PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-6 (6)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
1.  Outbreak of Henipavirus Infection, Philippines, 2014 
Emerging Infectious Diseases  2015;21(2):328-331.
During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats. Ongoing surveillance is needed for rapid diagnosis, risk factor investigation, control measure implementation, and further virus characterization.
doi:10.3201/eid2102.141433
PMCID: PMC4313660  PMID: 25626011
outbreak; henipavirus; emerging disease; viruses; Philippines
2.  Altered specificity of single-chain antibody fragments bound to pandemic H1N1-2009 influenza virus after conversion of the phage-bound to the soluble form 
BMC Research Notes  2012;5:483.
Background
In 2009, a novel influenza A/H1N1 virus (H1N1pdm) quickly spread worldwide and co-circulated with then-existing seasonal H1N1 virus (sH1N1). Distinguishing between these 2 viruses was necessary to better characterize the epidemiological properties of the emergent virus, including transmission patterns, pathogenesis, and anti-influenza drug resistance. This situation prompted us to develop a point-of-care virus differentiation system before entering the 2009–2010 influenza season. Aiming to establish H1N1pdm-specific detection tools rapidly, we employed phage display libraries to select H1N1pdm-specific single-chain variable fragments (scFvs).
Findings
Human single-fold scFv libraries (Tomlinson I + J) underwent selection for the ability to bind H1N1pdm virus particles. Three rounds of panning brought 1152 phage-bound scFvs, of which 58 clones reacted with H1N1pdm specifically or preferentially over sH1N1 in an enzyme-linked immunosorbent assay (ELISA). After conversion of the scFvs to soluble form, 7 clones demonstrating high/stable expression were finally obtained. However, all the soluble scFvs except No. 29 were found to have lost their specificity/preference for H1N1pdm in ELISA. The specificity/preference of No. 29 was also confirmed by immunofluorescence assay and immunoprecipitation, and the viral nucleoprotein was identified by ELISA as its target protein. The change in specificity associated with scFv conversion from phage-bound to soluble form could be due to loss of phage scaffold pIII protein, which likely provides structural support for the scFv antigen-binding site. It is also possible that the similar antigenic properties of H1N1pdm and sH1N1 led to the observed alterations in scFv specificity.
Discussion
Using a phage display library, we obtained 7 soluble scFv clones reactive against H1N1pdm; however, only 1 showed specificity/preference toward H1N1pdm. Our results confirmed that using phage display libraries was highly advantageous for the rapid development of molecules to detect target antigens. However, our results also indicated that this strategy might not have been effective for selecting H1N1pdm-specific antibodies during the 2009 pandemic, where the co-circulating sH1N1 virus shared similar antigenic properties. This suggests that it might be advisable to use a synthetic scFv phage display library by strategically considering the characteristics of target antigens and the potential situations.
doi:10.1186/1756-0500-5-483
PMCID: PMC3492028  PMID: 22943792
Influenza; Pandemic; Diagnosis; Single-chain variable fragment (scFv); Altered specificity
3.  Serologic Evidence of Nipah Virus Infection in Bats, Vietnam 
Emerging Infectious Diseases  2012;18(3):536-537.
doi:10.3201/eid1803.111121
PMCID: PMC3309638  PMID: 22377109
Nipah virus; Nipah-like virus; henipavirus; bats; Vietnam; Rousettus leschenaulti; Cynopterus sphinx; ELISA; neutralization test; viruses
4.  Functional Analyses of RNA Structures Shared between the Internal Ribosome Entry Sites of Hepatitis C Virus and the Picornavirus Porcine Teschovirus 1 Talfan 
Journal of Virology  2006;80(3):1271-1279.
The internal ribosome entry site (IRES) of porcine teschovirus 1 (PTV-1), a member of the Picornaviridae family, is quite distinct from other well-characterized picornavirus IRES elements, but it displays functional similarities to the IRES from hepatitis C virus (HCV), a member of the Flaviviridae family. In particular, a dominant negative mutant form of eIF4A does not inhibit the activity of the PTV-1 IRES. Furthermore, there is a high level (ca. 50%) of identity between the PTV-1 and HCV IRES sequences. A secondary-structure model of the whole PTV-1 IRES has been derived which includes a pseudoknot. Validation of specific features within the model has been achieved by mutagenesis and functional assays. The differences and similarities between the PTV-1 and HCV IRES elements should assist in defining the critical features of this type of IRES.
doi:10.1128/JVI.80.3.1271-1279.2006
PMCID: PMC1346926  PMID: 16415004
5.  Functional and Structural Similarities between the Internal Ribosome Entry Sites of Hepatitis C Virus and Porcine Teschovirus, a Picornavirus 
Journal of Virology  2004;78(9):4487-4497.
Initiation of protein synthesis on picornavirus RNA requires an internal ribosome entry site (IRES). Typically, picornavirus IRES elements contain about 450 nucleotides (nt) and use most of the cellular translation initiation factors. However, it is now shown that just 280 nt of the porcine teschovirus type 1 Talfan (PTV-1) 5′ untranslated region direct the efficient internal initiation of translation in vitro and within cells. In toeprinting assays, assembly of 48S preinitiation complexes from purified components on the PTV-1 IRES was achieved with just 40S ribosomal subunits plus eIF2 and Met-tRNAiMet. Indeed, a binary complex between 40S subunits and the PTV-1 IRES is formed. Thus, the PTV-1 IRES has properties that are entirely different from other picornavirus IRES elements but highly reminiscent of the hepatitis C virus (HCV) IRES. Comparison between the PTV-1 IRES and HCV IRES elements revealed islands of high sequence identity that occur in regions critical for the interactions of the HCV IRES with the 40S ribosomal subunit and eIF3. Thus, there is significant functional and structural similarity between the IRES elements from the picornavirus PTV-1 and HCV, a flavivirus.
doi:10.1128/JVI.78.9.4487-4497.2004
PMCID: PMC387690  PMID: 15078929
6.  Unique Characteristics of a Picornavirus Internal Ribosome Entry Site from the Porcine Teschovirus-1 Talfan 
Journal of Virology  2002;76(22):11721-11728.
The teschoviruses constitute a recently defined picornavirus genus. Most of the genome sequence of the porcine teschovirus-1 (PTV) Talfan and several other strains is known. We now demonstrate that initiation of protein synthesis occurs at nucleotide (nt) 412 on the PTV Talfan RNA and that nt 1 to 405 contains an internal ribosome entry site (IRES) that functions efficiently in vitro and within mammalian cells. In comparison with other picornavirus IRES elements, the PTV IRES is relatively short and lacks a significant polypyrimidine tract near the 3′ end. Expression of an enterovirus 2A protease, which induces cleavage of eIF4G within the translation initiation complex eIF4F, has little effect on the PTV IRES activity within BHK cells. The PTV IRES has a unique set of properties and represents a new class of picornavirus IRES element.
doi:10.1128/JVI.76.22.11721-11728.2002
PMCID: PMC136790  PMID: 12388732

Results 1-6 (6)