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Found 37769 matches. Displaying 7011-7020
Liehl P, Zuzarte-Luis V, Chan JN, Zillinger T, Baptista F, Carapau D, Konert M, Hanson KK, Carret C, Lassnig C, Muller M, Kalinke U, Saeed M, Chora AF, Golenbock DT, Strobl B, Prudencio M, Coelho LP, Kappe SH, Superti-Furga G, Pichlmair A, Vigario AM, Rice CM, Fitzgerald KA, Barchet W, Mota MM
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Host-cell sensors for Plasmodium activate innate immunity against liver-stage infection

NATURE MEDICINE 2014 JAN; 20(1):47-+
Before they infect red blood cells and cause malaria, Plasmodium parasites undergo an obligate and clinically silent expansion phase in the liver that is supposedly undetected by the host. Here, we demonstrate the engagement of a type I interferon (IFN) response during Plasmodium replication in the liver. We identified Plasmodium RNA as a previously unrecognized pathogen-associated molecular pattern (PAMP) capable of activating a type I IFN response via the cytosolic pattern recognition receptor Mda5. This response, initiated by liver-resident cells through the adaptor molecule for cytosolic RNA sensors, Mavs, and the transcription factors Irf3 and Irf7, is propagated by hepatocytes in an interferon-alpha/beta receptor-dependent manner. This signaling pathway is critical for immune cell-mediated host resistance to liver-stage Plasmodium infection, which we find can be primed with other PAMPs, including hepatitis C virus RNA. Together, our results show that the liver has sensor mechanisms for Plasmodium that mediate a functional antiparasite response driven by type I IFN.
Bournazos S, DiLillo DJ, Ravetch JV
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Humanized Mice to Study Fc gamma R Function

FC RECEPTORS 2014; 382(?):237-248
Passive immunotherapy represents a promising therapeutic intervention for a number of neoplastic, chronic inflammatory, and infectious diseases, with several monoclonal antibodies currently under development or already in use in the clinic. While Fab-antigen interactions play a crucial role in the activity of an antibody, it has become clear that Fc-mediated effector functions are involved during antibody-mediated activities in vivo. A complete understanding of the contributions of effector activities mediated by an antibody during its in vivo function is required for the development of antibodies with improved therapeutic efficacies. Animal models that are commonly used for the preclinical evaluation of antibodies include murine and non-human primate species, whose Fc gamma Rs present substantial structural, functional, and genetic variation compared with their human counterparts. Therefore, the use of such animal models provides limited information on the role of human IgG Fc-Fc gamma R interactions during the in vivo activities of antibodies intended for human therapeutics. In this chapter, we describe the development and evaluation of an Fc gamma R-humanized mouse model for the study of human Fc gamma R function in vivo. In this model, endogenous mouse Fc gamma R genes have been deleted and human Fc gamma Rs are expressed as transgenes that faithfully recapitulate the unique pattern of human Fc gamma R expression. Evaluation of the in vivo activities of a number of cytotoxic or therapeutic antibodies using Fc gamma R-humanized mice provided useful insights into human IgG Fc effector function. This mouse model has become a vital preclinical model for testing therapeutic human antibodies to treat malignancies, autoimmunity, inflammation, and infectious disease.
Nam T, Pardo TA
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Understanding Municipal Service Integration: An Exploratory Study of 311 Contact Centers

JOURNAL OF URBAN TECHNOLOGY 2014 JAN; 21(1):55-76
We consider 311 non-emergency contact centers as city-level service integration initiatives. By using a cross-case study of 311 centers at New York and Philadelphia, we found critical success factors and challenges of service integration. This paper suggests multidimensional (technological, organizational, and cross-organizational) implications. Stable operation of 311 centers requires timely investment in having a technological system best fitting for service integration, but city governments with limited resources should instead consider adaptive strategies for overcoming under-equipped situations. While the lack of interoperability remains as a critical barrier to system-level integration, customer service agents play a pivotal role in connecting non-interoperable systems to front office systems and back office systems. Thus training for qualified customer service professionals is key to the seamless operation of 311 contact centers. Turf guarding often raises cross-organizational concerns, but the top management's administrative and political support helps resolve inter-organizational conflicts. Based on these findings from the exploratory study, this article proposes significant ideas for further research on municipal service integration through 311 contact centers.
Ouederni M, Sanal O, Ikinciogullari A, Tezcan I, Dogu F, Sologuren I, Pedraza-Sanchez S, Keser M, Tanir G, Nieuwhof C, Colino E, Kumararatne D, Levy J, Kutukculer N, Aytekin C, Herrera-Ramos E, Bhatti M, Karaca N, Barbouche R, Broides A, Goudouris E, Jose LF, Parvaneh N, Reisli I, Strickler A, Shcherbina A, Somer A, Segal A, Angel-Moreno A, Lezana-Fernandez JL, Bejaoui M, Bobadilla-Del Valle M, Kachboura S, Sentongo T, Ben-Mustapha I, Bustamante J, Picard C, Puel A, Boisson-Dupuis S, Abel L, Casanova JL, Rodriguez-Gallego C
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Clinical Features of Candidiasis in Patients With Inherited Interleukin 12 Receptor beta 1 Deficiency

CLINICAL INFECTIOUS DISEASES 2014 JAN 15; 58(2):204-213
Background. Interleukin 12R beta 1 (IL-12R beta 1)-deficient patients are prone to clinical disease caused by mycobacteria, Salmonella, and other intramacrophagic pathogens, probably because of impaired interleukin 12-dependent interferon gamma production. About 25% of patients also display mucocutaneous candidiasis, probably owing to impaired interleukin 23-dependent interleukin 17 immunity. The clinical features and outcome of candidiasis in these patients have not been described before, to our knowledge. We report here the clinical signs of candidiasis in 35 patients with IL-12R beta 1 deficiency. Results. Most (n = 71) of the 76 episodes of candidiasis were mucocutaneous. Isolated oropharyngeal candidiasis (OPC) was the most common presentation (59 episodes, 34 patients) and was recurrent or persistent in 26 patients. Esophageal candidiasis (n = 7) was associated with proven OPC in 2 episodes, and cutaneous candidiasis (n = 2) with OPC in 1 patient, whereas isolated vulvovaginal candidiasis (VVC; n = 3) was not. Five episodes of proven invasive candidiasis were documented in 4 patients; 1 of these episodes was community acquired in the absence of any other comorbid condition. The first episode of candidiasis occurred earlier in life (median age +/- standard deviation, 1.5 +/- 7.87 years) than infections with environmental mycobacteria (4.29 +/- 11.9 years), Mycobacterium tuberculosis (4 +/- 3.12 years), or Salmonella species (4.58 +/- 4.17 years) or other rare infections (3 +/- 11.67 years). Candidiasis was the first documented infection in 19 of the 35 patients, despite the vaccination of 10 of these 19 patients with live bacille Calmette-Guerin. Conclusions. Patients who are deficient in IL-12R beta 1 may have candidiasis, usually mucocutaneous, which is frequently recurrent or persistent. Candidiasis may be the first clinical manifestation in these patients.
Schramek D, Sendoel A, Segal JP, Beronja S, Heller E, Oristian D, Reva B, Fuchs E
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Vaccine Activation of the Nutrient Sensor GCN2 in Dendritic Cells Enhances Antigen Presentation

SCIENCE 2014 JAN 17; 343(6168):309-313
The yellow fever vaccine YF-17D is one of the most successful vaccines ever developed in humans. Despite its efficacy and widespread use in more than 600 million people, the mechanisms by which it stimulates protective immunity remain poorly understood. Recent studies using systems biology approaches in humans have revealed that YF-17D-induced early expression of general control nonderepressible 2 kinase (GCN2) in the blood strongly correlates with the magnitude of the later CD8(+) T cell response. We demonstrate a key role for virus-induced GCN2 activation in programming dendritic cells to initiate autophagy and enhanced antigen presentation to both CD4(+) and CD8(+) T cells. These results reveal an unappreciated link between virus-induced integrated stress response in dendritic cells and the adaptive immune response.
Hsu Ya-Chieh, Li Lishi, Fuchs Elaine
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Transit-amplifying cells orchestrate stem cell activity and tissue regeneration.

Cell 2014 2014-May-8; 157(4):935-49
Transit-amplifying cells (TACs) are an early intermediate in tissue regeneration. Here, using hair follicles (HFs) as a paradigm, we show that emerging TACs constitute a signaling center that orchestrates tissue growth. Whereas primed stem cells (SCs) generate TACs, quiescent SCs only proliferate afterTACs form and begin expressing Sonic Hedgehog (SHH). TAC generation is independent of autocrine SHH, but the TAC pool wanes if they can't produce SHH. We trace this paradox to two direct actions of SHH: promoting quiescent-SC proliferation and regulating dermal factors that stoke TAC expansion. Ingrained within quiescent SCs' special sensitivity to SHH signaling is their high expression of GAS1. Without sufficient input from quiescent SCs, replenishment of primed SCs for the next hair cycle is compromised, delaying regeneration and eventually leading to regeneration failure. Our findings unveil TACs as transient but indispensable integrators of SC niche components and reveal an intriguing interdependency of primed and quiescent SC populations on tissue regeneration.
Yuferov Vadim, Butelman Eduardo R, Ho Ann, Morgello Susan, Kreek Mary Jeanne
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Neurocognitive and neuroinflammatory correlates of PDYN and OPRK1 mRNA expression in the anterior cingulate in postmortem brain of HIV-infected subjects.

Journal of neuroinflammation 2014 2014 Jan 09; 11(1):5-5
Chronic inflammation may contribute to neuropsychological impairments in individuals with HIV, and modulation of this inflammatory response by opiate receptor ligands is important in light of the prevalence of drug use in HIV populations. Exogenous MOR and KOR agonists have differential effects on central nervous system (CNS) immunity and, while some data suggest KOR agonists are immunosuppressive, the KOR agonist dynorphin has been shown to stimulate human monocyte chemotaxis. In this study, we examined mRNA levels of endogenous opioid receptors OPRK1 and OPRM1, prodynorphin (PDYN), macrophage scavenger receptor CD163, and microglia/macrophage marker CD68 in the caudate and anterior cingulate of postmortem brains from HIV-positive and HIV-negative subjects. Brain tissues of HIV-infected (n=24) and control subjects (n=15) were obtained from the Manhattan HIV Brain Bank. Quantification of the gene mRNA was performed using SYBR Green RT-PCR. CD68 and CD163 were increased in HIV-positive (HIV+) compared to HIV-negative (HIV-) individuals in both brain regions. There were higher OPRK1 (P <0.005), and lower PDYN mRNA (P <0.005) levels in the anterior cingulate of HIV+compared to HIV- subjects. This difference between the clinical groups was not found in the caudate. There was no difference in the levels of OPRM1 mRNA between HIV+and HIV- subjects. Using linear regression analysis, we examined the relationship of OPRK1 and PDYN mRNA levels in the HIV+subjects with seven cognitive domain T scores of a neuropsychological test battery. Within the HIV+subjects, there was a positive correlation between anterior cingulate PDYN mRNA levels and better T-scores in the motor domain. Within the HIV+subjects there were also positive correlations of both OPRK1 and PDYN mRNA levels with the anti-inflammatory marker CD163, but not with proinflammatory CD68 levels. In this setting, decreased PDYN mRNA may reflect a homeostatic mechanism to reduce monocyte migration, accompanied by compensatory increases in the cognate receptor (KOR) to dampen pro-inflammatory responses. It is possible that enhanced neuroprotection and better motor performance are associated with higher levels of dynorphin and the recruitment of neuroprotective CD163-positive macrophages. Further studies are needed to test this hypothesis.
Ahn HJ, Strickland S, Krueger J, Gareau D
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Optical Fiber Spectroscopy Measures Perfusion of the Brain in a Murine Alzheimer's Disease Model

OPTICAL FIBERS AND SENSORS FOR MEDICAL DIAGNOSTICS AND TREATMENT APPLICATIONS XIV 2014; 8938(?):? Article 89380Q
Optical fiber spectroscopy is a versatile tool for measuring diffuse reflectance and extracting absorption information that can noninvasively quantify the presence of chromophores such as oxyhemoglobin and deoxy-hemoglobin in tissues. Cerebrovascular abnormalities were widely recognized in Alzheimer's disease (AD) patients. We analyzed blood volume fraction and level of oxygenated hemoglobin in Tg6799 mice, which are transgenic mice expressing five different familial Alzheimer disease-associated mutations in the human amyloid precursor protein and presenilin-1 genes. Diffuse reflectance spectra were iteratively fit as weighted sums of oxy- and deoxy-hemoglobin. Our observations showed slightly hypoxic conditions and significantly increased blood volume in the Alzheimer's mice versus wild type. These results suggest that hyperperfusion of our AD mice may be a compensating mechanism for impaired cerebral vascular function and somehow relevant with early stage of AD patients. Ongoing work focuses on developing a cannula fixture that allows measurement in awake, behaving animals.
Jabbari A, Suarez-Farinas M, Fuentes-Duculan J, Gonzalez J, Cueto I, Franks AG, Krueger JG
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Dominant Th1 and Minimal Th17 Skewing in Discoid Lupus Revealed by Transcriptomic Comparison with Psoriasis

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2014 JAN; 134(1):87-95
Discoid lupus erythematosus (DLE) is the most common skin manifestation of lupus. Despite its high frequency in systemic lupus in addition to cases without extracutaneous manifestations, targeted treatments for DLE are lacking, likely because of a dearth of knowledge of the molecular landscape of DLE skin. Here, we profiled the transcriptome of DLE skin in order to identify signaling pathways and cellular signatures that may be targeted for treatment purposes. Further comparison of the DLE transcriptome with that of psoriasis, a useful reference given our extensive knowledge of molecular pathways in this disease, provided a framework to identify potential therapeutic targets. Although a growing body of data support a role for IL-17 and T helper type 17 (Th17) cells in systemic lupus, we show a relative enrichment of IFN-gamma-associated genes without that for IL-17-associated genes in DLE. Extraction of T cells from the skin of DLE patients identified a predominance of IFN-gamma-producing Th1 cells and an absence of IL-17-producing Th17 cells, complementing the results from whole-skin transcriptomic analyses. These data therefore support investigations into treatments for DLE that target Th1 cells or the IFN-gamma signaling pathway.
Georgescu RE, Yao NN, Indiani C, Yurieva O, O'Donnell ME
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Replisome mechanics: lagging strand events that influence speed and processivity

NUCLEIC ACIDS RESEARCH 2014; 42(10):6497-6510
The antiparallel structure of DNA requires lagging strand synthesis to proceed in the opposite direction of the replication fork. This imposes unique events that occur only on the lagging strand, such as primase binding to DnaB helicase, RNA synthesis, and SS B antigen (SSB) displacement during Okazaki fragment extension. Single-molecule and ensemble techniques are combined to examine the effect of lagging strand events on the Escherichia coli replisome rate and processivity. We find that primase activity lowers replisome processivity but only when lagging strand extension is inoperative. rNTPs also lower replisome processivity. However, the negative effects of primase and rNTPs on processivity are overcome by the extra grip on DNA provided by the lagging strand polymerases. Visualization of single molecules reveals that SSB accumulates at forks and may wrap extensive amounts of single-strand DNA. Interestingly SSB has an inter-strand positive effect on the rate of the leading strand based in its interaction with the replicase chi-subunit. Further, the lagging strand polymerase is faster than leading strand synthesis, indicating that replisome rate is limited by the helicase. Overall, lagging strand events that impart negative effects on the replisome are counterbalanced by the positive effects of SSB and additional sliding clamps during Okazaki fragment extension.