bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass Spectrometric Characterization of a Discontinuous Epitope of the HIV Envelope Protein HIV-gp120 Recognized by the Human Monoclonal Antibody 1331A
Authors: Hochleitner Elisabeth O. , Gorny Miroslaw K. , Zolla-Pazner Susan , Tomer Kenneth B. 
Published: April 2014

AbstractThe characterization of a discontinuous epitope in the C5 region of the HIV envelope protein HIV-gp120, recognized by 1331A, a human mAb, is reported. Regions involved in affinity binding in the HIV-gp120 molecule were identified by epitope excision/extraction methods followed by matrix assisted laser desorption-time of flight mass spectrometry. In epitope excision, the protein is bound in its native conformation to an immobilized Ab and then digested with proteolytic enzymes. In epitope extraction, the protein is first digested and subsequently allowed to react with the Ab. A series of proteolytic digestions of the 1331A/HIV-gp120 complex allowed the identification of protected amino acids in two noncontinuous regions of the C5 region of HIV-gp120. Interaction of the Ab with amino acids I487 and E507 of HIV-gp120 is essential for efficient binding. This is the first application of this approach for the identification and characterization of a discontinuous epitope. The results are consistent with molecular modeling results, indicating that these amino acids are located on opposite sides of a hydrophobic pocket. This pocket is thought to be of importance for the interaction of HIV-gp120 with the transmembrane protein HIV-gp41.
Six X-Linked Agammaglobulinemia-Causing Missense Mutations in the Src Homology 2 Domain of Bruton’s Tyrosine Kinase: Phosphotyrosine-Binding and Circular Dichroism Analysis
Authors: Mattsson Pekka T. , Lappalainen Ilkka , Bäckesjö Carl-Magnus , Brockmann Eeva , Laurén Susanna , Vihinen Mauno , Smith C. I. Edvard 
Published: April 2014

AbstractSrc homology 2 (SH2) domains recognize phosphotyrosine (pY)-containing sequences and thereby mediate their association to ligands. Bruton’s tyrosine kinase (Btk) is a cytoplasmic protein tyrosine kinase, in which mutations cause a hereditary immunodeficiency disease, X-linked agammaglobulinemia (XLA). Mutations have been found in all Btk domains, including SH2. We have analyzed the structural and functional effects of six disease-related amino acid substitutions in the SH2 domain: G302E, R307G, Y334S, L358F, Y361C, and H362Q. Also, we present a novel Btk SH2 missense mutation, H362R, leading to classical XLA. Based on circular dichroism analysis, the conformation of five of the XLA mutants studied differs from the native Btk SH2 domain, while mutant R307G is structurally identical. The binding of XLA mutation-containing SH2 domains to pY-Sepharose was reduced, varying between 1 and 13% of that for the native SH2 domain. The solubility of all the mutated proteins was remarkably reduced. SH2 domain mutations were divided into three categories: 1) Functional mutations, which affect residues presumably participating directly in pY binding (R307G); 2) structural mutations that, via conformational change, not only impair pY binding, but severely derange the structure of the SH2 domain and possibly interfere with the overall conformation of the Btk molecule (G302E, Y334S, L358F, and H362Q); and 3) structural-functional mutations, which contain features from both categories above (Y361C).
Haemophilus influenzaeStimulates ICAM-1 Expression on Respiratory Epithelial Cells
Authors: Frick Annette G. , Joseph Theresa D. , Pang Liyi , Rabe Autumn M. , St. Geme Joseph W. , Look Dwight C. 
Published: April 2014

AbstractEpithelial cells interact directly with bacteria in the environment and play a critical role in airway defense against microbial pathogens. In this study, we examined the response of respiratory epithelial cells to infection with nontypable Haemophilus influenzae. Using an in vitro cell culture model, we found that epithelial cell monolayers released significant quantities of IL-8 and expressed increased levels of ICAM-1 mRNA and surface protein in response to H. influenzae. In contrast, levels of IL-1β, TNF-α, and MHC class I were not significantly affected, suggesting preferential activation of a specific subset of epithelial genes directed toward defense against bacteria. Induction of ICAM-1 required direct bacterial interaction with the epithelial cell surface and was not reproduced by purified H. influenzae lipooligosaccharide. Consistent with a functional role for this response, induction of ICAM-1 by H. influenzae mediated increased neutrophil adherence to the epithelial cell surface. Furthermore, in an in vivo murine model of airway infection with H. influenzae, increased epithelial cell ICAM-1 expression coincided with increased chemokine levels and neutrophil recruitment in the airway. These results indicate that ICAM-1 expression on human respiratory epithelial cells is induced by epithelial cell interaction with H. influenzae and suggest that an ICAM-1-dependent mechanism can mediate neutrophil adherence to these cells independent of inflammatory mediator release by other cell types. Direct induction of specific epithelial cell genes (such as ICAM-1 and IL-8) by bacterial infection may allow for rapid and efficient innate defense in the airway.
Nitric Oxide Mediates Intestinal Pathology But Not Immune Expulsion DuringTrichinella spiralisInfection in Mice
Authors: Lawrence Catherine E. , Paterson Jacqueline C. M. , Wei Xiao-Qing , Liew Foo Y. , Garside Paul , Kennedy Malcolm W. 
Published: April 2014

AbstractThe relationship between intestinal pathology and immune expulsion of gastrointestinal (GI) nematodes remains controversial. Although immune expulsion of GI helminth parasites is usually associated with Th2 responses, the effector mechanisms directly responsible for parasite loss have not been identified. We have previously shown that while the intestinal pathology accompanying the expulsion of the GI parasite Trichinella spiralis may be dependent on IL-4 and mediated by TNF, parasite loss is independent of TNF. In contrast, intestinal pathology in other disease models has been attributed to Th1 cytokines, although it closely resembles that seen in helminth infections. Whereas production of inducible NO synthase (iNOS) in the gut is important for both homeostasis of the epithelial layer and in protection against pathogenic microorganisms, overproduction of NO has been implicated in the pathogenesis of a number of inflammatory conditions. We therefore investigated the role of NO in T. spiralis infection using iNOS-deficient mice. iNOS−/− and iNOS-/+ mice were infected with T. spiralis, and parasite expulsion and intestinal pathology were followed. Parasite expulsion proceeded similarly in both groups of animals, but significant intestinal pathology was only observed in the heterozygous mice. Thus it appears that, although the protective effects of Th2 responses in GI helminth infection do not require NO, this mediator contributes substantially to the associated enteropathy. NO may therefore be an important mediator of enteropathy in both Th1- and Th2-inducing conditions.
Ongoing Murine T1 or T2 Immune Responses to the Hepatitis B Surface Antigen Are Excluded from the Liver that Expresses Transgene-Encoded Hepatitis B Surface Antigen
Authors: Schirmbeck Reinhold , Wild Jens , Stober Detlef , Blum Hubert E. , Chisari Francis V. , Geissler Michael , Reimann Jörg 
Published: April 2014

AbstractDifferent protein- or DNA-based vaccination techniques are available that prime potent humoral and cellular, T1 or T2 immune responses to the hepatitis B surface Ag (HBsAg) in mice. T1 and T2 are immune responses with isotype profile indicating Th1 and Th2 immunoregulation. We tested whether HBsAg-specific immune responses can be established in transgenic mice that express HBsAg in the liver (HBs-tg mice) using either these different vaccination techniques or an adoptive transfer system. HBsAg-specific responses could not be primed in HBs-tg mice with the established, potent vaccine delivery techniques. In contrast, adoptive transfers of T1- and T2-type HBsAg-immune spleen cells into congenic HBs-tg hosts (that were not conditioned by pretreatment) suppressed HBsAg antigenemia and gave rise to HBsAg-specific serum Ab titers. The establishment of continuously rising anti-HBsAg serum Ab levels with alternative isotype profiles (reflecting T1 or T2 polarization) in transplanted HBs-tg hosts required donor CD4+ T cell-dependent restimulation of adoptively transferred immune cells by transgene-derived HBsAg. Injections of HBsAg-specific Abs into HBs-tg mice did not establish stable humoral immunity. The expanding T1 or T2 immune responses to HBsAg in HBs-tg hosts did not suppress transgene-directed HBsAg expression in the liver and did not induce liver injury. In addition to priming functional antiviral effector cells, the conditioning of the liver microenvironment to enable delivery of antiviral effector functions to this organ are therefore critical for effective antiviral defense. A major challenge in the development of a therapeutic vaccine against chronic hepatitis B or C virus infection is thus the efficient targeting of specifically induced immune effector specificities to the liver.
IL-13-Mediated Worm Expulsion Is B7 Independent and IFN-γ Sensitive
Authors: Urban Joseph , Fang Hui , Liu Qian , Ekkens Melinda J. , Chen Shen-Jue , Nguyen Diep , Mitro Velia , Donaldson Debra D. , Byrd Colleen , Peach Robert , Morris Suzanne C. , Finkelman Fred D. , Schopf Lisa , Gause William C. 
Published: April 2014

AbstractB7 costimulation is a required component of many type 2 immune responses, including allergy and protective immunity to many nematode parasites. This response includes elevations in Th2 cytokines and associated effector functions including elevations in serum IgG1 and IgE and parasite expulsion. In studies of mice infected with Trichuris muris, blocking B7 ligand interactions inhibited protective immunity, suppressed IL-4 production, and enhanced IFN-γ production, but unexpectedly did not inhibit production of the Th2 cytokine, IL-13. Blocking both IFN-γ and B7 restored protective immunity, which was IL-13 dependent, but did not restore IL-4 or associated IgE responses. Although IL-13 was required for worm expulsion in mice in which both IFN-γ and B7 were blocked, IL-4 could mediate expulsion in the absence of both IL-13 and IFN-γ. These studies demonstrate that 1) B7 costimulation is required to induce IL-4, but not IL-13 responses; 2) IL-13 is elevated in association with the IFN-γ response that occurs following inhibition of B7 interactions, but can only mediate IL-4-independent protection when IFN-γ is also inhibited; and 3) increased IL-13 production, in the absence of increased IL-4 production, is not associated with an IgE response, even in the absence of IFN-γ.
Crucial Role of the Amino-Terminal Tyrosine Residue 42 and the Carboxyl-Terminal PEST Domain of IκBα in NF-κB Activation by an Oxidative Stress
Authors: Schoonbroodt Sonia , Ferreira Valérie , Best-Belpomme Martin , Boelaert Johan R. , Legrand-Poels Sylvie , Korner Marie , Piette Jacques 
Published: April 2014

AbstractActivation of transcription factor NF-κB involves the signal-dependent degradation of basally phosphorylated inhibitors such as IκBα. In response to proinflammatory cytokines or mitogens, the transduction machinery has recently been characterized, but the activation mechanism upon oxidative stress remains unknown. In the present work, we provide several lines of evidence that NF-κB activation in a T lymphocytic cell line (EL4) by hydrogen peroxide (H2O2) did not involve phosphorylation of the serine residues 32 and 36 in the amino-terminal part of IκBα. Indeed, mutation of Ser32 and Ser36 blocked IL-1β- or PMA-induced NF-κB activation, but had no effect on its activation by H2O2. Although IκBα was phosphorylated upon exposure to H2O2, tyrosine residue 42 and the C-terminal PEST (proline-glutamic acid-serine-threonine) domain played an important role. Indeed, mutation of tyrosine 42 or serine/threonine residues of the PEST domain abolished NF-κB activation by H2O2, while it had no effect on activation by IL-1β or PMA-ionomycin. This H2O2-inducible phosphorylation was not dependent on IκB kinase activation, but could involve casein kinase II, because an inhibitor of this enzyme (5,6-dichloro-1-β-d-ribofuranosyl-benzimidazole) blocks NF-κB activation. H2O2-induced IκBα phosphorylation was followed by its degradation by calpain proteases or through the proteasome. Taken together, our findings suggest that NF-κB activation by H2O2 involves a new mechanism that is totally distinct from those triggered by proinflammatory cytokines or mitogens.
IL-1 Receptor-Associated Kinase Modulates Host Responsiveness to Endotoxin
Authors: Swantek Jennifer L. , Tsen May F. , Cobb Melanie H. , Thomas James A. 
Published: April 2014

AbstractEndotoxin triggers many of the inflammatory, hemodynamic, and hematological derangements of Gram-negative septic shock. Recent genetic studies in mice have identified the Toll-like receptor 4 as the transmembrane endotoxin signal transducer. The IL-1 intracellular signaling pathway has been implicated in Toll-like receptor signal transduction. LPS-induced activation of the IL-1 receptor-associated kinase (IRAK), and the influence of IRAK on intracellular signaling and cellular responses to endotoxin has not been explored in relevant innate immune cells. We demonstrate that LPS activates IRAK in murine macrophages. IRAK-deficient macrophages, in contrast, are resistant to LPS. Deletion of IRAK disrupts several endotoxin-triggered signaling cascades. Furthermore, macrophages lacking IRAK exhibit impaired LPS-stimulated TNF-α production, and IRAK-deficient mice withstand the lethal effects of LPS. These findings, coupled with the critical role for IRAK in IL-1 and IL-18 signal transduction, demonstrate the importance of this kinase and the IL-1/Toll signaling cassette in sensing and responding to Gram-negative infection.
A Role for Complement in Antibody-Mediated Inflammation: C5-Deficient DBA/1 Mice Are Resistant to Collagen-Induced Arthritis
Authors: Wang Yi , Kristan Jane , Hao Liming , Lenkoski Catherine S. , Shen Yamin , Matis Louis A. 
Published: April 2014

AbstractCollagen-induced arthritis (CIA) represents an animal model of autoimmune polyarthritis with significant similarities to human rheumatoid arthritis that can be induced upon immunization with native type II collagen. As in rheumatoid arthritis, both cellular and humoral immune mechanisms contribute to disease pathogenesis. Genotypic studies have identified at least six genetic loci contributing to arthritis susceptibility, including the class II MHC. We have examined the mechanism of Ab-mediated inflammation in CIA joints, specifically the role of complement activation, by deriving a line of mice from the highly CIA-susceptible DBA/1LacJ strain that are congenic for deficiency of the C5 complement component. We show that such C5-deficient DBA/1LacJ animals mount normal cellular and humoral immune responses to native type II collagen, with the activation of collagen-specific TNF-α-producing T cells in the periphery and substantial intra-articular deposition of complement-fixing IgG Abs. Nevertheless, these C5-deficient mice are highly resistant to the induction of CIA. These data provide evidence for an important role of complement in Ab-triggered inflammation and in the pathogenesis of autoimmune arthritis.
Mechanism for the Isotype Dependence of Antibody-Mediated Toxicity inCryptococcus neoformans-Infected Mice
Authors: Lendvai Nikoletta , Qu Xiao-Wu , Hsueh Wei , Casadevall Arturo 
Published: April 2014

AbstractAb-based therapies have undergone a renaissance in recent years, but infusion-related reactions are a significant clinical problem. Administration of certain mAbs to Swiss Webster mice infected with Cryptococcus neoformans can result in acute lethal toxicity (ALT) characterized by cardiovascular collapse. The ability of a mAb to produce ALT is isotype dependent and occurs with IgG1 but not IgG3. To investigate this phenomenon, we measured spleen and liver cytokine responses and platelet-activating factor (PAF) content in mice given C. neoformans glucuronoxylomannan (GXM) followed by specific Ab of IgG1 or IgG3 isotype. We found no evidence to suggest that the differences in IgG1 and IgG3 toxicity were due to differences in chemokine or cytokine response. In contrast, liver and spleen tissue PAF content was significantly greater in mice IgG1. Furthermore, our results show differences in the response to IgG1- and IgG3-GXM complexes regarding: 1) macrophage-inflammatory protein-1α and monocyte chemoattractant protein-1 regulation, 2) splenic and hepatic PAF content, and 3) hepatic PAF content in infected mice. IgG1-associated ALT appears to be the result of greater production of PAF in response to IgG1-GXM complex formation. The results are consistent with the view that IgG1 and IgG3 interact with different Fc receptors. Our findings strongly suggest that the mechanism for Ab-mediated ALT is different from the cytokine release syndrome described after administration of other therapeutic mAbs.
A Tumor-Infiltrating Lymphocyte from a Melanoma Metastasis with Decreased Expression of Melanoma Differentiation Antigens Recognizes MAGE-12
Authors: Panelli Monica C. , Bettinotti Maria P. , Lally Kate , Ohnmacht Galen A. , Li Yong , Robbins Paul , Riker Adam , Rosenberg Steven A. , Marincola Francesco M. 
Published: April 2014

Abstract
Twenty separate tumor infiltrating lymphocyte (TIL) bulk cultures and a tumor cell line were originated simultaneously from a fine needle aspiration biopsy of a metastasis in a patient with melanoma (F001) previously immunized with the HLA-A*0201-associated gp100:209–217(210 M) peptide. None of the TIL recognized gp100. However, 12 recognized autologous (F001-MEL) and allogeneic melanoma cells expressing the HLA haplotype A*0201, B*0702, Cw*0702. Further characterization of F001-MEL demonstrated loss of gp100/PMel17, severely decreased expression of other melanoma differentiation Ags and retained expression of tumor-specific Ags. Transfection of HLA class I alleles into B*0702/Cw*0702-negative melanoma cell lines identified HLA-Cw*0702 as the restriction element for F001-TIL. A cDNA library from F001-MEL was used to transfect IFN-α-stimulated 293 human embryonal kidney (293-HEK) cells expressing HLA-Cw*0702. A 100-gene pool was identified that induced recognition of 293-HEK cells by F001-TIL. Subsequent cloning of the pool identified a cDNA sequence homologous, except for one amino acid (aa 187 D→A), to MAGE-12. Among 25 peptide sequences from MAGE-12 with the HLA-Cw*0702 binding motif, MAGE-12:170–178 (VRIGHLYIL) induced IFN-γ release by F001-TIL when pulsed on F001-EBV-B cells at concentrations as low as 10 pg/ml. Peptide sequences from MAGE-1, 2, 3, 4a, and 6 aligned to MAGE-12:170–178 were not recognized by F001-TIL. In summary a TIL recognizing a MAGE protein was developed from an HLA-A*0201 expressing tumor with strongly reduced expression of melanoma differentiation Ags. Persisting tumor-specific Ag expression maintained tumor immune competence suggesting that tumor-specific Ags/melanoma differentiation Ags may complement each other in the context of melanoma Ag-specific vaccination.
Characterization of T Cell Responses to Hev b 3, an Allergen Associated with Latex Allergy in Spina Bifida Patients
Authors: Bohle Barbara , Wagner Birgit , Vollmann Ute , Buck Dietke , Niggemann Bodo , Szépfalusi Zsolt , Fischer Gottfried , Scheiner Otto , Breiteneder Heimo , Ebner Christof 
Published: April 2014

AbstractThe prevalence of type I allergy to Hevea brasiliensis latex is particularly high among individuals with frequent exposure such as health care workers and patients with spina bifida (SB). Due to a birth defect of the spinal canal and the resulting neurological and orthopedic defects, these patients require multiple surgeries during childhood. SB patients display a unique pattern of sensitization: IgE-reactivity is preferentially directed against Hev b 3 and Hev b 1, two latex allergens with high sequence similarity. In this study, we analyzed the T cell response to Hev b 3 in latex-allergic SB patients using poly-, oligo-, and monoclonal T lymphocyte cultures. All T cell clones (TCC) were CD3/CD4-positive and expressed the αβ TCR. According to their cytokine production pattern (IL-4 vs IFN-γ), 12 of 21 TCC were classified as Th2-like, 2 of 21 were Th1-like, and 7 of 21 belonged to a Th0-like subset. Using 11 T cell lines and 21 TCC, nine T cell stimulating fragments were determined out of 52 overlapping 12-mer peptides representing the complete amino acid sequence of Hev b 3. Ag presentation of one dominant T cell epitope could be associated with a four-amino acid binding motif (YSTS, position 11–13) in the β1 chain of HLA-DR molecules expressed by the respective patients. No reactivity was observed when Hev b 3-reactive T cell lines or TCC were incubated with peptides representing homologous parts of the Hev b 1 molecule, i.e., no cross-reactivity between Hev b 3 and Hev b 1 at the T cell level was evident.
Fine Mapping ofIGAD1in IgA Deficiency and Common Variable Immunodeficiency: Identification and Characterization of Haplotypes Shared by Affected Members of 101 Multiple-Case Families
Authors: Vořechovský Igor , Cullen Michael , Carrington Mary , Hammarström Lennart , Webster A. David B. 
Published: April 2014

AbstractTo limit the region containing a mutation predisposing to selective IgA deficiency (IgAD) and common variable immunodeficiency (CVID), 554 informative members of 101 multiple-case families were haplotyped at the IGAD1 candidate locus in the MHC. Microsatellite markers were placed onto the physical map of IGAD1 to establish their order and permit rapid haplotype analyses. Linkage analysis of this extended family set provided additional support for a strong susceptibility locus at IGAD1 with a maximum multipoint nonparametric linkage score in excess of 3. Although the transmission of maternal IGAD1 haplotypes from unaffected heterozygous parents to the affected offspring was in excess, this was not apparent in multiple-case families with a predominance of affected mothers, suggesting that this parental bias is influenced by the affection status of transmitting parents and supporting a maternal effect in disease susceptibility. Of 110 haplotypes shared by 258 affected family members, a single haplotype (H1) was found in 44 pairs of affected relatives, accounting for the majority of the IGAD1 contribution to the development of IgAD/CVID in our families. The H1 allelic variability was higher in the telomeric part of the class III region than in the distal part of the class II region in both single- and multiple-case families. Incomplete H1 haplotypes had most variant alleles in the telomeric part of the analyzed region in homozygous IgAD/CVID patients, whereas this was not observed in unaffected homozygotes. These data suggest that a telomeric part of the class II region or centromeric part of the class III region is the most likely location of IGAD1.1 This study was supported by the Swedish and British Medical Research Councils, the Swedish Strategic Research Foundation, the Primary Immunodeficiency Association of the United Kingdom MSMT VS96097, the Karolinska Institute, and federal funds from the National Cancer Institute, National Institutes of Health, under Contract NO1-CO-56000. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. 2 Address correspondence and reprint requests to Dr. Igor Vořechovský, Department of Biosciences at NOVUM, Karolinska Institute, CBT Hälsovägen 7, SE-14157 Huddinge, Sweden. E-mail address: igvosmtp.biosci.ki.se Abbreviations used in this paper: IgAD, selective IgA deficiency; CVID, common variable immunodeficiency; TDT, transmission disequilibrium test; NPL, nonparametric linkage; PCR-SSP, PCR using sequence-specific oligonucleotide primers.