bluuebunny/crossref_metadata_2025_split huggingface dataset:
From immunity to susceptibility: virus resistance induced in tomato by a silenced transgene is lost as TGS overcomes PTGS
Authors: Catoni Marco , Lucioli Alessandra , Doblas‐Ibáñez Paula , Accotto Gian Paolo , Vaira Anna Maria 
Published: June 2013

SummaryTomato line 30.4 was obtained engineering the nucleocapsid (N) gene of tomato spotted wilt virus into plant genome, and immunity to tomato spotted wilt virus infection of its self‐pollinated homozygous progeny was observed. Despite the presence of a high amount of transgenic transcripts, transgenic proteins have not been detected, suggesting a mechanism of resistance mediated by RNA. In the present study, we identify post‐transcriptional gene silencing as the main mechanism of resistance, which is able to spread systemically through grafting, and show that the line 30.4 resistant plants produce both 24 and 21–22 nt N‐gene specific siRNA classes. The transgenic locus in chromosome 4 shows complex multiple insertions of four T‐DNA copies in various orientations, all with 3′ end deletions in the terminator and part of the N gene. However, for three of them, polyadenylated transcripts are produced, due to flanking tomato genome sequences acting as alternative terminators. Interestingly, starting at the fifth generation after the transformation event, some individual plants show a tomato spotted wilt virus‐susceptible phenotype. The change is associated with the disappearance of transgene‐specific transcripts and siRNAs, and with hyper‐methylation of the transgene, which proceeds gradually through the generations. Once it reaches a critical threshold, the shift from post‐transcriptional gene silencing to transcriptional silencing of the transgene eliminates the previously well established virus resistance.
Ultrasonography of theHarderian gland in the rabbit, guinea pig, and chinchilla
Authors: Hittmair Katharina M. , Tichy Alexander , Nell Barbara 
Published: June 2013

AbstractObjectiveTo evaluate theHarderian gland in rabbits, guinea pigs, and chinchillas usingB‐mode ultrasound and to determine normal size and changes in size and/or location in normal and diseased eyes and orbits by ultrasonographic measurements.ProcedureNormalHarderian glands were evaluated ultrasonographically in 20 rabbits, 10 guinea pigs, and eight chinchillas. TheHarderian gland was measured ultrasonographically in horizontal and vertical planes. NormalHarderian gland sizes were then compared with sizes in 27 rabbits, 13 guinea pigs, and three chinchillas that had exophthalmos.ResultsHarderian glands in normal rabbits were 0.69 ± 0.07 cm (mean value ± SD) horizontally and 1.33 ± 0.14 cm vertically. Harderian glands in normal guinea pigs were 0.58 ± 0.05 cm horizontally and 0.61 ± 0.10 vertically. In normal chinchillas, theHarderian glands were 0.53 ± 0.04 cm horizontally and 0.53 ± 0.03 cm vertically. Harderian glands were significantly larger in the vertical plane in rabbits with exophthalmos (P = 0.001) and in the horizontal plane in guinea pigs with exophthalmos (P = 0.018). Harderian glands of rabbits with exophthalmos were significantly larger in both diseased and healthy glands in both planes compared with those of normal rabbits. Guinea pigs and chinchillas with exophthalmos had largerHarderian glands bilaterally in only the vertical plane.ConclusionsUltrasonography is a valuable diagnostic imaging technique to evaluate theHarderian gland in the rabbit, guinea pig, and chinchilla. Retrobulbar pathologic processes cause enlargement of theHarderian gland, which may be attributable to inflammation or possible obstruction of the excretory ducts.
Evaluation of intraorbital prosthetic pigmentation using 0.3 and 1.5Tesla magnetic resonance imaging and computed tomography
Authors: Dustin Dees D. , MacLaren Nicole E. , Fritz Kevin J. , Broome Michael R. , Esson Douglas W. 
Published: June 2013

AbstractPurposeTo investigate the magnetic susceptibility artifact associated with pigmented intraorbital prosthetics when performing magnetic resonance imaging (MRI) and computed tomography (CT). Potential artifact reduction techniques were also investigated.Study DesignProspective study.MethodsFive different‐colored 20‐millimeter small animal silicone intraorbital prosthetics and two equine prosthetics were evaluated using 0.3 and 1.5Tesla (T)MRIandCT.MRIsequences includedT1‐ (T1WI) andT2‐weighted spin echo (T2WI),T2 gradient echo (T2*), short tau inversion recovery (STIR), and fluid‐attenuated inversion recovery (FLAIR). When present, artifact size was measured using computerized software by three separate observers. Artifact reduction techniques included alterations in receiver bandwidth, field of view, slice thickness, and matrix size.ResultsThe ferrous brown‐pigmented prosthetic resulted in a magnetic susceptibility artifact withMRI. No artifact was observed onCTimages. Interobserver variability was not statistically significant. For both the 0.3Tand 1.5T MRI, theT2* sequence exhibited the largest artifact surface area followed byT2WI,T1WI,STIR, andFLAIR. Decreasing slice thickness showed a decrease in artifact size; however, this difference was not statistically significant.ConclusionsThe ferrous substances in the brown intraorbital prosthetic resulted in a significant magnetic susceptibility artifact when performingMRI. Artifact reduction techniques did not significantly decrease artifact surface area. The use of ferrous brown‐pigmented prosthetics and their potential to affect futureMRimaging studies should be adequately discussed with pet owners.
Comparison of Different Assays To Assess Human Papillomavirus (HPV) Type 16- and 18-Specific Antibodies after HPV Infection and Vaccination
Authors: Scherpenisse Mirte , Schepp Rutger M. , Mollers Madelief , Mooij Sofie H. , Meijer Chris J. L. M. , Berbers Guy A. M. , van der Klis Fiona R. M. 
Published: June 2013

ABSTRACT

We compared the measurement of human papillomavirus (HPV)-specific serum antibody levels with the virus-like-particle multiplex immunoassay (VLP-MIA), competitive Luminex immunoassay (cLIA), and glutathione
S
-transferase (GST) L1-based MIA. Using a large panel of serum samples, these assays showed mutually good correlations for both naturally induced and vaccine-derived HPV-specific antibody levels. However, an adaptation of the GST L1-based MIA resulted in an improved correlation with both cLIA and VLP-MIA.
Acquired Antibodies to Merozoite Antigens in Children from Uganda with Uncomplicated or Severe Plasmodium falciparum Malaria
Authors: Ahmed Ismail Hodan , Ribacke Ulf , Reiling Linda , Normark Johan , Egwang Tom , Kironde Fred , Beeson James G. , Wahlgren Mats , Persson Kristina E. M. 
Published: June 2013

ABSTRACT

Malaria can present itself as an uncomplicated or severe disease. We have here studied the quantity and quality of antibody responses against merozoite antigens, as well as multiplicity of infection (MOI), in children from Uganda. We found higher levels of IgG antibodies toward erythrocyte-binding antigen EBA181, MSP2 of
Plasmodium falciparum
3D7 and FC27 (MSP2-3D7/FC27), and apical membrane antigen 1 (AMA1) in patients with uncomplicated malaria by enzyme-linked immunosorbent assay (ELISA) but no differences against EBA140, EBA175, MSP1, and reticulocyte-binding protein homologues Rh2 and Rh4 or for IgM against MSP2-3D7/FC27.Patients with uncomplicated malaria were also shown to have higher antibody affinities for AMA1 by surface plasmon resonance (SPR). Decreased invasion of two clinical
P. falciparum
isolates in the presence of patient plasma correlated with lower initial parasitemia in the patients, in contrast to comparisons of parasitemia to ELISA values or antibody affinities, which did not show any correlations. Analysis of the heterogeneity of the infections revealed a higher MOI in patients with uncomplicated disease, with the
P. falciparum
K1 MSP1 (MSP1-K1) and MSP2-3D7 being the most discriminative allelic markers. Higher MOIs also correlated positively with higher antibody levels in several of the ELISAs. In conclusion, certain antibody responses and MOIs were associated with differences between uncomplicated and severe malaria. When different assays were combined, some antibodies, like those against AMA1, seemed particularly discriminative. However, only decreased invasion correlated with initial parasitemia in the patient, signaling the importance of functional assays in understanding development of immunity against malaria and in evaluating vaccine candidates.
Oral Inoculation of Chickens with a Candidate Fowl Adenovirus 9 Vector
Authors: Deng Li , Sharif Shayan , Nagy Éva 
Published: June 2013

ABSTRACTFowl adenoviruses (FAdVs) are a potential alternative to human adenovirus-based vaccine vectors. Our previous studies demonstrated that a 2.4-kb region at the left end of the FAdV-9 genome is nonessential for virus replication and is suitable for the insertion or replacement of transgenes. Ourin vivostudy showed that the virus FAdV-9Δ4, lacking six open reading frames (ORFs) at the left end of its genome, replicates less efficiently than wild-type FAdV-9 (wtFAdV-9) in chickens that were infected intramuscularly. However, the fecal-oral route is the natural route of FAdV infection, and the oral administration of a vaccine confers some advantages compared to administration through other routes, especially when developing an adenovirus as a vaccine vector. Therefore, we sought to investigate the effects of FAdV-9 in orally inoculated chickens. In the present study, we orally inoculated specific-pathogen-free (SPF) chickens with FAdV-9 and FAdV-9Δ4 and assessed virus shedding, antibody response, and viral genome copy number and cytokine gene expression in tissues. Our data showed that FAdV-9Δ4 replicated less efficiently than did wtFAdV-9, as evidenced by reduced virus shedding in feces, lower viral genome copy number in tissues, and lower antibody response, which are consistent with the results of the intramuscular route of immunization. Furthermore, we found that both wtFAdV-9 and FAdV-9Δ4 upregulated the mRNA expression of alpha interferon (IFN-α), IFN-γ, and interleukin-12 (IL-12). In addition, there was a trend toward downregulation of IL-10 gene expression caused by both viruses. These findings indicate that one or more of the six deleted ORFs contribute to modulating the host response against virus infection as well as virus replicationin vivo.
Rapid Wuchereria bancrofti-Specific Antigen Wb123-Based IgG4 Immunoassays as Tools for Surveillance following Mass Drug Administration Programs on Lymphatic Filariasis
Authors: Steel Cathy , Golden Allison , Kubofcik Joseph , LaRue Nicole , de los Santos Tala , Domingo Gonzalo J. , Nutman Thomas B. 
Published: June 2013

ABSTRACT

The Global Programme to Eliminate Lymphatic Filariasis has an urgent need for rapid assays to detect ongoing transmission of lymphatic filariasis (LF) following multiple rounds of mass drug administration (MDA). Current WHO guidelines support using the antigen card immunochromatographic test (ICT), which detects active filarial infection but does not detect early exposure to LF. Recent studies found that antibody-based assays better serve this function. In the present study, two tests, a rapid IgG4 enzyme-linked immunosorbent assay (ELISA) and a lateral-flow strip immunoassay, were developed based on the highly sensitive and specific
Wuchereria bancrofti
antigen Wb123. A comparison of
W. bancrofti
-infected and -uninfected patients (with or without other helminth infections) demonstrated that both tests had high sensitivities and specificities (93 and 97% [ELISA] and 92 and 96% [strips], respectively). When the
W. bancrofti
-uninfected group was separated into those with other filarial/helminth infections (i.e., onchocerciasis, loiasis, and strongyloidiasis) and those who were parasite uninfected, the specificities of the assays varied between 91 and 100%. In addition, the geometric mean response by ELISA of
W. bancrofti
-infected patients was significantly higher than the response of those without
W. bancrofti
infection (
P
< 0.0001). Furthermore, the Wb123 ELISA and the lateral-flow strips had high positive and negative predictive values, giving valuable information on the size of survey population needed to be reasonably certain whether or not transmission is ongoing. These highly sensitive and specific IgG4 tests to the
W. bancrofti
Wb123 protein give every indication that they will serve as useful tools for post-MDA monitoring.
Serodiagnosis of Mycobacterium avium Complex and Mycobacterium abscessus Complex Pulmonary Disease by Use of IgA Antibodies to Glycopeptidolipid Core Antigen
Authors: Jeong Byeong-Ho , Kim Su-Young , Jeon Kyeongman , Lee Soo-Youn , Shin Sung Jae , Koh Won-Jung 
Published: June 2013

ABSTRACT

An enzyme immunoassay kit that detects serum IgA antibody reacting to glycopeptidolipid core antigen derived from
Mycobacterium avium
complex (MAC) was not useful for differentiating MAC pulmonary disease (PD) from
Mycobacterium abscessus
complex PD (MAB-PD). However, this assay could be useful for differentiating MAC- and MAB-PD from pulmonary tuberculosis. (This study has been registered at ClinicalTrials.gov under registration no. NCT00970801.)
Cell Extract-Containing Medium for Culture of Intracellular Fastidious Bacteria
Authors: Singh Sudhir , Kowalczewska Malgorzata , Edouard Sophie , Eldin Carole , Perreal Céline , Weber Pascal , Azza Said , Raoult Didier 
Published: June 2013

ABSTRACTThe culture of fastidious microorganisms is a critical step in infectious disease studies. As a proof-of-concept experiment, we evaluated an empirical medium containing eukaryotic cell extracts for its ability to support the growth ofCoxiella burnetii. Here, we demonstrate the exponential growth of several bacterial strains, including theC. burnetiiNine Mile phase I and phase II strains, andC. burnetiiisolates from humans and animals. Low-oxygen-tension conditions and the presence of small hydrophilic molecules and short peptides were critical for facilitating growth. Moreover, bacterial antigenicity was conserved, revealing the potential for this culture medium to be used in diagnostic tests and in the elaboration of vaccines againstC. burnetii. We were also able to grow the majority of previously tested intracellular and fastidious bacterial species, includingTropheryma whipplei,Mycobacterium bovis,Leptospiraspp.,Borreliaspp., and most putative bioterrorism agents. However, we were unable to cultureRickettsia africaeandLegionellaspp. in this medium. The versatility of this medium should encourage its use as a replacement for the cell-based culture systems currently used for growing several facultative and putative intracellular bacterial species.
The Kinase Activity of Ataxia-Telangiectasia Mutated Interferes with Adenovirus E4 Mutant DNA Replication
Authors: Gautam Dipendra , Bridge Eileen 
Published: June 2013

ABSTRACT
Adenovirus (Ad) mutants that lack early region 4 (E4) are unable to produce the early regulatory proteins that normally inactivate the Mre11/Rad50/Nbs1 (MRN) sensor complex, which is a critical component for the ability of cells to respond to DNA damage. E4 mutant infection therefore activates a DNA damage response, which in turn interferes with a productive viral infection. MRN complex proteins localize to viral DNA replication centers in E4 mutant-infected cells, and this complex is critical for activating the kinases ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR), which phosphorylate numerous substrates important for DNA repair, cell cycle checkpoint activation, and apoptosis. E4 mutant growth defects are substantially rescued in cells lacking an intact MRN complex. We have assessed the role of the downstream ATM and ATR kinases in several MRN-dependent E4 mutant phenotypes. We did not identify a role for either ATM or ATR in “repair” of E4 mutant genomes to form concatemers. ATR was also not observed to contribute to E4 mutant defects in late protein production. In contrast, the kinase activity of ATM was important for preventing efficient E4 mutant DNA replication and late gene expression. Our results suggest that the MRN complex interferes with E4 mutant DNA replication at least in part through its ability to activate ATM.
Obstruction of Dengue Virus Maturation by Fab Fragments of the 2H2 Antibody
Authors: Wang Zhiqing , Li Long , Pennington Janice G. , Sheng Ju , Yap Moh Lan , Plevka Pavel , Meng Geng , Sun Lei , Jiang Wen , Rossmann Michael G. 
Published: June 2013

ABSTRACT

The 2H2 monoclonal antibody recognizes the precursor peptide on immature dengue virus and might therefore be a useful tool for investigating the conformational change that occurs when the immature virus enters an acidic environment. During dengue virus maturation, spiky, immature, noninfectious virions change their structure to form smooth-surfaced particles in the slightly acidic environment of the
trans
-Golgi network, thereby allowing cellular furin to cleave the precursor-membrane proteins. The dengue virions become fully infectious when they release the cleaved precursor peptide upon reaching the neutral-pH environment of the extracellular space. Here we report on the cryo-electron microscopy structures of the immature virus complexed with the 2H2 antigen binding fragments (Fab) at different concentrations and under various pH conditions. At neutral pH and a high concentration of Fab molecules, three Fab molecules bind to three precursor-membrane proteins on each spike of the immature virus. However, at a low concentration of Fab molecules and pH 7.0, only two Fab molecules bind to each spike. Changing to a slightly acidic pH caused no detectable change of structure for the sample with a high Fab concentration but caused severe structural damage to the low-concentration sample. Therefore, the 2H2 Fab inhibits the maturation process of immature dengue virus when Fab molecules are present at a high concentration, because the three Fab molecules on each spike hold the precursor-membrane molecules together, thereby inhibiting the normal conformational change that occurs during maturation.
Prion Replication Elicits Cytopathic Changes in Differentiated Neurosphere Cultures
Authors: Iwamaru Yoshifumi , Takenouchi Takato , Imamura Morikazu , Shimizu Yoshihisa , Miyazawa Kohtaro , Mohri Shirou , Yokoyama Takashi , Kitani Hiroshi 
Published: June 2013

ABSTRACTThe molecular mechanisms of prion-induced cytotoxicity remain largely obscure. Currently, only a few cell culture models have exhibited the cytopathic changes associated with prion infection. In this study, we introduced a cell culture model based on differentiated neurosphere cultures isolated from the brains of neonatal prion protein (PrP)-null mice and transgenic mice expressing murine PrP (dNP0 and dNP20 cultures). Upon exposure to mouse Chandler prions, dNP20 cultures supported thede novoformation of abnormal PrP and the resulting infectivity, as assessed by bioassays. Furthermore, this culture was susceptible to various prion strains, including mouse-adapted scrapie, bovine spongiform encephalopathy, and Gerstmann-Sträussler-Scheinker syndrome prions. Importantly, a subset of the cells in the infected culture that was mainly composed of astrocyte lineage cells consistently displayed late-occurring, progressive signs of cytotoxicity as evidenced by morphological alterations, decreased cell viability, and increased lactate dehydrogenase release. These signs of cytotoxicity were not observed in infected dNP0 cultures, suggesting the requirement of endogenous PrP expression for prion-induced cytotoxicity. Degenerated cells positive for glial fibrillary acidic protein accumulated abnormal PrP and exhibited features of apoptotic death as assessed by active caspase-3 and terminal deoxynucleotidyltransferase nick-end staining. Furthermore, caspase inhibition provided partial protection from prion-mediated cell death. These results suggest that differentiated neurosphere cultures can provide anin vitrobioassay for mouse prions and permit the study of the molecular basis for prion-induced cytotoxicity at the cellular level.
A Novel Hepacivirus with an Unusually Long and Intrinsically Disordered NS5A Protein in a Wild Old World Primate
Authors: Lauck Michael , Sibley Samuel D. , Lara James , Purdy Michael A. , Khudyakov Yury , Hyeroba David , Tumukunde Alex , Weny Geoffrey , Switzer William M. , Chapman Colin A. , Hughes Austin L. , Friedrich Thomas C. , O'Connor David H. , Goldberg Tony L. 
Published: June 2013

ABSTRACT

GB virus B (GBV-B; family
Flaviviridae
, genus
Hepacivirus
) has been studied in New World primates as a model for human hepatitis C virus infection, but the distribution of GBV-B and its relatives in nature has remained obscure. Here, we report the discovery of a novel and highly divergent GBV-B-like virus in an Old World monkey, the black-and-white colobus (
Colobus guereza
), in Uganda. The new virus,
guereza
hepacivirus (GHV), clusters phylogenetically with GBV-B and recently described hepaciviruses infecting African bats and North American rodents, and it shows evidence of ancient recombination with these other hepaciviruses. Direct sequencing of reverse-transcribed RNA from blood plasma from three of nine colobus monkeys yielded near-complete GHV genomes, comprising two distinct viral variants. The viruses contain an exceptionally long nonstructural 5A (NS5A) gene, approximately half of which codes for a protein with no discernible homology to known proteins. Computational structure-based analyses indicate that the amino terminus of the GHV NS5A protein may serve a zinc-binding function, similar to the NS5A of other viruses within the family
Flaviviridae
. However, the 521-amino-acid carboxy terminus is intrinsically disordered, reflecting an unusual degree of structural plasticity and polyfunctionality. These findings shed new light on the natural history and evolution of the hepaciviruses and on the extent of structural variation within the
Flaviviridae
.
Topological Analysis of HIV-1 Glycoproteins Expressed
In Situ
on Virus Surfaces Reveals Tighter Packing but Greater Conformational Flexibility than for Soluble gp120
Authors: Tong Tommy , Osawa Keiko , Robinson James E. , Crooks Ema T. , Binley James M. 
Published: June 2013

ABSTRACT

In natural infection, antibodies interact with HIV-1 primarily through nonfunctional forms of envelope glycoproteins (Env), including uncleaved (UNC) gp160 and gp41 stumps. These antigens are important to fully characterize, as they may be decoys that promote nonneutralizing responses and may also be targets for nonneutralizing effector responses. In this study, we compared the antigenic properties of Env expressed
in situ
on pseudovirion virus-like particle (VLP) surfaces and soluble gp120 using harmonized enzyme-linked immunosorbent assays (ELISAs) and a panel of 51 monoclonal antibodies (MAbs). Only 32 of 46 soluble gp120-reactive MAbs recognized the primary UNC gp160 antigen of VLPs. Indeed, many epitopes were poorly exposed (C1, V2, C1-C4, C4, C4-V3, CD4 induced [CD4i], and PGT group 3) or obscured (C2, C5, and C1-C5) on VLPs. In further studies, VLP Env exhibited an increased degree of inter-MAb competition, the epicenter of which was the base of the V3 loop, where PGT, 2G12, V3, and CD4 binding site specificities competed. UNC gp160 also underwent more drastic soluble CD4 (sCD4)-induced conformational changes than soluble gp120, exposing CD4i, C1-C4, and V2 epitopes. A greater propensity of UNC gp160 to undergo conformational changes was also suggested by the induction of CD4i MAb binding to VLPs by a V3 MAb as well as by soluble CD4. The same effect was not observed for soluble gp120. Taken together, our data suggest that membrane-expressed UNC gp160 exists in a less “triggered” conformational state than soluble gp120 and that MAb binding to UNC gp160 tends to have greater conformational consequences.