to women pertaining the HCV infection; anti-D immunoglobulin (Ig) therapy may be one of them. Our objectives were to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. Materials and methods: A cross sectional study was conducted. A sample of 154 Rhesus negative (Rh - ve) pregnant women regardless of the anti-D Ig therapy was collected. Anti-HCV were tested using third generation enzyme immunoassay (EIA-3) and immunoblot assay (Lia Tek-111), subsequently. In addition, 89 serum samples were subjected to molecular analysis using RT-PCR and DNA enzyme immunoassay (DEIA) method for the detection of HCV-RNA and genotypes. Results: Anti-HCV, and HCV-RNA seroprevalence were significantly higher (17.1, 35.5%) among women with anti-D Ig than their counter group (6.4, 13.16%), p = .038, .018, respectively. Significant direct positive dose response correlation (r = 0.78, p = .005) had been seen between number of anti-D Ig therapy and anti-HCV seropositive rate. Anti-D Ig therapy act as a risk factor (odds ratio (OR) = 3.01, 95%CI: 1.01-8.9) especially from the third dose onward. Women with anti-D Ig therapy were at higher risk (3.6 times more) of positive HCV-RNA (OR =3.6, 95%CI =1.19-10.837). Genotype HCV-1b showed higher prevalent (52.9%) among the recipients of anti-D Ig therapy while genotype HCV-3a (6.6%) was the lowest. Conclusions: Our study showed that Anti-D immunoglobulin therapy acts as a risk factor for acquiring HCV infection. Screening for HCV should be recommended for all recipients of anti-D Ig. Not only HCV antibodies but HCV-RNA detection being recommended for the diagnosis of HCV infection. A brief rational: Pregnant women with HCV infection are at risk of adverse obstetric outcome. Anti-D Ig therapy may be a risk factor for HCV infection. Hence, we conducted a cross sectional study with the objectives to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. We found that anti-HCV and HCV-RNA seroprevalence were significantly higher in women with anti-D Ig. In addition, women with anti-D Ig therapy were 3.6 times more at risk of positive HCV-RNA with genotype HCV-1b showed higher prevalence. Therefore, anti-D Ig therapy is a risk factor for acquiring HCV infection and we recommend screening for HCV for all recipients of anti-D Ig. In addition, the diagnosis of HCV infection, should be made with HCV antibodies and HCV-RNA detection.
    Matched MeSH terms: RNA, Viral/genetics
  13. Fulltext Interferon-stimulated gene of 20 kDa protein (ISG20) degrades RNA of hepatitis B virus to impede the replication of HBV in vitro and in vivo
    Leong CR, Funami K, Oshiumi H, Mengao D, Takaki H, Matsumoto M, et al.
    Oncotarget, 2016 10 18;7(42):68179-68193.
    PMID: 27626689 DOI: 10.18632/oncotarget.11907
    Hepatitis B virus (HBV) barely induces host interferon (IFN)-stimulated genes (ISGs), which allows efficient HBV replication in the immortalized mouse hepatocytes as per human hepatocytes. Here we found that transfection of Isg20 plasmid robustly inhibits the HBV replication in HBV-infected hepatocytes irrespective of IRF3 or IFN promoter activation. Transfection of Isg20 is thus effective to eradicate HBV in the infected hepatocytes. Transfection of HBV genome or ε-stem of HBV pgRNA (active pgRNA moiety) failed to induce Isg20 in the hepatocytes, while control polyI:C (a viral dsRNA analogue mimic) activated MAVS pathway leading to production of type I IFN and then ISGsg20 via the IFN-α/β receptor (IFNAR). Consistently, addition of IFN-α induced Isg20 and partially suppressed HBV replication in hepatocytes. Chasing HBV RNA, DNA and proteins by blotting indicated that ISG20 expression decreased HBV RNA and replicative DNA in HBV-transfected cells, which resulted in low HBs antigen production and virus titer. The exonuclease domains of ISG20 mainly participated in HBV-RNA decay. In vivo hydrodynamic injection, ISG20 was crucial for suppressing HBV replication without degrading host RNA in the liver. Taken together, ISG20 acts as an innate anti-HBV effector that selectively degrades HBV RNA and blocks replication of infectious HBV particles. ISG20 would be a critical effector for ameliorating chronic HBV infection in the IFN therapy.
    Matched MeSH terms: RNA, Viral/genetics*
  14. Identification and evolutionary dynamics of two novel human coronavirus OC43 genotypes associated with acute respiratory infections: phylogenetic, spatiotemporal and transmission network analyses
    Oong XY, Ng KT, Takebe Y, Ng LJ, Chan KG, Chook JB, et al.
    Emerg Microbes Infect, 2017 Jan 04;6(1):e3.
    PMID: 28050020 DOI: 10.1038/emi.2016.132
    Human coronavirus OC43 (HCoV-OC43) is commonly associated with respiratory tract infections in humans, with five genetically distinct genotypes (A to E) described so far. In this study, we obtained the full-length genomes of HCoV-OC43 strains from two previously unrecognized lineages identified among patients presenting with severe upper respiratory tract symptoms in a cross-sectional molecular surveillance study in Kuala Lumpur, Malaysia, between 2012 and 2013. Phylogenetic, recombination and comparative genomic analyses revealed two distinct clusters diverging from a genotype D-like common ancestor through recombination with a putative genotype A-like lineage in the non-structural protein (nsp) 10 gene. Signature amino acid substitutions and a glycine residue insertion at the N-terminal domain of the S1 subunit of the spike gene, among others, exhibited further distinction in a recombination pattern, to which these clusters were classified as genotypes F and G. The phylogeographic mapping of the global spike gene indicated that the genetically similar HCoV-OC43 genotypes F and G strains were potentially circulating in China, Japan, Thailand and Europe as early as the late 2000s. The transmission network construction based on the TN93 pairwise genetic distance revealed the emergence and persistence of multiple sub-epidemic clusters of the highly prevalent genotype D and its descendant genotypes F and G, which contributed to the spread of HCoV-OC43 in the region. Finally, a more consistent nomenclature system for non-recombinant and recombinant HCoV-OC43 lineages is proposed, taking into account genetic recombination as an important feature in HCoV evolution and classification.
    Matched MeSH terms: RNA, Viral/genetics
  15. Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression
    Faiz NM, Cortes AL, Guy JS, Reddy SM, Gimeno IM
    J Gen Virol, 2018 07;99(7):927-936.
    PMID: 29767614 DOI: 10.1099/jgv.0.001076
    Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective of this study was to evaluate whether the attenuation of MDV-induced tumours and late-MDV-IS occurs simultaneously or can be dissociated. The immunosuppressive ability of three viruses derived from vv+ MDV strain 686 (wild-type 686, the somewhat attenuated molecular clone 686-BAC, and the nononcogenic molecular clone lacking the two copies of the oncogene meq 686-BACΔMEQ) was evaluated. Late-MDV-IS was evaluated indirectly by assessing the negative effect of MDV strains on the protection conferred by infectious laryngotracheitis (ILT) vaccines. Our results showed that the ability to induce late-MDV-IS was attenuated before the ability to induce tumours. Strain 686 induced both tumours and late-MDV-IS, 686-BAC induced tumours but did not induce late-MDV-IS and 686-BACΔMEQ did not induce either tumours or late-MDV-IS. Further comparison of strains 686 and 686-BAC revealed that strain 686 reduced the humoral immune responses to ILTV (1132 vs 2167) more severely, showed higher levels of meq transcripts (2.1E+09 vs 4.98E+8) and higher expression of MDV microRNAs (mdv1-miR-M4-5p and mdv1-miR-M2-3p) in the spleen, and further reduced the percentage of CD45+-MHC-I+splenocytes (13 vs32 %) compared to molecular clone 686-BAC. This study suggests that the immunosuppressive ability of MDV might follow a continuous spectrum and only the most virulent MDVs can overcome a certain threshold level and induce clinical MDV-IS in the ILT model.
    Matched MeSH terms: RNA, Viral/genetics
  16. Fulltext EBV-encoded miRNAs target ATM-mediated response in nasopharyngeal carcinoma
    Lung RW, Hau PM, Yu KH, Yip KY, Tong JH, Chak WP, et al.
    J Pathol, 2018 Apr;244(4):394-407.
    PMID: 29230817 DOI: 10.1002/path.5018
    Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignancy that is prevalent in southern China and Southeast Asia. It is consistently associated with latent Epstein-Barr virus (EBV) infection. In NPC, miR-BARTs, the EBV-encoded miRNAs derived from BamH1-A rightward transcripts, are abundantly expressed and contribute to cancer development by targeting various cellular and viral genes. In this study, we establish a comprehensive transcriptional profile of EBV-encoded miRNAs in a panel of NPC patient-derived xenografts and an EBV-positive NPC cell line by small RNA sequencing. Among the 40 miR-BARTs, predominant expression of 22 miRNAs was consistently detected in these tumors. Among the abundantly expressed EBV-miRNAs, BART5-5p, BART7-3p, BART9-3p, and BART14-3p could negatively regulate the expression of a key DNA double-strand break (DSB) repair gene, ataxia telangiectasia mutated (ATM), by binding to multiple sites on its 3'-UTR. Notably, the expression of these four miR-BARTs represented more than 10% of all EBV-encoded miRNAs in tumor cells, while downregulation of ATM expression was commonly detected in all of our tested sequenced samples. In addition, downregulation of ATM was also observed in primary NPC tissues in both qRT-PCR (16 NP and 45 NPC cases) and immunohistochemical staining (35 NP and 46 NPC cases) analysis. Modulation of ATM expression by BART5-5p, BART7-3p, BART9-3p, and BART14-3p was demonstrated in the transient transfection assays. These findings suggest that EBV uses miRNA machinery as a key mechanism to control the ATM signaling pathway in NPC cells. By suppressing these endogenous miR-BARTs in EBV-positive NPC cells, we further demonstrated the novel function of miR-BARTs in inhibiting Zta-induced lytic reactivation. These findings imply that the four viral miRNAs work co-operatively to modulate ATM activity in response to DNA damage and to maintain viral latency, contributing to the tumorigenesis of NPC. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
    Matched MeSH terms: RNA, Viral/genetics*
  17. The utilization of SiNWs/AuNPs-modified indium tin oxide (ITO) in fabrication of electrochemical DNA sensor
    Rashid JI, Yusof NA, Abdullah J, Hashim U, Hajian R
    Mater Sci Eng C Mater Biol Appl, 2014 Dec;45:270-6.
    PMID: 25491829 DOI: 10.1016/j.msec.2014.09.010
    This work describes the incorporation of SiNWs/AuNPs composite as a sensing material for DNA detection on indium tin-oxide (ITO) coated glass slide. The morphology of SiNWs/AuNPs composite as the modifier layer on ITO was studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The morphological studies clearly showed that SiNWs were successfully decorated with 20 nm-AuNPs using self-assembly monolayer (SAM) technique. The effective surface area for SiNWs/AuNPs-modified ITO enhanced about 10 times compared with bare ITO electrode. SiNWs/AuNPs nanocomposite was further explored as a matrix for DNA probe immobilization in detection of dengue virus as a bio-sensing model to evaluate its performance in electrochemical sensors. The hybridization of complementary DNA was monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as the redox indicator. The fabricated biosensor was able to discriminate significantly complementary, non-complementary and single-base mismatch oligonucleotides. The electrochemical biosensor was sensitive to target DNA related to dengue virus in the range of 9.0-178.0 ng/ml with detection limit of 3.5 ng/ml. In addition, SiNWs/AuNPs-modified ITO, regenerated up to 8 times and its stability was up to 10 weeks at 4°C in silica gel.
    Matched MeSH terms: RNA, Viral/genetics
  18. Genetic and immunologic relationships between vaccine and field strains for vaccine selection of type A foot-and-mouth disease virus circulating in East Asia
    Lee SY, Park ME, Kim RH, Ko MK, Lee KN, Kim SM, et al.
    Vaccine, 2015 Jan 29;33(5):664-9.
    PMID: 25528521 DOI: 10.1016/j.vaccine.2014.12.007
    Of the seven known serotypes of foot-and-mouth disease virus (FMDV), type A has the most diverse variations. Genetic variations also occur frequently at VP1, VP2, VP3, and VP4 because these proteins constitute the viral capsid. The structural proteins of FMDV, which are closely related to immunologic correlations, are the most easily analyzed because they have highly accessible information. In this study we analyzed the type A vaccine viruses by alignment of available sequences in order to find appropriate vaccine strains. The matching rate of ASIA topotype-specific sites (20 amino acids) located on the viral surface, which are mainly VP1 and VP2, was highly related to immunologic reactivity. Among the available vaccines analyzed in this study, we suggest that A Malaysia 97 could be used as a vaccine virus as it has the highest genetic similarity and immunologic aspects to field strains originating in East Asia.
    Matched MeSH terms: RNA, Viral/genetics
  19. Hepatitis C virus prevalence and genotyping among hepatocellular carcinoma patients in Baghdad
    Al-Kubaisy WA, Obaid KJ, Noor NA, Ibrahim NS, Al-Azawi AA
    Asian Pac J Cancer Prev, 2014;15(18):7725-30.
    PMID: 25292053
    Hepatocellular carcinoma (HCC) is the third most common cause for cancer death in the world, now being especially linked to chronic hepatitis C virus (HCV) infection. This case-control study consisting of 65 HCC patients and 82 patients with other malignant tumours as controls was conducted to determine the association of HCV markers with HCC. Serum of each participant was obtained for detection of HCV Ab and RNA by DNA enzyme immunoassay (DEIA). Twenty six per cent (26.0%) of HCC patients had positive anti-HCV which was significantly greater than the control group (p=0.001). HCC patients significantly have a risk of exposure to HCV infection almost 3 times than the control group (OR=2.87, 95% C.I=1.1-7). Anti-HCV seropositive rate was significantly (p=0.03) higher among old age HCC patients and increases with age. Males with HCC significantly showed to have more than 9 times risk of exposure to HCV infection (OR=9.375, 95 % CI=1.299-67.647) than females. HCV-RNA seropositive rate was (70.8%) significantly higher among HCC patients compared to (22.2%) the control group (p=0.019). The most prevalent genotype (as a single or mixed pattern of infection) was HCV- 1b. This study detected a significantly higher HCV seropositive rate of antibodies and RNA in HCC patients.
    Matched MeSH terms: RNA, Viral/genetics*
  20. Fulltext Lineage diversification of pigeon paramyxovirus effect re-emergence potential in chickens
    Chong YL, Kim O, Poss M
    Virology, 2014 Aug;462-463:309-17.
    PMID: 25010480 DOI: 10.1016/j.virol.2014.06.007
    Genotype VI-paramyxovirus (GVI-PMV1) is a major cause of epidemic Newcastle-like disease in Columbiformes. This genotype of avian paramyxovirus type 1 has diversified rapidly since its introduction into the US in 1982 resulting in two extant lineages, which have different population growth properties. Although some GVI-PMV1s replicate poorly in chickens, it is possible that variants with different replicative or pathogenic potential in chickens exist among the genetically-diverse GVI-PMV1s strains. To determine if variants of Columbiform GVI-PMV1 with different phylogenetic affiliations have distinct phenotypic properties in chickens, we investigated the replicative properties of 10 naturally circulating pigeon-derived isolates representing four subgroups of GVI-PMV1 in primary chicken lung epithelial cells and in chicken embryos. Our data demonstrate that GVI-PMV1 variants have different infection phenotypes in their chicken source host and that properties reflect subgroup affiliation. These subgroup replicative properties are consistent with observed dynamics of viral population growth.
    Matched MeSH terms: RNA, Viral/genetics
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