bluuebunny/crossref_metadata_2025_split huggingface dataset:
Type II Toxoplasma gondii Induction of CD40 on Infected Macrophages Enhances Interleukin-12 Responses
Authors: Morgado Pedro , Sudarshana Dattanand M. , Gov Lanny , Harker Katherine S. , Lam Tonika , Casali Paolo , Boyle Jon P. , Lodoen Melissa B. 
Published: July 2014

ABSTRACTToxoplasma gondiiis an obligate intracellular parasite that can cause severe neurological disease in infected humans. CD40 is a receptor on macrophages that plays a critical role in controllingT. gondiiinfection. We examined the regulation of CD40 on the surface ofT. gondii-infected bone marrow-derived macrophages (BMdMs).T. gondiiinduced CD40 expression both at the transcript level and on the cell surface, and interestingly, the effect was parasite strain specific: CD40 levels were dramatically increased in type IIT. gondii-infected BMdMs compared to type I- or type III-infected cells. Type II induction of CD40 was specific to cells harboring intracellular parasites and detectable as early as 6 h postinfection (hpi) at the transcript level. CD40 protein expression peaked at 18 hpi. Using forward genetics with progeny from a type II × type III cross, we found that CD40 induction mapped to a region of chromosome X that included the gene encoding the dense granule protein 15 (GRA15). Using type I parasites stably expressing the type II allele ofGRA15(GRA15II), we found that type I GRA15IIparasites induced the expression of CD40 on infected cells in an NF-κB-dependent manner. In addition, stable expression of hemagglutinin-tagged GRA15IIin THP-1 cells resulted in CD40 upregulation in the absence of infection. Since CD40 signaling contributes to interleukin-12 (IL-12) production, we examined IL-12 from infected macrophages and found that CD40L engagement of CD40 amplified the IL-12 response in type II-infected cells. These data indicate that GRA15IIinduction of CD40 promotes parasite immunity through the production of IL-12.
The Legionella longbeachae Icm/Dot Substrate SidC Selectively Binds Phosphatidylinositol 4-Phosphate with Nanomolar Affinity and Promotes Pathogen Vacuole-Endoplasmic Reticulum Interactions
Authors: Dolinsky Stephanie , Haneburger Ina , Cichy Adam , Hannemann Mandy , Itzen Aymelt , Hilbi Hubert 
Published: July 2014

ABSTRACT

Legionella
spp. cause the severe pneumonia Legionnaires' disease. The environmental bacteria replicate intracellularly in free-living amoebae and human alveolar macrophages within a distinct, endoplasmic reticulum (ER)-derived compartment termed the
Legionella
-containing vacuole (LCV). LCV formation requires the bacterial Icm/Dot type IV secretion system (T4SS) that translocates into host cells a plethora of different “effector” proteins, some of which anchor to the pathogen vacuole by binding to phosphoinositide (PI) lipids. Here, we identified by unbiased pulldown assays in
Legionella longbeachae
lysates a 111-kDa SidC homologue as the major phosphatidylinositol 4-phosphate [PtdIns(4)
P
]-binding protein. The PI-binding domain was mapped to a 20-kDa P4C [
P
tdIns(
4
)
P
binding of Sid
C
] fragment. Isothermal titration calorimetry revealed that SidC of
L. longbeachae
(SidC
Llo
) binds PtdIns(4)
P
with a

K
d

(dissociation constant) of 71 nM, which is 3 to 4 times lower than that of the SidC orthologue of
Legionella pneumophila
(SidC
Lpn
). Upon infection of RAW 264.7 macrophages with
L. longbeachae
, endogenous SidC
Llo
or ectopically produced SidC
Lpn
localized in an Icm/Dot-dependent manner to the PtdIns(4)
P
-positive LCVs. An
L. longbeachae
Δ
sidC
deletion mutant was impaired for calnexin recruitment to LCVs in
Dictyostelium discoideum
amoebae and outcompeted by wild-type bacteria in
Acanthamoeba castellanii
. Calnexin recruitment was restored by SidC
Llo
or its orthologues SidC
Lpn
and SdcA
Lpn
. Conversely, calnexin recruitment was restored by SidC
Llo
in
L. pneumophila
lacking
sidC
and
sdcA
. Together, biochemical, genetic, and cell biological data indicate that SidC
Llo
is an
L. longbeachae
effector that binds through a P4C domain with high affinity to PtdIns(4)
P
on LCVs, promotes ER recruitment to the LCV, and thus plays a role in pathogen-host interactions.
Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles Are Internalized in Human Host Cells and Trigger NOD1- and NOD2-Dependent NF-κB Activation
Authors: Thay Bernard , Damm Anna , Kufer Thomas A. , Wai Sun Nyunt , Oscarsson Jan 
Published: July 2014

ABSTRACT

Aggregatibacter actinomycetemcomitans
is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. We recently demonstrated that outer membrane vesicles (OMVs) disseminated by
A. actinomycetemcomitans
could deliver multiple proteins, including biologically active cytolethal distending toxin (CDT), into the cytosol of HeLa cells and human gingival fibroblasts (HGF). In the present work, we have used immunoelectron and confocal microscopy analysis and fluorescently labeled vesicles to further investigate mechanisms for
A. actinomycetemcomitans
OMV-mediated delivery of bacterial antigens to these host cells. Our results supported that OMVs were internalized into the perinuclear region of HeLa cells and HGF. Colocalization analysis revealed that internalized OMVs colocalized with the endoplasmic reticulum and carried antigens, detected using an antibody specific to whole
A. actinomycetemcomitans
serotype a cells. Consistent with OMV internalization mediating intracellular antigen exposure, the vesicles acted as strong inducers of cytoplasmic peptidoglycan sensor NOD1- and NOD2-dependent NF-κB activation in human embryonic kidney cells. Moreover, NOD1 was the main sensor of OMV-delivered peptidoglycan in myeloid THP1 cells, contributing to the overall inflammatory responses induced by the vesicles. This work reveals a role of
A. actinomycetemcomitans
OMVs as a trigger of innate immunity via carriage of NOD1- and NOD2-active pathogen-associated molecular patterns (PAMPs).
Early Induction of Interleukin-10 Limits Antigen-Specific CD4+T Cell Expansion, Function, and Secondary Recall Responses during Persistent Phagosomal Infection
Authors: Singh Abinav Kumar , Thirumalapura Nagaraja R. 
Published: July 2014

ABSTRACTDiverse pathogens have evolved to survive and replicate in the endosomes or phagosomes of the host cells and establish persistent infection. Ehrlichiae are Gram-negative, intracellular bacteria that are transmitted by ticks. Ehrlichiae reside in the endosomes of the host phagocytic or endothelial cells and establish persistent infection in their vertebrate reservoir hosts. CD4+T cells play a critical role in protection against phagosomal infections. In the present study, we investigated the expansion, maintenance, and functional status of antigen-specific CD4+T cells during persistentEhrlichia murisinfection in wild-type and interleukin-10 (IL-10)-deficient mice. Our study indicated that early induction of IL-10 led to reduced inflammatory responses and impaired bacterial clearance during persistentEhrlichiainfection. Notably, we demonstrated that the functional production of gamma interferon (IFN-γ) by antigen-specific CD4+T cells maintained during a persistent phagosomal infection progressively deteriorates. The functional loss of IFN-γ production by antigen-specific CD4+T cells was reversed in the absence of IL-10. Furthermore, we demonstrated that transient blockade of IL-10 receptor during the T cell priming phase early in infection was sufficient to enhance the magnitude and the functional capacity of antigen-specific effector and memory CD4+T cells, which translated into an enhanced recall response. Our findings provide new insights into the functional status of antigen-specific CD4+T cells maintained during persistent phagosomal infection. The study supports the concept that a better understanding of the factors that influence the priming and differentiation of CD4+T cells may provide a basis to induce a protective immune response against persistent infections.
Effect of Apoptotic Cell Recognition on Macrophage Polarization and Mycobacterial Persistence
Authors: de Oliveira Fulco Tatiana , Andrade Priscila Ribeiro , de Mattos Barbosa Mayara Garcia , Pinto Thiago Gomes Toledo , Ferreira Paula Fernandez , Ferreira Helen , da Costa Nery José Augusto , Real Suzana Côrte , Borges Valéria Matos , Moraes Milton Ozório , Sarno Euzenir Nunes , Sampaio Elizabeth Pereira , Pinheiro Roberta Olmo 
Published: July 2014

ABSTRACTIntracellularMycobacterium lepraeinfection modifies host macrophage programming, creating a protective niche for bacterial survival. The milieu regulating cellular apoptosis in the tissue plays an important role in defining susceptible and/or resistant phenotypes. A higher density of apoptotic cells has been demonstrated in paucibacillary leprosy lesions than in multibacillary ones. However, the effect of apoptotic cell removal onM. leprae-stimulated cells has yet to be fully elucidated. In this study, we investigated whether apoptotic cell removal (efferocytosis) induces different phenotypes in proinflammatory (Mϕ1) and anti-inflammatory (Mϕ2) macrophages in the presence ofM. leprae. We stimulated Mϕ1 and Mϕ2 cells withM. lepraein the presence or absence of apoptotic cells and subsequently evaluated theM. lepraeuptake, cell phenotype, and cytokine pattern in the supernatants. In the presence ofM. lepraeand apoptotic cells, Mϕ1 macrophages changed their phenotype to resemble the Mϕ2 phenotype, displaying increased CD163 and SRA-I expression as well as higher phagocytic capacity. Efferocytosis increasedM. lepraesurvival in Mϕ1 cells, accompanied by reduced interleukin-15 (IL-15) and IL-6 levels and increased transforming growth factor beta (TGF-β) and IL-10 secretion. Mϕ1 cells primed withM. lepraein the presence of apoptotic cells induced the secretion of Th2 cytokines IL-4 and IL-13 in autologous T cells compared with cultures stimulated withM. lepraeor apoptotic cells alone. Efferocytosis did not alter the Mϕ2 cell phenotype or cytokine secretion profile, except for TGF-β. Based on these data, we suggest that, in paucibacillary leprosy patients, efferocytosis contributes to mycobacterial persistence by increasing the Mϕ2 population and sustaining the infection.
Combined SFK/mTOR Inhibition Prevents Rapamycin-Induced Feedback Activation of AKT and Elicits Efficient Tumor Regression
Authors: Yori Jennifer L. , Lozada Kristen L. , Seachrist Darcie D. , Mosley Jonathan D. , Abdul-Karim Fadi W. , Booth Christine N. , Flask Chris A. , Keri Ruth A. 
Published: July 2014

Abstract
Resistance to receptor tyrosine kinase (RTK) blockade in breast cancer is often mediated by activation of bypass pathways that sustain growth. Src and mammalian target of rapamycin (mTOR) are two intrinsic targets that are downstream of most RTKs. To date, limited clinical efficacy has been observed with either Src or mTOR inhibitors when used as single agents. Resistance to mTOR inhibitors is associated with loss of negative feedback regulation, resulting in phosphorylation and activation of AKT. Herein, we describe a novel role for Src in contributing to rapalog-induced AKT activation. We found that dual activation of Src and the mTOR pathway occurs in nearly half of all breast cancers, suggesting potential cross-talk. As expected, rapamycin inhibition of mTOR results in feedback activation of AKT in breast cancer cell lines. Addition of the Src/c-Abl inhibitor, dasatinib, completely blocks this feedback activation, confirming convergence between Src and the mTOR pathway. Analysis in vivo revealed that dual Src and mTOR inhibition is highly effective in two mouse models of breast cancer. In a luminal disease model, combined dasatinib and rapamycin is more effective at inducing regression than either single agent. Furthermore, the combination of dasatinib and rapamycin delays tumor recurrence following the cessation of treatment. In a model of human EGFR-2–positive (HER2+) disease, dasatinib alone is ineffective, but potentiates the efficacy of rapamycin. These data suggest that combining mTOR and Src inhibitors may provide a new approach for treating multiple breast cancer subtypes that may circumvent resistance to targeted RTK therapies. Cancer Res; 74(17); 4762–71. ©2014 AACR.
A Randomized Phase II Presurgical Trial of Transdermal 4-Hydroxytamoxifen Gel versus Oral Tamoxifen in Women with Ductal Carcinoma In Situ of the Breast
Authors: Lee Oukseub , Page Katherine , Ivancic David , Helenowski Irene , Parini Vamsi , Sullivan Megan E. , Margenthaler Julie A. , Chatterton Robert T. , Jovanovic Borko , Dunn Barbara K. , Heckman-Stoddard Brandy M. , Foster Kathleen , Muzzio Miguel , Shklovskaya Julia , Skripkauskas Silvia , Kulesza Piotr , Green David , Hansen Nora M. , Bethke Kevin P. , Jeruss Jacqueline S. , Bergan Raymond , Khan Seema A. 
Published: July 2014

Abstract
Purpose: Local transdermal therapy to the breast may achieve effective target-organ drug delivery, while diminishing systemic effects. We conducted a randomized, double-blind, placebo-controlled phase II trial comparing transdermal 4-hydroxytamoxifen gel (4-OHT) to oral tamoxifen (oral-T) in women with ductal carcinoma in situ (DCIS).
Methods: Twenty-seven pre- and postmenopausal women were randomized to 4-OHT (4 mg/day) or oral-T (20 mg/day) for 6 to 10 weeks before surgery. Plasma, nipple aspirate fluid, and breast adipose tissue concentrations of tamoxifen and its major metabolites were determined by liquid chromatography/tandem mass spectrometry. The primary endpoint was Ki67 labeling in DCIS lesions, measured by immunohistochemistry. In plasma, insulin-like growth factor-1 (IGFI), sex hormone–binding globulin (SHBG), and coagulation protein concentrations were determined.
Results: Posttherapy Ki67 decreased by 3.4% in the 4-OHT and 5.1% in the oral-T group (P ≤ 0.03 in both, between-group P = 0. 99). Mean plasma 4-OHT was 0.2 and 1.1 ng/mL in 4-OHT and oral groups, respectively (P = 0.0003), whereas mean breast adipose tissue concentrations of 4-OHT were 5.8 ng/g in the 4-OHT group and 5.4 ng/g in the oral group (P = 0.88). There were significant increases in plasma SHBG, factor VIII, and von Willebrand factor and a significant decrease in plasma IGFI with oral-T, but not with 4-OHT. The incidence of hot flashes was similar in both groups.
Conclusions: The antiproliferative effect of 4-OHT gel applied to breast skin was similar to that of oral-T, but effects on endocrine and coagulation parameters were reduced. These findings support the further evaluation of local transdermal therapy for DCIS and breast cancer prevention. Clin Cancer Res; 20(14); 3672–82. ©2014 AACR.
Phenotypic and Functional Activation of Hyporesponsive KIRnegNKG2Aneg Human NK-Cell Precursors Requires IL12p70 Provided by Poly(I:C)-Matured Monocyte-Derived Dendritic Cells
Authors: Curran Shane A. , Romano Emanuela , Kennedy Michael G. , Hsu Katharine C. , Young James W. 
Published: July 2014

AbstractA functionally responsive natural killer (NK)–cell repertoire requires the acquisition of inhibitory NKG2A and killer immunoglobulin-like receptors (KIR) through pathways that remain undefined. Functional donor NK cells expressing KIRs for non-self class I MHC ligands contribute to a positive outcome after allogeneic hematopoietic stem cell transplantation (alloHSCT) by targeting HLA-matched recipient leukemic cells. Insofar as circulating donor conventional dendritic cells (DC) reconstitute with comparable kinetics with donor NK cells after alloHSCT, we used hyporesponsive KIRnegNKG2Aneg precursor cells to evaluate how specific DC subtypes generate a functionally active NK-cell repertoire. Both monocyte-derived DCs (moDC) and Langerhans-type DCs (LC) induce KIRnegNKG2Aneg precursor cells to express the inhibitory receptors NKG2A and KIR, without requiring cell proliferation. Poly(I:C)-matured moDCs significantly augmented the expression of NKG2A, but not KIR, in an IL12p70-dependent manner. Although all DC-stimulated KIRnegNKG2Aneg cells were able to acquire cytolytic activity against class I MHC-negative targets, the ability to secrete IFNγ was restricted to cells that were stimulated by IL12p70-producing, poly(I:C)-matured moDCs. This critical ability of poly(I:C)-matured moDCs to provide IL12p70 to developing KIRnegNKG2Aneg precursors results in a dominant, multifunctional, NKG2Apos NK-cell population that is capable of both cytolysis and IFNγ production. Poly(I:C)-matured moDCs are, therefore, the most effective conventional DC subtype for generating a functionally competent NK-cell repertoire by an IL12p70-dependent mechanism. Cancer Immunol Res; 2(10); 1000–10. ©2014 AACR.
Analysis of Metabolic Syndrome Components in >15 000 African Americans Identifies Pleiotropic Variants
Authors: Carty Cara L. , Bhattacharjee Samsiddhi , Haessler Jeff , Cheng Iona , Hindorff Lucia A. , Aroda Vanita , Carlson Christopher S. , Hsu Chun-Nan , Wilkens Lynne , Liu Simin , Selvin Elizabeth , Jackson Rebecca , North Kari E. , Peters Ulrike , Pankow James S. , Chatterjee Nilanjan , Kooperberg Charles 
Published: July 2014

Background—
Metabolic syndrome (MetS) refers to the clustering of cardiometabolic risk factors, including dyslipidemia, central adiposity, hypertension, and hyperglycemia, in individuals. Identification of pleiotropic genetic factors associated with MetS traits may shed light on key pathways or mediators underlying MetS.

Methods and Results—

Using the Metabochip array in 15 148 African Americans from the Population Architecture using Genomics and Epidemiology (PAGE) study, we identify susceptibility loci and investigate pleiotropy among genetic variants using a subset-based meta-analysis method, ASsociation-analysis-based-on-subSETs (ASSET). Unlike conventional models that lack power when associations for MetS components are null or have opposite effects, Association-analysis-based-on-subsets uses 1-sided tests to detect positive and negative associations for components separately and combines tests accounting for correlations among components. With Association-analysis-based-on-subsets, we identify 27 single nucleotide polymorphisms in 1 glucose and 4 lipids loci (
TCF7L2
,
LPL
,
APOA5
,
CETP
, and
APOC1/APOE/TOMM40
) significantly associated with MetS components overall, all
P
<2.5e−7, the Bonferroni adjusted
P
value. Three loci replicate in a Hispanic population, n=5172. A novel African American-specific variant, rs12721054/
APOC1
, and rs10096633/
LPL
are associated with ≥3 MetS components. We find additional evidence of pleiotropy for
APOE
,
TOMM40
,
TCF7L2
, and
CETP
variants, many with opposing effects (eg, the same rs7901695/
TCF7L2
allele is associated with increased odds of high glucose and decreased odds of central adiposity).

Conclusions—
We highlight a method to increase power in large-scale genomic association analyses and report a novel variant associated with all MetS components in African Americans. We also identify pleiotropic associations that may be clinically useful in patient risk profiling and for informing translational research of potential gene targets and medications.
Understanding Midlatitude Jet Variability and Change Using Rossby Wave Chromatography: Wave–Mean Flow Interaction
Authors: Lorenz David J. 
Published: July 2014

Abstract
Rossby wave chromatography (RWC) is implemented in a linearized barotropic model as a tool to understand the interaction between the midlatitude jet and the eddy momentum fluxes (uυ) in an idealized GCM. Given the background zonal-mean flow and the space–time structure of the baroclinic wave activity source, RWC calculates the space–time structure of the upper-tropospheric uυ. RWC allows a clean separation of the effects of phase speed changes and index of refraction changes (i.e., changes in background flow) on uυ.
It is found that uυ reinforces imposed zonal-mean zonal wind (u) anomalies that are collocated with the centers of action of the first empirical orthogonal function (EOF1) of the GCM. Critical-level dynamics are essential for the positive feedback when u is equatorward of the mean jet, and “reflecting level” dynamics are essential for the positive feedback when u is poleward of the jet. The eddy momentum flux caused by changes in the phase speeds of the wave sources, on the other hand, are associated with a negative feedback. When the imposed u is out of phase with EOF1, the eddies tend to shift the imposed u poleward (equatorward) for anomalies that are equatorward (poleward) of the poleward center of action of EOF1. Critical (reflecting)-level dynamics is most important for the poleward shift in the subtropics (midlatitudes). Because there are no baroclinic feedbacks in these experiments, these results suggest that barotropic feedbacks alone can account for the structure of the u variability in the midlatitudes.
A Bayesian Approach for Uncertainty Quantification of Extreme Precipitation Projections Including Climate Model Interdependency and Nonstationary Bias
Authors: Sunyer Maria Antonia , Madsen Henrik , Rosbjerg Dan , Arnbjerg-Nielsen Karsten 
Published: July 2014

AbstractClimate change impact studies are subject to numerous uncertainties and assumptions. One of the main sources of uncertainty arises from the interpretation of climate model projections. Probabilistic procedures based on multimodel ensembles have been suggested in the literature to quantify this source of uncertainty. However, the interpretation of multimodel ensembles remains challenging. Several assumptions are often required in the uncertainty quantification of climate model projections. For example, most methods often assume that the climate models are independent and/or that changes in climate model biases are negligible. This study develops a Bayesian framework that accounts for model dependencies and changes in model biases and compares it to estimates calculated based on a frequentist approach. The Bayesian framework is used to investigate the effects of the two assumptions on the uncertainty quantification of extreme precipitation projections over Denmark. An ensemble of regional climate models from the Ensemble-Based Predictions of Climate Changes and their Impacts (ENSEMBLES) project is used for this purpose.The results confirm that the climate models cannot be considered independent and show that the bias depends on the value of precipitation. This has an influence on the results of the uncertainty quantification. Both the mean and spread of the change in extreme precipitation depends on both assumptions. If the models are assumed independent and the bias constant, the results will be overconfident and may be treated as more precise than they really are. This study highlights the importance of investigating the underlying assumptions in climate change impact studies, as these may have serious consequences for the design of climate change adaptation strategies.