bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualization of Early APC/T Cell Interactions in the Mouse Lung Following Intranasal Challenge
Authors: Byersdorfer Craig A. , Chaplin David D. 
Published: April 2014

AbstractWe have used fluorescent latex beads, with or without covalently conjugated OVA, to facilitate study of Ag trafficking in the mouse lung and draining peribronchial lymph node (LN). At 6 h, and up to 48 h after intranasal administration, beads were observed as intracellular clusters in the tissue parenchyma. Flow cytometry of bead-positive (bead+) cells from the bronchoalveolar lavage demonstrated that a majority of these cells are CD11c+, F4/80+, and CD11b−. Furthermore, fluorescent microscopy confirmed that a major subset of bead+ cells in the lung tissue was also CD11c+. In the draining peribronchial LNs, small numbers of beads were present in the subcapsular sinus as early as 6 h after inhalation. By 12 h and beyond, bead+ cells had localized exclusively to the LN T zone. OVA-conjugated latex beads, in addition to stimulating brisk proliferation of naive, OVA-specific DO11.10 transgenic T cells in vitro, could also recruit OVA-specific T cells in vivo. In some cases, bead+ APCs and CD4+ Th1 cells were found adjacently localized in the lung tissue 6 h after airway challenge. Thus, interactions of bead+ APCs with Ag-specific CD4+ T cells occurred earlier in the peripheral airways than these same interactions occurred in the draining peribronchial LN. Lastly, after adoptive transfer, in vitro differentiated Th1 cells accumulated at peripheral sites in the lung tissue and airways before Ag challenge and therefore were ideally positioned to influence subsequent immune reactions of the airway.
Pre-Existing Tumor-Sensitized T Cells Are Essential for Eradication of Established Tumors by IL-12 and Cyclophosphamide Plus IL-12
Authors: Le Hop N. , Lee Natalie C. , Tsung Kangla , Norton Jeffrey A. 
Published: April 2014

AbstractThe antitumor immune response activated by IL-12, especially by a combination of cyclophosphamide and IL-12 (Cy+IL-12), is clinically significant in certain experimental tumor models, in that a number of well-established (10–20 mm in diameter) s.c. tumors are completely eradicated. Furthermore, Cy+IL-12 treatment is also able to eradicate well-established grossly detectable experimental lung metastases and advanced ascites tumors. Despite the dramatic antitumor effects seen in some tumor models, Cy+IL-12 fails to induce regression of other established tumors. Characterization of tumor immunogenicity shows that all tumors responding to IL-12 and Cy+IL-12 treatments are immunogenic tumors, in that an antitumor immune response is detectable in tumor-bearing hosts upon tumor establishment. In contrast, none of the nonimmunogenic tumor responds to IL-12 and Cy+IL-12 treatments. Analysis of cellular requirements for successful tumor rejection through an adoptive cell transfer approach reveals that the presence of tumor-sensitized, but not naive, T cells is essential for tumor rejection by IL-12 and Cy+IL-12. Transfer of these tumor-sensitized T cells must be conducted before, but not after, IL-12 treatment in order for tumor rejection to occur. The requirement of sensitized T cells is also tumor specific. In mice bearing immunogenic tumors, the presence of pre-existing tumor-sensitized T cells is demonstrated by adoptive cell transfer experiments using purified spleen T cells from these mice. Results from our study show that Cy+IL-12-based immunotherapy of cancer may be highly effective and that pre-existing tumor-sensitized T cells are essential for the success of the therapy.
Essential Contribution of Germline-Encoded Lysine Residues in Jγ1.2 Segment to the Recognition of Nonpeptide Antigens by Human γδ T Cells
Authors: Miyagawa Fumi , Tanaka Yoshimasa , Yamashita Seiji , Mikami Bunzo , Danno Kiichiro , Uehara Masami , Minato Nagahiro 
Published: April 2014

AbstractHuman γδ T cells display unique repertoires of Ag specificities largely imposed by selective usages of distinct Vγ and Vδ genes. Among them, Vγ2/Vδ2+ T cells predominate in the circulation of healthy adults and respond to various microbial small molecular mass nonpeptide Ags. The present results indicate that the primary Vγ2/Vδ2+ T cells stimulated with the distinct groups of nonpeptide Ags, including monoethyl pyrophosphate, isobutyl amine, and aminobisphosphonate, invariably exhibit Jγ1.2 in the Vγ2+ TCR-γ chains. Gene transfer studies revealed that most of the randomly cloned Vγ2/Jγ1.2+ TCR-γ genes bearing diverse Vγ/Jγ junctional sequences could confer the responsiveness to all these nonpeptide Ags, while none of the Vγ2/Jγ1.1+ or Vγ2/Jγ1.3+ TCR-γ genes could do so. Furthermore, mutation of the lysine residues encoded by the Jγ1.2 gene, which are unique in human Jγ1.2 and absent in other human or mouse Jγ segments, completely abrogated the responsiveness to all the nonpeptide Ags without affecting the response to anti-CD3 mAb. These results strongly suggested that the positively charged lysine residues in the TCR-γ chain CDR3 region encoded by the germline Jγ1.2 gene play a key role in the recognition of diverse small molecular mass nonpeptide Ags.
Resolution of Three Nonproliferative Immature Splenic B Cell Subsets Reveals Multiple Selection Points During Peripheral B Cell Maturation
Authors: Allman David , Lindsley R. Coleman , DeMuth William , Rudd Kristina , Shinton Susan A. , Hardy Richard R. 
Published: April 2014

AbstractAlthough immature/transitional peripheral B cells may remain susceptible to selection pressures before full maturation, the nature and timing of these selection events remain unclear. We show that correlated expression of surface (s) IgM (sIgM), CD23, and AA4 defines three nonproliferative subpopulations of immature/transitional peripheral B cells. We designate these populations transitional (T) 1 (AA4+CD23−sIgMhigh), T2 (AA4+CD23+sIgMhigh), and T3 (AA4+CD23+sIgMlow). Cells within all three subsets are functionally immature as judged by their failure to proliferate following sIgM cross-linking in vitro, and their rapid rate of turnover in vivo as assessed by 5-bromo-2′-deoxyuridine labeling. These labeling studies also reveal measurable cell loss at both the T1-T2 and T2-T3 transitions, suggesting the existence of multiple selection points within the peripheral immature B cell pool. Furthermore, we find that Btk-deficient (xid) mice exhibit an incomplete developmental block at the T2-T3 transition within the immature B cell pool. This contrasts markedly with lyn−/− mice, which exhibit depressed numbers but normal ratios of each immature peripheral B cell subset and severely reduced numbers of mature B cells. Together, these data provide evidence for multiple selection points among immature peripheral B cells, suggesting that the B cell repertoire is shaped by multiple unique selection events that occur within the immature/transitional peripheral B cell pool.
CR2/CD21 Proximal Promoter Activity Is Critically Dependent on a Cell Type-Specific Repressor
Authors: Ulgiati Daniela , Holers V. Michael 
Published: April 2014

AbstractTranscription of the human complement receptor type 2 (CR2/CD21) gene is controlled by both proximal promoter and intronic elements. CR2 is primarily expressed on B cells from the immature through mature cell stages. We have previously described the presence of an intronic element that is required for both cell- and stage-specific expression of CR2. In this study, we report the identification of a cell type-specific repressor element within the proximal promoter. This repressor sequence is shown by linker scanning mutagenesis to comprise an E box motif. By supershift analysis this element binds members of the basic helix-loop-helix family of proteins, in particular E2A gene products. Mutational analysis demonstrates that binding of E2A proteins is critical for functioning of this repressor. Thus, E2A activity is key not only for early B cell development, but also for controlling CR2 expression, a gene expressed only during later stages of ontogeny.
Localizing a Control Region in the Pathway to Leukotriene C4 Secretion Following Stimulation of Human Basophils with Anti-IgE Antibody
Authors: Miura Katsushi , Lavens-Phillips Sandra , MacGlashan Donald W. 
Published: April 2014

AbstractMediator release from human basophils is a self-limited process, but down-regulation of the signaling cascades leading to secretion of leukotriene C4 (LTC4) is controlled independently of the pathway leading to IL-4 secretion. In the current studies, we have explored the regulation of upstream signaling events leading to activation of extracellular signal-related kinases (ERKs; previously shown to be required for LTC4 generation) in human basophils. IgE-, but not FMLP-mediated activation, induced sustained tyrosine phosphorylation of syk, of shc, and an association of shc to the Grb2/son of sevenless 2 complex. In contrast, IgE-mediated activation resulted in transient activation of p21ras and mitogen-activated protein/ERK kinase 1, which were kinetically associated with phosphorylation of ERKs. The canonical Shc/Grb2/son of sevenless pathway to activation of p21ras is therefore sustained, while p21ras activity is not. We have previously shown that phosphatidylinositol 3 kinase activity is required for p21ras activity and, in the current studies, we show that of the p85-sensitive forms of p110 possible, basophils express only p110 δ and that there are no changes in association between p21ras and p110 δ in stimulated basophils. We used the generation of phospho-Akt as a marker of the presence of phosphatidylinositol-3,4,5-trisphosphate and found that phospho-Akt is transient on a time scale consistent with p21ras activity. On the basis of information obtained in these and other studies, we localize down-regulation of IgE-mediated LTC4 secretion to a region of the signaling cascade antecedent to p21ras activation, downstream of phosphatidylinositol 3 kinase activity and probably involving regulation of phosphatidylinositol-3,4,5-trisphosphate levels.
Expression and Release of IL-18 Binding Protein in Response to IFN-γ
Authors: Paulukat Jens , Bosmann Markus , Nold Marcel , Garkisch Stefanie , Kämpfer Heiko , Frank Stefan , Raedle Jochen , Zeuzem Stefan , Pfeilschifter Josef , Mühl Heiko 
Published: April 2014

AbstractIL-18 and IL-18 binding protein (IL-18BP) are two newly described opponents in the cytokine network. Local concentrations of these two players may determine biological functions of IL-18 in the context of inflammation, infection, and cancer. As IL-18 appears to be involved in the pathogenesis of Crohn’s disease and may modulate tumor growth, we investigated the IL-18/IL-18BPa system in the human colon carcinoma/epithelial cell line DLD-1. In this study, we report that IFN-γ induces expression and release of IL-18BPa from DLD-1 cells. mRNA induction and secretion of IL-18BPa immunoreactivity were associated with an activity that significantly impaired release of IFN-γ by IL-12/IL-18-stimulated PBMC. Inducibility of IL-18BPa by IFN-γ was also observed in LoVo, Caco-2, and HCT116 human colon carcinoma cell lines and in the human keratinocyte cell line HaCaT. Induction of IL-18BPa in colon carcinoma/epithelial cell lines was suppressed by coincubation with sodium butyrate. IFN-γ-mediated IL-18BPa and its suppression by sodium butyrate were confirmed in organ cultures of intestinal colonic biopsy specimens. In contrast, sodium butyrate did not modulate expression of IL-18. The present data suggest that IFN-γ may limit biological functions of IL-18 at sites of colonic immune activation by inducing IL-18BPa production. Down-regulation of IL-18BPa by sodium butyrate suggests that reinforcement of local IL-18 activity may contribute to actions of this short-chain fatty acid in the colonic microenvironment.
CXCR3 Internalization Following T Cell-Endothelial Cell Contact: Preferential Role of IFN-Inducible T Cell α Chemoattractant (CXCL11)
Authors: Sauty Alain , Colvin Richard A. , Wagner Ludwig , Rochat Sophie , Spertini Francois , Luster Andrew D. 
Published: April 2014

AbstractChemokine receptors are rapidly desensitized and internalized following ligand binding, a process that attenuates receptor-mediated responses. However, the physiological settings in which this process occurs are not clear. Therefore, we examined the fate of CXCR3, a chemokine receptor preferentially expressed on activated T cells following contact with endothelial cells. By immunofluorescence microscopy and flow cytometry, we found that CXCR3 was rapidly internalized when T cells were incubated with IFN-γ-activated human saphenous vein endothelial cells (HSVEC), but not with resting HSVEC. Similar results were obtained using human CXCR3-transfected murine 300-19 B cells. CXCR3 down-regulation was significantly more pronounced when T cells were in contact with HSVEC than with their supernatants, suggesting that CXCR3 ligands were efficiently displayed on the surface of HSVEC. Using neutralizing mAbs to IFN-induced protein-10 (CXCL10), monokine induced by IFN-γ (CXCL9), and IFN-inducible T cell α chemoattractant (I-TAC; CXCL11), we found that even though I-TAC was secreted from IFN-γ-activated HSVEC to lower levels than IFN-induced protein-10 or the monokine induced by IFN-γ, it was the principal chemokine responsible for CXCR3 internalization. This correlated with studies using recombinant chemokines, which revealed that I-TAC was the most potent inducer of CXCR3 down-regulation and of transendothelial migration. Known inhibitors of chemokine-induced chemotaxis, such as pertussis toxin or wortmannin, did not reduce ligand-induced internalization, suggesting that a distinct signal transduction pathway mediates internalization. Our data demonstrate that I-TAC is the physiological inducer of CXCR3 internalization and suggest that chemokine receptor internalization occurs in physiological settings, such as leukocyte contact with an activated endothelium.
T Cell Epitopes of Human Myelin Oligodendrocyte Glycoprotein Identified in HLA-DR4 (DRB1*0401) Transgenic Mice Are Encephalitogenic and Are Presented by Human B Cells
Authors: Forsthuber Thomas G. , Shive Carey L. , Wienhold Wolfgang , de Graaf Katrien , Spack Edward G. , Sublett Robert , Melms Arthur , Kort Jens , Racke Michael K. , Weissert Robert 
Published: April 2014

AbstractMyelin oligodendrocyte glycoprotein (MOG) is an Ag present in the myelin sheath of the CNS thought to be targeted by the autoimmune T cell response in multiple sclerosis (MS). In this study, we have for the first time characterized the T cell epitopes of human MOG restricted by HLA-DR4 (DRB1*0401), an MHC class II allele associated with MS in a subpopulation of patients. Using MHC binding algorithms, we have predicted MOG peptide binding to HLA-DR4 (DRB1*0401) and subsequently defined the in vivo T cell reactivity to overlapping MOG peptides by testing HLA-DR4 (DRB1*0401) transgenic mice immunized with recombinant human (rh)MOG. The data indicated that MOG peptide 97–108 (core 99–107, FFRDHSYQE) was the immunodominant HLA-DR4-restricted T cell epitope in vivo. This peptide has a high in vitro binding affinity for HLA-DR4 (DRB1*0401) and upon immunization induced severe experimental autoimmune encephalomyelitis in the HLA-DR4 transgenic mice. Interestingly, the same peptide was presented by human B cells expressing HLA-DR4 (DRB1*0401), suggesting a role for the identified MOG epitopes in the pathogenesis of human MS.
Activation of βγ Subunits of Gi2 and Gi3 Proteins by Basic Secretagogues Induces Exocytosis Through Phospholipase Cβ and Arachidonate Release Through Phospholipase Cγ in Mast Cells
Authors: Ferry Xavier , Eichwald Virginie , Daeffler Laurent , Landry Yves 
Published: April 2014

Abstract
Mast cells are activated by Ag-induced clustering of IgE bound to FcεRI receptors or by basic secretagogues that stimulate pertussis toxin-sensitive heterotrimeric G proteins. The cell response includes the secretion of stored molecules, such as histamine, through exocytosis and of de novo synthesized mediators, such as arachidonate metabolites. The respective roles of G proteins α and βγ subunits as well as various types of phospholipase C (PLC) in the signaling pathways elicited by basic secretagogues remain unknown. We show that a specific Ab produced against the C-terminus of Gαi3 and an anti-recombinant Gαi2 Ab inhibited, with additive effects, both exocytosis and arachidonate release from permeabilized rat peritoneal mast cells elicited by the basic secretagogues mastoparan and spermine. A specific Ab directed against Gβγ dimers prevented both secretions. Anti-PLCβ Abs selectively prevented exocytosis. The selective phosphatidylinositol 3-kinase inhibitor LY 294002 prevented arachidonate release without modifying exocytosis. Gβγ coimmunoprecipitated with PLCβ and phosphatidylinositol 3-kinase. The anti-PLCγ1 and anti-phospholipase A2 Abs selectively blocked arachidonate release. Protein tyrosine phosphorylation was inhibited by anti-Gβγ Abs, LY294002, and anti PLCγ1 Abs. These data show that the early step of basic secretagogue transduction is common to both signaling pathways, involving βγ subunits of Gi2 and Gi3 proteins. Activated Gβγ interacts, on one hand, with PLCβ to elicit exocytosis and, on the other hand, with phosphatidylinositol 3-kinase to initiate the sequential activation of PLCγ1, tyrosine kinases, and phospholipase A2, leading to arachidonate release.
Primary Tumor Tissue Lysates Are Enriched in Heat Shock Proteins and Induce the Maturation of Human Dendritic Cells
Authors: Somersan Selin , Larsson Marie , Fonteneau Jean Francois , Basu Sreyashi , Srivastava Pramod , Bhardwaj Nina 
Published: April 2014

AbstractUpon exposure to lysates or supernatants of necrotic transformed cell lines, human dendritic cells (DCs) undergo maturation. In contrast, DCs exposed to apoptotic transformed cell lines or necrotic lysates of primary cells remain immature. Analysis of supernatants of necrotic transformed cell lines showed them to be enriched in the heat shock proteins (hsp)70 and gp96, in contrast to supernatants of primary cells. Likewise, cells from a variety of primary human tumors contained considerably higher levels of hsp than their normal autologous tissue counterparts. Of the majority of human tumors enriched in hsps (hsp70 and/or gp96), their corresponding lysates matured DCs. The maturation effect of tumor cell lysates was abrogated by treatment with boiling, proteinase K, and geldanamycin, an inhibitor of hsps, suggesting that hsps rather than endotoxin or DNA were the responsible factors. Supporting this idea, highly purified, endotoxin-depleted hsp70, induced DC maturation similar to that seen with standard maturation stimuli LPS and monocyte conditioned medium. These results suggest that the maturation activity inherent within tumor cells and lines is mediated at least in part by hsps. The release of hsps in vivo as a result of cell injury should promote immunity through the maturation of resident DCs.
Staining of Celiac Disease-Relevant T Cells by Peptide-DQ2 Multimers
Authors: Quarsten Hanne , McAdam Stephen N. , Jensen Tore , Arentz-Hansen Helene , Molberg Øyvind , Lundin Knut E. A. , Sollid Ludvig M. 
Published: April 2014

AbstractGluten-specific T cells in the small intestinal mucosa are thought to play a central role in the pathogenesis of celiac disease (CD). The vast majority of these T cells recognize gluten peptides when presented by HLA-DQ2 (DQA1*05/DQB1*02), a molecule which immunogenetic studies have identified as conferring susceptibility to CD. We have previously identified and characterized three DQ2-restricted gluten epitopes that are recognized by intestinal T cells isolated from CD patients, two of which are immunodominant. Because almost all of the gluten epitopes are restricted by DQ2, and because we have detailed knowledge of several of these epitopes, we chose to develop peptide-DQ2 tetramers as a reagent to further investigate the role of these T cells in CD. In the present study, stable soluble DQ2 was produced such that it contained leucine zipper dimerization motif and a covalently coupled peptide. We have made four different peptide-DQ2 staining reagents, three containing the gluten epitopes and one containing a DQ2-binding self-peptide that provides a negative control for staining. We show in this study that peptide-DQ2 when adhered to plastic specifically stimulates T cell clones and that multimers comprising these molecules specifically stain peptide-specific T cell clones and lines. Interestingly, T cell activation caused severe reduction in staining intensities obtained with the multimers and an Ab to the TCR. The problem of TCR down-modulation must be taken into consideration when using class II multimers to stain T cells that may have been recently activated in vivo.
Dendritic Cell-Derived IL-12 Is Not Required for the Generation of Cytotoxic, IFN-γ-Secreting, CD8+ CTL In Vivo
Authors: Wan Yonghong , Lu Lingmin , Bramson Jonathan L. , Baral Stefan , Zhu Qing , Pilon Andrew , Dayball Kelley 
Published: April 2014

Abstract
By using adoptive transfer of Ag-loaded bone marrow-derived dendritic cells (BMDC), we have established an in vivo model of CTL priming. Activation of CTL in these experiments required both CD4+ T cells and CD154, demonstrating that this model reflects CD4+ T cell-dependent dendritic cell (DC) licensing. Because IL-12 has been suggested to play an important role in CTL activation by DC, we examined the ability of BMDC to prime CTL in the complete absence of IL-12 using p40-deficient mice. We observed that the absence of IL-12 does not affect the phenotype or allostimulatory function of BMDC after in vitro maturation. Moreover, there was no difference in the ability of Ag-loaded DC to elicit CTL cytotoxicity, whether the Ag was delivered by virus infection or peptide pulsing. Equal frequencies of Ag-specific, IFN-γ-secreting CD8+ T cells developed in both wild-type and IL-12-deficient backgrounds. Finally, CTL generated in the IL-12-deficient environment were capable of protecting immunized mice against tumor challenge, demonstrating that these CTL were fully functional, despite the absence of IL-12 during the maturation process in vivo. These results indicate that IL-12 is not critical for the development of IFN-γ secreting, CD8+ T cells and that another mechanism must be used by licensed DC to prime and activate CTL.
Targeting of Tumor Cells for Human γδ T Cells by Nonpeptide Antigens
Authors: Kato Yu , Tanaka Yoshimasa , Miyagawa Fumi , Yamashita Seiji , Minato Nagahiro 
Published: April 2014

AbstractHuman Vγ2/Vδ2+ γδ T cells respond to low molecular-mass nonpeptide Ags in a γδ TCR-dependent manner. Although requirements of Ag presentation have remained controversial, we have indicated that specific responses of the primary γδ T cells to pamidronate were dependent on monocytic adherent cells for Ag presentation. Here, we show that human tumor cells can efficiently present aminobisphosphonate and pyrophosphomonoester compounds to γδ T cells, inducing specific proliferation and IFN-γ production. γδ TCR dependency of the response to Ag-pulsed tumor cells was confirmed by using a Jurkat line transfected with a Vγ2/Vδ2 γδ TCR. Furthermore, γδ T cells exhibited markedly enhanced cytotoxicity against the Ag-pulsed tumor cells as compared with untreated tumor cells. Survey of a number of human tumor cell lines of different origins revealed that the majority of them became susceptible for γδ T cell-mediated cytotoxicity following the Ag pulsing except for breast cancer lines so far examined, while normal PHA blast cells remained resistant. The results not only imply a unique mode of nonpeptide Ag recognition by human γδ T cells but also may provide a novel strategic clue for immunotherapy of human malignancy.