bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three-Dimensional Structure of the Cross-Reactive Pollen Allergen Che a 3: Visualizing Cross-Reactivity on the Molecular Surfaces of Weed, Grass, and Tree Pollen Allergens
Authors: Verdino Petra , Barderas Rodrigo , Villalba Mayte , Westritschnig Kerstin , Valenta Rudolf , Rodriguez Rosalia , Keller Walter 
Published: April 2014

Abstract
Two EF-hand calcium-binding allergens (polcalcins) occur in the pollen of a wide variety of unrelated plants as highly cross-reactive allergenic molecules. We report the expression, purification, immunological characterization, and the 1.75-Å crystal structure of recombinant Che a 3 (rChe a 3), the polcalcin from the weed Chenopodium album. The three-dimensional structure of rChe a 3 resembles an α-helical fold that is essentially identical with that of the two EF-hand allergens from birch pollen, Bet v 4, and timothy grass pollen, Phl p 7. The extensive cross-reactivity between Che a 3 and Phl p 7 is demonstrated by competition experiments with IgE Abs from allergic patients as well as specific Ab probes. Amino acid residues that are conserved for the two EF-hand allergen family were identified in multiple sequence alignments of polcalcins from 15 different plants. Next, the three-dimensional structures of rChe a 3, rPhl p 7, and rBet v 4 were used to identify conserved amino acids with high surface exposition to visualize surface patches as potential targets for the polyclonal IgE Ab response of allergic patients. The essentially identical three-dimensional structures of rChe a 3, rPhl p 7, and rBet v 4 explain the extensive cross-reactivity of allergic patients IgE Abs with two EF-hand allergens from unrelated plants. In addition, analyzing the three-dimensional structures of cross-reactive Ags for conserved and surface exposed amino acids may be a first approach to mapping the conformational epitopes on disease-related Ags that are recognized by polyclonal patient Abs.
Protective Effect of IL-18 on Kainate- and IL-1β-Induced Cerebellar Ataxia in Mice
Authors: Andoh Tsugunobu , Kishi Hiroyuki , Motoki Kazumi , Nakanishi Kenji , Kuraishi Yasushi , Muraguchi Atsushi 
Published: April 2014

Abstract
The pathogenesis of sporadic cerebellar ataxia remains unknown. In this study, we demonstrate that proinflammatory cytokines, IL-18 and IL-1β, reciprocally regulate kainate-induced cerebellar ataxia in mice. We show that systemic administration of kainate activated IL-1β and IL-18 predominantly in the cerebellum of mice, which was accompanied with ataxia. Mice deficient in caspase-1, IL-1R type I, or MyD88 were resistant to kainate-induced ataxia, while IL-18- or IL-18R α-deficient mice displayed significant delay of recovery from ataxia. A direct intracerebellar injection of IL-1β-induced ataxia and intracerebellar coinjection of IL-18 counteracted the effect of IL-1β. Our data firstly show that IL-18 and IL-1β display differential direct regulation in kainate-induced ataxia in mice. Our results might contribute toward the development of a new therapeutic strategy for cerebellar ataxia in humans.
C1q Binds Phosphatidylserine and Likely Acts as a Multiligand-Bridging Molecule in Apoptotic Cell Recognition
Authors: Païdassi Helena , Tacnet-Delorme Pascale , Garlatti Virginie , Darnault Claudine , Ghebrehiwet Berhane , Gaboriaud Christine , Arlaud Gérard J. , Frachet Philippe 
Published: April 2014

Abstract
Efficient apoptotic cell clearance is critical for maintenance of tissue homeostasis, and to control the immune responses mediated by phagocytes. Little is known about the molecules that contribute “eat me” signals on the apoptotic cell surface. C1q, the recognition unit of the C1 complex of complement, also senses altered structures from self and is a major actor of immune tolerance. HeLa cells were rendered apoptotic by UV-B treatment and a variety of cellular and molecular approaches were used to investigate the nature of the target(s) recognized by C1q. Using surface plasmon resonance, C1q binding was shown to occur at early stages of apoptosis and to involve recognition of a cell membrane component. C1q binding and phosphatidylserine (PS) exposure, as measured by annexin V labeling, proceeded concomitantly, and annexin V inhibited C1q binding in a dose-dependent manner. As shown by cosedimentation, surface plasmon resonance, and x-ray crystallographic analyses, C1q recognized PS specifically and avidly (KD = 3.7–7 × 10−8 M), through multiple interactions between its globular domain and the phosphoserine group of PS. Confocal microscopy revealed that the majority of the C1q molecules were distributed in membrane patches where they colocalized with PS. In summary, PS is one of the C1q ligands on apoptotic cells, and C1q-PS interaction takes place at early stages of apoptosis, in newly organized membrane patches. Given its versatile recognition properties, these data suggest that C1q has the unique ability to sense different markers which collectively would provide strong eat me signals, thereby allowing efficient apoptotic cell removal.
HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway
Authors: Jindra Peter T. , Jin Yi-Ping , Rozengurt Enquire , Reed Elaine F. 
Published: April 2014

Abstract
Anti-HLA Abs have been shown to contribute to the process of transplant vasculopathy by binding to HLA class I molecules expressed by the endothelial and smooth muscle cells of the graft and transducing intracellular signals that elicit cell proliferation. The aim of this study was to determine the role of mammalian target of rapamycin (mTOR) in HLA class I-induced endothelial cell proliferation and to explore in depth the relationship between mTOR complexes and their downstream targets following ligation of HLA class I molecules by anti-HLA Abs. We used small interfering RNA technology to abrogate mTOR, rapamycin-insensitive companion of mTOR (rictor), or regulatory associated protein of mTOR (raptor) to study the function of these gene products to activate proteins involved in MHC class I-induced cell proliferation and survival. Knockdown of mTOR inhibited class I-mediated phosphorylation of proteins downstream of mTOR complex 1 and mTOR complex 2. Furthermore, knockdown of mTOR, rictor, or raptor blocked HLA class I-induced endothelial cell proliferation. Long-term pretreatment with the mTOR inhibitor rapamycin significantly blocked both mTOR-raptor and mTOR-rictor complex formation. Interestingly, rapamycin also blocked class I-induced Akt phosphorylation at Ser473 and Bcl-2 expression. These results support the role of anti-HLA Abs in the process of transplant vasculopathy and suggest that exposure of the graft endothelium to anti-HLA Abs may promote proliferation through the mTOR pathway.
Human Trophoblasts Recruited T Lymphocytes and Monocytes into Decidua by Secretion of Chemokine CXCL16 and Interaction with CXCR6 in the First-Trimester Pregnancy
Authors: Huang Yu , Zhu Xiao-Yong , Du Mei-Rong , Li Da-Jin 
Published: April 2014

Abstract
During human early pregnancy, fetus-derived trophoblasts come into direct contact with maternal immune cells at the maternofetal interface. At sites of placental attachment, invasive extravillous trophoblasts encounter decidual leukocytes (DLC) that accumulate within the decidua. Because we first found chemokine CXCL16 was highly expressed in and secreted by the first-trimester human trophoblasts previously, in this study we tested the hypothesis of whether the fetal trophoblasts can direct migration of maternal T lymphocyte and monocytes into decidua by secreting CXCL16. We analyzed the transcription and translation of CXCL16 in the isolated first-trimester human trophoblast, and examined the kinetic secretion of CXCL16 in the supernatant of the primary-cultured trophoblasts. We demonstrated that the sole receptor of CXCL16, CXCR6, is preferentially expressed in T lymphocytes, NKT cells, and monocytes, hardly expressed in two subsets of NK cells from either the peripheral blood or decidua. We further demonstrated the chemotactic activity of CXCL16 in the supernatant of the primary trophoblast on the peripheral mononuclear cells and DLC. Moreover, the CXCL16/CXCR6 interaction is involved in the migration of the peripheral T lymphocytes, γδ T cells, and monocytes, but not NKT cells. In addition, the trophoblast-conditioned medium could enrich PBMC subsets selectively to constitute a leukocyte population with similar composition to that of DLC, which suggests that the fetus-derived trophoblasts can attract T cells, γδ T cells, and monocytes by producing CXCL16 and interaction with CXCR6 on these cells, leading to forming a specialized immune milieu at the maternofetal interface.
IL-13 Is Required for Eosinophil Entry into the Lung during Respiratory Syncytial Virus Vaccine-Enhanced Disease
Authors: Castilow Elaine M. , Meyerholz David K. , Varga Steven M. 
Published: April 2014

Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract disease in children. Children previously vaccinated with a formalin-inactivated RSV vaccine experienced enhanced morbidity and mortality upon natural RSV infection. Histological analysis revealed the presence of eosinophils in the pulmonary infiltrate of the vaccinated children. Eosinophils are characteristic of Th2 responses, and Th2 cells are known to be necessary to induce pulmonary eosinophilia in RSV-infected BALB/c mice previously immunized with a recombinant vaccinia virus (vv) expressing the RSV G protein (vvG). Using IL-13-deficient mice, we find that IL-13 is necessary for eosinophils to reach the lung parenchyma and airways of vvG-immunized mice undergoing RSV challenge infection. IL-13 acts specifically on eosinophils as the magnitude of pulmonary inflammation, RSV G protein-specific CD4 T cell responses, and virus clearance were not altered in IL-13-deficient mice. After RSV challenge, eosinophils were readily detectable in the blood and bone marrow of vvG-immunized IL-13-deficient mice, suggesting that IL-13 is required for eosinophils to transit from the blood into the lung. Pulmonary levels of CCL11 and CCL22 protein were significantly reduced in IL-13-deficient mice indicating that IL-13 mediates the recruitment of eosinophils into the lungs by inducing the production of chemokines important in Th2 cell and eosinophil chemotaxis.
Pneumococcal Capsular Polysaccharide Is Immunogenic When Present on the Surface of Macrophages and Dendritic Cells: TLR4 Signaling Induced by a Conjugate Vaccine or by Lipopolysaccharide Is Conducive
Authors: Cohen Noam , Stolarsky-Bennun Michal , Amir-Kroll Hila , Margalit Raanan , Nussbaum Gabriel , Cohen-Sfady Michal , Pevsner-Fischer Meirav , Fridkin Mati , Bercovier Herve , Eisenbach Lea , Jung Steffen , Cohen Irun R. 
Published: April 2014

Abstract
Previously, we reported that a peptide, p458, from the sequence of the mammalian 60-kDa heat shock protein (hsp60) molecule can serve as a carrier in conjugate vaccines with capsular polysaccharide (CPS) molecules of various bacteria. These conjugate vaccines were effective injected in PBS without added adjuvants. We now report that p458 conjugated to pneumococcal CPS type 4 (PS4) manifests innate adjuvant effects: it stimulated mouse macrophages to secrete IL-12 and induced the late appearance of PS4 on the macrophage surface in a TLR4-dependent manner; PS4 alone or conjugated to other carriers did not stimulate macrophages in vitro. The injection of macrophages manifesting PS4 on the surface into mice induced long-term resistance to lethal Streptococcus pneumoniae challenge. The TLR4 ligand LPS could also induce the late appearance on the surface of unconjugated PS4 and resistance to challenge in injected mice. Resistance was not induced by macrophages containing only internalized PS4 or by pulsed macrophages that had been lysed. Glutaraldehyde-fixed macrophages pulsed with PS4 did induce resistance to lethal challenge. Moreover, bone marrow-derived dendritic cells activated by LPS and pulsed with unconjugated CPS were also effective in inducing resistance to lethal challenge. Resistance induced by the PS4-pulsed bone marrow-derived dendritic cell was specific for pneumococcal CPS serotypes (type 3 or type 4) and was associated with the induction of CPS-specific IgG and IgM Abs.
Integrin β1 Regulates Phagosome Maturation in Macrophages through Rac Expression
Authors: Wang Qing-Qing , Li Hong , Oliver Tim , Glogauer Michael , Guo Jian , He You-Wen 
Published: April 2014

Abstract
Phagocytosis and subsequent phagosome maturation by professional phagocytes are essential in the clearance of infectious microbial pathogens. The molecular regulation of phagosome maturation is largely unknown. We show that integrin β1 plays critical roles in the phagocytosis of microbial pathogens and phagosome maturation. Macrophages lacking integrin β1 expression exhibit reduced phagocytosis of bacteria, including group B streptococcus and Staphylococcus aureus. Furthermore, phagosomes from macrophages lacking integrin β1 show lowered maturation rate, defective acquisition of lysosome membrane markers, and reduced F-actin accumulation in the periphagosomal region. Integrin β1-deficient macrophages exhibit impaired bactericidal activity. We found that the expression of the Rho family GTPases Rac1, Rac2, and Cdc42 was reduced in integrin β1-deficient macrophages. Ectopic expression of Rac1, but not Cdc42, in integrin β1-deficient macrophages restored defective phagosome maturation and F-actin accumulation in the periphagosomal region. Importantly, macrophages lacking Rac1/2 also exhibit defective maturation of phagosomes derived from opsonized Escherichia coli or IgG beads. Taken together, these results suggest that integrin β1 regulates phagosome maturation in macrophages through Rac expression.
A238L Inhibits NF-ATc2, NF-κB, and c-Jun Activation through a Novel Mechanism Involving Protein Kinase C-θ-Mediated Up-Regulation of the Amino-Terminal Transactivation Domain of p300
Authors: Granja Aitor G. , Perkins Neil D. , Revilla Yolanda 
Published: April 2014

Abstract
The transcriptional coactivators CREB-binding protein and p300 regulate inducible transcription in multiple cellular processes and during the establishment of inflammatory and immune response. Several viruses have been shown to interfere with CREB-binding protein/p300 function, modulating their transcriptional activity. In this study, we report that the viral protein A238L interacts with the amino-terminal region of p300, inhibiting the acetylation and transcriptional activation of NF-ATc2, NF-κB, and c-Jun in stimulated human T cells. We demonstrate that A238L modulates the autoacetylation of p300 without altering its intrinsic histone acetyl transferase activity. Furthermore, we show that the molecular mechanism of the inhibition executed by the viral protein is conducted through blocking protein kinase C (PKC)-p300 interaction and further acetylation in the amino-terminal transactivation domain of the coactivator, and that Ser384, within the CH1 domain, is essential for the full transcriptional activation of the coactivator. Moreover, we show that overexpression of an active form of PKC-θ reverts the A238L-mediated inhibition of the transcriptional activity of p300, showing, for the first time, a PKC-θ-mediated up-regulation of the coactivator. These findings provide new strategies to develop therapies potentially useful in the control of disorders related to p300 deregulation.
Injury Enhances Resistance to Escherichia coli Infection by Boosting Innate Immune System Function
Authors: Maung Adrian A. , Fujimi Satoshi , MacConmara Malcolm P. , Tajima Goro , McKenna Ann M. , Delisle Adam J. , Stallwood Christopher , Onderdonk Andrew B. , Mannick John A. , Lederer James A. 
Published: April 2014

Abstract
Major injury is widely thought to predispose the injured host to opportunistic infections. This idea is supported by animal studies showing that major injury causes reduced resistance to polymicrobial sepsis induced by cecal ligation and puncture. Although cecal ligation and puncture represents a clinically relevant sepsis model, we wanted to test whether injury might also lead to greater susceptibility to peritoneal infection caused by a single common pathogen, Escherichia coli. Contrary to our expectation, we show herein that the LD50 for sham-injured mice was 103 CFU of E. coli, whereas the LD50 for burn-injured mice was 50 × 103 CFU at 7 days postinjury. This injury-associated enhanced resistance was apparent as early as 1 day after injury, and maximal resistance was observed at days 7 and 14. We found that burn-injured mice had higher numbers of circulating neutrophils and monocytes than did sham mice before infection and that injured mice were able to recruit greater numbers of neutrophils to the site of infection. Moreover, the peritoneal neutrophils in burn-injured mice were more highly activated than neutrophils from sham mice as determined by Mac-1 expression, superoxide generation, and bactericidal activity. Our findings suggest that the enhanced innate immune response that develops following injury, although it is commonly accepted as the mediator of the detrimental systemic inflammatory response syndrome, may also, in some cases, benefit the injured host by boosting innate immune antimicrobial defenses.
IL-23 Is Required for the Development of Severe Egg-Induced Immunopathology in Schistosomiasis and for Lesional Expression of IL-17
Authors: Rutitzky Laura I. , Bazzone Lindsey , Shainheit Mara G. , Joyce-Shaikh Barbara , Cua Daniel J. , Stadecker Miguel J. 
Published: April 2014

Abstract
In infection with the trematode helminth Schistosoma mansoni, the severity of CD4 T cell-mediated hepatic granulomatous and fibrosing inflammation against parasite eggs varies considerably in humans and among mouse strains. In mice, either the natural high pathology, or high pathology induced by concomitant immunization with schistosome egg Ags (SEA) in CFA (SEA/CFA), results from a failure to contain a net proinflammatory cytokine environment. We previously demonstrated that the induction of severe immunopathology was dependent on the IL-12/IL-23 common p40 subunit, and correlated with an increase in IL-17, thus implying IL-23 in the pathogenesis. We now show that mice lacking the IL-23-specific subunit p19 are impaired in developing severe immunopathology following immunization with SEA/CFA, which is associated with a marked drop of IL-17 in the granulomas, but not in the draining mesenteric lymph nodes, and with a markedly suppressed SEA-specific IFN-γ response regulated by a striking increase in IL-10. The granulomas are characterized by a significant reduction in Gr-1+ cell recruitment and by alternative macrophage activation. Taken together, these results demonstrate that IL-23 per se is not necessary for the generation of IL-17-producing T cells, but is essential for the development of severe schistosome egg-induced immunopathology, and its absence cannot be overcome with other possible compensatory mechanisms.
Malaria Parasites Require TLR9 Signaling for Immune Evasion by Activating Regulatory T Cells
Authors: Hisaeda Hajime , Tetsutani Kohhei , Imai Takashi , Moriya Chikako , Tu Liping , Hamano Shinjiro , Duan Xuefeng , Chou Bin , Ishida Hidekazu , Aramaki Akiko , Shen Jianying , Ishii Ken J. , Coban Cevayir , Akira Shizuo , Takeda Kiyoshi , Yasutomo Koji , Torii Motomi , Himeno Kunisuke 
Published: April 2014

Abstract
Malaria is still a life-threatening infectious disease that continues to produce 2 million deaths annually. Malaria parasites have acquired immune escape mechanisms and prevent the development of sterile immunity. Regulatory T cells (Tregs) have been reported to contribute to immune evasion during malaria in mice and humans, suggesting that activating Tregs is one of the mechanisms by which malaria parasites subvert host immune systems. However, little is known about how these parasites activate Tregs. We herein show that TLR9 signaling to dendritic cells (DCs) is crucial for activation of Tregs. Infection of mice with the rodent malaria parasite Plasmodium yoelii activates Tregs, leading to enhancement of their suppressive function. In vitro activation of Tregs requires the interaction of DCs with parasites in a TLR9-dependent manner. Furthermore, TLR9−/− mice are partially resistant to lethal infection, and this is associated with impaired activation of Tregs and subsequent development of effector T cells. Thus, malaria parasites require TLR9 to activate Tregs for immune escape.
Regulatory T Cells Prevent Control of Experimental African Trypanosomiasis
Authors: Wei Guojian , Tabel Henry 
Published: April 2014

Abstract
African trypanosomes are single-cell, extra-cellular blood parasites causing profound immunosuppression. Susceptible BALB/c mice infected s.c. into a footpad with 104 Trypanosoma congolense die with fulminating parasitemia within 10 days. We injected BALB/c mice 2 days before such an infection with different doses of a depleting mAb specific for CD25, a surface marker of regulatory T cells (Tregs). Pretreatment with a low, optimal dose of anti-CD25 resulted in a dramatic effect, in that the infected mice did not develop parasitemia, as well as eliminated all parasites and showed no signs of disease. Their spleens showed a 100% reduction of CD4+CD25high T cells and overall a 70% reduction of CD4+CD25+Foxp3+ T cells 7 days postinfection. The protective effect of treatment with an optimal dose of anti-CD25 could be reversed by administration of l-N6-(1-imminoethyl) lysine, a specific inhibitor of inducible NO synthase or administration of anti-CD8 Ab. Analysis of the cytokine patterns and cell surface marker in infected mice pretreated with anti-CD25 Abs pointed to a potential NKT cell response. We then conducted infections in CD1d−/− mice. From our observations, we conclude that CD4+CD25highFoxp3+ Tregs prevent, in normal infected susceptible mice, an early protective response mediated by CD8+ NKT cell-dependent activation of macrophages to kill parasites by production of NO. Our results also indicate that different populations of NKT cells have protective or suppressive effects. Our observations lead us to propose a hypothesis of cross-regulation of NKT cells and Tregs in trypanosome infections.
Auto-Oxidation and Oligomerization of Protein S on the Apoptotic Cell Surface Is Required for Mer Tyrosine Kinase-Mediated Phagocytosis of Apoptotic Cells
Authors: Uehara Hiroshi , Shacter Emily 
Published: April 2014

Abstract
Prompt phagocytosis of apoptotic cells prevents inflammatory and autoimmune responses to dying cells. We have previously shown that the blood anticoagulant factor protein S stimulates phagocytosis of apoptotic human B lymphoma cells by human monocyte-derived macrophages. In this study, we show that protein S must first undergo oxidative activation to stimulate phagocytosis. Binding of human protein S to apoptotic cells or to phosphatidylserine multilamellar vesicles promotes auto-oxidation of Cys residues in protein S, resulting in covalent, disulfide-linked dimers and oligomers that preferentially bind to and activate the human Mer tyrosine kinase (MerTK) receptor on the macrophages. The prophagocytic activity of protein S is eliminated when disulfide-mediated oligomerization is prevented, or when MerTK is blocked with neutralizing Abs. Protein S oligomerization is independent of phospholipid oxidation. The data suggest that membranes containing phosphatidylserine serve as a scaffold for protein S-protein S interactions and that the resulting auto-oxidation and oligomerization is required for the prophagocytic activity of protein S. In this way, apoptotic cells facilitate their own uptake by macrophages. The requirement for oxidative modification of protein S can explain why this abundant blood protein does not constitutively activate MerTK in circulating monocytes and tissue macrophages.