bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cutting Edge: Extracellular High Mobility Group Box-1 Protein Is a Proangiogenic Cytokine
Authors: Mitola Stefania , Belleri Mirella , Urbinati Chiara , Coltrini Daniela , Sparatore Bianca , Pedrazzi Marco , Melloni Edon , Presta Marco 
Published: April 2014

Abstract
The chromosomal high mobility group box-1 (HMGB1) protein acts as a proinflammatory cytokine when released in the extracellular environment by necrotic and inflammatory cells. In the present study, we show that HMGB1 exerts proangiogenic effects by inducing MAPK ERK1/2 activation, cell proliferation, and chemotaxis in endothelial cells of different origin. Accordingly, HMGB1 stimulates membrane ruffling and repair of a mechanically wounded endothelial cell monolayer and causes endothelial cell sprouting in a three-dimensional fibrin gel. In keeping with its in vitro properties, HMGB1 stimulates neovascularization when applied in vivo on the top of the chicken embryo chorioallantoic membrane whose blood vessels express the HMGB1 receptor for advanced glycation end products (RAGE). Accordingly, RAGE blockade by neutralizing Abs inhibits HMGB1-induced neovascularization in vivo and endothelial cell proliferation and membrane ruffling in vitro. Taken together, the data identify HMGB1/RAGE interaction as a potent proangiogenic stimulus.
Allograft Rejection Requires STAT5a/b-Regulated Antiapoptotic Activity in T Cells but Not B Cells
Authors: Zhang Ye , Kirken Robert A. , Furian Lucrezia , Janczewska Slawa , Qu Xiumei , Hancock Wayne W. , Wang Mouer , Tejpal Neelam , Kerman Ronald , Kahan Barry D. , Stepkowski Stanislaw M. 
Published: April 2014

Abstract
STATs play key roles in immune function. We examined the role of STAT5a/b in allograft rejection. STAT5a/b-deficient mice showed a 4-fold increased survival time of heart allografts (p &lt; 0.01). Unlike wild type, purified STAT5a/b−/− T cells transferred to Rag1−/− recipients failed to mediate heart allograft rejection until supplemented with STAT5a/b−/− B cells. In vitro, STAT5a/b−/− T cells did not proliferate in response to Con A or alloantigens but entered apoptosis within 48 h (95%). Activated STAT5a/b−/− T cells showed increased expression of proapoptotic (caspases, DNA repair genes, TNF/TNFR-associated factor family genes) and decreased antiapoptotic mRNAs in microarrays, while Western blots confirmed reduced antiapoptotic Bcl-2 and elevated proapoptotic Bax protein expression. Interestingly, at 24 h postactivation, STAT5a/b+/+ and STAT5a/b−/− T cells produced similar levels of IL-2, IL-4, IL-10, and IFN-γ mRNA; ELISPOT assay showed an equivalent number of IL-4- and IFN-γ-producing T cells in both STAT5a/b+/+ and STAT5a/b−/− splenic populations. Sera from STAT5a/b+/+ and STAT5a/b−/− rejectors had donor-specific IgM, IgG1, IgG2a, and IgG2b Ab, while STAT5a/b deficiency had no impact on B cell survival or proliferation in response to LPS. Compared with allografts from STAT5a/b+/+ recipients, heart allografts from STAT5a/b−/− recipients had markedly reduced infiltration by CD4 and CD8 T cells but increased infiltration by B cells and dense endothelial deposition of C4d, a marker of humoral rejection. Thus, activated STAT5a/b−/− T cells produce cytokines prior to entering apoptosis, thereby promoting differentiation of B cells yielding donor-specific IgM and IgG Ab that mediate allograft rejection.
Helminth-Modified Pulmonary Immune Response Protects Mice from Allergen-Induced Airway Hyperresponsiveness
Authors: Mangan Niamh E. , van Rooijen Nico , McKenzie Andrew N. J. , Fallon Padraic G. 
Published: April 2014

Abstract
It has been shown that the presence of certain helminth infections in humans, including schistosomes, may reduce the propensity to develop allergies in infected populations. Using a mouse model of schistosome worm vs worm + egg infection, our objective was to dissect the mechanisms underlying the inverse relationship between helminth infections and allergies. We have demonstrated that conventional Schistosoma mansoni egg-laying male and female worm infection of mice exacerbates airway hyperresponsiveness. In contrast, mice infected with only schistosome male worms, precluding egg production, were protected from OVA-induced airway hyperresponsiveness. Worm-infected mice developed a novel modified type 2 cytokine response in the lungs, with elevated allergen-specific IL-4 and IL-13 but reduced IL-5, and increased IL-10. Although schistosome worm-only infection is a laboratory model, these data illustrate the complexity of schistosome modulation of host immunity by the worm vs egg stages of this helminth, with the potential of infections to aggravate or suppress allergic pulmonary inflammation. Thus, infection of mice with a human parasitic worm can result in reduced airway inflammation in response to a model allergen.
The TLR-7 Agonist, Imiquimod, Enhances Dendritic Cell Survival and Promotes Tumor Antigen-Specific T Cell Priming: Relation to Central Nervous System Antitumor Immunity
Authors: Prins Robert M. , Craft Noah , Bruhn Kevin W. , Khan-Farooqi Haumith , Koya Richard C. , Stripecke Renata , Miller Jeff F. , Liau Linda M. 
Published: April 2014

Abstract
Immunotherapy represents an appealing option to specifically target CNS tumors using the immune system. In this report, we tested whether adjunctive treatment with the TLR-7 agonist imiquimod could augment antitumor immune responsiveness in CNS tumor-bearing mice treated with human gp100 + tyrosine-related protein-2 melanoma-associated Ag peptide-pulsed dendritic cell (DC) vaccination. Treatment of mice with 5% imiquimod resulted in synergistic reduction in CNS tumor growth compared with melanoma-associated Ag-pulsed DC vaccination alone. Continuous imiquimod administration in CNS tumor-bearing mice, however, was associated with the appearance of robust innate immune cell infiltration and hemorrhage into the brain and the tumor. To understand the immunological mechanisms by which imiquimod augmented antitumor immunity, we tested whether imiquimod treatment enhanced DC function or the priming of tumor-specific CD8+ T cells in vivo. With bioluminescent, in vivo imaging, we determined that imiquimod dramatically enhanced both the persistence and trafficking of DCs into the draining lymph nodes after vaccination. We additionally demonstrated that imiquimod administration significantly increased the accumulation of tumor-specific CD8+ T cells in the spleen and draining lymph nodes after DC vaccination. The results suggest that imiquimod positively influences DC trafficking and the priming of tumor-specific CD8+ T cells. However, inflammatory responses induced in the brain by TLR signaling must also take into account the local microenvironment in the context of antitumor immunity to induce clinical benefit. Nevertheless, immunotherapeutic targeting of malignant CNS tumors may be enhanced by the administration of the innate immune response modifier imiquimod.
Reduced Ability of Neonatal and Early-Life Bone Marrow Stromal Cells to Support Plasmablast Survival
Authors: Pihlgren Maria , Friedli Mathieu , Tougne Chantal , Rochat Anne-Françoise , Lambert Paul-Henri , Siegrist Claire-Anne 
Published: April 2014

Abstract
In human infants (&lt;1 year), circulating IgG Abs elicited in response to most T-dependent Ags rapidly decline and return to baseline within a few months after immunization for yet-unknown reasons. In mice immunized between 1 and 4 wk of age, a limited establishment of the bone marrow (BM) pool of long-lived plasma cells is observed. In this study, we show that tetanus toxoid (TT)-specific plasmablasts generated in the spleen are efficiently attracted in vitro and in vivo toward early-life BM stromal cells, which express adult levels of CXCL12. Similarly, adoptively transferred TT plasmablasts efficiently reach the BM compartment of 2-wk-old and adult mice. In contrast, TT plasmablasts fail to persist in the early-life BM compartment, as indicated by the persistence of a significantly lower number of TT plasmablasts in the early-life compartment than in the adult BM compartment 48 h after transfer. This limited persistence is associated with an increased rate of in vivo apoptosis of TT-specific plasmablasts that have reached the early-life BM and with a significantly lower survival rate of TT-specific plasmablasts cocultured on early-life BM stromal cells compared with adult BM stromal cells. Thus, early-life BM stromal cells fail to provide the molecular signals that support plasmablast survival and differentiation into surviving plasma cells.
The CD8+ T Cell Population Elicited by Recombinant Adenovirus Displays a Novel Partially Exhausted Phenotype Associated with Prolonged Antigen Presentation That Nonetheless Provides Long-Term Immunity
Authors: Yang Teng-Chih , Millar James , Groves Timothy , Grinshtein Natalie , Parsons Robin , Takenaka Shunsuke , Wan Yonghong , Bramson Jonathan L. 
Published: April 2014

Abstract
We have previously reported that the CD8+ T cell response elicited by recombinant adenovirus vaccination displayed a delayed contraction in the spleen. In our current study, we demonstrate that this unusual kinetic is a general phenomenon observed in multiple tissues. Phenotypic analysis of transgene-specific CD8+ T cells present 30 days postimmunization with recombinant adenovirus revealed a population with evidence of partial exhaustion, suggesting that the cells had been chronically exposed to Ag. Although Ag expression could no longer be detected 3 wk after immunization, examination of Ag presentation within the draining lymph nodes demonstrated that APCs were loaded with Ag peptide for at least 40 days postimmunization, suggesting that Ag remains available to the system for a prolonged period, although the exact source of this Ag remains to be determined. At 60 days postimmunization, the CD8+ T cell population continued to exhibit a phenotype consistent with partially exhausted effector memory cells. Nonetheless, these CD8+ T cells conferred sterilizing immunity against virus challenge 7–12 wk postimmunization, suggesting that robust protective immunity can be provided by CD8+ T cells with an exhausted phenotype. These data demonstrate that prolonged exposure to Ag may not necessarily impair protective immunity and prompt a re-evaluation of the impact of persistent exposure to Ag on T cell function.
Expression of CD161 (NKR-P1A) Defines Subsets of Human CD4 and CD8 T Cells with Different Functional Activities
Authors: Takahashi Tsuyoshi , Dejbakhsh-Jones Sussan , Strober Samuel 
Published: April 2014

Abstract
A subset of T cells in human peripheral blood expresses CD161 (NKR-P1A) receptors that are primarily associated with NK cells. In the current study we isolated blood T cell subsets according to the expression of CD161 and examined their contents of naive, central memory, and effector memory cells and their capacities for proliferation, cytokine secretion, and natural cytolysis. We found that CD4+CD161− and CD8+CD161− subsets contained predominantly naive T cells that secreted high levels of IL-2 after in vitro stimulation, and CD4+CD161int and CD8+CD161int subsets contained predominantly effector and central memory T cells that secreted high levels of IFN-γ and TNF-α. All of these subsets showed vigorous proliferation after stimulation in vitro, but none had NK lytic activity. Unexpectedly, the CD8+CD161+ cells contained an anergic CD8α+CD8βlow/−CD161high T cell subset that failed to proliferate, secrete cytokines, or mediate NK lytic activity.
IL-27 Limits IL-2 Production during Th1 Differentiation
Authors: Villarino Alejandro V. , Stumhofer Jason S. , Saris Christiaan J. M. , Kastelein Robert A. , de Sauvage Frederic J. , Hunter Christopher A. 
Published: April 2014

Abstract
Although the ability of IL-27 to promote T cell responses is well documented, the anti-inflammatory properties of this cytokine remain poorly understood. The current work demonstrates that during infection with Toxoplasma gondii, IL-27R-deficient mice generate aberrant IL-2 responses that are associated with the development of a lethal inflammatory disease. Because in vivo depletion of IL-2 prolongs the survival of infected IL-27R−/− mice, these data suggest that IL-27 curbs the development of immunopathology by limiting parasite-induced IL-2 production. Consistent with this hypothesis, IL-27R−/− CD4+ T cells produce more IL-2 than wild-type counterparts during in vitro differentiation, and when rIL-27 is introduced, it can suppress the expression of IL-2 mRNA and protein by the latter group. Additionally, these studies reveal that, like IL-27, IL-12 can inhibit IL-2 production, and although each employs distinct mechanisms, they can synergize to enhance the effect. In contrast, this property is not shared by closely related cytokines IL-6 and IL-23. Thus, while traditionally viewed as proinflammatory agents, the present findings establish that IL-27 and IL-12 cooperate to limit the availability of IL-2, a potent T cell growth and survival factor. Moreover, because the current studies demonstrate that both can induce expression of suppressor of cytokine signaling 3, a protein that tempers cytokine receptor signaling, they also suggest that IL-27 and IL-12 share additionally inhibitory properties.
The Novel Cytokine p43 Induces IL-12 Production in Macrophages via NF-κB Activation, Leading to Enhanced IFN-γ Production in CD4+ T Cells
Authors: Kim Eugene , Kim Seung Hyun , Kim Sunghoon , Kim Tae Sung 
Published: April 2014

Abstract
Recently, we determined that p43, an auxiliary factor of mammalian multiaminoacyl-tRNA synthetases, is secreted, and functions as a novel pleiotropic cytokine. In this study, we have attempted to characterize the effects of p43 on the generation of IL-12 in mouse macrophages. p43 was determined to induce significant IL-12 production from mouse macrophages in a dose-dependent manner. The stimulatory effect of p43 on the activation of IL-12p40 promoter was mapped to a region harboring an NF-κB binding site. The nuclear extracts from the p43-stimulated macrophages exhibited profound NF-κB DNA-binding activity, as determined by the EMSA. In addition, the p43-stimulated IL-12 induction and NF-κB DNA-binding activity were significantly suppressed by caffeic acid phenethyl ester and BAY11-7082, both inhibitors of NF-κB activation, indicating that p43 induced the production of IL-12 in macrophages mainly via the activation of NF-κB. Importantly, p43 increased the level of IFN-γ production in the Ag-primed lymph node cells, but had no effect on IL-4 levels. The addition of a neutralizing anti-IL-12p40 mAb to the cell cultures resulted in a decrease of the production of p43-enhanced IFN-γ by the keyhole limpet hemocyanin-primed lymph node cells. Furthermore, coincubation with p43-pretreated macrophages enhanced the production of IFN-γ by the keyhole limpet hemocyanin-primed CD4+ T cells, thereby indicating that p43 may enhance IFN-γ expression in CD4+ T cells via the induction of IL-12 production in macrophages. These results indicate that p43 may play an essential role in the development of the Th1 immune responses associated with cancer immunotherapy and protective immunity against intracellular pathogens.
Hydrolytic and Nonenzymatic Functions of Acetylcholinesterase Comodulate Hemopoietic Stress Responses
Authors: Grisaru Dan , Pick Marjorie , Perry Chava , Sklan Ella H. , Almog Ronit , Goldberg Ilan , Naparstek Elizabeth , Lessing Joseph B. , Soreq Hermona , Deutsch Varda 
Published: April 2014

Abstract
Glucocorticoid-initiated granulocytosis, excessive proliferation of granulocytes, persists after cortisol levels are lowered, suggesting the involvement of additional stress mediator(s). In this study, we report that the stress-induced acetylcholinesterase variant, AChE-R, and its cleavable, cell-penetrating C-terminal peptide, ARP, facilitate granulocytosis. In postdelivery patients, AChE-R-expressing granulocyte counts increased concomitantly with serum cortisol and AChE activity levels, yet persisted after cortisol had declined. Ex vivo, mononuclear cells of adult peripheral blood responded to synthetic ARP26 by overproduction of hemopoietically active proinflammatory cytokines (e.g., IL-6, IL-10, and TNF-α). Physiologically relevant ARP26 levels promoted AChE gene expression and induced the expansion of cultured CD34+ progenitors and granulocyte maturation more effectively than cortisol, suggesting autoregulatory prolongation of ARP effects. In vivo, transgenic mice overexpressing human AChE-R, unlike matched controls, showed enhanced expression of the myelopoietic transcription factor PU.1 and maintained a stable granulocytic state following bacterial LPS exposure. AChE-R accumulation and the consequent inflammatory consequences can thus modulate immune responses to stress stimuli.
Synergistic Activation of Macrophages via CD40 and TLR9 Results in T Cell Independent Antitumor Effects
Authors: Buhtoiarov Ilia N. , Lum Hillary D. , Berke Gideon , Sondel Paul M. , Rakhmilevich Alexander L. 
Published: April 2014

Abstract
We have previously shown that macrophages (Mφ) can be activated by CD40 ligation to become cytotoxic against tumor cells in vitro. Here we show that treatment of mice with agonistic anti-CD40 mAb (anti-CD40) induced up-regulation of intracellular TLR9 in Mφ and primed them to respond to CpG-containing oligodeoxynucleotides (CpG), resulting in synergistic activation. The synergy between anti-CD40 and CpG was evidenced by increased production of IFN-γ, IL-12, TNF-α, and NO by Mφ, as well as by augmented apoptogenic effects of Mφ against tumor cells in vitro. The activation of cytotoxic Mφ after anti-CD40 plus CpG treatment was dependent on IFN-γ but not TNF-α or NO, and did not require T cells and NK cells. Anti-CD40 and CpG also synergized in vivo in retardation of tumor growth in both immunocompetent and immunodeficient mice. Inactivation of Mφ in SCID/beige mice by silica treatment abrogated the antitumor effect. Taken together, our results show that Mφ can be activated via CD40/TLR9 ligation to kill tumor cells in vitro and inhibit tumor growth in vivo even in immunocompromised tumor-bearing hosts, indicating that this Mφ-based immunotherapeutic strategy may be appropriate for clinical testing.
Immunodomination in the Evolution of Dominant Epitope-Specific CD8+ T Lymphocyte Responses in Simian Immunodeficiency Virus-Infected Rhesus Monkeys
Authors: Newberg Michael H. , McEvers Kimberly J. , Gorgone Darci A. , Lifton Michelle A. , Baumeister Susanne H. C. , Veazey Ronald S. , Schmitz Jörn E. , Letvin Norman L. 
Published: April 2014

Abstract
Because the control of HIV-1 replication is largely dependent on CD8+ T lymphocyte responses specific for immunodominant viral epitopes, vaccine strategies that increase the breadth of dominant epitope-specific responses should contribute to containing HIV-1 spread. Developing strategies to elicit such broad immune responses will require an understanding of the mechanisms responsible for focusing CD8+ T lymphocyte recognition on a limited number of epitopes. To explore this biology, we identified cohorts of rhesus monkeys that expressed the MHC class I molecules Mamu-A*01, Mamu-A*02, or both, and assessed the evolution of their dominant epitope-specific CD8+ T lymphocyte responses (Gag p11C- and Tat TL8-specific in the Mamu-A*01+ and Nef p199RY-specific in the Mamu-A*02+ monkeys) following acute SIV infection. The Mamu-A*02+ monkeys that also expressed Mamu-A*01 exhibited a significant delay in the evolution of the CD8+ T lymphocyte responses specific for the dominant Mamu-A*02-restricted SIV epitope, Nef p199RY. This delay in kinetics was not due to differences in viral load kinetics or magnitude or in viral escape mutations, but was associated with the evolution of the Mamu-A*01-restricted CD8+ T lymphocyte responses to the highly dominant SIV epitopes Gag p11C and Tat TL8. Thus, the evolution of dominant epitope-specific CD8+ T lymphocyte responses can be suppressed by other dominant epitope-specific responses, and this immunodomination is important in determining the kinetics of dominant epitope-specific responses.
Specificity of CD4+CD25+ Regulatory T Cell Function in Alloimmunity
Authors: Sánchez-Fueyo Alberto , Sandner Sigrid , Habicht Antje , Mariat Christophe , Kenny James , Degauque Nicolas , Zheng Xin Xiao , Strom Terry B. , Turka Laurence A. , Sayegh Mohamed H. 
Published: April 2014

Abstract
CD4+CD25+ regulatory T cells (TRegs) are critical for the acquisition of peripheral allograft tolerance. However, it is unclear whether TRegs are capable of mediating alloantigen-specific suppressive effects and, hence, contributing to the specificity of the tolerant state. In the current report we have used the ABM TCR transgenic (Tg) system, a C57BL/6-derived strain in which CD4+ T cells directly recognize the allogeneic MHC-II molecule I-Abm12, to assess the capacity of TRegs to mediate allospecific effects. In these mice, 5–6% of Tg CD4+ T cells exhibit conventional markers of the TReg phenotype. ABM TRegs are more effective than wild-type polyclonal TRegs at suppressing effector immune responses directed against I-Abm12 alloantigen both in vitro and in vivo. In contrast, they are incapable of suppressing responses directed against third-party alloantigens unless these are expressed in the same allograft as I-Abm12. Taken together, our results indicate that in transplantation, TReg function is dependent on TCR stimulation, providing definitive evidence for their specificity in the regulation of alloimmune responses.
Src-Like Adaptor Protein Regulates B Cell Development and Function
Authors: Dragone Leonard L. , Myers Margaret D. , White Carmen , Sosinowski Tomasz , Weiss Arthur 
Published: April 2014

Abstract
The avidity of BCRs and TCRs influences signal strength during processes of lymphocyte development. Avidity is determined by both the intrinsic affinity for Ag and surface levels of the Ag receptor. The Src-like adaptor protein (SLAP) is a regulator of TCR levels on thymocytes, and its deficiency alters thymocyte development. We hypothesized that SLAP, which is expressed in B cells, also is important in regulating BCR levels, signal strength, and B cell development. To test this hypothesis, we analyzed the B cell compartment in SLAP-deficient mice. We found increased splenic B cell numbers and decreased surface IgM levels on mature, splenic B cells deficient in SLAP. Immature bone marrow and splenic B cells from BCR-transgenic, SLAP-deficient mice were found to express higher surface levels of IgM. In contrast, mature splenic B cells from BCR-transgenic mice expressed decreased levels of surface BCR associated with decreased calcium flux and activation-induced markers, compared with controls. These data suggest that SLAP regulates BCR levels and signal strength during lymphocyte development.