bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Human Monoclonal IgE Antibody Defines a Highly Allergenic Fragment of the Major Timothy Grass Pollen Allergen, Phl p 5: Molecular, Immunological, and Structural Characterization of the Epitope-Containing Domain
Authors: Flicker Sabine , Vrtala Susanne , Steinberger Peter , Vangelista Luca , Bufe Albrecht , Petersen Arnd , Ghannadan Minoo , Sperr Wolfgang R. , Valent Peter , Norderhaug Lars , Bohle Barbara , Stockinger Hannes , Suphioglu Cenk , Ong Eng Kok , Kraft Dietrich , Valenta Rudolf 
Published: April 2014

AbstractAlmost 90% of grass pollen-allergic patients are sensitized against group 5 grass pollen allergens. We isolated a monoclonal human IgE Fab out of a combinatorial library prepared from lymphocytes of a grass pollen-allergic patient and studied its interaction with group 5 allergens. The IgE Fab cross-reacted with group 5A isoallergens from several grass and corn species. By allergen gene fragmentation we mapped the binding site of the IgE Fab to a 11.2-kDa N-terminal fragment of the major timothy grass pollen allergen Phl p 5A. The IgE Fab-defined Phl p 5A fragment was expressed in Escherichia coli and purified to homogeneity. Circular dichroism analysis revealed that the rPhl p 5A domain, as well as complete rPhl p 5A, assumed a folded conformation consisting predominantly of an α helical secondary structure, and exhibited a remarkable refolding capacity. It reacted with serum IgE from 76% of grass pollen-allergic patients and revealed an extremely high allergenic activity in basophil histamine release as well as skin test experiments. Thus, the rPhl p 5A domain represents an important allergen domain containing several IgE epitopes in a configuration optimal for efficient effector cell activation. We suggest the rPhl p 5A fragment and the corresponding IgE Fab as paradigmatic tools to explore the structural requirements for highly efficient effector cell activation and, perhaps later, for the development of generally applicable allergen-specific therapy strategies.
Alanine Scanning Mutants of Rat Proinsulin I Show Functional Diversity of Anti-Insulin Monoclonal Antibodies
Authors: Tikhomirov O. Yu , Thomas James W. 
Published: April 2014

Abstract
In contrast to autoantibodies that are functionally silenced or deleted, IgG Abs that react with autologous insulin routinely follow hormone administration and arise spontaneously in autoimmune (type I) diabetes mellitus. To understand Ab interactions with autologous insulin, rat proinsulin I and 32 alanine substituted analogues were expressed as fusion proteins and used to examine 16 anti-insulin mAb in ELISA. The results identify several amino acid residues that contribute to binding by a large majority (&gt;75%) of mAb, although no single residue is uniformly required for binding by all mAb. Replacements at charged or polar residues on the insulin surface including A4 (Asp), A5 (Gln), A9 (Ser) A12 (Ser), A17 (Gln), A18 (Asn), B13 (Glu), and B21 (Glu) consistently decreased mAb binding. Single alanine substitutions at positions A16 (Leu), A11 (Cys), B8 (Gly), and B15 (Leu) that are predicted to alter the core structure or chain folding vary widely in their impact on Ab binding. mAb that bind insulin preferentially on solid phase (i.e., ELISA) are highly sensitive to replacement of single residues, and substitutions that alter conformation abolish binding. In contrast, high affinity mAb that bind insulin in solution are relatively insensitive to substitutions at single residues, and they maintain binding to all mutants, including those with disrupted conformation. For such high affinity mAb, replacement of long hydrophobic side chains can augment binding, suggesting mAb interactions with insulin include an induced fit. Thus, the ability of insulin to function as a “molten globule” may contribute to the diversity and autoreactivity of the anti-insulin repertoire.
Signal Joint Formation Is Also Impaired in DNA-Dependent Protein Kinase Catalytic Subunit Knockout Cells
Authors: Fukumura Ryutaro , Araki Ryoko , Fujimori Akira , Tsutsumi Yoko , Kurimasa Akihiro , Li Gloria C. , Chen David J. , Tatsumi Kouichi , Abe Masumi 
Published: April 2014

Abstract
The effort to elucidate the mechanism of V(D)J recombination has given rise to a dispute as to whether DNA-dependent protein kinase catalytic subunit (DNA-PKcs) contributes to signal joint formation (sjf). Observations reported to date are confusing. Analyses using DNA-PKcs-deficient cells could not conclude the requirement of DNA-PKcs for sjf, because sjf can be formed by end-joining activities which are diverse among cells other than those participating in V(D)J recombination. Here, we observed V(D)J recombination in DNA-PKcs knockout cells and showed that both signal and coding joint formation were clearly impaired in the cells. Subsequently, to directly demonstrate the requirement of DNA-PKcs for sjf, we introduced full-length cDNA of DNA-PKcs into the knockout cells. Furthermore, several mutant DNA-PKcs cDNA constructs designed from mutant cell lines (irs-20, V3, murine scid, and SX9) were also introduced into the cells to obtain further evidence indicating the involvement of DNA-PKcs in sjf. We found as a result that the full-length cDNA complemented the aberrant sjf and that the mutant cDNAs constructs also partially complemented it. Lastly, we looked at whether the kinase activity of DNA-PKcs is necessary for sjf and, as a result, demonstrated a close relationship between them. Our observations clearly indicate that the DNA-PKcs controls not only coding joint formation but also the sjf in V(D)J recombination through its kinase activity.
Allergy-Associated Polymorphisms of the FcεRIβ Subunit Do Not Impact Its Two Amplification Functions
Authors: Donnadieu Emmanuel , Cookson William O. , Jouvin Marie-Hélène , Kinet Jean-Pierre 
Published: April 2014

AbstractTwo variants of the β-chain of the high affinity IgE receptor FcεRI, I181L-V183L and E237G, have been found associated with allergy. We have previously shown that the β-chain plays at least two distinct amplifier functions. It amplifies FcεRI surface expression and signaling, resulting in an estimated 12- to 30-fold amplification of downstream events. To test the hypothesis that the I181L-V183L and E237G β variants may be functionally relevant and could directly contribute to an allergic phenotype, we have evaluated the functional impact of the β variants on the two amplifier functions of β. We found that these variants have no direct effect on the β amplifier functions. However, the possibility remains that these variants are in linkage disequilibrium with other more relevant polymorphisms or are affecting unknown β-chain functions.
Group BStreptococcusInduces Apoptosis in Macrophages
Authors: Fettucciari Katia , Rosati Emanuela , Scaringi Lucia , Cornacchione Paola , Migliorati Graziella , Sabatini Rita , Fetriconi Ilaria , Rossi Ruggero , Marconi Pierfrancesco 
Published: April 2014

AbstractGroup B Streptococcus (GBS) is a pathogen that has developed some strategies to resist host immune defenses. Because phagocytic killing is an important pathogenetic mechanism for bacteria, we investigated whether GBS induces apoptosis in murine macrophages. GBS type III strain COH31 r/s (GBS-III) first causes a defect in cell membrane permeability, then at 24 h, apoptosis. Apoptosis was confirmed by several techniques based on morphological changes and DNA fragmentation. Cytochalasin D does not affect apoptosis, suggesting that GBS-III needs not be within the macrophage cytoplasm to promote apoptosis. Inhibition of host protein synthesis prevents apoptosis, whereas inhibition of caspase-1 or -3, does not. Therefore, GBS can trigger an apoptotic pathway independent of caspase-1 and -3, but dependent on protein synthesis. Inhibition of apoptosis by EGTA and PMA, and enhancement of apoptosis by calphostin C and GF109203X suggests that an increase in the cytosolic calcium level and protein kinase C activity status are important in GBS-induced apoptosis. Neither alteration of plasma membrane permeability nor apoptosis were induced by GBS grown in conditions impeding hemolysin expression or when we used dipalmitoylphosphatidylcholine, which inhibited GBS β-hemolytic activity, suggesting that GBS β-hemolysin could be involved in apoptosis. β-Hemolysin, by causing membrane permeability defects, could allow calcium influx, which initiates macrophage apoptosis. GBS also induces apoptosis in human monocytes but not in tumor lines demonstrating the specificity of its activity. This study suggests that induction of macrophage apoptosis by GBS is a novel strategy to overcome host immune defenses.
Exaggerated Human Monocyte IL-10 Concomitant to Minimal TNF-α Induction by Heat-Shock Protein 27 (Hsp27) Suggests Hsp27 Is Primarily an Antiinflammatory Stimulus
Authors: De Asit K. , Kodys Karen M. , Yeh Berhan S. , Miller-Graziano Carol 
Published: April 2014

AbstractUnlike more well-studied large heat shock proteins (hsp) that induce both T cell antiinflammatory (IL-10, IL-4) and macrophage proinflammatory (TNF-α, IL-15, IL-12) cytokines, hsp27, a small hsp, has been primarily identified as a substrate of mitogen-activated protein kinase-activated protein kinase-2 involved in the p38 signaling pathway and activated during monocyte IL-10 production. Hsp27 can also act as an endogenous protein circulating in the serum of breast cancer patients and a protein whose induction correlates to protection from LPS shock. However, the cytokine-stimulating properties of hsp27 have been unexplored. In this study, exogenous hsp27 is demonstrated for the first time as a potent activator of human monocyte IL-10 production, but only a modest inducer of TNF-α. Although exogenous hsp27 stimulation activated all three monocyte mitogen-activated protein kinase pathways (extracellular signal-related kinase (ERK) 1/2, c-Jun N-terminal kinase, and p38), only p38 activation was sustained and required for hsp27 induction of monocyte IL-10, while both ERK 1/2 and p38 activation were required for induction of TNF-α when using the p38 inhibitor SB203580 or the ERK inhibitor PD98059. Hsp27’s transient activation of the c-Jun N-terminal kinase pathway, which can down-regulate IL-10, may contribute to its potent IL-10 induction. Hsp27’s ERK 1/2 activation was also less sustained than activation by stimuli like LPS, possibly contributing to its modest TNF-α induction. The failure of either PD98059 or anti-TNF-α Ab to substantially inhibit IL-10 induction implied that hsp27 induces IL-10 via activation of p38 signaling independently of TNF-α activation and may be predominantly an antiinflammatory monokine stimulus.
Capsaicin Inhibits Platelet-Activating Factor-Induced Cytosolic Ca2+ Rise and Superoxide Production
Authors: Choi Se-Young , Ha Hyunjung , Kim Kyong-Tai 
Published: April 2014

AbstractPlatelet-activating factor (PAF) is an important participant in the inflammatory process. We studied the regulation of PAF activity by capsaicin in human promyelocytic leukemia HL-60 cells. Capsaicin inhibited PAF-induced superoxide production in a concentration-dependent manner. In addition to PAF, the fMLP- and extracellular ATP-induced superoxide productions were inhibited by capsaicin, whereas PMA-induced superoxide production was not affected. In the PAF-stimulated cytosolic Ca2+ increase, capsaicin inhibited in particular the sustained portion of the raised Ca2+ level without attenuation of the peak height. In the absence of extracellular Ca2+, the PAF-induced Ca2+ elevation was not inhibited by capsaicin because capsaicin only inhibited the Ca2+ influx from the extracellular space. In addition, capsaicin did not affect PAF-induced inositol 1,4,5-trisphosphate production, suggesting that phospholipase C activation by PAF is not affected by capsaicin. Store-operated Ca2+ entry (SOCE) induced by thapsigargin was inhibited by capsaicin in a concentration-dependent manner. This capsaicin effect was also observed on thapsigargin-induced Ba2+ and Mn2+ influx. Furthermore, capsaicin’s inhibitory effect on the thapsigargin-induced Ca2+ rise overlapped with that of SK&F96365, an inhibitor of SOCE. Both capsaicin and SK&F96365 also inhibited PAF-induced cytosolic superoxide generation in HL-60 cells differentiated by all-trans-retinoic acid. Our data suggest that capsaicin exerts its anti-inflammatory effect by inhibiting SOCE elicited via PLC activation, which occurs upon PAF activation and results in the subsequent superoxide production.
Macrophage Inflammatory Protein-2 and KC Induce Chemokine Production by Mouse Astrocytes
Authors: Luo Yi , Fischer Falko R. , Hancock Wayne W. , Dorf Martin E. 
Published: April 2014

AbstractAstrocytes are specialized cells of the CNS that are implicated in the pathogenesis of multiple sclerosis and experimental allergic encephalomyelitis. In acute and relapsing-remitting experimental allergic encephalomyelitis, the neutrophil chemoattractant CXC chemokines macrophage-inflammatory protein (MIP)-2 and KC are associated with reactive astrocytes in the parenchyma. In vitro treatment of primary astrocyte cultures with nanomolar concentrations of MIP-2 or KC markedly up-regulated expression of the monocyte/T cell chemoattractants monocyte chemoattractant protein-1, inflammatory protein-10, and RANTES by a mechanism that includes stabilization of mRNA. Production of TNF-α and IL-6 transcripts were also noted, as was autocrine induction of MIP-2 and KC message. In addition, low levels of MIP-1α and MIP-1β were induced following treatment with MIP-2 or KC. These effects are specific to astrocytes as MIP-2 treatment of microglial cells failed to elicit chemokine production. The astrocyte chemokine receptor for MIP-2 has 2.5 nM affinity for ligand. Astrocytes from CXCR2-deficient mice still respond to KC and MIP-2, indicating the presence of an alternative or novel high affinity receptor for these ligands. We propose that this KC/MIP-2 chemokine cascade may contribute to the persistence of mononuclear cell infiltration in demyelinating autoimmune diseases.
Studies on a Mechanism by Which Cytosolic Phospholipase A2 Regulates the Expression and Function of Type IIA Secretory Phospholipase A2
Authors: Kuwata Hiroshi , Yamamoto Shinji , Miyazaki Yoshitaka , Shimbara Satoko , Nakatani Yoshihito , Suzuki Hiroshi , Ueda Natsuo , Yamamoto Shozo , Murakami Makoto , Kudo Ichiro 
Published: April 2014

Abstract
Although it has been proposed that arachidonate release by several secretory phospholipase A2 (sPLA2) isozymes is modulated by cytosolic PLA2 (cPLA2), the cellular component(s) that intermediates between these two signaling PLA2s remains unknown. Here we provide evidence that 12- or 15-lipoxygenase (12/15-LOX), which lies downstream of cPLA2, plays a pivotal role in cytokine-induced gene expression and function of sPLA2-IIA. The sPLA2-IIA expression and associated PGE2 generation induced by cytokines in rat fibroblastic 3Y1 cells were markedly attenuated by antioxidants that possess 12/15-LOX inhibitory activity. 3Y1 cells expressed 12/15-LOX endogenously, and forcible overexpression of 12/15-LOX in these cells greatly enhanced cytokine-induced expression of sPLA2-IIA, with a concomitant increase in delayed PG generation. Moreover, studies using 293 cells stably transfected with sPLA2-IIA revealed that stimulus-dependent hydrolysis of membrane phospholipids by sPLA2-IIA was enhanced by overexpression of 12/15-LOX. These results indicate that the product(s) generated by the cPLA2-12/15-LOX pathway following cell activation may play two roles: enhancement of sPLA2-IIA gene expression and membrane sensitization that leads to accelerated sPLA2-IIA-mediated hydrolysis.
Endogenous and Exogenous IL-6 Inhibit Aeroallergen-Induced Th2 Inflammation
Authors: Wang Jingming , Homer Robert J. , Chen Qingsheng , Elias Jack A. 
Published: April 2014

AbstractChronic Th2-dominated inflammation and exaggerated IL-6 production are characteristic features of the asthmatic airway. To understand the processes that are responsible for the chronicity of this response and the role(s) of IL-6 in the regulation of airway Th2 inflammation, we compared the responses induced by OVA in sensitized wild-type mice, IL-6 deficient (−/−) mice, and transgenic mice in which IL-6 was overexpressed in the airway (CC10-IL-6 mice). When compared with wild-type mice, IL-6−/− mice manifest exaggerated inflammation and eosinophilia, increased levels of IL-4, IL-5, and IL-13 protein and mRNA, exaggerated levels of eotaxin, JE/monocyte chemoattractant protein-1, macrophage inflammatory protein-1α and -2, and mRNA, increased bronchoalveolar lavage (BAL) TGF-β1, and exaggerated airway responses to aerosolized methacholine. In contrast, CC10-IL-6 mice, on both C57BL/6 and BALB/c backgrounds, manifest diminished inflammation and eosinophilia, decreased levels of IL-4, IL-5, and IL-13 protein and mRNA, and decreased levels of bronchoalveolar lavage TGF-β1. IL-6 also decreased the expression of endothelial VCAM-1 and airway responsiveness to methacholine in these animals. These alterations in the IL-6−/− and CC10-IL-6 mice were not associated with significant decreases or increases in the levels of IFN-γ, respectively. These studies demonstrate that endogenous and exogenous IL-6 inhibit aeroallergen-induced Th2 inflammation and that this inhibition is not mediated by regulatory effects of IFN-γ. IL-6 may be an important anti-inflammatory, counterregulatory, and healing cytokine in the airway.
Peptide Dose, MHC Affinity, and Target Self-Antigen Expression Are Critical for Effective Immunotherapy of Nonobese Diabetic Mouse Prediabetes
Authors: Winer Shawn , Gunaratnam Lakshman , Astsatourov Igor , Cheung Roy K. , Kubiak Violetta , Karges Wolfram , Hammond-McKibben Denise , Gaedigk Roger , Graziano Daniel , Trucco Massimo , Becker Dorothy J. , Dosch H.-Michael 
Published: April 2014

AbstractCross-reactive T cells that recognize both Tep69 (dominant nonobese diabetic (NOD) T cell epitope in ICA69 (islet cell autoantigen of 69 kDa)) and ABBOS (dominant NOD T cell epitope in BSA) are routinely generated during human and NOD mouse prediabetes. Here we analyzed how systemic administration of these mimicry peptides affects progressive autoimmunity in adoptively transferred and cyclophosphamide-accelerated NOD mouse diabetes. These models were chosen to approximate mid to late stage prediabetes, the typical status of probands in human intervention trials. Unexpectedly, high dose (100 μg) i.v. ABBOS prevented, while Tep69 exacerbated, disease in both study models. Peptide effects required cognate recognition of endogenous self-Ag, because both treatments were ineffective in ICA69null NOD congenic mice adoptively transferred with wild-type, diabetic splenocytes. The affinity of ABBOS for NOD I-Ag7 was orders of magnitude higher than that of Tep69. This explained 1) the expansion of the mimicry T cell pool following i.v. Tep69, 2) the long-term unresponsiveness of these cells after i.v. ABBOS, and 3) precipitation of the disease after low dose i.v. ABBOS. Disease precipitation and prevention in mid to late stage prediabetes are thus governed by affinity profiles and doses of therapeutic peptides. ABBOS or ABBOS analogues with even higher MHC affinity may be candidates for experimental intervention strategies in human prediabetes, but the dose translation from NOD mice to humans requires caution.
B Lymphoblastoid Cell Lines as Efficient APC to Elicit CD8+ T Cell Responses Against a Cytomegalovirus Antigen
Authors: Sun Qi , Burton Robert L. , Dai Li-Jun , Britt William J. , Lucas Kenneth G. 
Published: April 2014

AbstractPotent and readily accessible APC are critical for development of immunotherapy protocols to treat viral disease and cancer. We have shown that B lymphoblastoid cell lines (BLCL) that stably express CMV phosphoprotein 65 (BLCLpp65), as a result of retroviral transduction, can be used to generate ex vivo CTL cultures that possess cytotoxicity against CMV and EBV. In this report, we demonstrate that the EBV-specific cytotoxicity in the BLCLpp65-primed culture had a spectrum of EBV-Ag recognition similar to that of the BLCL-primed counterpart, suggesting that retroviral transduction and expression of the CMV Ag would not compromise the Ag-presenting capacity of BLCL. In addition, BLCLpp65 appeared to present multiple natural pp65 epitopes, because pp65-specific CTL, which recognized different CMV clinical isolates, were generated in BLCLpp65-primed cultures from individuals with various HLA backgrounds. Consistent with a polyclonal expansion of virus-specific CTL, T cell lines established from the BLCLpp65-primed CTL cultures expressed different TCR-Vβ. Although most of the virus-specific T cell isolates were CD8+, EBV-specific CD4+ lines were also established from BLCLpp65-primed cultures. Western blot analysis revealed that the CD8+ lines, but not the CD4+ line, expressed granzyme B, consistent with features of classic CTL. Thus, our results suggested that BLCL stably expressing a foreign Ag might be used as a practical APC to elicit CD8+ T cell responses.
Impairment of STAT Activation by IL-12 in a Patient with Atypical Mycobacterial and Staphylococcal Infections
Authors: Gollob Jared A. , Veenstra Korina G. , Jyonouchi Harumi , Kelly Anne M. , Ferrieri Patricia , Panka David J. , Altare Frédéric , Fieschi Claire , Casanova Jean-Laurent , Frank David A. , Mier James W. 
Published: April 2014

AbstractIL-12 plays a pivotal role in the stimulation of immune responses against intracellular infections. This role is manifested in the increased susceptibility to atypical mycobacterial and salmonella infections among individuals whose lymphocytes lack expression of IL-12Rβ1. Here, we report on a patient with Mycobacterium avium infection, recurrent Staphylococcus aureus sinusitis, and multiple adverse drug reactions whose T cells were unable to produce IFN-γ or proliferate in response to IL-12 despite the expression of wild-type IL-12Rβ1 and IL-12Rβ2. The defect in these functional responses to IL-12 was selective, as cytolytic activity induced by IL-12 was intact, and lymphocytes were responsive to stimulation by IL-2. An examination of cytokine signaling revealed that STAT4 and extracellular regulated kinase 1 (ERK1) activation by IL-12 was intact, whereas the activation of STAT1, -3, and -5 by IL-12 was lost. This impairment of STAT activation was specific for IL-12, as STAT activation by IL-2, IL-15, and IFN-γ was unaffected. These findings demonstrate that the activation of STAT4 alone is not sufficient for IL-12-induced IFN-γ production and proliferation and suggest that other STATs play a role in these responses to IL-12. While the etiology of the impaired IL-12 signaling in this patient has not yet been elucidated, the absence of mutations in IL-12Rβ1 or IL-12Rβ2 and the preservation of STAT4 activation raise the possibility that there may be a mutation in an as yet undiscovered component of the IL-12 signaling complex that is normally required for the recruitment and activation of STAT1, -3, and -5.