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Phenotypic and genotypic characterization of induced acyclovir-resistant clinical isolates of herpes simplex virus type 1

Hussin A, Md Nor NS, Ibrahim N

Antiviral Res, 2013 Nov;100(2):306-13.
PMID: 24055837 DOI: 10.1016/j.antiviral.2013.09.008

Eleven strains of acyclovir (ACV)-resistant herpes simplex virus type 1 (HSV-1) were generated from HSV-1 clinical isolates by exposure to ACV. Genotype of the thymidine kinase (TK) and DNA polymerase (pol) genes from these mutants were further analyzed. Genotypic analysis revealed four non-synonymous mutations in TK gene associated with gene polymorphism and two to three non-synonymous mutations in DNA pol gene. Seven and six strains contained at least one resistance-associated mutation at TK and DNA pol gene, respectively. Resistance-associated mutations within the TK gene consisted of 64% of non-synonymous frameshift mutations within the homopolymer region of G's and C's, and 36% of non-synonymous nucleotide substitutions of the conserved gene region (C336Y, R51W and R222H), nucleotide that produced stop codon (L288Stop) and two amino acid substitutions outside the conserved region (E39G & L208F). There were 10 non-synonymous amino acid substitutions located outside the conserved region with the unclear significance to confer resistance observed. Resistance-associated mutations in DNA pol gene include insertion of G at the homopolymer region of G's (794-797) and amino acid substitutions inside (V621S) or outside (H1228D) the conserved region. In silico analysis of the mutated TK (C336Y, R51W and L208F), and DNA pol (V621S and H1228D) suggested structural changes that might alter the stability of these proteins. However, there were several mutations with unclear significance to confer ACV-resistance identified, especially mutations outside the conserved region.

Matched MeSH terms: Viral Proteins/genetics
Immunogenic properties of recombinant ectodomain of Newcastle disease virus hemagglutinin-neuraminidase protein expressed in Escherichia coli

Wong SK, Tan WS, Omar AR, Tan CS, Yusoff K

Acta Virol., 2009;53(1):35-41.
PMID: 19301949

Hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) plays a vital role in the viral infectivity, host immunity, and disease diagnosis. A portion of the HN gene encoding the ectodomain (nt 142-1739) was cloned and expressed in Escherichia coli yielding an insoluble HN protein and a soluble NusA-HN protein containing N-utilization substance A (NusA) fusion component. Both recombinant proteins were purified and used for immunization of chickens. The recombinant HN protein induced higher antibody titers as compared to the recombinant NusA-HN protein. These antibodies were able to react in immunoblot analysis with the corresponding recombinant proteins as well as with the HN protein of NDV.

Matched MeSH terms: Viral Proteins/immunology*
In vitro isolation and molecular identification of reptarenavirus in Malaysia

Abba Y, Hassim H, Hamzah H, Ibrahim OE, Ilyasu Y, Bande F, et al.

Virus Genes, 2016 Oct;52(5):640-50.
PMID: 27142080 DOI: 10.1007/s11262-016-1345-7

Boid inclusion body disease (BIBD) is a viral disease of boids caused by reptarenavirus. In this study, tissue from naturally infected boid snakes were homogenized and propagated in African Monkey kidney (Vero) and rat embryonic fibroblast (REF) cells. Virus replication was determined by the presence of cytopathic effect, while viral morphology was observed using transmission electron microscopy. Viral RNA was amplified using RT-PCR with primers specific for the L-segment of reptarenavirus; similarly, quantification of viral replication was done using qPCR at 24-144 h postinfection. Viral cytopathology was characterized by cell rounding and detachment in both Vero and REF cells. The viral morphology showed round-to-pleomorphic particles ranging from 105 to 150 nm which had sand-like granules. Sanger sequencing identified four closely associated reptarenavirus species from 15 (37.5 %) of the total samples tested, and these were named as follows: reptarenavirus UPM-MY 01, 02, 03, and 04. These isolates were phylogenetically closely related to the University Helsinki virus (UHV), Boa Arenavirus NL (ROUTV; BAV), and unidentified reptarenavirus L20 (URAV-L20). Comparison of deduced amino acid sequences further confirmed identities to L-protein of UHV, L-polymerase of BAV and RNA-dependent RNA polymerase of URAV-L20. Viral replication in Vero cells increased steadily from 24 to 72 h and peaked at 144 h. This is the first study in South East Asia to isolate and characterize reptarenavirus in boid snakes with BIBD.

Matched MeSH terms: Viral Proteins/genetics
Molecular characterization of Nipah virus, a newly emergent paramyxovirus

Harcourt BH, Tamin A, Ksiazek TG, Rollin PE, Anderson LJ, Bellini WJ, et al.

Virology, 2000 Jun 5;271(2):334-49.
PMID: 10860887

Recently, a new paramyxovirus, now known as Nipah virus (NV), emerged in Malaysia and Singapore, causing fatal encephalitis in humans and a respiratory syndrome in pigs. Initial studies had indicated that NV is antigenically and genetically related to Hendra virus (HV). We generated the sequences of the N, P/C/V, M, F, and G genes of NV and compared these sequences with those of HV and other members of the family Paramyxoviridae. The intergenic regions of NV were identical to those of HV, and the gene start and stop sequences of NV were nearly identical to those of HV. The open reading frames (ORFs) for the V and C proteins within the P gene were found in NV, but the ORF encoding a potential short basic protein found in the P gene of HV was not conserved in NV. The N, P, C, V, M, F, and G ORFs in NV have nucleotide homologies ranging from 88% to 70% and predicted amino acid homologies ranging from 92% to 67% in comparison with HV. The predicted fusion cleavage sequence of the F protein of NV had a single amino acid substitution (K to R) in comparison with HV. Phylogenetic analysis demonstrated that although HV and NV are closely related, they are clearly distinct from any of the established genera within the Paramyxoviridae and should be considered a new genus.

Matched MeSH terms: Viral Proteins/genetics
Further biological, serological and biochemical characterization of North American, European and Southeast Asian strains of bovine herpesvirus 1 compared with other alphaherpesvirinae members

Trépanier P, Minocha HC, Ibrahim AL, Sheikh-Omar AR, Montpetit C, Lecomte J, et al.

Vet Microbiol, 1988 Dec;18(3-4):219-31.
PMID: 2852870

Hemagglutination activity, structural protein profiles and neutralization assays were used in a comparative study of bovine herpesvirus 1 strains from the U.S.A., Canada, Great Britain, Denmark and Malaysia with equine, feline and human herpesviruses in order to further characterize the bovine herpesvirus 1 hemagglutinin. Bovine herpesvirus 1 strains of different geographical origins all showed hemagglutinating activity for mouse erythrocytes; furthermore, feline herpesvirus 1 was also shown to hemagglutinate mouse erythrocytes. Analyses of partly purified viruses showed that a distinctive and specific polypeptides profile is associated with each species of herpesviruses used in our study; strains of bovine herpesvirus 1 from North America, Europe and Southeast Asia however, presented a remarkable similarity as to their electrophoretic protein patterns. A protein similar to the 97-kDa bovine viral hemagglutinin was not identified with the hemagglutinating feline herpesvirus. An important neutralization epitope on the bovine viral hemagglutinin was also not found on feline, equine and human herpesviruses but was identified on all bovine strains tested from North America, Europe and Southeast Asia stressing the importance of the bovine hemagglutinin for eventual prophylactic purposes.

Matched MeSH terms: Viral Proteins/analysis
Characterization of significant molecular determinants of virulence of Enterovirus 71 sub-genotype B4 in Rhabdomyosarcoma cells

Yee PTI, Mohamed RAH, Ong SK, Tan KO, Poh CL

Virus Res, 2017 06 15;238:243-252.
PMID: 28705680 DOI: 10.1016/j.virusres.2017.07.010

One of the leading causes of the hand, foot and mouth disease (HFMD) is Enterovirus 71 (EV-A71), displaying symptoms such as fever and ulcers in children but some strains can produce cardiopulmonary oedema which leads to death. There is no FDA-approved vaccine for prevention of severe HFMD. The molecular determinants of virulence for EV-A71 are unclear. It could be a single or a combination of amino acids that determines virulence in different EV-A71 genotype/sub-genotypes. Several EV-A71 strains bearing single nucleotide (nt) mutations were constructed and the contribution of each mutation to virulence was evaluated. The nt(s) that contributed to significant reduction in virulence in vitro were selected and each mutation was introduced separately into the genome to construct the multiply mutated EV-A71 strain (MMS) which carried six substitutions of nt(s) at the 5'-NTR (U700C), VP1-145 (E to G), VP1-98E, VP1-244K and G64R in the vaccine seed strain that had a partial deletion within the 5'-NTR region (nt. 475-485) of Δ11bp. In comparison to the wild type strain, the MMS showed low virulence as it produced very low RNA copy number, plaque count, VP1 and had 105-fold higher TCID50, indicative of a promising LAV candidate that should be further evaluated in vivo.

Matched MeSH terms: Viral Proteins/analysis
P-TEFb goes viral

Zaborowska J, Isa NF, Murphy S

Bioessays, 2016 07;38 Suppl 1:S75-85.
PMID: 27417125 DOI: 10.1002/bies.201670912

Positive transcription elongation factor b (P-TEFb), which comprises cyclin-dependent kinase 9 (CDK9) kinase and cyclin T subunits, is an essential kinase complex in human cells. Phosphorylation of the negative elongation factors by P-TEFb is required for productive elongation of transcription of protein-coding genes by RNA polymerase II (pol II). In addition, P-TEFb-mediated phosphorylation of the carboxyl-terminal domain (CTD) of the largest subunit of pol II mediates the recruitment of transcription and RNA processing factors during the transcription cycle. CDK9 also phosphorylates p53, a tumor suppressor that plays a central role in cellular responses to a range of stress factors. Many viral factors affect transcription by recruiting or modulating the activity of CDK9. In this review, we will focus on how the function of CDK9 is regulated by viral gene products. The central role of CDK9 in viral life cycles suggests that drugs targeting the interaction between viral products and P-TEFb could be effective anti-viral agents.

Matched MeSH terms: Viral Proteins/metabolism*
Fulltext Molecular phylogenetics of a recently isolated goat pox virus from Vietnam

Pham TH, Rahaman NYA, Lila MAM, Lai HLT, Nguyen LT, Van Nguyen G, et al.

BMC Vet Res, 2021 Mar 08;17(1):115.
PMID: 33685458 DOI: 10.1186/s12917-021-02777-1

BACKGROUND: After a decade of silence, an outbreak of the contagious and Asian endemic disease, goat pox re-emerged in North Vietnam affecting more than 1800 heads with a mortality rate of 6.5%. The inevitable impact of goat pox on hide quality, breeding, chevon and milk production has resulted in a significant economic losses to the developing goat industry of Vietnam. In the act of establishing an effective control of this devastating disease, tracing the source of re-emergence via a phylogenetic study was carried out to reveal their genetic relatedness. Either skin scab or papule from the six affected provinces were collected, cultured into Vero cells followed by restricted enzyme digestion of targeted P32 gene DNA encoding. The P32 gene was then cloned and transformed into E.coli competent cells for further sequencing.
RESULTS: The isolated sequence is deposited into GenBank under Accession No. MN317561/VNUAGTP1. The phylogenetic tree revealed high similarity of nucleotide and amino acid sequences to references goat pox strains accounting for 99.6 and 99.3, respectively. The Vietnamese strain is clustered together with currently circulating goat pox virus in China, India and Pakistan which suggested the origin of South China.
CONCLUSIONS: This Vietnam isolate is clustered together with other Asian goat pox strains indicating the dissemination of a common goat pox virus within this continent.

Matched MeSH terms: Viral Proteins/genetics
Phylogenetic and genetic analyses of the emerging Nipah virus from bats to humans

Shi J, Sun J, Hu N, Hu Y

Infect Genet Evol, 2020 11;85:104442.
PMID: 32622923 DOI: 10.1016/j.meegid.2020.104442

Little is known about the genetic features of Nipah virus (NiV) associated with virulence and transmission. Herein, phylogenetic and genetic analyses for all available NiV strains revealed sequence variations between the two genetic lineages of NiV with pathogenic differences, as well as among different strains within Bangladesh lineage. A total of 143 conserved amino acid differences, distributed among viral nucleocapsid (N), phosphoprotein (P), matrix protein (M), fusion protein (F) and glycoprotein (G), were revealed. Structural modeling revealed one key substitution (S3554N) in the viral G protein that might mediate a 12-amino-acid structural change from a loop into a β sheet. Multiple key amino acids substitutions in viral G protein were observed, which may alter viral fitness and transmissibility from bats to humans.

Matched MeSH terms: Viral Proteins/genetics*
A Novel Recombinant Canine Adenovirus Type 1 Detected from Acute Lethal Cases of Infectious Canine Hepatitis

Wong M, Woolford L, Hasan NH, Hemmatzadeh F

Viral Immunol, 2017 05;30(4):258-263.
PMID: 28426340 DOI: 10.1089/vim.2016.0041

In this study, canine adenoviruses (CAdVs) from two acute fatal cases of infectious canine hepatitis (ICH) were analyzed using molecular detection and sequencing of the pVIII, E3, and fiber protein genes. Pathological findings in affected dogs were typical for CAdV-1 associated disease, characterized by severe centrilobular to panlobular necrohemorrhagic hepatitis and the development of disseminated intravascular coagulation in the terminal stages of disease. Comparison of partial genome sequences revealed that although these newly detected viruses mainly had CAdV-1 genome characteristics, their pVIII gene was more similar to that of CAdV-2. This likely suggests that a recombination has occurred between CAdV-1 and CAdV-2, which possibly explains the cause of vaccine failure or increased virulence of the virus in the observed ICH cases.

Matched MeSH terms: Viral Proteins/genetics
Identification of strain diversity and phylogenetic analysis based on two major essential proteins of Orf viruses isolated from several clinical cases reported in Malaysia

Bala JA, Balakrishnan KN, Jesse FFA, Abdullah AA, Noorzahari MSB, Ghazali MT, et al.

Infect Genet Evol, 2020 01;77:104076.
PMID: 31678648 DOI: 10.1016/j.meegid.2019.104076

There is a little information on the characterization of Orf virus strains that are endemic in Malaysia. The relationship between the severity of disease and the molecular genetic profile of Orf virus strains has not been fully elucidated. This study documented the first confirmed report of contagious ecthyma causing by Orf virus in goats from a selected state of eastern peninsular Malaysia. The disease causes significant debilitation due to the inability of affected animals to suckle which brings a great economic loss to the farmers. A total of 504 animals were examined individually to recognize the affected animals with Orf lesion. Skin scrapping was used to collect the scab material from the infected animals. The presence of Orf virus was confirmed by combination of methods including virus isolation on vero cells, identification by Transmission Electron Microscopy (TEM) and molecular technique using PCR and Sanger sequencing. The results showed the successful isolation of four Orf virus strains with a typical cytopathic effects on the cultured vero cells line. The morphology was confirmed to be Orf virus with a distinctive ovoid and criss cross structure. The phylogenetic analysis revealed that these isolated strains were closely related to each other and to other previously isolated Malaysian orf viruses. In addition these Orf virus strains were closely related to Orf viruses from China and India. This study provides more valuable insight in terms of genotype of Orf virus circulating in Malaysia.

Matched MeSH terms: Viral Proteins/genetics*
Fulltext Binding of Duck Tembusu Virus Nonstructural Protein 2A to Duck STING Disrupts Induction of Its Signal Transduction Cascade To Inhibit Beta Interferon Induction

Zhang W, Jiang B, Zeng M, Duan Y, Wu Z, Wu Y, et al.

J Virol, 2020 04 16;94(9).
PMID: 32075929 DOI: 10.1128/JVI.01850-19

Duck Tembusu virus (DTMUV), which is similar to other mosquito-borne flaviviruses that replicate well in most mammalian cells, is an emerging pathogenic flavivirus that has caused epidemics in egg-laying and breeding waterfowl. Immune organ defects and neurological dysfunction are the main clinical symptoms of DTMUV infection. Preinfection with DTMUV makes the virus impervious to later interferon (IFN) treatment, revealing that DTMUV has evolved some strategies to defend against host IFN-dependent antiviral responses. Immune inhibition was further confirmed by screening for DTMUV-encoded proteins, which suggested that NS2A significantly inhibited IFN-β and IFN-stimulated response element (ISRE) promoter activity in a dose-dependent manner and facilitated reinfection with duck plague virus (DPV). DTMUV NS2A was able to inhibit duck retinoic acid-inducible gene-I (RIG-I)-, and melanoma differentiation-associated gene 5 (MDA5)-, mitochondrial-localized adaptor molecules (MAVS)-, stimulator of interferon genes (STING)-, and TANK-binding kinase 1 (TBK1)-induced IFN-β transcription, but not duck TBK1- and interferon regulatory factor 7 (IRF7)-mediated effective phases of IFN response. Furthermore, we found that NS2A competed with duTBK1 in binding to duck STING (duSTING), impaired duSTING-duSTING binding, and reduced duTBK1 phosphorylation, leading to the subsequent inhibition of IFN production. Importantly, we first identified that the W164A, Y167A, and S361A mutations in duSTING significantly impaired the NS2A-duSTING interaction, which is important for NS2A-induced IFN-β inhibition. Hence, our data demonstrated that DTMUV NS2A disrupts duSTING-dependent antiviral cellular defenses by binding with duSTING, which provides a novel mechanism by which DTMUV subverts host innate immune responses. The potential interaction sites between NS2A and duSTING may be the targets of future novel antiviral therapies and vaccine development.IMPORTANCE Flavivirus infections are transmitted through mosquitos or ticks and lead to significant morbidity and mortality worldwide with a spectrum of manifestations. Infection with an emerging flavivirus, DTMUV, manifests with clinical symptoms that include lesions of the immune organs and neurological dysfunction, leading to heavy egg drop and causing serious harm to the duck industry in China, Thailand, Malaysia, and other Southeast Asian countries. Mosquito cells, bird cells, and mammalian cell lines are all susceptible to DTMUV infection. An in vivo study revealed that BALB/c mice and Kunming mice were susceptible to DTMUV after intracerebral inoculation. Moreover, there are no reports about DTMUV-related human disease, but antibodies against DTMUV and viral RNA were detected in serum samples of duck industry workers. This information implies that DTMUV has expanded its host range and may pose a threat to mammalian health. However, the pathogenesis of DTMUV is largely unclear. Our results show that NS2A strongly blocks the STING-induced signal transduction cascade by binding with STING, which subsequently blocks STING-STING binding and TBK1 phosphorylation. More importantly, the W164, Y167, or S361 residues in duSTING were identified as important interaction sites between STING and NS2A that are vital for NS2A-induced IFN production and effective phases of IFN response. Uncovering the mechanism by which DTMUV NS2A inhibits IFN in the cells of its natural hosts, ducks, will help us understand the role of NS2A in DTMUV pathogenicity.

Matched MeSH terms: Viral Proteins/metabolism*
QSAR model for predicting neuraminidase inhibitors of influenza A viruses (H1N1) based on adaptive grasshopper optimization algorithm

Algamal ZY, Qasim MK, Lee MH, Ali HTM

SAR QSAR Environ Res, 2020 Nov;31(11):803-814.
PMID: 32938208 DOI: 10.1080/1062936X.2020.1818616

High-dimensionality is one of the major problems which affect the quality of the quantitative structure-activity relationship (QSAR) modelling. Obtaining a reliable QSAR model with few descriptors is an essential procedure in chemometrics. The binary grasshopper optimization algorithm (BGOA) is a new meta-heuristic optimization algorithm, which has been used successfully to perform feature selection. In this paper, four new transfer functions were adapted to improve the exploration and exploitation capability of the BGOA in QSAR modelling of influenza A viruses (H1N1). The QSAR model with these new quadratic transfer functions was internally and externally validated based on MSEtrain, Y-randomization test, MSEtest, and the applicability domain (AD). The validation results indicate that the model is robust and not due to chance correlation. In addition, the results indicate that the descriptor selection and prediction performance of the QSAR model for training dataset outperform the other S-shaped and V-shaped transfer functions. QSAR model using quadratic transfer function shows the lowest MSEtrain. For the test dataset, proposed QSAR model shows lower value of MSEtest compared with the other methods, indicating its higher predictive ability. In conclusion, the results reveal that the proposed QSAR model is an efficient approach for modelling high-dimensional QSAR models and it is useful for the estimation of IC50 values of neuraminidase inhibitors that have not been experimentally tested.

Matched MeSH terms: Viral Proteins/antagonists & inhibitors*
Isolation of an influenza C virus introduced into Japan by a traveler from Malaysia

Matsuzaki Y, Sato K, Sugawara K, Takashita E, Muraki Y, Morishita T, et al.

J Clin Microbiol, 2005 Feb;43(2):993-5.
PMID: 15695727

An influenza C virus was isolated from a Japanese traveler who had visited Malaysia in April 1999. Phylogenetic analysis indicated that the genome composition of this virus was distinct from that of any other strain isolated in Japan. The possibility that a genetically unique influenza C virus was introduced into Japan by a traveler is shown.

Matched MeSH terms: Viral Proteins/genetics
Fulltext Phylogeography, Transmission, and Viral Proteins of Nipah Virus

Sun B, Jia L, Liang B, Chen Q, Liu D

Virol Sin, 2018 Oct;33(5):385-393.
PMID: 30311101 DOI: 10.1007/s12250-018-0050-1

Nipah virus (NiV), a zoonotic paramyxovirus belonging to the genus Henipavirus, is classified as a Biosafety Level-4 pathogen based on its high pathogenicity in humans and the lack of available vaccines or therapeutics. Since its initial emergence in 1998 in Malaysia, this virus has become a great threat to domestic animals and humans. Sporadic outbreaks and person-to-person transmission over the past two decades have resulted in hundreds of human fatalities. Epidemiological surveys have shown that NiV is distributed in Asia, Africa, and the South Pacific Ocean, and is transmitted by its natural reservoir, Pteropid bats. Numerous efforts have been made to analyze viral protein function and structure to develop feasible strategies for drug design. Increasing surveillance and preventative measures for the viral infectious disease are urgently needed.

Matched MeSH terms: Viral Proteins/chemistry*
Characterisation of mouse monoclonal antibodies targeting linear epitopes on Chikungunya virus E2 glycoprotein

Chua CL, Chan YF, Sam IC

J Virol Methods, 2014 Jan;195:126-33.
PMID: 24134938 DOI: 10.1016/j.jviromet.2013.10.015

Chikungunya virus (CHIKV) is a mosquito-borne arbovirus which has recently re-emerged globally and poses a major threat to public health. Infection leads to severe arthralgia, and disease management remains supportive in the absence of vaccines and anti-viral interventions. The high specificities of monoclonal antibodies (mAbs) have been exploited in immunodiagnostics and immunotherapy in recent decades. In this study, eight different clones of mAbs were generated and characterised. These mAbs targeted the linear epitopes on the CHIKV E2 envelope glycoprotein, which is the major target antigen during infection. All the mAbs showed binding activity against the purified CHIKV virion or recombinant E2 when analysed by immunofluorescence, ELISA and Western blot. The epitopes of each mAb were mapped by overlapping synthetic peptide-based ELISA. The epitopes are distributed at different functional domains of E2 glycoprotein, namely at domain A, junctions of β-ribbons with domains A and B, and domain C. Alignment of mAb epitope sequences revealed that some are well-conserved within different genotypes of CHIKV, while some are identical to and likely to cross-react with the closely-related alphavirus O'nyong-nyong virus. These mAbs with their mapped epitopes are useful for the development of diagnostic or research tools, including immunofluorescence, ELISA and Western blot.

Matched MeSH terms: Viral Proteins/immunology*
Genetic characterization of Nipah virus, Bangladesh, 2004

Harcourt BH, Lowe L, Tamin A, Liu X, Bankamp B, Bowden N, et al.

Emerg Infect Dis, 2005 Oct;11(10):1594-7.
PMID: 16318702

Until 2004, identification of Nipah virus (NV)-like outbreaks in Bangladesh was based on serology. We describe the genetic characterization of a new strain of NV isolated during outbreaks in Bangladesh (NV-B) in 2004, which confirms that NV was the etiologic agent responsible for these outbreaks.

Matched MeSH terms: Viral Proteins/genetics
Epstein-Barr virus DNA detection in the diagnosis of nasopharyngeal carcinoma

Yap YY, Hassan S, Chan M, Choo PK, Ravichandran M

Otolaryngol Head Neck Surg, 2007 Jun;136(6):986-91.
PMID: 17547993

OBJECTIVES: This study examines the presence of Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC) by using polymerase chain reaction (PCR).
STUDY DESIGN: Eighty-six postnasal biopsy samples and 71 fine-needle aspirate samples of neck masses were obtained from patients who were clinically suspect for NPC. Genomic DNA was extracted from the samples, and EBNA1, EBNA2, and LMP genes of EBV were detected by PCR. PCR results were compared with NPC histopathology findings.
RESULTS: The sensitivity of PCR to detect EBNA1 (97.14%), EBNA2 (88.57%), and LMP (91.43%) genes of EBV in nasopharyngeal biopsy samples were higher than those in fine-needle aspirate samples.
CONCLUSION: Detection of EBV by PCR in tissue obtained from nasopharyngeal biopsy and fine-needle aspirate samples of neck masses is a relatively inexpensive, reliable, and accurate method of diagnosing NPC. Detection of EBV genes is on par with histopathological examination (HPE) and superior to fine-needle aspirate cytology.
SIGNIFICANCE: PCR is an ideal tool for suggesting NPC and guiding the diagnostic workup in occult primary tumors, facilitating earlier diagnosis and reducing morbidity and mortality.

Matched MeSH terms: Viral Proteins/analysis; Viral Proteins/genetics
Fulltext Antigenic cell associated dengue 2 virus proteins detected in vitro using dengue fever patients sera

Abubakar S, Azila A, Suzana M, Chang LY

Malays J Pathol, 2002 Jun;24(1):29-36.
PMID: 16329553

At least three major antigenic dengue 2 virus proteins were recognized by pooled dengue fever patients' sera in infected Aedes albopictus (C6/36) mosquito cells. Dengue virus envelope (E), premembrane (PrM) and non-structural protein 1 (NS 1) dimer were detected beginning on day 3 postinfection in both the cell membrane and cytosolic fractions. Using the patients' sera, the presence of antigenic intermediate core protein (C)-PrM and NS1-non-structural protein 2a (NS2a) in the cytoplasmic fraction of dengue 2 virus infected cells was revealed. The presence of a approximately 92 and approximately 84 kDa NS 1 dimer in the membrane (NS 1m) and cytosolic (NS 1c) fractions of C6/36 cells, respectively, was also recognized. Using individual patient's serum, it was further confirmed that all patients' sera contained antibodies that specifically recognized E, NS 1 and PrM present in the dengue 2 virus-infected cell membrane fractions, suggesting that these glycosylated virus proteins were the main antigenic proteins recognized in vivo. Detection of dengue 2 virus C antibody in some patients further suggested that C could be antigenic if presented in vivo.

Matched MeSH terms: Viral Proteins/immunology*; Viral Proteins/metabolism
Detection of human herpesvirus 7 in salivary glands

Yadav M, Nambiar S, Khoo SP, Yaacob HB

Arch Oral Biol, 1997 Aug;42(8):559-67.
PMID: 9347118

The prevalence and cellular distribution of human herpesvirus 7 (HHV-7) in archival labial salivary glands was analysed for virus-specific DNA sequences by polymerase chain reaction (PCR) and in situ hybridization signals. In addition, the cellular expression of HHV-7-encoded protein was detected by immunohistochemical staining with a virus-specific monoclonal antibody. Eleven of 20 samples were positive for the HHV-7 DNA sequence by PCR. Eighteen of 20 tissues analysed by in situ hybridization showed signals in ductal, serous and mucous cells. Some nuclei of these cells and also the myoepithelial population were positive. In immunolocalization studies, all 20 salivary glands consistently showed HHV-7-expressed protein in the cytoplasm of ductal cuboidal and columnar cells. The protein was also found in the cytoplasm of mucous and serous acinar cells that were immunopositive for HHV-7. The observations are consistent with the suggestion that the labial salivary gland is a site for virus replication, potential persistence and a source of infective HHV-7 in saliva.

Matched MeSH terms: Viral Proteins/analysis; Viral Proteins/genetics

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