bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishment of a Swiss Webster Mouse Model of Pneumonic Plague To Meet Essential Data Elements under the Animal Rule
Authors: Fellows Patricia , Lin Winston , Detrisac Carol , Hu Shu-Chieh , Rajendran Narayanan , Gingras Bruce , Holland Louis , Price Jessica , Bolanowski Mark , House Robert V. 
Published: February 2012

ABSTRACTA recombinant vaccine (rF1V) is being developed for protection against pneumonic plague. This study was performed to address essential data elements to establish a well-characterized Swiss Webster mouse model for licensing the rF1V vaccine using the FDA's Animal Rule. These elements include the documentation of challenge material characteristics, aerosol exposure parameters, details of the onset and severity of clinical signs, pathophysiological response to disease, and relevance to human disease. Prior to animal exposures, an evaluation of the aerosol system was performed to determine and understand the variability of the aerosol exposure system. Standardized procedures for the preparation ofYersinia pestischallenge material also were developed. The 50% lethal dose (LD50) was estimated to be 1,966 CFU using Probit analysis. Following the LD50determination, pathology was evaluated by exposing mice to a target LD99(42,890 CFU). Mice were euthanized at 12, 24, 36, 48, 60, and 72 h postexposure. At each time point, samples were collected for clinical pathology, detection of bacteria in blood and tissues, and pathology evaluations. A general increase in incidence and severity of microscopic findings was observed in the lung, lymph nodes, spleen, and liver from 36 to 72 h postchallenge. Similarly, the incidence and severity of pneumonia increased throughout the study; however, some mice died in the absence of pneumonia, suggesting that disease progression does not require the development of pneumonia. Disease pathology in the Swiss Webster mouse is similar to that observed in humans, demonstrating the utility of this pneumonic plague model that can be used by researchers investigating plague countermeasures.
Secondary Peritonitis Caused by Streptomyces viridis
Authors: Datta Priya , Arora Shilpa , Jain Ruby , Chander Jagdish , van de Sande Wendy 
Published: February 2012

ABSTRACT

Streptomyces
organisms are soil inhabitants rarely causing nonmycetomic infections. We describe a case of secondary peritonitis caused by
Streptomyces viridis
in a chronic alcoholic patient who presented with fever, abdominal distension, and pain in the abdomen. The most likely source of infection was by inoculation through multiple paracenteses, done for treatment of ascites, before the patient came to our health care center. This is the second case report of
Streptomyces
peritonitis and the first case caused by
Streptomyces viridis
, which is usually found in the soil in our geographic region.
Corynebacterium Prosthetic Joint Infection
Authors: Cazanave Charles , Greenwood-Quaintance Kerryl E. , Hanssen Arlen D. , Patel Robin 
Published: February 2012

ABSTRACTIdentification ofCorynebacteriumspecies may be challenging.Corynebacteriumspecies are occasional causes of prosthetic joint infection (PJI), but few data are available on the subject. Based on the literature,C. amycolatum,C. aurimucosum,C. jeikeium, andC. striatumare the most commonCorynebacteriumspecies that cause PJI. We designed a rapid PCR assay to detect the most common humanCorynebacteriumspecies, with a specific focus on PJI. A polyphosphate kinase gene identified using whole-genome sequence was targeted. The assay differentiates the antibiotic-resistant speciesC. jeikeiumandC. urealyticumfrom other species in a single assay. The assay was applied to a collection of humanCorynebacteriumisolates from multiple clinical sources, and clinically relevant species were detected. The assay was then tested onCorynebacteriumisolates specifically associated with PJI; all were detected. We also describe the first case ofC. simulansPJI.
Use of 5-Cyano-2,3-Ditolyl-Tetrazolium Chloride Staining as an Indicator of Biocidal Activity in a Rapid Assay for Anti-Acanthamoeba Agents
Authors: Kobayashi Takeshi , Mito Tsuyoshi , Watanabe Narumi , Suzuki Takashi , Shiraishi Atsushi , Ohashi Yuichi 
Published: February 2012

ABSTRACT

The usefulness of 5-cyano-2,3-ditolyl-tetrazolium chloride (CTC) staining to determine the respiratory activity of
Acanthamoeba
was evaluated in this study.
Acanthamoeba
trophozoites and cysts have a red fluorescence after staining with CTC. To determine the effectiveness of CTC staining as a CTC biocidal assay for
Acanthamoeba
, the trophozoites and cysts of
Acanthamoeba castellanii
(ATCC 5037) were treated with serial concentrations of disinfectant solutions, namely, polyhexamethylene biguanide (PHMB) and commercial soft contact lens (SCL) disinfectant solutions. The treated
Acanthamoeba
organisms were stained with CTC, and their respiratory activity was determined by the intensity of fluorescence in a fluorescence microplate reader. The survival rates of the same samples were determined by a culture-dependent biocidal assay using the Spearman-Karber method. Our results showed that the respiratory activities determined by the CTC biocidal assay and the survival rates determined by the culture-dependent biocidal assay for
Acanthamoeba
trophozoites and cysts decreased in a dose-dependent way after PHMB treatments, and the results were significantly correlated (
r
= 0.83 and
P
< 0.01 for trophozoites;
r
= 0.60 and
P
< 0.01 for cysts; Spearman rank correlation test). The respiratory activities in the trophozoites and cysts treated with SCL disinfectant solutions were significantly correlated with the survival rate (
r
= 0.70 and
P
< 0.01 for trophozoites;
r
= 0.64 and
P
< 0.01 for cysts; Spearman rank correlation test). The significant correlation of the results indicated that the CTC biocidal assay can be used as an alternative method to a culture-dependent biocidal assay. The CTC biocidal assay is a rapid and simple method to test the effectiveness of disinfectant solutions against
Acanthamoeba
trophozoites and cysts.
Empyema Caused by Mycoplasma salivarium
Authors: Baracaldo Rafael , Foltzer Michael , Patel Robin , Bourbeau Paul 
Published: February 2012

ABSTRACT

Mycoplasma salivarium
infections outside the oral cavity are rare. We describe a 49-year-old man with laryngeal cancer and right pleural space infection with
M. salivarium
. To our knowledge, this is the first report of empyema due to
Mycoplasma salivarium
.
The UL36 Tegument Protein of Herpes Simplex Virus 1 Has a Composite Binding Site at the Capsid Vertices
Authors: Cardone Giovanni , Newcomb William W. , Cheng Naiqian , Wingfield Paul T. , Trus Benes L. , Brown Jay C. , Steven Alasdair C. 
Published: February 2012

ABSTRACT
Herpesviruses have an icosahedral nucleocapsid surrounded by an amorphous tegument and a lipoprotein envelope. The tegument comprises at least 20 proteins destined for delivery into the host cell. As the tegument does not have a regular structure, the question arises of how its proteins are recruited. The herpes simplex virus 1 (HSV-1) tegument is known to contact the capsid at its vertices, and two proteins, UL36 and UL37, have been identified as candidates for this interaction. We show that the interaction is mediated exclusively by UL36. HSV-1 nucleocapsids extracted from virions shed their UL37 upon incubation at 37°C. Cryo-electron microscopy (cryo-EM) analysis of capsids with and without UL37 reveals the same penton-capping density in both cases. As no other tegument proteins are retained in significant amounts, it follows that this density feature (∼100 kDa) represents the ordered portion of UL36 (336 kDa). It binds between neighboring UL19 protrusions and to an adjacent UL17 molecule. These observations support the hypothesis that UL36 plays a major role in the tegumentation of the virion, providing a flexible scaffold to which other tegument proteins, including UL37, bind. They also indicate how sequential conformational changes in the maturing nucleocapsid control the ordered binding, first of UL25/UL17 and then of UL36.
Paucity of HIV DNA Methylation in Latently Infected, Resting CD4
+
T Cells from Infected Individuals Receiving Antiretroviral Therapy
Authors: Blazkova Jana , Murray Danielle , Justement J. Shawn , Funk Emily K. , Nelson Amy K. , Moir Susan , Chun Tae-Wook , Fauci Anthony S. 
Published: February 2012

ABSTRACT

Maintenance of HIV latency
in vitro
has been linked to methylation of HIV DNA. However, examinations of the degree of methylation of HIV DNA in the latently infected, resting CD4
+
T cells of infected individuals receiving antiretroviral therapy have been limited. Here, we show that methylation of the HIV 5′ long terminal repeat (LTR) in the latent viral reservoir of HIV-infected aviremic individuals receiving therapy is rare, suggesting that other mechanisms are likely involved in the persistence of viral latency.
Live-Cell Imaging Reveals Multiple Interactions between Epstein-Barr Virus Nuclear Antigen 1 and Cellular Chromatin during Interphase and Mitosis
Authors: Jourdan Nathalie , Jobart-Malfait Aude , Dos Reis Gabriel , Quignon Frédérique , Piolot Tristan , Klein Christophe , Tramier Marc , Coppey-Moisan Maïté , Marechal Vincent 
Published: February 2012

ABSTRACT
Epstein-Barr virus (EBV) establishes a life-long latent infection in humans. In proliferating latently infected cells, EBV genomes persist as multiple episomes that undergo one DNA replication event per cell cycle and remain attached to the mitotic chromosomes. EBV nuclear antigen 1 (EBNA-1) binding to the episome and cellular genome is essential to ensure proper episome replication and segregation. However, the nature and regulation of EBNA-1 interaction with chromatin has not been clearly elucidated. This activity has been suggested to involve EBNA-1 binding to DNA, duplex RNA, and/or proteins. EBNA-1 binding protein 2 (EBP2), a nucleolar protein, has been proposed to act as a docking protein for EBNA-1 on mitotic chromosomes. However, there is no direct evidence thus far for EBP2 being associated with EBNA-1 during mitosis. By combining video microscopy and Förster resonance energy transfer (FRET) microscopy, we demonstrate here for the first time that EBNA-1 and EBP2 interact in the nucleoplasm, as well as in the nucleoli during interphase. However, in strong contrast to the current proposed model, we were unable to observe any interaction between EBNA-1 and EBP2 on mitotic chromosomes. We also performed a yeast double-hybrid screening, followed by a FRET analysis, that led us to identify HMGB2 (high-mobility group box 2), a well-known chromatin component, as a new partner for EBNA-1 on chromatin during interphase and mitosis. Although the depletion of HMGB2 partly altered EBNA-1 association with chromatin in HeLa cells during interphase and mitosis, it did not significantly impact the maintenance of EBV episomes in Raji cells.
Hsp70 Protein Positively Regulates Rabies Virus Infection
Authors: Lahaye Xavier , Vidy Aurore , Fouquet Baptiste , Blondel Danielle 
Published: February 2012

ABSTRACTThe Hsp70 chaperone plays a central role in multiple processes within cells, including protein translation, folding, intracellular trafficking, and degradation. This protein is implicated in the replication of numerous viruses. We have shown that rabies virus infection induced the cellular expression of Hsp70, which accumulated in Negri body-like structures, where viral transcription and replication take place. In addition, Hsp70 is present in both nucleocapsids purified from infected cells and in purified virions. Hsp70 has been shown to interact with the nucleoprotein N. The downregulation of Hsp70, using specific chaperone inhibitors, such as quercetin or RNA interference, resulted in a significant decrease of the amount of viral mRNAs, viral proteins, and virus particles. These results indicate that Hsp70 has a proviral function during rabies virus infection and suggest that Hsp70 is involved in at least one stage(s) of the viral life cycle, such as viral transcription, translation, and/or production. The mechanism by which Hsp70 controls viral infection will be discussed.
Anti-HIV-1 Activity of Elafin Is More Potent than Its Precursor's, Trappin-2, in Genital Epithelial Cells
Authors: Drannik Anna G. , Nag Kakon , Yao Xiao-Dan , Henrick Bethany M. , Jain Sumiti , Ball T. Blake , Plummer Francis A. , Wachihi Charles , Kimani Joshua , Rosenthal Kenneth L. 
Published: February 2012

ABSTRACT

Cervicovaginal lavage fluid (CVL) is a natural source of anti-HIV-1 factors; however, molecular characterization of the anti-HIV-1 activity of CVL remains elusive. In this study, we confirmed that CVLs from HIV-1-resistant (HIV-R) compared to HIV-1-susceptible (HIV-S) commercial sex workers (CSWs) contain significantly larger amounts of serine antiprotease trappin-2 (Tr) and its processed form, elafin (E). We assessed anti-HIV-1 activity of CVLs of CSWs and recombinant E and Tr on genital epithelial cells (ECs) that possess (TZM-bl) or lack (HEC-1A) canonical HIV-1 receptors. Our results showed that immunodepletion of 30% of Tr/E from CVL accounted for up to 60% of total anti-HIV-1 activity of CVL. Knockdown of endogenous Tr/E in HEC-1A cells resulted in significantly increased shedding of infectious R5 and X4 HIV-1. Pretreatment of R5, but not X4 HIV-1, with either Tr or E led to inhibition of HIV-1 infection of TZM-bl cells. Interestingly, when either HIV-1 or cells lacking canonical HIV-1 receptors were pretreated with Tr or E, HIV-1 attachment and transcytosis were significantly reduced, and decreased attachment was not associated with altered expression of syndecan-1 or CXCR4. Determination of 50% inhibitory concentrations (IC
50
) of Tr and E anti-HIV-1 activity indicated that E is ∼130 times more potent than its precursor, Tr, despite their equipotent antiprotease activities. This study provides the first experimental evidence that (i) Tr and E are among the principal anti-HIV-1 molecules of CVL; (ii) Tr and E affect cell attachment and transcytosis of HIV-1; (iii) E is more efficient than Tr regarding anti-HIV-1 activity; and (iv) the anti-HIV-1 effect of Tr and E is contextual.
The Lipid Raft-Associated Protein CD98 Is Required for Vaccinia Virus Endocytosis
Authors: Schroeder Nina , Chung Che-Sheng , Chen Chein-Hung , Liao Chung-Lin , Chang Wen 
Published: February 2012

ABSTRACTMature vaccinia virus (vaccinia MV) infects a broad range of animalsin vivoand cell culturesin vitro; however, the cellular receptors that determine vaccinia MV tropism and entry pathways are poorly characterized. Here, we performed quantitative proteomic analyses of lipid raft-associated proteins upon vaccinia MV entry into HeLa cells. We found that a type II membrane glycoprotein, CD98, is enriched in lipid rafts upon vaccinia MV infection compared to mock-infected HeLa cells. The knockdown of CD98 expression in HeLa cells significantly reduced vaccinia MV entry. Furthermore, CD98 knockout (KO) mouse embryonic fibroblasts (MEFs) also exhibited reduced vaccinia MV infectivity without affecting MV attachment to cells, suggesting a role for CD98 in the postbinding step of virus entry. Further characterization with inhibitors and dominant negative proteins that block different endocytic pathways revealed that vaccinia MV entry into MEFs occurs through a clathrin-independent, caveolin-independent, dynamin-dependent, fluid-phase endocytic pathway, implying that CD98 plays a specific role in the vaccinia MV endocytic pathway. Infections of wild-type and CD98 KO MEF cells with different strains of vaccinia MV provided further evidence that CD98 plays a specific role in MV endocytosis but not in plasma membrane fusion. Finally, different CD98-C69 chimeric proteins were expressed in CD98 KO MEFs, but none were able to reconstitute MV infectivity, suggesting that the overall structure of the CD98 protein is required for vaccinia MV endocytosis.
Strain-Specific Contribution of NS1-Activated Phosphoinositide 3-Kinase Signaling to Influenza A Virus Replication and Virulence
Authors: Ayllon Juan , Hale Benjamin G. , García-Sastre Adolfo 
Published: February 2012

ABSTRACT
We generated influenza A viruses expressing mutant NS1 proteins unable to activate phosphoinositide 3-kinase (PI3K) in two mouse-lethal strains. The recombinant A/Puerto Rico/8/34 (rPR8) mutant virus strain was attenuated and caused reduced morbidity/mortality. For the recombinant A/WSN/33 (rWSN) virus strain, the inability to stimulate PI3K had minimal impact on replication or morbidity/mortality. Cell-based assays revealed subtly distinct intracellular sites of NS1 localization and PI3K activation between the strains. We hypothesize that specific spatially regulated NS1-activated PI3K signaling, rather than simply the total level of active PI3K, is important for virus replication and virulence.
Temperature-Sensitive Mutants and Revertants in the Coronavirus Nonstructural Protein 5 Protease (3CLpro) Define Residues Involved in Long-Distance Communication and Regulation of Protease Activity
Authors: Stobart Christopher C. , Lee Alice S. , Lu Xiaotao , Denison Mark R. 
Published: February 2012

ABSTRACT

Positive-strand RNA virus genomes are translated into polyproteins that are processed by viral proteases to yield functional intermediate and mature proteins. Coronaviruses (CoVs) carry genes that encode an nsp5 protease (also known as 3CLpro or Mpro) responsible for 11 maturation cleavages. The nsp5 structure contains two chymotrypsin-like domains (D1 and D2) and a unique domain (D3), and forms functional dimers. However, little is known of interactions or communication across the structure of the protease during nsp5 activity. Using reverse genetic mutagenesis of the CoV murine hepatitis virus (MHV) nsp5, we identified a new temperature-sensitive (
ts
) mutation in D2 of nsp5 (Ser133Ala) and confirmed a
ts
residue in D3 (Phe219Leu). Both D2
-ts
S133A and D3-
ts
F219L were impaired for viral replication and nsp5-mediated polyprotein processing at the nonpermissive temperature. Passage of
ts
S133A and
ts
F219L at the nonpermissive temperature resulted in emergence of multiple second-site suppressor mutations, singly and in combinations. Among the second-site mutations, a D2 His134Tyr change suppressed the
ts
phenotype of D2-
ts
S133A and D3-
ts
F219L, as well as the previously reported D2-
ts
V148A. Analysis of multiple CoV nsp5 structures, and alignment of nonredundant nsp5 primary sequences, demonstrated that
ts
and suppressor residues are not conserved across CoVs and are physically distant (>10 Å) from each other, from catalytic and substrate-binding residues, and from the nsp5 dimer interface. These findings demonstrate that long-distance communication pathways between multiple residues and domains of nsp5 play a significant role in nsp5 activity and viral replication, suggesting possible novel targets for non-active site inhibitors of nsp5.
Latency Type-Dependent Modulation of Epstein-Barr Virus-Encoded Latent Membrane Protein 1 Expression by Type I Interferons in B Cells
Authors: Salamon Daniel , Adori Monika , Ujvari Dorina , Wu Liang , Kis Lorand L. , Madapura Harsha S. , Nagy Noemi , Klein George , Klein Eva 
Published: February 2012

ABSTRACTWe report that type I interferons (IFNs) upregulate latent membrane protein 1 (LMP-1) expression by direct activation of the ED-L1 promoter in several Epstein-Barr virus (EBV)-carrying Burkitt's lymphoma lines. In EBV-infected primary B cells, IFN-α transiently upregulates LMP-1 mRNA, but not protein levels, followed by downregulation of both, suggesting a novel antiproliferative mechanism of type I IFNs. Furthermore, our results may explain the expression of LMP-1 in memory B cells of systemic lupus erythematosus patients.
Efficient Nef-Mediated Downmodulation of TCR-CD3 and CD28 Is Associated with High CD4
+
T Cell Counts in Viremic HIV-2 Infection
Authors: Khalid Mohammad , Yu Hangxing , Sauter Daniel , Usmani Shariq M. , Schmokel Jan , Feldman Jerome , Gruters Rob A. , van der Ende Marchina E. , Geyer Matthias , Rowland-Jones Sarah , Osterhaus Albert D. , Kirchhoff Frank 
Published: February 2012

ABSTRACT

The role of the multifunctional accessory Nef protein in the immunopathogenesis of HIV-2 infection is currently poorly understood. Here, we performed comprehensive functional analyses of 50
nef
genes from 21 viremic (plasma viral load, >500 copies/ml) and 16 nonviremic (<500) HIV-2-infected individuals. On average,
nef
alleles from both groups were equally active in modulating CD4, TCR-CD3, CD28, MHC-I, and Ii cell surface expression and in enhancing virion infectivity. Thus, many HIV-2-infected individuals efficiently control the virus in spite of efficient Nef function. However, the potency of
nef
alleles in downmodulating TCR-CD3 and CD28 to suppress the activation and apoptosis of T cells correlated with high numbers of CD4
+
T cells in viremic patients. No such correlations were observed in HIV-2-infected individuals with undetectable viral load. Further functional analyses showed that the Nef-mediated downmodulation of TCR-CD3 suppressed the induction of Fas, Fas-L, PD-1, and CTLA-4 cell surface expression as well as the secretion of gamma interferon (IFN-γ) by primary CD4
+
T cells. Moreover, we identified a single naturally occurring amino acid variation (I132T) in the core domain of HIV-2 Nef that selectively disrupts its ability to downmodulate TCR-CD3 and results in functional properties highly reminiscent of HIV-1 Nef proteins. Taken together, our data suggest that the efficient Nef-mediated downmodulation of TCR-CD3 and CD28 help viremic HIV-2-infected individuals to maintain normal CD4
+
T cell homeostasis by preventing T cell activation and by suppressing the induction of death receptors that may affect the functionality and survival of both virally infected and uninfected bystander cells.
PGV04, an HIV-1 gp120 CD4 Binding Site Antibody, Is Broad and Potent in Neutralization but Does Not Induce Conformational Changes Characteristic of CD4
Authors: Falkowska Emilia , Ramos Alejandra , Feng Yu , Zhou Tongqing , Moquin Stephanie , Walker Laura M. , Wu Xueling , Seaman Michael S. , Wrin Terri , Kwong Peter D. , Wyatt Richard T. , Mascola John R. , Poignard Pascal , Burton Dennis R. 
Published: February 2012

ABSTRACT
Recently, several broadly neutralizing monoclonal antibodies (bnMAbs) directed to the CD4-binding site (CD4bs) of gp120 have been isolated from HIV-1-positive donors. These include VRC01, 3BNC117, and NIH45-46, all of which are capable of neutralizing about 90% of circulating HIV-1 isolates and all of which induce conformational changes in the HIV-1 gp120 monomer similar to those induced by the CD4 receptor. In this study, we characterize PGV04 (also known as VRC-PG04), a MAb with potency and breadth that rivals those of the prototypic VRC01 and 3BNC117. When screened on a large panel of viruses, the neutralizing profile of PGV04 was distinct from those of CD4, b12, and VRC01. Furthermore, the ability of PGV04 to neutralize pseudovirus containing single alanine substitutions exhibited a pattern distinct from those of the other CD4bs MAbs. In particular, substitutions D279A, I420A, and I423A were found to abrogate PGV04 neutralization. In contrast to VRC01, PGV04 did not enhance the binding of 17b or X5 to their epitopes (the CD4-induced [CD4i] site) in the coreceptor region on the gp120 monomer. Furthermore, in contrast to CD4, none of the anti-CD4bs MAbs induced the expression of the 17b epitope on cell surface-expressed cleaved Env trimers. We conclude that potent CD4bs bnMAbs can display differences in the way they recognize and access the CD4bs and that mimicry of CD4, as assessed by inducing conformational changes in monomeric gp120 that lead to enhanced exposure of the CD4i site, is not uniquely correlated with effective neutralization at the site of CD4 binding on HIV-1.