bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dengue Virus Type 2 Antagonizes IFN-α but Not IFN-γ Antiviral Effect via Down-Regulating Tyk2-STAT Signaling in the Human Dendritic Cell
Authors: Ho Ling-Jun , Hung Li-Feng , Weng Chun-Yi , Wu Wan-Lin , Chou Ping , Lin Yi-Ling , Chang Deh-Ming , Tai Tong-Yuan , Lai Jenn-Haung 
Published: April 2014

AbstractThe immunopathogenesis mechanism of dengue virus (DV) infection remains elusive. We previously showed that the target of DV in humans is dendritic cells (DCs), the primary sentinels of immune system. We also observed that despite the significant amount of IFN-α induced; DV particles remain massively produced from infected DCs. It suggests that DV may antagonize the antiviral effect of IFN-α. Recent work in animal studies demonstrated the differential critical roles of antiviral cytokines, namely IFN-α/IFN-β and IFN-γ, in blocking early viral production and in preventing viral-mediated disease, respectively. In this study, we examined the effects of IFN-α and IFN-γ in DV infection of monocyte-derived DCs. We showed that the preinfection treatment with either IFN-α or IFN-γ effectively armed DCs and limited viral production in infected cells. However, after infection, DV developed mechanisms to counteract the protection from lately added IFN-α, but not IFN-γ. Such a selective antagonism on antiviral effect of IFN-α, but not IFN-γ, correlated with down-regulated tyrosine-phosphorylation and DNA-binding activities of STAT1 and STAT3 transcription factors by DV. Furthermore, subsequent studies into the underlying mechanisms revealed that DV attenuated IFN-α-induced tyrosine-phosphorylation of Tyk2, an upstream molecule of STAT activation, but had no effect on expression of both IFN-α receptor 1 and IFN-α receptor 2. Moreover, DV infection by itself could activate STAT1 and STAT3 through IFN-α-dependent and both IFN-α-dependent and IFN-α-independent mechanisms, respectively. These observations provide very useful messages with physiological significance in investigation of the pathogenesis, the defense mechanisms of human hosts and the therapeutic considerations in DV infection.
The Critical Role of LIGHT in Promoting Intestinal Inflammation and Crohn’s Disease
Authors: Wang Jing , Anders Robert A. , Wang Yang , Turner Jerrold R. , Abraham Clara , Pfeffer Klaus , Fu Yang-Xin 
Published: April 2014

AbstractCrohn’s disease (CD) is a type of inflammatory bowel disease associated with increased Th1 cytokines and unique pathological features. However, its pathogenesis has not been fully understood. Previous studies showed that homologous to lymphotoxin, exhibits inducible expression, competes with herpesvirus glycoprotein D for HVEM on T cells (LIGHT) transgenic (Tg) mice develop autoimmunity including intestinal inflammation with a variable time course. In this study, we establish an experimental model for CD by adoptive transfer of Tg mesenteric lymph node cells into RAG−/− mice. The recipients of Tg lymphocytes rapidly develop a disease strikingly similar to the key pathologic features and cytokine characterization observed in CD. We demonstrate that, as a costimulatory molecule, LIGHT preferentially drives Th1 responses. LIGHT-mediated intestinal disease is dependent on both of its identified signaling receptors, lymphotoxin β receptor and herpes virus entry mediator, because LIGHT Tg mesenteric lymph node cells do not cause intestinal inflammation when transferred into the lymphotoxin β receptor-deficient mice, and herpes virus entry mediator on donor T cells is required for the full development of disease. Furthermore, we demonstrated that up-regulation of LIGHT is associated with active CD. These data establish a new mouse model resembling CD and suggest that up-regulation of LIGHT may be an important mediator of CD pathogenesis.
Thymic Stromal Lymphopoietin Expression Is Increased in Asthmatic Airways and Correlates with Expression of Th2-Attracting Chemokines and Disease Severity
Authors: Ying Sun , O’Connor Brian , Ratoff Jonathan , Meng Qiu , Mallett Kirsty , Cousins David , Robinson Douglas , Zhang Guizhen , Zhao Jisheng , Lee Tak H. , Corrigan Chris 
Published: April 2014

AbstractThymic stromal lymphopoietin (TSLP) is said to increase expression of chemokines attracting Th2 T cells. We hypothesized that asthma is characterized by elevated bronchial mucosal expression of TSLP and Th2-attracting, but not Th1-attracting, chemokines as compared with controls, with selective accumulation of cells bearing receptors for these chemokines. We used in situ hybridization and immunohistochemistry to examine the expression and cellular provenance of TSLP, Th2-attracting (thymus and activation-regulated chemokine (TARC)/CCL17, macrophage-derived chemokine (MDC)/CCL22, I-309/CCL1) and Th1-attracting (IFN-γ-inducible protein 10 (IP-10)/CXCL10, IFN-inducible T cell α-chemoattractant (I-TAC)/CXCL11) chemokines and expression of their receptors CCR4, CCR8, and CXCR3 in bronchial biopsies from 20 asthmatics and 15 normal controls. The numbers of cells within the bronchial epithelium and submucosa expressing mRNA for TSLP, TARC/CCL17, MDC/CCL22, and IP-10/CXCL10, but not I-TAC/CXCL11 and I-309/CCL1, were significantly increased in asthmatics as compared with controls (p ≤ 0.018). TSLP and TARC/CCL17 expression correlated with airway obstruction. Although the total numbers of cells expressing CCR4, CCR8, and CXCR3 did not significantly differ in the asthmatics and controls, there was evidence of selective infiltration of CD4+/CCR4+ T cells in the asthmatic biopsies which correlated with TARC and MDC expression and airway obstruction. Epithelial cells, endothelial cells, neutrophils, macrophages, and mast cells were significant sources of TSLP and chemokines. Our data implicate TSLP, TARC/CCL17, MDC/CCL22, and IP-10/CXCL10 in asthma pathogenesis. These may act partly through selective development and retention, or recruitment of Th2 cells bearing their receptors.
Correlates of Delayed Disease Progression in HIV-1-Infected Kenyan Children
Authors: Chakraborty Rana , Morel Anne-Sophie , Sutton Julian K. , Appay Victor , Ripley Ruth M. , Dong Tao , Rostron Tim , Ogola Simon , Palakudy Tresa , Musoke Rachel , D’Agostino Angelo , Ritter Mary , Rowland-Jones Sarah L. 
Published: April 2014

Abstract
Without treatment most HIV-1-infected children in Africa die before their third birthday (&gt;89%) and long-term nonprogressors are rare. The mechanisms underlying nonprogression in HIV-1-infected children are not well understood. In the present study, we examined potential correlates of delayed HIV disease progression in 51 HIV-1-infected African children. Children were assigned to progression subgroups based on clinical characterization. HIV-1-specific immune responses were studied using a combination of ELISPOT assays, tetramer staining, and FACS analysis to characterize the magnitude, specificity, and functional phenotype of HIV-1-specific CD8+ and CD4+ T cells. Host genetic factors were examined by genotyping with sequence-specific primers. HIV-1 nef gene sequences from infecting isolates from the children were examined for potential attenuating deletions. Thymic output was measured by T cell rearrangement excision circle assays. HIV-1-specific CD8+ T cell responses were detected in all progression groups. The most striking attribute of long-term survivor nonprogressors was the detection of HIV-1-specific CD4+ Th responses in this group at a magnitude substantially greater than previously observed in adult long-term nonprogressors. Although long-term survivor nonprogressors had a significantly higher percentage of CD45RA+CD4+ T cells, nonprogression was not associated with higher thymic output. No protective genotypes for known coreceptor polymorphisms or large sequence deletions in the nef gene associated with delayed disease progression were identified. In the absence of host genotypes and attenuating mutations in HIV-1 nef, long-term surviving children generated strong CD4+ T cell responses to HIV-1. As HIV-1-specific helper cells support anti-HIV-1 effector responses in active disease, their presence may be important in delaying disease progression.
Human BDCA-1-Positive Blood Dendritic Cells Differentiate into Phenotypically Distinct Immature and Mature Populations in the Absence of Exogenous Maturational Stimuli: Differentiation Failure in HIV Infection
Authors: Patterson Steven , Donaghy Heather , Amjadi Parisa , Gazzard Brian , Gotch Frances , Kelleher Peter 
Published: April 2014

Abstract
Current immunological opinion holds that myeloid dendritic cell (mDC) precursors migrate from the blood to the tissues, where they differentiate into immature dermal- and Langerhans-type dendritic cells (DC). Tissue DC require appropriate signals from pathogens or inflammatory cytokines to mature and migrate to secondary lymphoid tissue. We show that purified blood mDC cultured in vitro with GM-CSF and IL-4, but in the absence of added exogenous maturation stimuli, rapidly differentiate into two maturational and phenotypically distinct populations. The major population resembles immature dermal DC, being positive for CD11b, CD1a, and DC-specific ICAM-3-grabbing nonintegrin. They express moderate levels of MHC class II and low levels of costimulatory molecules. The second population is CD11b−/low and lacks CD1a and DC-specific ICAM-3-grabbing nonintegrin but expresses high levels of MHC class II and costimulatory molecules. Expression of CCR7 on the CD11b−/low population and absence on the CD11b+ cells further supports the view that these cells are mature and immature, respectively. Differentiation into mature and immature populations was not blocked by polymyxin B, an inhibitor of LPS. Neither population labeled for Langerin, E-cadherin, or CCR6 molecules expressed by Langerhans cells. Stimulation of 48-h cultured DC with LPS, CD40L, or poly(I:C) caused little increase in MHC or costimulatory molecule expression in the CD11b−/low DC but caused up-regulated expression in the CD11b+ cells. In HIV-infected individuals, there was a marked decrease in the viability of cultured blood mDC, a failure to differentiate into the two populations described for normal donors, and an impaired ability to stimulate T cell proliferation.
Ex Vivo Characterization of Multiepitopic Tumor-Specific CD8 T Cells in Patients with Chronic Myeloid Leukemia: Implications for Vaccine Development and Adoptive Cellular Immunotherapy
Authors: Gannagé Monique , Abel Michal , Michallet Anne-Sophie , Delluc Stéphanie , Lambert Marion , Giraudier Stéphane , Kratzer Roland , Niedermann Gabriele , Saveanu Loredana , Guilhot François , Camoin Luc , Varet Bruno , Buzyn Agnès , Caillat-Zucman Sophie 
Published: April 2014

AbstractIdentification of tumor-associated Ags is a prerequisite for vaccine-based and adoptive immune therapies. Some tumor-associated Ags elicit specific CD8 T cells in patients with chronic myeloid leukemia (CML). Here, we characterized ex vivo responses of CD8 T cells from CML patients to extrajunction bcr-abl peptides and telomerase 540–548 hTert, PR1, and WT1 peptides. CML-specific CD8 T cells were present in most treated patients and were usually multiepitopic: WT1, hTert, PR1, and bcr74 tetramer+ cells were detected in 85, 82, 67, and 61% of patients, respectively. The breadth and magnitude of these responses did not differ significantly according to treatment or disease status. CML-specific tetramer+ CD8 T cells had a predominantly memory phenotype, an intermediate perforin content, and low intracellular IFN-γ accumulation in the presence of the relevant peptide. However, in short-term culture with HLA-matched leukemia cells, the patients’ memory T cells were specifically reactivated to become IFN-γ-producing effector cells, suggesting that CD8 T cell precursors with lytic potential are present in vivo and can be activated by appropriate stimulation. In conclusion, this study shows that multiepitopic tumor-specific CD8 T cell responses occur naturally in most CML patients, opening the way to new strategies for enhancing anti-CML immunity, in particular in patients with minimal residual disease.
Variegation of the Immune Response with Dendritic Cells and Pathogen Recognition Receptors
Authors: Pulendran Bali 
Published: April 2014

Abstract
One of the most fundamental questions in biology is: “How do cells differentiate in the right place, at the right time, into the right kinds?” Understanding the phenomenon of cell differentiation in its spatial and temporal framework is a prelude to understanding the development and physiology of all multicellular systems, including the immune system. Insights over the past 2300 years, since Aristotle, suggest that biological differentiation is guided by the interplay between genetic programs and specific environmental signals. This is exemplified by the mammalian immune response to pathogens, where qualitatively different types can emerge. Although it is appreciated that this type immunity is critical for optimal defense against different pathogens, the early “decision-making mechanisms” are largely obscure. Recent developments in innate immunity and genomics, especially in the biology of dendritic cells (DCs) and pathogen recognition receptors, have stimulated intense research in understanding the mechanisms guiding the differentiation of Th1, Th2, and T regulatory responses. In this study, I summarize recent findings which suggest that activation of DCs via distinct pathogen recognition receptors stimulate different gene expression programs and signaling networks in DCs that guide the variegation of immune responses.
Cutting Edge: All-trans Retinoic Acid Down-Regulates TLR2 Expression and Function
Authors: Liu Philip T. , Krutzik Stephan R. , Kim Jenny , Modlin Robert L. 
Published: April 2014

Abstract
A major consequence of microbial infection is the tissue injury that results from the host inflammatory response. In acne, inflammation is due in part to the ability of Propionibacterium acnes to activate TLR2. Because all-trans retinoic acid (ATRA) decreases inflammation in acne, we investigated whether it regulates TLR2 expression and function. Treatment of primary human monocytes with ATRA led to the down-regulation of TLR2 as well as it’s coreceptor CD14, but not TLR1 or TLR4. The ability of a TLR2/1 ligand to trigger monocyte cytokine release was inhibited by pre- and cotreatment with ATRA; however, TLR4 activation was affected by cotreatment only. ATRA also down-regulated monocyte cytokine induction by P. acnes. These data indicate that ATRA exerts an anti-inflammatory effect on monocytes via two pathways, one specifically affecting TLR2/1 and CD14 expression and one independent of TLR expression. Agents that target TLR expression and function represent a novel strategy to treat inflammation in humans.
Cutting Edge: Microbial Products Elicit Formation of Dendritic Cell Aggresome-Like Induced Structures in Macrophages
Authors: Canadien Veronica , Tan Tracy , Zilber Rachelle , Szeto Jason , Perrin Andrew J. , Brumell John H. 
Published: April 2014

Abstract
In response to a maturation stimulus, dendritic cells undergo the formation of ubiquitinated protein aggregates known as dendritic cell aggresome-like induced structures (DALIS). DALIS are thought to act as Ag storage structures, allowing for the prioritized degradation of proteins during infection. In this study, we demonstrate that murine macrophages can also form ubiquitinated protein aggregates that are indistinguishable from DALIS. These were formed in a dose- and time-dependent manner, and in response to a variety of microbial products. Surprisingly, the proteasome did not accumulate on these ubiquitinated protein structures, further underlining the difference between DALIS and aggresomes. Our studies suggest that DALIS formation is important for the function of Ag-presenting immune cells during infection.
Cutting Edge: Priming of CTL by Transcutaneous Peptide Immunization with Imiquimod
Authors: Rechtsteiner Gerd , Warger Tobias , Osterloh Philipp , Schild Hansjörg , Radsak Markus P. 
Published: April 2014

Abstract
CTL are important in combating cancer and viruses. Therefore, triggering the complete potential of CTL effector functions by new vaccination strategies will not only improve prophylaxis of tumor or virus-related diseases, but also open opportunities for effective therapeutic immunizations. Using transcutaneous immunization, we show that epicutaneous (e.c.)4 application of an ointment containing a CTL epitope and the TLR7 ligand imiquimod is highly effective in activating T cells in mice using TCR-transgenic CTL or in wild-type mice. Transcutaneous immunization-activated CTL mount a full-blown immune response against the target epitope characterized by proliferation, cytolytic activity, and the production of IFN-γ that is completely restricted to the epitope used for vaccination. Our results obtained by simple e.c. application of an ointment, without further skin irritating procedures, provide the basis for the development of new, easy to use vaccines against cancer or virus-associated diseases.
Cutting Edge: p27Kip1 Deficiency Reduces the Requirement for CD28-Mediated Costimulation in Naive CD8+ but Not CD4+ T Lymphocytes
Authors: Wolfraim Lawrence A. , Letterio John J. 
Published: April 2014

Abstract
Cell cycle re-entry of quiescent T cells is dependent upon cyclin-dependent kinase 2. Inhibition of cyclin-dependent kinase 2 by p27Kip1 is believed to be the principal constraint on S-phase entry in T cells. We report that deficiency for p27Kip1 has a more pronounced effect on the expansion of murine naive CD8+ T cells and that this disparity is due to a reduced requirement for CD28-mediated costimulation in CD8+ but not CD4+ T cells lacking p27Kip1. These data highlight a previously unappreciated difference in the way CD28 signaling is coupled to the core cell cycle machinery in these two T cell subsets.
Cutting Edge: Regulation of T Cell Trafficking and Primary Immune Responses by Sphingosine 1-Phosphate Receptor 1
Authors: Chi Hongbo , Flavell Richard A. 
Published: April 2014

Abstract
Signaling by sphingosine 1-phosphate (S1P) through its receptor S1P1 has recently been shown to promote thymocyte egress. In the periphery, S1P1 is expressed on naive T cells but lost upon T cell activation. To determine the significance of S1P1 down-regulation and function of S1P1 in peripheral T cells, we developed transgenic mice that constitutively express S1P1 in T cells. Mature T cells from these mice exhibited enhanced chemotactic response toward S1P, and preferentially distributed to the blood rather than secondary lymphoid organs. S1P1-transgenic mice showed significant delay in the onset of experimental autoimmune encephalomyelitis, and had defective contact hypersensitivity reaction and local Ag-induced responses. These impairments were associated with reduced numbers of Ag-activated T cells in the draining lymph nodes. Our studies demonstrate that S1P1 signaling affects systemic trafficking of peripheral T cells and immune responses and highlight that levels of S1P1 expression represent an important mechanism of immune regulation.
Cutting Edge: Back to “One-Way” Germinal Centers
Authors: Meyer-Hermann Michael E. , Maini Philip K. 
Published: April 2014

AbstractThe present status of germinal center (GC) research is revisited using in silico simulations based on recent lymphocyte motility data in mice. The generally adopted view of several rounds of somatic hypermutations and positive selection is analyzed with special emphasis on the spatial organization of the GC reaction. We claim that the development of dark zones is not necessary for successful GC reactions to develop. We find that a recirculation of positively selected centrocytes to the dark zone is rather unlikely. Instead we propose a scenario that combines a multiple-step mutation and selection concept with a “one-way” GC in the sense of cell migration.
Cutting Edge: IL-4 Induces Suppressor of Cytokine Signaling-3 Expression in B Cells by a Mechanism Dependent on Activation of p38 MAPK
Authors: Canfield Stephen , Lee Youngnam , Schröder Andreas , Rothman Paul 
Published: April 2014

AbstractThe signaling cascade initiated by IL-4 is classically divisible into two major pathways: one mediated by STAT6, and the other by insulin receptor substrates-1 and -2 via activation of PI3K. In murine splenic B cells, the suppressor of cytokine signaling (SOCS)3 is inducible by IL-4 via a mechanism independent of STAT6 and PI3K. SOCS3 expression increases 9-fold within 5 h of IL-4 treatment. This induction occurs normally in B cells deficient in STAT6 and is unaffected by pretreatment with the PI3K inhibitor wortmannin, or with the ERK pathway inhibitor, PD98059. However, the IL-4 induction of SOCS3 is blocked by inhibitors of either the JNK or p38 MAPK pathways (SP600125 and SB203580, respectively). Direct examination of these pathways reveals rapid, IL-4-directed activation of p38 MAPK, uncovering a previously unappreciated pathway mediating IL-4 signal transduction.
IFN-α Induces Early Lethal Lupus in Preautoimmune (New Zealand Black × New Zealand White)F1 but Not in BALB/c Mice
Authors: Mathian Alexis , Weinberg Arthur , Gallegos Mike , Banchereau Jacques , Koutouzov Sophie 
Published: April 2014

AbstractRecent studies indicate that IFN-α is involved in pathogenesis of systemic lupus erythematosus. However, direct proof that IFN-α is not only necessary, but also sufficient to induce lupus pathogenicity is lacking. In this study, we show that in vivo adenovector-mediated delivery of murine IFN-α results in preautoimmune (New Zealand Black (NZB) × New Zealand White (NZW))F1, but not in normal, mice, in a rapid and severe disease with all characteristics of systemic lupus erythematosus. Anti-dsDNA Abs appeared as soon as day 10 after initiation of IFN-α treatment. Proteinuria and death caused by glomerulonephritis occurred in all treated mice within, respectively, ∼9 and ∼18 wk, at a time when all untreated (NZB × NZW)F1 did not show any sign of disease. IFN-α in vivo induced an overexpression of B lymphocyte stimulator in circulation at similar levels in both the preautoimmune and the normal mouse strains. All effects elicited by IFN-α were dose dependent. (NZB × NZW)F1 infused with purified murine IFN-α also showed acceleration of lupus. Thus, prolonged expression of IFN-α in vivo induces early lethal lupus in susceptible animals.
PolycombGroup Genemel-18Regulates Early T Progenitor Expansion by Maintaining the Expression ofHes-1, a Target of the Notch Pathway
Authors: Miyazaki Masaki , Kawamoto Hiroshi , Kato Yuko , Itoi Manami , Miyazaki Kazuko , Masuda Kyoko , Tashiro Satoshi , Ishihara Hiroto , Igarashi Kazuhiko , Amagai Takashi , Kanno Rieko , Kanno Masamoto 
Published: April 2014

AbstractPolycomb group (PcG) proteins play a role in the maintenance of cellular identity throughout many rounds of cell division through the regulation of gene expression. In this report we demonstrate that the loss of the PcG gene mel-18 impairs the expansion of the most immature T progenitor cells at a stage before the rearrangement of the TCR β-chain gene in vivo and in vitro. This impairment of these T progenitors appears to be associated with increased susceptibility to cell death. We also show that the expression of Hes-1, one of the target genes of the Notch signaling pathway, is drastically down-regulated in early T progenitors isolated from mel-18−/− mice. In addition, mel-18−/− T precursors could not maintain the Hes-1 expression induced by Delta-like-1 in monolayer culture. Collectively, these data indicate that mel-18 contributes to the maintenance of the active state of the Hes-1 gene as a cellular memory system, thereby supporting the expansion of early T progenitors.