bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Level Cellular and Humoral Immune Responses in Guinea Pigs Immunized Intradermally with a Heat-Inactivated Varicella-Zoster Virus Vaccine
Authors: Sarkadi Julia , Jankovics Mate , Fodor Kinga , Kis Zoltan , Takacs Maria , Visontai Ildiko , Jankovics Istvan , Gonczol Eva 
Published: March 2015

ABSTRACTThe threat of varicella and herpes zoster in immunocompromised individuals necessitates the development of a safe and effective varicella-zoster virus (VZV) vaccine. The immune responses of guinea pigs to the intradermal (i.d.) or subcutaneous (s.c.) administration of a heat-inactivated or live VZV vaccine were investigated. Relative to nonimmunized animals, a single 399-PFU dose of vaccine induced nonsignificant increases in gamma interferon (IFN-γ), granzyme B, and perforin mRNA expression in the splenocytes of all groups, while two i.d. administrations of the inactivated vaccine increased IFN-γ mRNA expression significantly (P< 0.005). A single 1,995-PFU dose significantly increased the expression of IFN-γ mRNA in the groups receiving the vaccine either i.d. (P< 0.005) or s.c. (P< 0.05), that of granzyme B mRNA in the groups immunized i.d. with the inactivated (P< 0.005) or live (P< 0.005) vaccine, and that of perforin mRNA in the animals that received the inactivated vaccine i.d. (P< 0.005). Importantly, increases in the expression of IFN-γ (P= 0.025), granzyme B (P= 0.004), and perforin (P> 0.05) mRNAs were observed in the animals immunized i.d. with 1,995 PFU of inactivated vaccine relative to those immunized s.c. with the same dose. The proportion of animals expressing IFN-γ mRNA mirrored the proportion expressing IFN-γ protein (correlation coefficient of 0.88). VZV glycoprotein-specific and virus-neutralizing antibodies were produced with no significant intergroup differences. A booster i.d. administration of the 399-PFU dose of heat-inactivated vaccine enhanced the antibody responses. These results demonstrate that i.d. administration of an inactivated VZV vaccine can be an efficient mode of immunization against VZV.
Avoidance of Autophagy Mediated by PlcA or ActA Is Required for Listeria monocytogenes Growth in Macrophages
Authors: Mitchell Gabriel , Ge Liang , Huang Qiongying , Chen Chen , Kianian Sara , Roberts Mary F. , Schekman Randy , Portnoy Daniel A. 
Published: March 2015

ABSTRACTListeria monocytogenesis a facultative intracellular pathogen that escapes from phagosomes and grows in the cytosol of infected host cells. Most of the determinants that govern its intracellular life cycle are controlled by the transcription factor PrfA, including the pore-forming cytolysin listeriolysin O (LLO), two phospholipases C (PlcA and PlcB), and ActA. We constructed a strain that lacked PrfA but expressed LLO from a PrfA-independent promoter, thereby allowing the bacteria to gain access to the host cytosol. This strain did not grow efficiently in wild-type macrophages but grew normally in macrophages that lacked ATG5, a component of the autophagy LC3 conjugation system. This strain colocalized more with the autophagy marker LC3 (42% ± 7%) at 2 h postinfection, which constituted a 5-fold increase over the colocalization exhibited by the wild-type strain (8% ± 6%). While mutants lacking the PrfA-dependent virulence factor PlcA, PlcB, or ActA grew normally, a double mutant lacking both PlcA and ActA failed to grow in wild-type macrophages and colocalized more with LC3 (38% ± 5%). Coexpression of LLO and PlcA in a PrfA-negative strain was sufficient to restore intracellular growth and decrease the colocalization of the bacteria with LC3. In a cell-free assay, purified PlcA protein blocked LC3 lipidation, a key step in early autophagosome biogenesis, presumably by preventing the formation of phosphatidylinositol 3-phosphate (PI3P). The results of this study showed that avoidance of autophagy byL. monocytogenesprimarily involves PlcA and ActA and that either one of these factors must be present forL. monocytogenesgrowth in macrophages.
Toll-Like Receptor 2-Dependent Extracellular Signal-Regulated Kinase Signaling in Mycobacterium tuberculosis-Infected Macrophages Drives Anti-Inflammatory Responses and Inhibits Th1 Polarization of Responding T Cells
Authors: Richardson Edward T. , Shukla Supriya , Sweet David R. , Wearsch Pamela A. , Tsichlis Philip N. , Boom W. Henry , Harding Clifford V. 
Published: March 2015

ABSTRACTMycobacterium tuberculosissurvives within macrophages and employs immune evasion mechanisms to persist in the host. Protective T helper type 1 (Th1) responses are induced, and the immune response in most individuals is sufficient to restrictM. tuberculosisto latent infection, but most infections are not completely resolved. As T cells and macrophages respond, a balance is established between protective Th1-associated and other proinflammatory cytokines, such as interleukin-12 (IL-12), interferon gamma (IFN-γ), and tumor necrosis factor alpha, and anti-inflammatory cytokines, such as IL-10. The mechanisms by whichM. tuberculosismodulates host responses to promote its survival remain unclear. In these studies, we demonstrate thatM. tuberculosisinduction of IL-10, suppression of IL-12, and inhibition of class II major histocompatibility complex (MHC-II) molecules in infected macrophages are all driven by Toll-like receptor 2 (TLR2)-dependent activation of the extracellular signal-regulated kinases (ERK). Elimination of ERK signaling downstream of TLR2 by pharmacologic inhibition with U0126 or genetic deletion ofTpl2blocks IL-10 secretion and enhances IL-12 p70 secretion. We demonstrate thatM. tuberculosisregulation of these pathways in macrophages affects T cell responses to infected macrophages. Thus, genetic blockade of the ERK pathway inTpl2−/−macrophages enhances Th1 polarization and IFN-γ production by antigen-specific CD4+T cells responding toM. tuberculosisinfection. These data indicate thatM. tuberculosisand its potent TLR2 ligands activate ERK signaling in macrophages to promote anti-inflammatory macrophage responses and blunt Th1 responses against the pathogen.
Glutamate Racemase Mutants of Bacillus anthracis
Authors: Oh So-Young , Richter Stefan G. , Missiakas Dominique M. , Schneewind Olaf 
Published: March 2015

ABSTRACT

d
-Glutamate is an essential component of bacterial peptidoglycan and a building block of the poly-γ-
d
-glutamic acid (PDGA) capsule of
Bacillus anthracis
, the causative agent of anthrax. Earlier work suggested that two glutamate racemases, encoded by
racE1
and
racE2
, are each essential for growth of
B. anthracis
, supplying
d
-glutamic acid for the synthesis of peptidoglycan and PDGA capsule. Earlier work could not explain, however, why two enzymes that catalyze the same reaction may be needed for bacterial growth. Here, we report that deletion of
racE1
or
racE2
did not prevent growth of
B. anthracis
Sterne (pXO1
+
pXO2
−
), the noncapsulating vaccine strain, or of
B. anthracis
Ames (pXO1
+
pXO2
+
), a fully virulent, capsulating isolate. While mutants with deletions in
racE1
and
racE2
were not viable,
racE2
deletion delayed vegetative growth of
B. anthracis
following spore germination and caused aberrant cell shapes, phenotypes that were partially restored by exogenous
d
-glutamate. Deletion of
racE1
or
racE2
from
B. anthracis
Ames did not affect the production or stereochemical composition of the PDGA capsule. A model is presented whereby
B. anthracis
, similar to
Bacillus subtilis
, utilizes two functionally redundant racemase enzymes to synthesize
d
-glutamic acid for peptidoglycan synthesis.

IMPORTANCE
Glutamate racemases, enzymes that convert
l
-glutamate to
d
-glutamate, are targeted for antibiotic development. Glutamate racemase inhibitors may be useful for the treatment of bacterial infections such as anthrax, where the causative agent,
B. anthracis
, requires
d
-glutamate for the synthesis of peptidoglycan and poly-γ-
d
-glutamic acid (PDGA) capsule. Here we show that
B. anthracis
possesses two glutamate racemase genes that can be deleted without abolishing either bacterial growth or PDGA synthesis. These data indicate that drug candidates must inhibit both glutamate racemases, RacE1 and RacE2, in order to block
B. anthracis
growth and achieve therapeutic efficacy.
The Sinorhizobium meliloti SyrM Regulon: Effects on Global Gene Expression Are Mediated by
syrA
and
nodD3
Authors: Barnett Melanie J. , Long Sharon R. 
Published: March 2015

ABSTRACT

In
Sinorhizobium meliloti
, three NodD transcriptional regulators activate bacterial nodulation (
nod
) gene expression. NodD1 and NodD2 require plant compounds to activate
nod
genes. The NodD3 protein does not require exogenous compounds to activate
nod
gene expression; instead, another transcriptional regulator, SyrM, activates
nodD3
expression. In addition, NodD3 can activate
syrM
expression. SyrM also activates expression of another gene,
syrA
, which when overexpressed causes a dramatic increase in exopolysaccharide production. In a previous study, we identified more than 200 genes with altered expression in a strain overexpressing
nodD3
. In this work, we define the transcriptomes of strains overexpressing
syrM
or
syrA
. The
syrM
,
nodD3
, and
syrA
overexpression transcriptomes share similar gene expression changes; analyses imply that
nodD3
and
syrA
are the only targets directly activated by SyrM. We propose that most of the gene expression changes observed when
nodD3
is overexpressed are due to NodD3 activation of
syrM
expression, which in turn stimulates SyrM activation of
syrA
expression. The subsequent increase in SyrA abundance results in broad changes in gene expression, most likely mediated by the ChvI-ExoS-ExoR regulatory circuit.

IMPORTANCE
Symbioses with bacteria are prevalent across the animal and plant kingdoms. Our system of study, the rhizobium-legume symbiosis (
Sinorhizobium meliloti
and
Medicago
spp.), involves specific host-microbe signaling, differentiation in both partners, and metabolic exchange of bacterial fixed nitrogen for host photosynthate. During this complex developmental process, both bacteria and plants undergo profound changes in gene expression. The
S. meliloti
SyrM-NodD3-SyrA and ChvI-ExoS-ExoR regulatory circuits affect gene expression and are important for optimal symbiosis. In this study, we defined the transcriptomes of
S. meliloti
overexpressing SyrM or SyrA. In addition to identifying new targets of the SyrM-NodD3-SyrA regulatory circuit, our work further suggests how it is linked to the ChvI-ExoS-ExoR regulatory circuit.
Has CXCL13 an Added Value in Diagnosis of Neurosyphilis?
Authors: Mothapo Khutso M. , Verbeek Marcel M. , van der Velden Lieven B. , Ang C. Wim , Koopmans Peter P. , van der Ven Andre , Stelma Foekje 
Published: March 2015

ABSTRACT

In patients with syphilis, central nervous system (CNS) involvement is often difficult to determine. In patients who also are infected with human immunodeficiency virus (HIV), this is even more challenging, as cerebrospinal fluid (CSF) pleocytosis can be attributed to HIV, syphilis, or both. Hence, this study investigated (i) CSF chemokine (C-X-C motif) ligand 13 (CXCL13) as a potential marker to diagnose neurosyphilis in HIV-infected individuals and (ii) the added value of CSF CXCL13 to conventional CSF biomarkers, such as the rapid plasma reagin test (RPR), in diagnosing neurosyphilis. We included 103 syphilis patients from two centers in The Netherlands: 47 non-HIV-infected patients and 56 HIV-infected patients. A positive CSF-RPR was regarded as the gold standard for neurosyphilis. CSF CXCL13 levels were significantly higher in neurosyphilis patients when neurosyphilis was diagnosed by CSF-RPR (
P
= 0.0002) than in the syphilis control group. The sensitivity and specificity of CSF CXCL13 (cutoff of 76.3 pg/ml) to diagnose neurosyphilis by using positive CSF-RPR as the gold standard were 50% and 90%, respectively. CSF CXCL13 had an added value to CSF-RPR positivity in 70% of HIV-positive patients and in 33% of HIV-negative patients. Our data show that CSF CXCL13 might be a potential additional marker in neurosyphilis when other markers are not conclusive. The added value of CSF CXCL13 measurement to the current neurosyphilis gold standard appears to benefit HIV-positive patients more than HIV-negative patients.
Macrophages Are Phenotypically and Functionally Diverse across Tissues in Simian Immunodeficiency Virus-Infected and Uninfected Asian Macaques
Authors: Ortiz Alexandra M. , DiNapoli Sarah R. , Brenchley Jason M. 
Published: March 2015

ABSTRACTMacrophages regulate tissue immunity, orchestrating the initiation and resolution of antimicrobial immune responses and repair of damaged tissue architecture. Their dysfunction can, thus, manifest in either pro- and anti-inflammatory responses. Indeed, despite the importance of macrophage function in health and disease, the role of tissue-resident macrophages in human immunodeficiency virus (HIV) disease progression remains incompletely defined. Here, we use flow cytometry to assess the phenotypes and functions of macrophages isolated from the spleens, axillary lymph nodes, colons, jejuna, and livers of healthy and chronically simian immunodeficiency virus (SIV)-infected Asian macaques, the prominent nonhuman primate model for HIV infection. Our data demonstrate that macrophages from healthy animals exhibit considerable phenotypic and functional heterogeneity across tissues and across a variety of stimuli. Further, our analysis reveals changes in the lipopolysaccharide (LPS) responsiveness of macrophages isolated from SIV-infected animals. We anticipate that our findings will inform future research into macrophage-directed immunity across a variety of primate diseases.IMPORTANCEThese findings highlight the functional and phenotypic heterogeneity of tissue macrophages in different anatomic sites and as a result of SIV infection. We believe that our data will lead to novel therapeutic interventions aimed at altering the proinflammatory capacity of tissue macrophages in progressively HIV-infected individuals.
A Single Amino Acid Substitution in the NS2A Protein of Japanese Encephalitis Virus Affects Virus Propagation
In Vitro
but Not
In Vivo
Authors: Takamatsu Yuki , Morita Kouichi , Hayasaka Daisuke 
Published: March 2015

ABSTRACT

We identified a unique amino acid of NS2A
113
, phenylalanine, that affects the efficient propagation of two Japanese encephalitis virus strains, JaTH160 and JaOArS982, in neuroblastoma Neuro-2a cells but not in cell lines of extraneural origin. This amino acid did not affect viral loads in the brain or survival curves in mice. These findings suggest that virus propagation
in vitro
may not reflect the level of virus neuroinvasiveness
in vivo
.
What Is the Reservoir of Emergent Human Norovirus Strains?
Authors: Karst Stephanie M. , Baric Ralph S. 
Published: March 2015

ABSTRACT

Since 1996, there have been at least six human norovirus pandemics. All of the pandemic strains are genetically related, segregating in the genogroup II, genotype 4 (GII.4) cluster within the
Norovirus
genus. Evidence indicates that these strains are closely related but antigenically distinct, supporting immune-driven viral evolution. Thus, norovirus vaccines will likely require periodic reformulation to protect from newly emergent strains. A major obstacle is that the reservoir of emergent strains is unknown. Noroviruses display tight species specificity and there is no evidence supporting zoonotic transmission, so an animal reservoir is considered unlikely. Moreover, available data indicate minimal viral diversity in most natural human infections. In this Gem, we discuss the widely speculated idea that chronically infected immunocompromised individuals are norovirus reservoirs and provide a rationale for the theory that elderly and malnourished hosts may also represent norovirus reservoirs.
Genome Diversity of Epstein-Barr Virus from Multiple Tumor Types and Normal Infection
Authors: Palser Anne L. , Grayson Nicholas E. , White Robert E. , Corton Craig , Correia Samantha , Ba abdullah Mohammed M. , Watson Simon J. , Cotten Matthew , Arrand John R. , Murray Paul G. , Allday Martin J. , Rickinson Alan B. , Young Lawrence S. , Farrell Paul J. , Kellam Paul 
Published: March 2015

ABSTRACT
Epstein-Barr virus (EBV) infects most of the world's population and is causally associated with several human cancers, but little is known about how EBV genetic variation might influence infection or EBV-associated disease. There are currently no published wild-type EBV genome sequences from a healthy individual and very few genomes from EBV-associated diseases. We have sequenced 71 geographically distinct EBV strains from cell lines, multiple types of primary tumor, and blood samples and the first EBV genome from the saliva of a healthy carrier. We show that the established genome map of EBV accurately represents all strains sequenced, but novel deletions are present in a few isolates. We have increased the number of type 2 EBV genomes sequenced from one to 12 and establish that the type 1/type 2 classification is a major feature of EBV genome variation, defined almost exclusively by variation of EBNA2 and EBNA3 genes, but geographic variation is also present. Single nucleotide polymorphism (SNP) density varies substantially across all known open reading frames and is highest in latency-associated genes. Some T-cell epitope sequences in EBNA3 genes show extensive variation across strains, and we identify codons under positive selection, both important considerations for the development of vaccines and T-cell therapy. We also provide new evidence for recombination between strains, which provides a further mechanism for the generation of diversity. Our results provide the first global view of EBV sequence variation and demonstrate an effective method for sequencing large numbers of genomes to further understand the genetics of EBV infection.

IMPORTANCE
Most people in the world are infected by Epstein-Barr virus (EBV), and it causes several human diseases, which occur at very different rates in different parts of the world and are linked to host immune system variation. Natural variation in EBV DNA sequence may be important for normal infection and for causing disease. Here we used rapid, cost-effective sequencing to determine 71 new EBV sequences from different sample types and locations worldwide. We showed geographic variation in EBV genomes and identified the most variable parts of the genome. We identified protein sequences that seem to have been selected by the host immune system and detected variability in known immune epitopes. This gives the first overview of EBV genome variation, important for designing vaccines and immune therapy for EBV, and provides techniques to investigate relationships between viral sequence variation and EBV-associated diseases.
Lantibiotic Resistance
Authors: Draper Lorraine A. , Cotter Paul D. , Hill Colin , Ross R. Paul 
Published: March 2015

SUMMARY
The dramatic rise in the incidence of antibiotic resistance demands that new therapeutic options will have to be developed. One potentially interesting class of antimicrobials are the modified bacteriocins termed lantibiotics, which are bacterially produced, posttranslationally modified, lanthionine/methyllanthionine-containing peptides. It is interesting that low levels of resistance have been reported for lantibiotics compared with commercial antibiotics. Given that there are very few examples of naturally occurring lantibiotic resistance, attempts have been made to deliberately induce resistance phenotypes in order to investigate this phenomenon. Mechanisms that hinder the action of lantibiotics are often innate systems that react to the presence of any cationic peptides/proteins or ones which result from cell well damage, rather than being lantibiotic specific. Such resistance mechanisms often arise due to altered gene regulation following detection of antimicrobials/cell wall damage by sensory proteins at the membrane. This facilitates alterations to the cell wall or changes in the composition of the membrane. Other general forms of resistance include the formation of spores or biofilms, which are a common mechanistic response to many classes of antimicrobials. In rare cases, bacteria have been shown to possess specific antilantibiotic mechanisms. These are often species specific and include the nisin lytic protein nisinase and the phenomenon of immune mimicry.
Psychological interventions for mental health disorders in children with chronic physical illness: a systematic review
Authors: Bennett Sophie , Shafran Roz , Coughtrey Anna , Walker Susan , Heyman Isobel 
Published: March 2015

BackgroundChildren with chronic physical illness are significantly more likely to develop common psychiatric symptoms than otherwise healthy children. These children therefore warrant effective integrated healthcare yet it is not established whether the known, effective, psychological treatments for symptoms of common childhood mental health disorders work in children with chronic physical illness.MethodsEMBASE, MEDLINE, PsycINFO and CINAHL databases were searched with predefined terms relating to evidence-based psychological interventions for psychiatric symptoms in children with chronic physical illness. We included all studies (randomised and non-randomised designs) investigating interventions aimed primarily at treating common psychiatric symptoms in children with a chronic physical illness in the review. Two reviewers independently assessed the relevance of abstracts identified, extracted data and undertook quality analysis.ResultsTen studies (209 children, including 70 in control groups) met the criteria for inclusion in the review. All studies demonstrated some positive outcomes of cognitive behavioural therapy for the treatment of psychiatric symptoms in children with chronic physical illness. Only two randomised controlled trials, both investigating interventions for symptoms of depression, were found.ConclusionsThere is preliminary evidence that cognitive behavioural therapy has positive effects in the treatment of symptoms of depression and anxiety in children with chronic physical illness. However, the current evidence base is weak and fully powered randomised controlled trials are needed to establish the efficacy of psychological treatments in this vulnerable population.