bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Characterization of B Cell Clonal Expansions in the Liver of Chronically Hepatitis C Virus-Infected Patients
Authors: Racanelli Vito , Sansonno Domenico , Piccoli Claudia , D’Amore Francesca Paola , Tucci Felicia Anna , Dammacco Franco 
Published: April 2014

Abstract
PCR DNA amplification of IgH genes was performed on liver biopsy samples of 42 unselected hepatitis C virus (HCV)-positive patients. Genotypic analysis and signal amplification by branched DNA were used to characterize and quantitate HCV RNA genomic sequences. Intraportal lymphoid follicle-like structures were isolated from surrounding hepatocytes by microdissection technique. IgH VDJ PCR products were cloned and sequenced. IgH VDJ gene rearrangements were detected in the liver of 26 (62%) patients. Unequivocal monoclonal or oligoclonal patterns of B cell expansions were found in 14 (33.3%) and 12 (28.6%) patients, respectively. Patients with intrahepatic B cell monoclonal expansions showed liver HCV RNA levels higher than those with oligoclonal or polyclonal features (1106.4 ± 593.5 vs 677.3 ± 424.3 vs 406.2 ± 354.3 pg HCV RNA/g tissue; p = 0.048 and p = 0.001, respectively). Although a single dominant band was obtained with total DNA, characterization of DNA recovered from intraportal inflammatory aggregates resulted in the detection of multiple IgH VDJ gene rearrangements, pointing to an oligoclonal pattern of lymphoproliferation. Cloning and sequence analyses showed that B cell clonalities were differently distributed in adjacent portal tracts of the same liver area. In addition, HCV RNA genomic sequences could be consistently amplified from each of the portal inflammatory aggregates examined. These data support the concept that in chronic HCV infection the intrahepatic B cell repertoire is frequently clonally restricted and that HCV may have a direct role in sustaining in situ B cell proliferation.
Positive Regulatory Role of IL-12 in Macrophages and Modulation by IFN-γ
Authors: Grohmann Ursula , Belladonna Maria L. , Vacca Carmine , Bianchi Roberta , Fallarino Francesca , Orabona Ciriana , Fioretti Maria C. , Puccetti Paolo 
Published: April 2014

Abstract
Similar to myeloid dendritic cells, murine macrophages and macrophage cell lines were found to express a surface receptor for IL-12. As a result, peritoneal macrophages could be primed by IL-12 to present an otherwise poorly immunogenic tumor peptide in vivo. Using binding analysis and RNase protection assay, we detected a single class of high affinity IL-12 binding sites (Kd of ∼35 pM) whose number per cell was increased by IFN-γ via up-regulation of receptor subunit expression. Autocrine production of IL-12 was suggested to be a major effect of IL-12 on macrophages when the cytokine was tested alone or after priming with IFN-γ in vitro. In vivo, combined treatment of macrophages with IFN-γ and IL-12 resulted in synergistic effects on tumor peptide presentation. Therefore, our findings suggest a general and critical role of IL-12 in potentiating the accessory function of myeloid APC.
Regulation of Dendritic Cell Recruitment into Resting and Inflamed Airway Epithelium: Use of Alternative Chemokine Receptors as a Function of Inducing Stimulus
Authors: Stumbles Philip A. , Strickland Deborah H. , Pimm Carolyn L. , Proksch Stephen F. , Marsh Amanda M. , McWilliam Andrew S. , Bosco Anthony , Tobagus Iriani , Thomas Jennifer A. , Napoli Sylvia , Proudfoot Amanda E. I. , Wells Timothy N. C. , Holt Patrick G. 
Published: April 2014

Abstract
Dendritic cells (DC) were purified by flow cytometry from rat tracheal mucosa; they exhibited the phenotypic characteristics of immature DC including high endocytic activity, low CD80/86 expression, and in vitro responsiveness to a broad range of CC chemokines. Daily treatment of adult rats with the selective CCR1 and CCR5 antagonist Met-RANTES reduced baseline numbers of tracheal intraepithelial DC by 50–60%, and pretreatment of animals with Met-RANTES before inhalation of aerosol containing heat-killed bacteria abolished the rapid DC influx into the epithelium that occurred in untreated controls, implicating CCR1 and CCR5 and their ligands in recruitment of immature DC precursors into resting airway tissues and during acute bacterial-induced inflammation. Comparable levels of DC recruitment were observed during airway mucosal Sendai virus infection and after aerosol challenge of sensitized animals with the soluble recall Ag OVA. However, Met-RANTES did not affect these latter responses, indicating the use of alternative chemokine receptors/ligands for DC recruitment, or possibly attraction of different DC subsets, depending on the nature of the eliciting stimulus.
B-Myb Overexpression Results in Activation and Increased Fas/Fas Ligand-Mediated Cytotoxicity of T and NK Cells
Authors: Powzaniuk Mark A. , Trotta Rossana , Loza Matthew J. , Harth Amy , Iozzo Renato V. , Eisenlohr Lawrence C. , Perussia Bice , Calabretta Bruno 
Published: April 2014

Abstract
The human B-myb gene encodes a transcriptional regulator that plays an important role in cell cycle progression, differentiation, and survival. To assess the in vivo role of B-myb, we investigated the phenotype of mouse transgenic lines in which B-Myb expression in lymphoid tissues was driven by the LCK proximal promoter. Overexpression of B-Myb had no measurable effect on the subsets of splenic and thymic lymphocytes, but was associated with increased expression of Fas ligand in NK and T cells. B-Myb-overexpressing splenocytes expressed higher IFN-γ levels and contained higher percentages of cytokine-producing cells than wild-type (wt) splenocytes, as detected by Western blot analysis and ELISPOT assays, respectively. Ex vivo-cultured transgenic thymocytes and splenocytes had decreased survival compared with the corresponding cells from wt mice, possibly dependent on increased expression of Fas ligand. In addition, Fas ligand-dependent cytotoxicity of transgenic T and NK cells was significantly higher than that mediated by their wt counterparts. Together, these results indicate that B-Myb overexpression results in T and NK cell activation and increased cytotoxicity. Therefore, in addition to its well-established role in proliferation and differentiation, B-myb also appears to be involved in activation of NK and T cells and in their regulation of Fas/Fas ligand-mediated cytotoxicity
Unequal VH Gene Rearrangement Frequency Within the Large VH7183 Gene Family Is Not Due to Recombination Signal Sequence Variation, and Mapping of the Genes Shows a Bias of Rearrangement Based on Chromosomal Location
Authors: Williams G. Stuart , Martinez Alan , Montalbano Alina , Tang Alan , Mauhar America , Ogwaro Kisani M. , Merz Denise , Chevillard Christophe , Riblet Roy , Feeney Ann J. 
Published: April 2014

AbstractMuch of the nonrandom usage of V, D, and J genes in the Ab repertoire is due to different frequencies with which gene segments undergo V(D)J rearrangement. The recombination signal sequences flanking each segment are seldom identical with consensus sequences, and this natural variation in recombination signal sequence (RSS) accounts for some differences in rearrangement frequencies in vivo. Here, we have sequenced the RSS of 19 individual VH7183 genes, revealing that the majority have one of two closely related RSS. One group has a consensus heptamer, and the other has a nonconsensus heptamer. In vitro recombination substrate studies show that the RSS with the nonconsensus heptamer, which include the frequently rearranging 81X, rearrange less well than the RSS with the consensus heptamer. Although 81X differs from the other 7183-I genes at three positions in the spacer, this does not significantly increase its recombination potency in vitro. The rearrangement frequency of all members of the family was determined in μMT mice, and there was no correlation between the in vitro recombination potential and VH gene rearrangement frequency in vivo. Furthermore, genes with identical RSS rearrange at different frequencies in vivo. This demonstrates that other factors can override differences in RSS potency in vivo. We have also determined the gene order of all VH7183 genes in a bacterial artificial chromosome contig and show that most of the frequently rearranging genes are in the 3′ half of the region. This suggests that chromosomal location plays an important role in nonrandom rearrangement of the VH7183 genes.
11β-Hydroxysteroid Dehydrogenase Type 1 Is Induced in Human Monocytes upon Differentiation to Macrophages
Authors: Thieringer Rolf , Le Grand Cheryl B. , Carbin Linda , Cai Tian-Quan , Wong Birming , Wright Samuel D. , Hermanowski-Vosatka Anne 
Published: April 2014

Abstract
11β-hydroxysteroid dehydrogenases (11β-HSD) perform prereceptor metabolism of glucocorticoids through interconversion of the active glucocorticoid, cortisol, with inactive cortisone. Although the immunosuppressive and anti-inflammatory activities of glucocorticoids are well documented, the expression of 11β-HSD enzymes in immune cells is not well understood. Here we demonstrate that 11β-HSD1, which converts cortisone to cortisol, is expressed only upon differentiation of human monocytes to macrophages. 11β-HSD1 expression is concomitant with the emergence of peroxisome proliferator activating receptor γ, which was used as a surrogate marker of monocyte differentiation. The type 2 enzyme, 11β-HSD2, which converts cortisol to cortisone, was not detectable in either monocytes or cultured macrophages. Incubation of monocytes with IL-4 or IL-13 induced 11β-HSD1 activity by up to 10-fold. IFN-γ, a known functional antagonist of IL-4 and IL-13, suppressed the induction of 11β-HSD1 by these cytokines. THP-1 cells, a human macrophage-like cell line, expressed 11β-HSD1 and low levels of 11β-HSD2. The expression of 11β-HSD1 in these cells is up-regulated 4-fold by LPS. In summary, we have shown strong expression of 11β-HSD1 in cultured human macrophages and THP-1 cells. The presence of the enzyme in these cells suggests that it may play a role in regulating the immune function of these cells.
Dendritic Cells Recruitment and In Vivo Priming of CD8+ CTL Induced by a Single Topical or Transepithelial Immunization Via the Buccal Mucosa with Measles Virus Nucleoprotein
Authors: Etchart Nathalie , Desmoulins Pierre-Olivier , Chemin Karine , Maliszewski Charles , Dubois Bertrand , Wild Fabian , Kaiserlian Dominique 
Published: April 2014

AbstractThe buccal mucosa, a prototype of pluristratified mucosal epithelia, contains a network of directly accessible class II+ epithelial dendritic cells (DC), similar to skin Langerhans cells. We showed that a single buccal immunization with measles virus nucleoprotein (NP), by either topical application onto or intradermal injection in the buccal mucosa, induced in vivo priming of protective class I-restricted specific CD8+ CTL. Both routes of immunization with NP induced a rapid recruitment of DC into the mucosa, which peaked at 2 h and decreased by 24 h. Treatment of mice with Flt3 ligand resulted in an increased number of DC in the buccal mucosa and enhanced the frequency of IFN-γ-producing NP-specific effectors and the NP-specific CTL response generated after buccal immunization with NP. Finally, NP-pulsed bone marrow-derived DC induced NP-specific IFN-γ-producing cells upon adoptive transfer to naive mice. These data demonstrate that a viral protein delivered to DC of the buccal mucosa induces in vivo priming of protective anti-viral CD8+ CTL.
The Distinct Roles of T Cell-Derived Cytokines and a Novel Follicular Dendritic Cell-Signaling Molecule 8D6 in Germinal Center-B Cell Differentiation
Authors: Zhang Xin , Li Li , Jung Jaeho , Xiang Shulin , Hollmann Christiane , Choi Yong Sung 
Published: April 2014

Abstract
Germinal center-B (GC-B) cells differentiate into memory B cells and plasma cells (PC) through interaction with T cells and follicular dendritic cells (FDC). Activated T cell and FDC play distinct roles in this process. The detailed kinetic experiments revealed that cytokines secreted by activated T cells determined the pathway of GC-B cell differentiation. IL-4 directs GC-B cells to differentiate into memory B cells, whereas IL-10 steers them into PC. FDC/HK cells do not direct either pathway, but provide signals for proliferation of GC-B cells. A novel FDC-signaling molecule 8D6 (FDC-SM-8D6) produced by FDC augments PC generation in the GC. FDC-SM-8D6-specific mAb blocked PC generation and IgG secretion but not memory B cell proliferation. COS cells expressing FDC-SM-8D6 enhanced GC-B cell proliferation and Ab secretion, which was blocked by mAb 8D6. In the cultures with B cell subsets, PC generation was inhibited by mAb 8D6 in the cultures with CD27+ B cells but not in the culture with CD27− B cells, suggesting that CD27+ PC precursor is the specific target of FDC-SM-8D6 stimulation.
Critical Role for IL-4 in the Development of Transplant Arteriosclerosis in the Absence of CD40-CD154 Costimulation
Authors: Ensminger Stephan M. , Spriewald Bernd M. , Sorensen Henrik V. , Witzke Oliver , Flashman Emily G. , Bushell Andrew , Morris Peter J. , Rose Marlene L. , Rahemtulla Amin , Wood Kathryn J. 
Published: April 2014

Abstract
Blockade of the CD40-CD154 pathway can inhibit CD4+ T cell activation but is unable to prevent immune responses mediated by CD8+ T cells. However, even in the absence of CD8+ T cells, inhibition of the CD40-CD154 pathway is insufficient to prevent the development of transplant arteriosclerosis. This study investigated the mechanisms of transplant arteriosclerosis in the absence of the CD40 pathway. C57BL/6 CD40−/− (H2b) recipients were transplanted with MHC-mismatched BALB/c (H2d) aortas. Transplant arteriosclerosis was evident in both CD40−/− and CD40+/− mice (intimal proliferation was 59 ± 5% for CD40−/− mice vs 58 ± 4% for CD40+/− mice) in the presence or absence of CD8+ T cells (intimal proliferation was 46 ± 7% for CD40−/− anti-CD8-treated mice vs 50 ± 10% for CD40+/− anti-CD8-treated mice), confirming that CD8+ T cells are not essential effector cells for the development of this disease. In CD40−/− recipients depleted of CD8+ T cells, the number of eosinophils infiltrating the graft was markedly increased (109 ± 24 eosinophils/grid for CD40−/− anti-CD8-treated mice vs 28 ± 7 for CD40+/− anti-CD8-treated mice). The increased presence of eosinophils correlated with augmented intragraft production of IL-4. To test the hypothesis that IL-4 was responsible for the intimal proliferation, CD8 T cell-depleted CD40−/− recipients were treated with anti-IL-4 mAb. This resulted in significantly reduced eosinophil infiltration into the graft (12 ± 5 eosinophils/grid for CD40−/− anti-CD8+, anti-IL-4-treated mice vs 109 ± 24 for CD40−/− anti-CD8-treated mice), intragraft eotaxin, CCR3 mRNA production, and the level of intimal proliferation (18 ± 5% for CD40−/− anti-CD8+-, anti-IL-4-treated mice vs 46 ± 7% for CD40−/− anti-CD8-treated mice). In conclusion, elevated intragraft IL-4 production results in an eosinophil infiltrate and is an important mechanism for CD8+ T cell-independent transplant arteriosclerosis in the absence of CD40-CD154 costimulation.
T Cell Epitope Mapping of the Smith Antigen Reveals That Highly Conserved Smith Antigen Motifs Are the Dominant Target of T Cell Immunity in Systemic Lupus Erythematosus
Authors: Talken Beth L. , Schäfermeyer Kim R. , Bailey Craig W. , Lee David R. , Hoffman Robert W. 
Published: April 2014

AbstractB cell and T cell immunity to the Smith Ag (Sm) is a characteristic feature of systemic lupus erythematosus (SLE). We have shown that T cell immunity against Sm can be detected in SLE patients, and that T and B cell immunity against Sm are linked in vivo. TCR usage by Sm-reactive T cells is highly restricted and characteristic of an Ag-driven immune response. Sm is a well-characterized complex Ag consisting of proteins B1, B2, D1, D2, D3, E, F, and G. A unique feature of all Sm proteins is the presence of homologous motifs, Sm motif 1 and Sm motif 2. We used limiting dilution cloning and synthetic peptide Ags to characterize the human T cell immune response against Sm in seven SLE patients. We sought to determine the precise antigenic peptides recognized, the common features of antigenic structure recognized, and the evolution of the T cell response against Sm. We found there was a highly restricted set of Sm self-peptides recognized by T cells, with three epitopes on Sm-B and two epitopes on Sm-D. We found that T cell immunity against Sm-B and Sm-D was encoded within the highly conserved Sm motif 1 and Sm motif 2, and that immunity against these epitopes appeared stable. The present study supports the concept that T cell immunity to Sm is an Ag-driven immune response directed against a highly restricted set of self-peptides, encoded within Sm motif 1 and Sm motif 2, that is shared among all Sm proteins.
Therapeutic Alteration of Insulin-Dependent Diabetes Mellitus Progression by T Cell Tolerance to Glutamic Acid Decarboxylase 65 Peptides In Vitro and In Vivo
Authors: Wilson Stephen S. , White Todd C. , DeLuca Dominick 
Published: April 2014

Abstract
We have reported previously that nonobese diabetic (NOD) fetal pancreas organ cultures lose the ability to produce insulin when maintained in contact with NOD fetal thymus organ cultures (FTOC). Initial studies indicated that exposure to glutamic acid decarboxylase (GAD65) peptides in utero resulted in delay or transient protection from insulin-dependent diabetes mellitus (IDDM) in NOD mice. We also found that exposure of young adult NOD mice to the same peptides could result in acceleration of the disease. To more closely examine the effects of early and late exposure to diabetogenic Ags on T cells, we applied peptides derived from GAD65 (GAD AA 246–266, 509–528, and 524–543), to our “in vitro IDDM” (ivIDDM) model. T cells derived from NOD FTOC primed during the latter stages of organ culture, when mature T cell phenotypes are present, had the ability to proliferate to GAD peptides. ivIDDM was exacerbated under these conditions, suggesting that GAD responsiveness correlates with the ivIDDM phenotype, and parallels the acceleration of IDDM we had seen in young adult NOD mice. When GAD peptides were present during the initiation of FTOC, GAD proliferative responses were inhibited, and ivIDDM was reduced. This result suggests that tolerance to GAD peptides may reduce the production of diabetogenic T cells or their capacity to respond, as suggested by the in utero therapies studied in NOD mice.
Lymphotactin Expression by Engineered Myeloma Cells Drives Tumor Regression: Mediation by CD4+ and CD8+ T Cells and Neutrophils Expressing XCR1 Receptor
Authors: Cairns Chantelle M. , Gordon John R. , Li Fang , Baca-Estrada Maria E. , Moyana Terence , Xiang Jim 
Published: April 2014

Abstract
The C chemokine lymphotactin has been characterized as a T cell chemoattractant both in vitro and in vivo. To determine whether lymphotactin expression within tumors could influence tumor growth, we transfected an expression vector for lymphotactin into SP2/0 myeloma cells and tested their ability to form tumors in BALB/c and nude mice. Transfection did not alter cell growth in vitro. Whereas SP2/0 cells gave rise to a 100% tumor incidence, lymphotactin-expressing SP2/0-Lptn tumors invariably regressed in BALB/c mice and became infiltrated with CD4+ and CD8+ T cells and neutrophils. Regression of the SP2/0-Lptn tumors was associated with a type 1 cytokine response and dependent on both CD4+ and CD8+ T cells, but not NK cells. Both SP2/0 and SP2/0-Lptn tumors grew in nude mice, but growth of the latter tumors was retarded and associated with heavy neutrophil responses; this retardation of SP2/0-Lptn tumor growth was reversed by neutrophil depletion of the mice. Our data also indicate that mouse neutrophils express the lymphotactin receptor XCR1 and that lymphotactin specifically chemoattracts these cells in vitro. Thus, lymphotactin has natural adjuvant activities that may augment antitumor responses via effects on both T cells and neutrophils and thereby could be important in gene transfer immunotherapies for some cancers.
Nitric Oxide Inhibits the Transcription Repressor Yin-Yang 1 Binding Activity at the Silencer Region of the Fas Promoter: A Pivotal Role for Nitric Oxide in the Up-Regulation of Fas Gene Expression in Human Tumor Cells
Authors: Garbán Hermes J. , Bonavida Benjamin 
Published: April 2014

Abstract
NO has been increasingly implicated in control of the transcriptional machinery and serves as an intracellular second messenger to modify gene expression. We have demonstrated that NO up-regulated Fas receptor expression in ovarian carcinoma cell lines, albeit the mechanism involved is not known. Thus, we hypothesized that NO, directly or indirectly, may modify the transcriptional machinery that is responsible for the increased expression of the Fas gene. We examined the effect of NO on Fas gene expression using a Fas promoter-driven luciferase reporter system. Transient transfection of AD10 cells with pGL-3-FasP demonstrated that the IFN-γ-dependent NO generation increases the trans-activation of the Fas promoter, and this increase was blocked by the NOS inhibitor (NG-monomethyl-l-arginine), but could be restored by the addition of the NO donor S-nitroso-N-acetylpenicillamine. Systematic deletion of the Fas promoter revealed that the functional region responsible for the NO-mediated effect was located at the silencer region, suggesting that NO may be responsible for the disruption of a repressor mechanism. We demonstrate that NO up-regulates the expression of the Fas receptor on AD10 cells via the specific inactivation of the transcription repressor yin-yang 1 DNA binding activity to the silencer region of the Fas promoter. These findings reveal a new mechanism of NO-mediated gene regulation by interfering with a repressor transcription factor at the silencer region of the Fas promoter.
Role of CD28-B7 Interactions in Generation and Maintenance of CD8 T Cell Memory
Authors: Suresh M. , Whitmire Jason K. , Harrington Laurie E. , Larsen Christian P. , Pearson Thomas C. , Altman John D. , Ahmed Rafi 
Published: April 2014

Abstract
Although the role of CD28-B7 interaction in the activation of naive T cells is well established, its importance in the generation and maintenance of T cell memory is not well understood. In this study, we examined the requirement for CD28-B7 interactions in primary T cell activation and immune memory. Ag-specific CD8 T cell responses were compared between wild-type (+/+) and CD28-deficient (CD28−/−) mice following an acute infection with lymphocytic choriomeningitis virus (LCMV). During the primary response, there was a substantial activation and expansion of LCMV-specific CD8 T cells in both +/+ and CD28−/− mice. However, the magnitude of the primary CD8 T cell response to both dominant and subdominant LCMV CTL epitopes was ∼2- to 3-fold lower in CD28−/− mice compared with +/+ mice; the lack of CD28-mediated costimulation did not lead to preferential suppression of CD8 T cell responses to the weaker subdominant epitopes. As seen in CD28−/− mice, blockade of B7-mediated costimulation by CTLA4-Ig treatment of +/+ mice also resulted in a 2-fold reduction in the anti-LCMV CD8 T cell responses. Loss of CD28/B7 interactions did not significantly affect the generation and maintenance of CD8 T cell memory; the magnitude of CD8 T cell memory was ∼2-fold lower in CD28−/− mice as compared with +/+ mice. Further, in CD28−/− mice, LCMV-specific memory CD8 T cells showed normal homeostatic proliferation in vivo and also conferred protective immunity. Therefore, CD28 signaling is not necessary for the proliferative renewal and maintenance of memory CD8 T cells.