bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural and Synthetic TLR7 Ligands Inhibit CpG-A- and CpG-C-Oligodeoxynucleotide-Induced IFN-α Production
Authors: Berghöfer Beate , Haley Gabriela , Frommer Ture , Bein Gregor , Hackstein Holger 
Published: April 2014

Abstract
Plasmacytoid dendritic cells (pDCs) are unique with respect to their capacity to produce unsurpassed amounts of IFN-α and coexpress TLR7 and TLR9, mediating IFN-α production. Although TLRs are critical receptors of innate immunity, little is known about the immunological effects of TLR7/TLR9 costimulation. We have analyzed the effects of TLR7/TLR9 costimulation on IFN-α production by leukocytes and pDCs. Our experiments revealed that both synthetic (resiquimod and loxoribine) and natural (ssRNA40) TLR7 ligands abrogate CpG-A- and CpG-C-oligodeoxynucleotide (ODN)-induced IFN-α production by human leukocytes. Because TLR7 ligands themselves represent important IFN-α inducers, we demonstrated that substimulatory TLR7 ligand concentrations significantly inhibited CpG-A-induced IFN-α. Delayed addition of TLR7 ligands still resulted in complete suppression of CpG-A-ODN-induced IFN-α production, suggesting that the inhibition is unlikely to be caused by a kinetic uptake advantage. Unlike for CpG-A and CpG-C, TLR7 ligands did not inhibit CpG-B-ODN-induced IFN-α production. Experiments with purified human pDCs demonstrated that the inhibitory effects of TLR7/TLR9 costimulation were mediated directly by pDCs. Suppression of IFN-α production was not related to increased cell death and was also detectable in enriched mouse pDCs. Analyses of pDCs suggested that the TLR7 signal regulates the outcome of TLR7 ligand/CpG-A-ODN costimulation and can either inhibit (IFN-α) or promote (IL-8/CD40) cytokine and surface marker expression. Our data reveal for the first time a strong inhibitory effect of TLR7 stimulation on IFN-α production induced by CpG-A- and CpG-C-ODNs. These findings provide novel insight into the effects of TLR7/TLR9 costimulation and may support the development of novel TLR9 inhibitors.
Delivery of Antigen to CD40 Induces Protective Immune Responses against Tumors
Authors: Schjetne Karoline W. , Fredriksen Agnete B. , Bogen Bjarne 
Published: April 2014

Abstract
Ligation of CD40 induces maturation of dendritic cells (DC) and could be a useful target for vaccines. In this study, we have constructed two types of Ab-based vaccine constructs that target mouse CD40. One type is a recombinant Ab with V regions specific for CD40 and has defined T cell epitopes inserted into its C region. The other type is a homodimer, each chain of which is composed of a targeting unit (single-chain fragment variable targeting CD40), a dimerization motif, and an antigenic unit. Such proteins bound CD40, stimulated maturation of DC, and enhanced primary and memory T cell responses. When delivered i.m. as naked DNA followed by electroporation, the vaccines induced T cell responses against MHC class II-restricted epitopes, Ab responses, and protection in two tumor models (myeloma and lymphoma). Two factors apparently contributed to these results: 1) agonistic ligation of CD40 and induction of DC maturation, and 2) delivery of Ag to APC and presentation on MHC class II molecules. These results highlight the importance of agonistic targeting of Ag to CD40 for induction of long-lasting and protective immune responses.
Distinct Cytokine-Driven Responses of Activated Blood γδ T Cells: Insights into Unconventional T Cell Pleiotropy
Authors: Vermijlen David , Ellis Peter , Langford Cordelia , Klein Anne , Engel Rosel , Willimann Katharina , Jomaa Hassan , Hayday Adrian C. , Eberl Matthias 
Published: April 2014

Abstract
Human Vγ9/Vδ2 T cells comprise a small population of peripheral blood T cells that in many infectious diseases respond to the microbial metabolite, (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), expanding to up to 50% of CD3+ cells. This “transitional response,” occurring temporally between the rapid innate and slower adaptive response, is widely viewed as proinflammatory and/or cytolytic. However, increasing evidence that different cytokines drive widely different effector functions in αβ T cells provoked us to apply cDNA microarrays to explore the potential pleiotropy of HMB-PP-activated Vγ9/Vδ2 T cells. The data and accompanying validations show that the related cytokines, IL-2, IL-4, or IL-21, each drive proliferation and comparable CD69 up-regulation but induce distinct effector responses that differ from prototypic αβ T cell responses. For example, the Th1-like response to IL-2 also includes expression of IL-5 and IL-13 that conversely are not induced by IL-4. The data identify specific molecules that may mediate γδ T cell effects. Thus, IL-21 induces a lymphoid-homing phenotype and high, unexpected expression of the follicular B cell-attracting chemokine CXCL13/BCA-1, suggesting a novel follicular B-helper-like T cell that may play a hitherto underappreciated role in humoral immunity early in infection. Such broad plasticity emphasizes the capacity of γδ T cells to influence the nature of the immune response to different challenges and has implications for the ongoing clinical application of cytokines together with Vγ9/Vδ2 TCR agonists.
Factor H Binding and Function in Sialylated Pathogenic Neisseriae is Influenced by Gonococcal, but Not Meningococcal, Porin
Authors: Madico Guillermo , Ngampasutadol Jutamas , Gulati Sunita , Vogel Ulrich , Rice Peter A. , Ram Sanjay 
Published: April 2014

Abstract
Neisseria gonorrhoeae and Neisseria meningitidis both express the lacto-N-neotetraose (LNT) lipooligosaccharide (LOS) molecule that can be sialylated. Although gonococcal LNT LOS sialylation enhances binding of the alternative pathway complement inhibitor factor H and renders otherwise serum-sensitive bacteria resistant to complement-dependent killing, the role of LOS sialylation in meningococcal serum resistance is less clear. We show that only gonococcal, but not meningococcal, LNT LOS sialylation enhanced factor H binding. Replacing the porin (Por) B molecule of a meningococcal strain (LOS sialylated) that did not bind factor H with gonococcal Por1B augmented factor H binding. Capsule expression did not alter factor H binding to meningococci that express gonococcal Por. Conversely, replacing gonococcal Por1B with meningococcal PorB abrogated factor H binding despite LNT LOS sialylation. Gonococcal Por1B introduced in the background of an unsialylated meningococcus itself bound small amounts of factor H, suggesting a direct factor H-Por1B interaction. Factor H binding to unsialylated meningococci transfected with gonococcal Por1B was similar to the sialylated counterpart only in the presence of higher (20 μg/ml) concentrations of factor H and decreased in a dose-responsive manner by ∼80% at 1.25 μg/ml. Factor H binding to the sialylated strain remained unchanged over this factor H concentration range however, suggesting that LOS sialylation facilitated optimal factor H-Por1B interactions. The functional counterpart of factor H binding showed that sialylated meningococcal mutants that possessed gonococcal Por1B were resistant to complement-mediated killing by normal human serum. Our data highlight the different mechanisms used by these two related species to evade complement.
IFN Mimetic as a Therapeutic for Lethal Vaccinia Virus Infection: Possible Effects on Innate and Adaptive Immune Responses
Authors: Ahmed Chulbul M. , Martin James P. , Johnson Howard M. 
Published: April 2014

Abstract
We have developed small peptide mimetics of IFN-γ that can bypass the poxvirus virulence factor B8R protein, which binds to intact IFN-γ and prevents its interaction with receptor extracellular domain. Thus, these peptides inhibit vaccinia virus replication in cell culture where intact IFN-γ is ineffective. We demonstrate here that the mouse IFN-γ-mimetic peptide, IFN-γ95–132, protects C57BL/6 mice against overwhelming lethal vaccinia virus infection. The mimetic peptide was synthesized with an attached lipophilic group for penetration of cell plasma membrane. Injection of mimetic i.p. before and at the time of intranasal (106 PFU) or i.p. (107 PFU) challenge with virus resulted in complete protection at 200 μg of mimetic and 40–60% protection at 5 μg of mimetic. Initiation of treatment of mice with IFN-γ mimetic up to 2 days postinfection resulted in complete protection against death, whereas initiation of treatment at 6 days postinfection resulted in 40% protection. Administration of mimetic by the oral route also completely protected mice against the intranasal route of a lethal dose of vaccinia virus challenge. In addition to its direct antiviral effect, the mimetic also possessed adjuvant effects in boosting humoral and cellular immunity to vaccinia virus. The combination of antiviral and adjuvant effects by the IFN mimetic probably plays a role in its potent anti-vaccinia virus properties. These results suggest an effective therapeutic against ongoing, lethal poxvirus infections that taps into innate and adaptive host defenses.
The Chemokine Binding Protein M3 Prevents Diabetes Induced by Multiple Low Doses of Streptozotocin
Authors: Martin Andrea P. , Alexander-Brett Jennifer M. , Canasto-Chibuque Claudia , Garin Alexandre , Bromberg Jonathan S. , Fremont Daved H. , Lira Sergio A. 
Published: April 2014

Abstract
Multiple injections of low-dose streptozotocin (MLDS) induce lymphocytic insulitis and diabetes in rodents. To test whether the influx of inflammatory cells was associated with changes in the expression of chemokines, we measured the expression of all known chemokine ligands by real-time quantitative PCR in isolated islets. With the exception of CCL20 and CCL19, chemokines were not significantly expressed in islets from wild-type mice before MLDS treatment. Ten days after treatment, the expression of several chemokines, including CXCL9, CCL1, CXCL10, and CCL21, was dramatically up-regulated. The expression of CCL1, CXCL9, and CCL21 protein was confirmed by immunohistochemistry and was mostly associated with the infiltrating cells. The mouse herpesvirus 68-encoded chemokine decoy receptor M3 can broadly engage these chemokines with high affinity. To test whether a blockade of chemokine function would alter the onset or magnitude of insulitis and diabetes, we used transgenic mice expressing M3 in β cells (rat insulin promoter (RIP)-M3 mice). RIP-M3 mice were normoglycemic and responded normally to glucose challenge but were remarkably resistant to diabetes induced by MLDS. Islets from MLDS-treated RIP-M3 mice had fewer inflammatory cells and expressed lower levels of chemokines than those from MLDS-treated controls. The role of M3 in chemokine blockade during insulitis was further supported by in vitro experiments demonstrating that multiple chemokines up-regulated during islet inflammation are high-affinity M3 ligands that can be simultaneously sequestered. These results implicate chemokines as key mediators of insulitis and suggest that their blockade may represent a novel strategy to prevent insulitis and islet destruction.
Grass Pollen Immunotherapy Induces an Allergen-Specific IgA2 Antibody Response Associated with Mucosal TGF-β Expression
Authors: Pilette Charles , Nouri-Aria Kayhan T. , Jacobson Mikila R. , Wilcock Louisa K. , Detry Bruno , Walker Samantha M. , Francis James N. , Durham Stephen R. 
Published: April 2014

Abstract
Allergen immunotherapy (IT) has long-term efficacy in IgE-mediated allergic rhinitis and asthma. IT has been shown to modify lymphocyte responses to allergen, inducing IL-10 production and IgG Abs. In contrast, a putative role for IgA and local TGF-β-producing cells remains to be determined. In 44 patients with seasonal rhinitis/asthma, serum IgA1, IgA2, and polymeric (J chain-containing) Abs to the major allergen Phl p 5 were determined by ELISA before and after a 2-year double-blind trial of grass pollen (Phleum pratense) injection IT. Nasal TGF-β expression was assessed by in situ hybridization. Sera from five IT patients were fractionated for functional analysis of the effects of IgA and IgG Abs on IL-10 production by blood monocytes and allergen-IgE binding to B cells. Serum Phl p 5-specific IgA2 Abs increased after a 2-year treatment (∼8-fold increase, p = 0.002) in contrast to IgA1. Increases in polymeric Abs to Phl p 5 (∼2-fold increase, p = 0.02) and in nasal TGF-β mRNA (p = 0.05) were also observed, and TGF-β mRNA correlated with serum Phl p 5 IgA2 (r = 0.61, p = 0.009). Post-IT IgA fractions triggered IL-10 secretion by monocytes while not inhibiting allergen-IgE binding to B cells as observed with IgG fractions. This study shows for the first time that the IgA response to IT is selective for IgA2, correlates with increased local TGF-β expression, and induces monocyte IL-10 expression, suggesting that IgA Abs could thereby contribute to the tolerance developed in IT-treated allergic patients.
Prothymosin α Lacking the Nuclear Localization Signal as an Effective Gene Therapeutic Strategy in Collagen-Induced Arthritis
Authors: Shiau Ai-Li , Chen Shih-Yao , Chang Meng-Ya , Su Chih-Hau , Chung Shih-Ye , Yo Yi-Te , Wang Chrong-Reen , Wu Chao-Liang 
Published: April 2014

Abstract
Prothymosin α (ProT) is regulated by c-Myc, an oncoprotein overexpressed in synovium of rheumatoid arthritis, and is associated with cell proliferation. However, ProT also exerts immunomodulatory activities. The growth-promoting activity of ProT can be abolished by deleting its nuclear localization signal (NLS). In this study, we showed that AdProTΔNLS, an adenoviral vector encoding ProT lacking the NLS, did not enhance the proliferation of synovial fibroblasts. AdProTΔNLS treatment abolished the up-regulation of the MIP-1α promoter activity induced by TNF-α in synovial fibroblasts. AdProTΔNLS suppressed macrophage chemotaxis and reduced macrophage infiltration into the ankle joints in rats with collagen-induced arthritis (CIA). Neutralization test confirmed the involvement of MIP-1α in macrophage chemotaxis. Administration of AdProTΔNLS reduced the severity of CIA in the clinical, radiographic, and histological aspects. The levels of TNF-α (mean ± SEM, 1261.9 ± 107.9 vs 2880.1 ± 561.4 pg/mg total protein; p &lt; 0.05), IL-1β (56.8 ± 8.0 vs 109.2 ± 4.9 pg/mg total protein; p &lt; 0.01), and MIP-1α (41.7 ± 3.6 vs 55.2 ± 1.1 pg/mg total protein; p &lt; 0.05) in the ankle joints were lower in the AdProTΔNLS-treated rats with CIA than those in their control counterparts. In the AdProTΔNLS-treated ankle joints, matrix metalloproteinase-9 expression was decreased by 40% and infiltrating macrophages reduced by 50%. Our results demonstrate that intra-articular delivery of AdProTΔNLS significantly ameliorated the clinical course of CIA in rats. This study is the first to suggest that ProT lacking the NLS may have therapeutic potential for the management of rheumatoid arthritis.
NK Cell Maturation and Peripheral Homeostasis Is Associated with KLRG1 Up-Regulation
Authors: Huntington Nicholas D. , Tabarias Hy , Fairfax Kirsten , Brady Jason , Hayakawa Yoshihiro , Degli-Esposti Mariapia A. , Smyth Mark J. , Tarlinton David M. , Nutt Stephen L. 
Published: April 2014

Abstract
NK cells are important for the clearance of tumors, parasites, and virus-infected cells. Thus, factors that control NK cell numbers and function are critical for the innate immune response. A subset of NK cells express the inhibitory killer cell lectin-like receptor G1 (KLRG1). In this study, we identify that KLRG1 expression is acquired during periods of NK cell division such as development and homeostatic proliferation. KLRG1+ NK cells are mature in phenotype, and we show for the first time that these cells have a slower in vivo turnover rate, reduced proliferative response to IL-15, and poorer homeostatic expansion potential compared with mature NK cells lacking KLRG1. Transfer into lymphopenic recipients indicate that KLRG1− NK cells are precursors of KLRG1+ NK cells and KLRG1 expression accumulates following cell division. Furthermore, KLRG1+ NK cells represent a significantly greater proportion of NK cells in mice with enhanced NK cell numbers such as Cd45−/− mice. These data indicate that NK cells acquire KLRG1 on their surface during development, and this expression correlates with functional distinctions from other peripheral NK cells in vivo.
IFN-α-Induced Signal Transduction, Gene Expression, and Antitumor Activity of Immune Effector Cells Are Negatively Regulated by Suppressor of Cytokine Signaling Proteins
Authors: Zimmerer Jason M. , Lesinski Gregory B. , Kondadasula Sri Vidya , Karpa Volodymyr I. , Lehman Amy , RayChaudhury Abhik , Becknell Brian , Carson William E. 
Published: April 2014

Abstract
Proteins belonging to the suppressors of cytokine signaling (SOCS) family have been shown to regulate cytokine signal transduction in various cell types but their role in modulating the response of immune cells to IFN-α has not been fully explored. We hypothesized that SOCS proteins would inhibit the antitumor activity of IFN-α-stimulated immune cells. Transcripts for SOCS1, SOCS2, SOCS3, and cytokine-inducible Src homology 2-containing protein were identified in total human PBMC (PBMCs, NK cells, and T cells) within 1–2 h of stimulation with IFN-α (103–105 U/ml). Immunoblot analysis confirmed the expression of these factors at the protein level. Transcripts for SOCS proteins were rapidly but variably induced in PBMCs from patients with metastatic melanoma following the i.v. administration of IFN-α-2b (20 million units/m2). Overexpression of SOCS1 and SOCS3, but not SOCS2, in the Jurkat T cell line inhibited IFN-α-induced phosphorylated STAT1 and the transcription of IFN-stimulated genes. Conversely, small inhibitory RNA-mediated down-regulation of SOCS1 and SOCS3 in Jurkat cells and normal T cells enhanced the transcriptional response to IFN-α. Loss of SOCS1 or SOCS3 in murine immune effectors was associated with enhanced IFN-induced phosphorylated STAT1, transcription of IFN-stimulated genes, and antitumor activity. Of note, IFN-α treatment eliminated melanoma tumors in 70% of SOCS1-deficient mice, whereas IFN-treated SOCS-competent mice all died. The antitumor effects of IFN-α in tumor-bearing SOCS1-deficient mice were markedly inhibited following depletion of CD8+ T cells. These results indicate that the antitumor response of immune effector cells to exogenous IFN-α is regulated by SOCS proteins.
Type 1 Sphingosine 1-Phosphate G Protein-Coupled Receptor (S1P1) Mediation of Enhanced IL-4 Generation by CD4 T Cells from S1P1 Transgenic Mice
Authors: Wang Wengang , Huang Mei-Chuan , Goetzl Edward J. 
Published: April 2014

Abstract
Sphingosine 1-phosphate (S1P) is a natural lipid mediator that regulates immune cell traffic, Ab production, and T cell cytokine generation by mechanisms that enhance Th2 activities. Responses to S1P are controlled principally by the diverse expression patterns of its receptors in different cells. In T cells, the type 1 (S1P1) and type 4 (S1P4) G protein-coupled receptors are predominant. S1P1 mainly transduces effects on T cell migration and trafficking, whereas S1P4 transduces immunosuppression via its effects on T cell proliferation and cytokine production. Using T cell-specific S1P1 transgenic (TG) mice, we investigated the regulatory effects of the S1P-S1P1 axis on T cell cytokine production. The production of IL-4, but not IL-2 or IFN-γ, was significantly up-regulated &gt;10-fold in activated CD4 T cells from S1P1 TG mice compared with those from wild-type mice. Quantitative real-time PCR analysis revealed that IL-4 up-regulation was initiated at the mRNA level as early as 4 h after T cell activation. The up-regulation of IL-4 mRNA was mediated by c-Maf, Jun B, and Gata3 as demonstrated by increases in their protein expression and DNA-binding activities. In contrast, the expression and DNA-binding activities of T-bet, FosB, C-Fos, Jun D, Fra-1, Fra-2, and c-Jun all were identical in wild-type and TG CD4 T cells. Immunological assays showed that increased IL-4 levels induced greater production of IgE. Thus, the S1P-S1P1 axis specifically up-regulates c-Maf, Jun B, and Gata3, which consequently enhance IL-4 production that may lead to a Th2 phenotype.
Stat3 and Stat4 Direct Development of IL-17-Secreting Th Cells
Authors: Mathur Anubhav N. , Chang Hua-Chen , Zisoulis Dimitrios G. , Stritesky Gretta L. , Yu Qing , O’Malley John T. , Kapur Reuben , Levy David E. , Kansas Geoffrey S. , Kaplan Mark H. 
Published: April 2014

Abstract
IL-17-secreting CD4+ T cells are critically involved in inflammatory immune responses. Development of these cells is promoted in vivo and in vitro by IL-23 or TGFβ1 plus IL-6. Despite growing interest in this inflammatory Th subset, little is known about the transcription factors that are required for their development. We demonstrate that Stat3 is required for programming the TGFβ1 plus IL-6 and IL-23-stimulated IL-17-secreting phenotype, as well as for RORγt expression in TGFβ1 plus IL-6-primed cells. Moreover, retroviral transduction of a constitutively active Stat3 into differentiating T cell cultures enhances IL-17 production from these cells. We further show that Stat4 is partially required for the development of IL-23-, but not TGFβ1 plus IL-6-primed IL-17-secreting cells, and is absolutely required for IL-17 production in response to IL-23 plus IL-18. The requirements for Stat3 and Stat4 in the development of these IL-17-secreting subsets reveal additional mechanisms in Th cell fate decisions during the generation of proinflammatory cell types.
Quantitative Network Signal Combinations Downstream of TCR Activation Can Predict IL-2 Production Response
Authors: Kemp Melissa L. , Wille Lucia , Lewis Christina L. , Nicholson Lindsay B. , Lauffenburger Douglas A. 
Published: April 2014

Abstract
Proximal signaling events activated by TCR-peptide/MHC (TCR-pMHC) binding have been the focus of intense ongoing study, but understanding how the consequent downstream signaling networks integrate to govern ultimate avidity-appropriate TCR-pMHC T cell responses remains a crucial next challenge. We hypothesized that a quantitative combination of key downstream network signals across multiple pathways must encode the information generated by TCR activation, providing the basis for a quantitative model capable of interpreting and predicting T cell functional responses. To this end, we measured 11 protein nodes across six downstream pathways, along five time points from 10 min to 4 h, in a 1B6 T cell hybridoma stimulated by a set of three myelin proteolipid protein 139–151 altered peptide ligands. A multivariate regression model generated from this data compendium successfully comprehends the various IL-2 production responses and moreover successfully predicts a priori the response to an additional peptide treatment, demonstrating that TCR binding information is quantitatively encoded in the downstream network. Individual node and/or time point measurements less effectively accounted for the IL-2 responses, indicating that signals must be integrated dynamically across multiple pathways to adequately represent the encoded TCR signaling information. Of further importance, the model also successfully predicted a priori direct experimental tests of the effects of individual and combined inhibitors of the MEK/ERK and PI3K/Akt pathways on this T cell response. Together, our findings show how multipathway network signals downstream of TCR activation quantitatively integrate to translate pMHC stimuli into functional cell responses.