bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification and Characterization of Two Mannan-Binding Lectins from Mouse Serum
Authors: Hansen Søren , Thiel Steffen , Willis Anthony , Holmskov Uffe , Jensenius Jens Christian 
Published: April 2014

Abstract
Mannan-binding lectin (MBL) is a serum protein that activates the complement system after binding to glycoconjugates found on the surface of microorganisms. By molecular cloning two forms of MBL have been identified in the mouse (mMBL-A and mMBL-C), but only mMBL-A has been purified and characterized at the protein level. MBL-C has been termed the liver form of MBL. The present report describes the purification and characterization of mMBL-A and mMBL-C from serum. The two forms of mMBL could be separated both by ion-exchange and carbohydrate-affinity chromatography. The initial identification by immunochemical technique was confirmed by N-terminal amino-acid sequencing. Both proteins give bands corresponding to polypeptide chains of 28 kDa on SDS-PAGE in the reduced state, but mMBL-A migrated more rapidly than mMBL-C in acid/urea-PAGE, in accordance with the calculated pIs. Both forms mediated activation of complement component C4 in mannan-coated microtiter wells. MBL-A showed a higher affinity for d-glucose and α-methyl-d-glucose then did MBL-C. Serum concentrations of mMBL-A in laboratory strains and wild mice were found to vary from 5 to 80 μg/ml, with wild mice tending to show higher levels than laboratory strains.
Role for IgE in Airway Secretions: IgE Immune Complexes Are More Potent Inducers Than Antigen Alone of Airway Inflammation in a Murine Model
Authors: Zuberi Riaz I. , Apgar John R. , Chen Swey-Shen , Liu Fu-Tong 
Published: April 2014

Abstract
IgE is present in airway secretions from human patients with allergic rhinitis and bronchial asthma. However, the contribution of IgE present locally to the overall airway inflammation is not well understood. We hypothesize that Ag-specific IgE can capture airborne Ags and form immune complexes. These immune complexes may function as potent inducers of immune responses in the lung, contributing to the perpetuation of airway inflammation. BALB/c mice were first sensitized with OVA in alum systemically and then challenged with nebulized OVA. Bronchoalveolar lavage (BAL) fluid from these mice contained significant amounts of IgE, of which &gt;50% was Ag specific. The IgE levels in airway secretions remained elevated for more than 15 days after the termination of Ag exposure. Significant amounts of IgE-OVA immune complexes were detected in BAL fluid from the OVA-challenged mice. For comparison of IgE immune complexes vs Ag alone, we treated OVA-immunized mice with intranasal administration of trinitrophenyl-OVA or trinitrophenyl-OVA-anti-DNP IgE. Those treated with the immune complexes showed significantly higher levels of IL-4 and more pronounced eosinophilia in BAL fluid than did those receiving the Ag alone. The IgE immune complexes did not augment the inflammatory response in high affinity IgE receptor (FcεRI)-deficient mice. We conclude that IgE present in the airways can capture the Ag and that the immune complexes thus formed may augment allergic airway response in an FcεRI-dependent manner. Thus, IgE present in airway secretions may facilitate Ag-mediated allergic airway inflammation.
IFN-γ Shapes Immune Invasion of the Central Nervous System Via Regulation of Chemokines
Authors: Tran Elise H. , Prince Esther N. , Owens Trevor 
Published: April 2014

AbstractDynamic interplay between cytokines and chemokines directs trafficking of leukocyte subpopulations to tissues in autoimmune inflammation. We have examined the role of IFN-γ in directing chemokine production and leukocyte infiltration to the CNS in experimental autoimmune encephalomyelitis (EAE). BALB/c and C57BL/6 mice are resistant to induction of EAE by immunization with myelin basic protein. However, IFN-γ-deficient (BALB/c) and IFN-γR-deficient (C57BL/6) mice developed rapidly progressing lethal disease. Widespread demyelination and disseminated leukocytic infiltration of spinal cord were seen, unlike the focal perivascular infiltrates in SJL/J mice. Gr-1+ neutrophils predominated in CNS, and CD4+ T cells with an activated (CD69+, CD25+) phenotype and eosinophils were also present. RANTES and macrophage chemoattractant protein-1, normally up-regulated in EAE, were undetectable in IFN-γ- and IFN-γR-deficient mice. Macrophage inflammatory protein-2 and T cell activation gene-3, both neutrophil-attracting chemokines, were strongly up-regulated. There was no induction of the Th2 cytokines, IL-4, IL-10, or IL-13. RNase protection assays and RT-PCR showed the prevalence of IL-2, IL-3, and IL-15, but no increase in IL-12p40 mRNA levels in IFN-γ- or IFN-γR-deficient mice with EAE. Lymph node cells from IFN-γ-deficient mice proliferated in response to myelin basic protein, whereas BALB/c lymph node cells did not. These findings show a regulatory role for IFN-γ in EAE, acting on T cell proliferation and directing chemokine production, with profound implications for the onset and progression of disease.
The Human UTY Gene Encodes a Novel HLA-B8-Restricted H-Y Antigen
Authors: Warren Edus H. , Gavin Marc A. , Simpson Elizabeth , Chandler Phillip , Page David C. , Disteche Christine , Stankey Kimberly A. , Greenberg Philip D. , Riddell Stanley R. 
Published: April 2014

Abstract
The mammalian Y chromosome encodes male-specific minor histocompatibility (H-Y) Ags that are recognized by female T cells in an MHC-restricted manner. Two human H-Y epitopes presented by HLA-A2 and HLA-B7, respectively, have been identified previously and both are derived from the SMCY gene. We previously isolated CD8+ CTL clones that recognized a male-specific minor histocompatibility Ag presented by HLA-B8. In contrast to the SMCY-encoded H-Y epitopes, the B8/H-Y Ag was not presented by fibroblasts from male donors, suggesting that it was encoded by a novel gene. We now report that the HLA-B8-restricted H-Y epitope is defined by the octameric peptide LPHNHTDL corresponding to aa residues 566–573 of the human UTY protein. Transcription of the UTY gene is detected in a wide range of human tissues, but presentation of the UTY-derived H-Y epitope to CTL by cultured human cells shows significant cell-type specificity. Identification of this CTL-defined H-Y epitope should facilitate analysis of its contribution to graft/host interactions following sex-mismatched organ and bone marrow transplantation.
High Levels of IL-17 in Rheumatoid Arthritis Patients: IL-15 Triggers In Vitro IL-17 Production Via Cyclosporin A-Sensitive Mechanism
Authors: Ziolkowska Maria , Koc Anna , Luszczykiewicz Grazyna , Ksiezopolska-Pietrzak Krystyna , Klimczak Ewa , Chwalinska-Sadowska Hanna , Maslinski Wlodzimierz 
Published: April 2014

Abstract
Recent data suggest that IL-15 plays an important role in the pathogenesis of rheumatoid arthritis. In the present study, we hypothesized that elevated in the joints of rheumatoid arthritis, but not osteoarthritis, patients, IL-15 may exert its proinflammatory properties via the induction of IL-17, a cytokine known to stimulate synoviocytes to release several mediators of inflammation including IL-6, IL-8, GM-CSF and PGE2. To test this hypothesis, we first measured the levels of IL-17 and IL-15 using specific ELISA and found that synovial fluids of patients with rheumatoid arthritis, but not with osteoarthritis, contain high levels of these cytokines. A strong correlation between IL-15 and IL-17 levels in synovial fluids was observed. Among tested factors, LPS and TNF-α failed, IL-15 and IL-2 were equipotent, and PMA + ionomycin was far more efficient in the induction of IL-17 secretion by PBMCs isolated from healthy blood donors. Interestingly, synovial fluid cells, in contrast to PBMCs isolated from patients with rheumatoid arthritis, but not osteoarthritis, respond to PMA + ionomycin with much lower, comparable to IL-15-triggered IL-17 secretion. Moreover, PMA + ionomycin-triggered IL-17 secretion is completely or partially blocked in the presence of low doses of cyclosporin A or high doses of methylprednisolone, respectively. IL-15-triggered IL-17 secretion by PBMCs was completely inhibited by these drugs. Thus, our results suggest for the first time that IL-15 may represent a physiological trigger that via cyclosporin A and steroid sensitive pathways leads to the overproduction of IL-17 in the joints of rheumatoid arthritis patients.
Integrated Signals Between IL-13, IL-4, and IL-5 Regulate Airways Hyperreactivity
Authors: Webb Dianne C. , McKenzie Andrew N. J. , Koskinen Aulikki M. L. , Yang Ming , Mattes Joërg , Foster Paul S. 
Published: April 2014

AbstractIn this investigation, we have examined the integrated relationship between IL-13, IL-4, and IL-5 for the development of airways hyperreactivity (AHR) in a model of asthma in BALB/c mice. Sensitization and aeroallergen challenge of both wild-type (WT) and IL-13 gene-targeted (IL-13−/−) mice induced allergic disease that was characterized by pulmonary eosinophilia and AHR to β-methacholine. Although these responses in IL-13−/− mice were heightened compared with WT, they could be reduced to the level in nonallergic mice by the concomitant neutralization of IL-4. Mice in which both IL-4 and IL-13 were depleted displayed a marked reduction in tissue eosinophils, despite the development of a blood eosinophilia. Similar neutralization of IL-4 in WT mice only partially reduced AHR with no effect on tissue eosinophilia. In addition, neutralization of IL-5 in IL-13−/− mice, but not in WT mice, inhibited AHR, suggesting that tissue eosinophilia is linked to the mechanism underlying AHR only in the absence of IL-13. Additionally, mucus hypersecretion was attenuated in IL-13−/− mice, despite the persistence of AHR. Taken together, our data suggest both a modulatory role for IL-13 during sensitization and a proinflammatory role during aeroallergen challenge. The latter process appears redundant with respect to IL-4.
Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase-Activating Polypeptide Inhibit T Cell-Mediated Cytotoxicity by Inhibiting Fas Ligand Expression
Authors: Delgado Mario , Ganea Doina 
Published: April 2014

AbstractWe reported recently that the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) protect CD4+ T cells against Ag-induced apoptosis by down-regulating the expression of Fas ligand (FasL). Because the cytotoxic activity of CD8+ CTLs is mediated through two mechanisms, which involve the perforin/granzyme and the FasL/Fas pathways, in this study we investigated the effects of VIP/PACAP on the generation and activity of allogeneic CTLs, of CD8+ T1 and T2 effector cells and of alloreactive peritoneal exudate cytotoxic T cells (PEL) generated in vivo. VIP/PACAP did not affect perforin/granzyme-mediated cytotoxicity, perforin gene expression, or granzyme B enzymatic activity, but drastically inhibited FasL/Fas-mediated cytotoxicity against allogeneic or syngeneic Fas-bearing targets. VIP/PACAP inhibit CTL generation, but not the activity of competent CTLs. The inhibition is associated with a profound down-regulation of FasL expression, and these effects are mediated through both VPAC1 and VPAC2 receptors. VIP/PACAP inhibit the FasL/Fas-mediated cytotoxicity of T1 effectors and do not affect T2 cytotoxicity, which is entirely perforin/granzyme mediated. Similar effects were observed in vivo. Both the FasL/Fas-mediated cytotoxicity and FasL expression of cytotoxic allogeneic PELs generated in vivo in the presence of VIP or PACAP were significantly reduced. We conclude that, similar to their effect on CD4+ T cells, the two structurally related neuropeptides inhibit FasL expression in CD8+ cytotoxic T cells and the subsequent lysis of Fas-bearing target cells.
Thapsigargin-Induced Degranulation of Mast Cells Is Dependent on Transient Activation of Phosphatidylinositol-3 Kinase
Authors: Huber Michael , Hughes Michael R. , Krystal Gerald 
Published: April 2014

Abstract
Thapsigargin, which elevates cytosolic calcium levels by inhibiting the sarcoplasmic/endoplasmic reticulum calcium-dependent ATPase, was tested for its ability to degranulate bone marrow-derived mast cells (BMMCs) from src homology 2-containing inositol phosphatase +/+ (SHIP+/+) and SHIP−/− mice. As was found previously with steel factor, thapsigargin stimulated far more degranulation in SHIP−/− than in SHIP+/+ BMMCs, and this was blocked with the phosphatidylinositol-3 (PI-3) kinase inhibitors, LY294002 and wortmannin. In contrast to steel factor, however, this heightened degranulation of SHIP−/− BMMCs was not due to a greater calcium influx into these cells, nor was the thapsigargin-induced calcium influx inhibited by LY294002, suggesting that the heightened thapsigargin-induced degranulation of SHIP−/− BMMCs was due to a PI-3 kinase-regulated step distinct from that regulating calcium entry. An investigation of thapsigargin-stimulated pathways in both cell types revealed that MAPK was heavily but equally phosphorylated. Interestingly, the protein kinase C inhibitor, bisindolylmaleimide (compound 3), totally blocked thapsigargin-induced degranulation in both SHIP+/+ and SHIP−/− BMMCs. As well, thapsigargin stimulated a PI-3 kinase-dependent, transient activation of protein kinase B, and this activation was far greater in SHIP−/− than in SHIP+/+ BMMCs. Consistent with this, thapsigargin was found to be a potent survival factor, following cytokine withdrawal, for both cell types and was more potent with SHIP−/− cells. These studies have both identified an additional PI-3 kinase-dependent step within the mast cell degranulation process, possibly involving 3-phosphoinositide-dependent protein kinase-1 and a diacylglycerol-independent protein kinase C isoform, and shown that the tumor-promoting activity of thapsigargin may be due to its activation of protein kinase B and subsequent promotion of cell survival.
Duplicated DQ Haplotypes Increase the Complexity of Restriction Element Usage in Cattle
Authors: Glass Elizabeth J. , Oliver Robert A. , Russell George C. 
Published: April 2014

AbstractThe MHC of cattle encodes two distinct isotypes of class II molecules, DR and DQ. Unlike humans, cattle lack the DP locus and about half the common haplotypes express duplicated DQ genes. The number and frequency of DQA and DQB alleles means that most cattle are heterozygous. If inter- and/or intrahaplotype pairing of DQA and DQB molecules occurs, cattle carrying DQ-duplicated haplotypes may express more restriction elements than would be predicted by the number of expressed alleles. We are investigating whether duplicated haplotypes cause differences in immune response, particularly in terms of generating protective immunity. We have analyzed the Ag-presenting function of DQ molecules in two heterozygous animals, one of which carries a duplicated haplotype. We compared the class II isotype specificity of T cell clones recognizing a putative vaccinal peptide from foot-and-mouth disease virus (FMDV15). We show for the first time that bovine T cells can recognize Ag in the context of DQ molecules. We also present evidence that interhaplotype pairings of DQA and DQB molecules form functional restriction elements. Both animals showed distinct biases to usage of particular restriction elements. Mainly DQ-restricted clones were derived from the animal with duplicated DQ genes, whereas the majority of clones from the animal with a single DQ gene pair were DR restricted. Furthermore, haplotype bias was observed with both animals. These experiments show that understanding of class II chain pairing in addition to knowledge of the genotype may be important in vaccine design where effective epitope selection is essential.
Cutting Edge: Hierarchy of Chemokine Receptor and TCR Signals Regulating T Cell Migration and Proliferation
Authors: Bromley Shannon K. , Peterson Daniel A. , Gunn Michael D. , Dustin Michael L. 
Published: April 2014

AbstractChemokines play an important role in establishing the distribution of lymphocyte subpopulations in primary and secondary lymphoid tissues and in the recruitment of leukocytes to sites of inflammation. However, the potential of chemokines to down-regulate immune responses has not been demonstrated. We now show that certain chemokine gradients have the potential to suppress T cell activation by preventing formation of the immunological synapse, the specialized cell-cell junction that forms before a T cell can be fully activated. Our data reveals an immunosuppressive potential of chemokines engaging the CXCR3 and CCR7 receptors, but not the CXCR4, CCR2, CCR4, or CCR5 receptors. These results suggest a novel mechanism for T cell ignorance of agonist MHC-peptide complexes based on dominant chemokine gradients.
IL-4 and IFN-γ Up-Regulate Substance P Receptor Expression in Murine Peritoneal Macrophages
Authors: Marriott Ian , Bost Kenneth L. 
Published: April 2014

AbstractWhile the ability of macrophages to express authentic substance P receptors (i.e., NK-1 receptors) has been inferred from radioreceptor binding assays and functional assays and, most recently, by identification of NK-1 receptor mRNA expression, we know little about NK-1 expression at the protein level or what host factors might up-regulate expression of this receptor. In the present study we demonstrate that the cytokines IL-4 and IFN-γ can increase the expression of NK-1 receptors on murine peritoneal macrophages. Specifically, we show that IL-4 and IFN-γ can elicit increases in the level of mRNA encoding the NK-1 receptor by up to 12- and 13-fold, respectively. Furthermore, these cytokines can significantly increase the expression of the NK-1 receptor protein as measured by Western blot and FACS analysis using specific Abs developed in our laboratory. In addition, we have demonstrated the ability of both IL-4 and IFN-γ to enhance the ability of macrophages to bind substance P as measured by radiolabeled binding assay. The observation that the level of expression of this receptor protein can be enhanced by cytokines that promote either cell-mediated (Th1) or humoral (Th2) immune responses supports the idea that this receptor can be induced during either type of immune response. As such, these results may point to a more ubiquitous role for substance P in the generation of optimal immune responses than previously appreciated.
The Duration of Nuclear Residence of NFAT Determines the Pattern of Cytokine Expression in Human SCID T Cells
Authors: Feske Stefan , Draeger Ruth , Peter Hans-Hartmut , Eichmann Klaus , Rao Anjana 
Published: April 2014

Abstract
The expression of cytokine genes and other inducible genes is crucially dependent on the pattern and duration of signal transduction events that activate transcription factor binding to DNA. Two infant patients with SCID and a severe defect in T cell activation displayed an aberrant regulation of the transcription factor NFAT. Whereas the expression levels of the NFAT family members NFAT1, -2, and -4 were normal in the patients’ T cells, dephosphorylation and nuclear translocation of these NFAT proteins occurred very transiently and incompletely upon stimulation. Only after inhibition of nuclear export with leptomycin B were we able to demonstrate a modest degree of nuclear translocation in the patients’ T cells. This transient activation of NFAT was not sufficient to induce the expression of several cytokines, including IL-2, IL-3, IL-4, and IFN-γ, whereas mRNA levels for macrophage inflammatory protein-1α, GM-CSF, and IL-13 were only moderately reduced. By limiting the time of NFAT activation in normal control cells using the calcineurin inhibitor cyclosporin A, we were able to mimic the cytokine expression pattern in SCID T cells, suggesting that the expression of different cytokine genes is differentially regulated by the duration of NFAT residence in the nucleus.
Tapasin-Mediated Retention and Optimization of Peptide Ligands During the Assembly of Class I Molecules
Authors: Barnden Megan J. , Purcell Anthony W. , Gorman Jeffrey J. , McCluskey James 
Published: April 2014

AbstractThe murine class I H-2Kb molecule achieves high level surface expression in tapasin-deficient 721.220 human cells. Compared with their behavior in wild-type cells, Kb molecules expressed on 721.220 cells are more receptive to exogenous peptide, undergo more rapid surface decay, and fail to form macromolecular peptide loading complexes. As a result, they are rapidly transported to the cell surface, reflecting a failure of endoplasmic reticulum retention mechanisms in the absence of loading complex formation. Despite the failure of Kb molecules to colocalize to the TAP and their rapid egress to the cell surface, Kb is still capable of presenting TAP-dependent peptides in the absence of tapasin. Furthermore, pool sequencing of peptides eluted from these molecules revealed strict conservation of their canonical H-2Kb-binding motif. There was a reduction in the total recovery of peptides associated with Kb molecules purified from the surface of tapasin-deficient cells. Comparison of the peptides bound to Kb in the presence and absence of tapasin revealed considerable overlap in peptide repertoire. These results indicate that in the absence of an interaction with tapasin, Kb molecules fail to assemble with calreticulin and TAP, yet they are still capable of acquiring a diverse array of peptides. However, a significant proportion of these peptides appear to be suboptimal, resulting in reduced cell surface stability of Kb complexes. Taken together, the findings indicate that tapasin plays an essential role in the formation of the class I loading complex, which retains class I heterodimers in the endoplasmic reticulum until optimal ligand selection is completed.
CD4+ T Cells Acting Independently of Antibody Contribute to Protective Immunity to Plasmodium chabaudi Infection After Apical Membrane Antigen 1 Immunization
Authors: Xu Huji , Hodder Anthony N. , Yan Huara , Crewther Pauline E. , Anders Robin F. , Good Michael F. 
Published: April 2014

Abstract
Apical membrane Ag 1 (AMA1) is a leading malaria vaccine candidate. Homologues of AMA1 can induce protection in mice and monkeys, but the mechanism of immunity is not understood. Mice immunized with a refolded, recombinant, Plasmodium chabaudi AMA1 fragment (AMA1B) can withstand subsequent challenge with P. chabaudi adami. Here we show that CD4+ T cell depletion, but not γδ T cell depletion, can cause a significant drop in antiparasite immunity in either immunized normal or immunized B cell KO mice. In normal mice, this loss of immunity is not accompanied by a decline in Ab levels. These observations indicate a role for AMA1-specific Ab-independent T cell-mediated immunity. However, the loss of immunity in normal CD4+ T cell-depleted mice is temporary. Furthermore, immunized B cell KO mice cannot survive infection, demonstrating the absolute importance of B cells, and presumably Ab, in AMA1-induced immunity. CD4+ T cells specific for a cryptic conserved epitope on AMA1 can adoptively transfer protection to athymic (nu/nu) mice, the level of which is enhanced by cotransfer of rabbit anti-AMA1-specific antisera. Recipients of rabbit antisera alone do not survive. Some protected recipients of T cells plus antisera do not develop their own AMA 1-specific Ab response, suggesting that AMA 1-specific CMI alone can protect mice. These data are the first to demonstrate the specificity of any protective CMI response in malaria and have important implications for developing a malaria vaccine.