bluuebunny/crossref_metadata_2025_split huggingface dataset:
STAT4 Expression in Human T Cells Is Regulated by DNA Methylation but Not by Promoter Polymorphism
Authors: Shin Hyun-Jin , Park Hye-Young , Jeong Sook-Jung , Park Heung-Woo , Kim Yoon-Keun , Cho Sang-Heon , Kim You-Young , Cho Mi-La , Kim Ho-Youn , Min Kyung-Up , Lee Chang-Woo 
Published: April 2014

AbstractSTAT4, which plays a pivotal role in Th1 immune responses, enhances IFN-γ transcription in response to the interaction of IL-12 with the IL-12R. Mice deficient in STAT4 lack IL-12-induced IFN-γ production and Th1 differentiation and display a predominantly Th2 phenotype. Although these findings indicate that STAT4 expression levels are important for the development of cytokine-producing Th1 cells, the transcriptional and posttranscriptional mechanisms regulating STAT4 expression are unknown. We sought to identify and characterize the transcriptional regulatory elements in the promoter region of the human STAT4 gene. We found that disruption of multiple transcriptional regions covering the CREB, OCT1, and SP1 motifs significantly reduced STAT4 promoter activity. However, genomic DNA isolated from 91 patients with asthma or rheumatoid arthritis showed no evidence of mutations in the defined STAT4 essential promoter region. The 5′ flanking region of the promoter was found to contain a −149A/G change in ∼20–35% of patients, but this polymorphism had no effect on promoter activity. Interestingly, STAT4 expression was drastically increased in human T cells following treatment with a DNA methyltransferase inhibitor, and truncation of methylation sites in the proximal regulatory elements of the STAT4 promoter markedly enhanced transcriptional activity. Thus, our findings provide molecular insight into STAT4 expression and suggest that, in human T cells, STAT4 expressional regulation is associated with DNA hypermethylation, but not promoter polymorphisms.
Sphingosine-1-Phosphate Agonists Increase Macrophage Homing, Lymphocyte Contacts, and Endothelial Junctional Complex Formation in Murine Lymph Nodes
Authors: Singer Irwin I. , Tian Min , Wickham L. Alexandra , Lin Jeffrey , Matheravidathu Scaria S. , Forrest Michael J. , Mandala Suzanne , Quackenbush Elizabeth J. 
Published: April 2014

Abstract
The sphingosine-1-phosphate (S1P) receptor agonist, phosphorylated FTY720 (FTY-P), causes lymphopenia, lymphocyte sequestration in mesenteric lymph nodes (MLNs), and immunosuppression. Using multiple techniques to analyze MLN cells harvested from mice treated with S1P receptor agonists, we saw a redistribution of lymphocytes out of nodal sinuses and an expansion of follicles. Although changes in circulating monocytes were not observed with overnight exposure to FTY720, we saw a significant increase in S1P receptor 1 (S1P1)-expressing CD68+ macrophages in subcapsular sinuses of FTY-P-treated MLNs. This was confirmed by quantitative analysis of F4/80+ cells in MLN suspensions. The sinus volume and number of S1P1-positive cells within sinuses were also increased by FTY-P. High endothelial venules and lymphatic endothelium expressed high levels of S1P1, and treatment with FTY-P resulted in intense staining and colocalization of CD31, β-catenin, and zona occludens 1 in junctions between sinus cells. Transmission electron microscopy showed that FTY-P greatly reduced lymphocyte microvilli and increased cell-cell contacts in the parenchyma. Immunoelectron microscopy revealed that intranodal lymphocytes lacked surface expression of S1P1, whereas S1P1 was evident on the surface and within the cytoplasm of macrophages, endothelial cells, and stromal cells. This subcellular pattern of intranodal receptor distribution was unchanged by treatment with FTY-P. We conclude that S1P1 agonists have profound effects on macrophages and endothelial cells, in addition to inducing lymphopenia.
Helicobacter pyloriActivates NF-κB via the Alternative Pathway in B Lymphocytes
Authors: Ohmae Tomoya , Hirata Yoshihiro , Maeda Shin , Shibata Wataru , Yanai Ayako , Ogura Keiji , Yoshida Haruhiko , Kawabe Takao , Omata Masao 
Published: April 2014

AbstractHelicobacter pylori causes various gastroduodenal diseases including gastric MALT lymphoma, but the mechanism underlying H. pylori-induced carcinogenesis is not known. The alternative pathway for NF-κB activation, which involves the processing of NF-κB2/p100 to p52, has been implicated in lymphocyte survival, attenuated apoptosis, and secondary lymphoid tissue development. In this study, we investigated H. pylori-induced activation of NF-κB through the alternative pathway in B lymphocytes. In immunoblot and EMSA, H. pylori induced NF-κB2/p100 processing to p52 and subsequent nuclear accumulation in IM-9 (human B cell line) cells and human peripheral blood B cells, but not in AGS (human gastric cancer cell line) cells. The activation of the alternative pathway was LPS-dependent but not cag pathogenicity island-dependent. Alternative pathway activation by H. pylori was associated with attenuated apoptosis. The expression levels of B lymphocyte chemoattractant, EBI-1 ligand chemokine, and stromal cell-derived factor-1α mRNAs were up-regulated in cocultured human B cells and in infected human gastric mucosa. In the infected mucosa, NF-κB2/p100 and p52 were detected immunohistochemically in the cytoplasm and nuclear compartments of lymphocytes, but not in epithelial cells. In summary, H. pylori activates the alternative NF-κB pathway in B lymphocytes. The effects on chemokine production and antiapoptosis mediated by H. pylori-induced processing of NF-κB2/p100 to p52 may drive lymphocytes to acquire malignant potential.
Apoptosis of Antigen-Specific T Lymphocytes upon the Engagement of CD8 by Soluble HLA Class I Molecules Is Fas Ligand/Fas Mediated: Evidence for the Involvement of p56lck, Calcium Calmodulin Kinase II, and Calcium-Independent Protein Kinase C Signaling Pathways and for NF-κB and NF-AT Nuclear Translocation
Authors: Contini Paola , Ghio Massimo , Merlo Andrea , Poggi Alessandro , Indiveri Francesco , Puppo Francesco 
Published: April 2014

AbstractThe binding of soluble HLA class I (sHLA-I) molecules to CD8 on EBV-specific CTL induced up-regulation of Fas ligand (FasL) mRNA and consequent sFasL protein secretion. This, in turn, triggered CTL apoptosis by FasL/Fas interaction. Molecular analysis of the biochemical pathways responsible for FasL up-regulation showed that sHLA-I/CD8 interaction firstly induced the recruitment of src-like p56lck and syk-like Zap-70 protein tyrosine kinases (PTK). Interestingly, p59fyn was activated upon the engagement of CD3/TCR complex but not upon the interaction of sHLA-I with CD8. In addition, sHLA-I/CD8 interaction, which is different from signaling through the CD3/TCR complex, did not induce nuclear translocation of AP-1 protein complex. These findings suggest that CD8− and CD3/TCR-mediated activating stimuli can recruit different PTK and transcription factors. Indeed, the engagement of CD8 by sHLA-I led to the activation of Ca2+ calmodulin kinase II pathway, which eventually was responsible for the NF-AT nuclear translocation. In addition, we found that the ligation of sHLA-I to CD8 recruited protein kinase C, leading to NF-κB activation. Both NF-AT and NF-κB were responsible for the induction of FasL mRNA and consequent CTL apoptosis. Moreover, FasL up-regulation and CTL apoptotic death were down-regulated by pharmacological specific inhibitors of Ca2+/calmodulin/calcineurin and Ca2+-independent protein kinase C signaling pathways. These findings clarify the intracellular signaling pathways triggering FasL up-regulation and apoptosis in CTL upon sHLA-I/CD8 ligation and suggest that sHLA-I molecules can be proposed as therapeutic tools to modulate immune responses.
The Inhibition of Autoreactive T Cell Functions by a Peptide Based on the CDR1 of an Anti-DNA Autoantibody Is via TGF-β-Mediated Suppression of LFA-1 and CD44 Expression and Function
Authors: Sela Uri , Mauermann Nora , Hershkoviz Rami , Zinger Heidy , Dayan Molly , Cahalon Liora , Liu Jian Ping , Mozes Edna , Lider Ofer 
Published: April 2014

AbstractSystemic lupus erythematosus (SLE), which is characterized by the increased production of autoantibodies and defective T cell responses, can be induced in mice by immunization with a human anti-DNA mAb that expresses a major Id, designated 16/6Id. A peptide based on the sequence of the CDR1 of the 16/6Id (human CDR1 (hCDR1)) ameliorated the clinical manifestations of SLE and down-regulated, ex vivo, the 16/6Id-induced T cell proliferation. In this study, we examined the mechanism responsible for the hCDR1-induced modulation of T cell functions related to the pathogenesis of SLE. We found that injection of hCDR1 into BALB/c mice concomitant with their immunization with 16/6Id resulted in a marked elevation of TGF-β secretion 10 days later. Addition of TGF-β suppressed the 16/6Id-stimulated T cell proliferation similarly to hCDR1. In addition, we provide evidence that one possible mechanism underlying the hCDR1- and TGFβ-induced inhibition of T cell proliferation is by down-regulating the expression, and therefore the functions, of a pair of key cell adhesion receptors, LFA-1 (αLβ2) and CD44, which operate as accessory molecules in mediating APC-T cell interactions. Indeed, T cells of mice treated with hCDR1 showed a TGF-β-induced suppression of adhesion to the LFA-1 and CD44 ligands, hyaluronic acid and ICAM-1, respectively, induced by stromal cell-derived factor-1α and PMA. The latter suppression is through the inhibition of ERK phosphorylation. Thus, the down-regulation of SLE-associated responses by hCDR1 treatment may be due to the effect of the up-regulated TGF-β on the expression and function of T cell adhesion receptors and, consequently, on T cell stimulation, adhesion, and proliferation.
Anti-CD25 Antibody Enhancement of Vaccine-Induced Immunogenicity: Increased Durable Cellular Immunity with Reduced Immunodominance
Authors: Moore Anne C. , Gallimore Awen , Draper Simon J. , Watkins Katherine R. , Gilbert Sarah C. , Hill Adrian V. S. 
Published: April 2014

AbstractAn efficacious vaccine strategy must be capable of inducing strong responses of an appropriate phenotype that are long lasting and sufficiently broad to prevent pathogen escape mechanisms. In the present study, we use anti-CD25 mAb to augment vaccine-induced immunity in mice. We demonstrate that coformulation of Ab and poxviral- or adenoviral-vectored vaccines induces significantly increased T cell responses to a malaria Ag; prior anti-CD25 Ab administration was not required for this effect. Furthermore, this vaccination approach subverts immunodominant epitope hierarchies by enhancing responses to subdominant epitopes induced by recombinant modified vaccinia virus Ankara immunization. Administration of anti-CD25 with a vaccine also induces more durable immunity compared with vaccine alone; significantly higher T cell responses were observed 100 days after the primary immunization. Enhanced immunogenicity is observed for multiple vaccine types with enhanced CD4+ and CD8+ T cell responses induced by bacillus Calmette-Guérin and a recombinant subunit protein vaccine to hepatitis B virus and with multiple Ags of tumor, viral, bacterial, and parasitic origin. Vaccine strategies incorporating anti-CD25 lead to improved protection against pre-erythrocytic malaria challenge. These data underpin new strategies for the design and development of more efficacious vaccines in clinical settings.
Early Kinetic Window of Target T Cell Susceptibility to CD25+ Regulatory T Cell Activity
Authors: Sojka Dorothy K. , Hughson Angela , Sukiennicki Teresa L. , Fowell Deborah J. 
Published: April 2014

Abstract
Peripheral tolerance is maintained in part by thymically derived CD25+CD4+ T cells (regulatory T cells (Tregs)). Their mechanism of action has not been well characterized. Therefore, to get a better understanding of Treg action, we investigated the kinetics of murine Treg activity in vitro. Tregs were suppressive within a surprisingly narrow kinetic window: necessary and sufficient only in the first 6–10 h of culture. Visualization of this time frame, using a sensitive single-cell assay for IL-2, revealed the early elaboration of target cell IL-2 producers in the first 6 h despite the presence of CD25+CD4+ Tregs. However, after 6 h, a rapid rise in the number of IL-2 producers in the absence of Tregs was dramatically abrogated by the presence of Tregs. Importantly, the timing of suppression was dictated by the kinetics of target T cell activation suggesting that early target T cell signals may alter susceptibility to suppression. Modulating target T cell activation signals with provision of CD28, IL-2, or high Ag dose all abrogated suppression of proliferation late in culture. However, only CD28 signals enabled target T cells to resist the early Treg-induced down-regulation of IL-2. Therefore the quality of early target T cell activation signals, in particular engagement of CD28, represents an important control point in the balance between vulnerability and resistance to Treg suppression.
A Novel Mucosal Vaccine Based on Live Lactococci Expressing E7 Antigen and IL-12 Induces Systemic and Mucosal Immune Responses and Protects Mice against Human Papillomavirus Type 16-Induced Tumors
Authors: Bermúdez-Humarán Luis G. , Cortes-Perez Naima G. , Lefèvre François , Guimarães Valeria , Rabot Sylvie , Alcocer-Gonzalez Juan M. , Gratadoux Jean-Jacques , Rodriguez-Padilla Cristina , Tamez-Guerra Reyes S. , Corthier Gérard , Gruss Alexandra , Langella Philippe 
Published: April 2014

Abstract
Current strategies to prevent or treat human papillomavirus type 16 (HPV-16) infection are promising, but remain costly. More economical but efficient vaccines are thus needed. In this study, we evaluated the protective effects of mucosally coadministered live Lactococcus lactis strains expressing cell wall-anchored E7 Ag and a secreted form of IL-12 to treat HPV-16-induced tumors in a murine model. When challenged with lethal levels of tumor cell line TC-1 expressing E7, immunized mice showed full prevention of TC-1-induced tumors, even after a second challenge, suggesting that this prophylactic immunization can provide long-lasting immunity. Therapeutic immunization with L. lactis recombinant strains, i.e., 7 days after TC-1 injection, induced regression of palpable tumors in treated mice. The antitumor effects of vaccination occurred through a CTL response, which is CD4+ and CD8+ dependent. Furthermore, immunized mice developed an E7-specific mucosal immune response. These preclinical results suggest the feasibility of the low-cost mucosal vaccination and/or immunotherapy strategies against HPV-related cervical cancer in humans.
Targeted Expression of Human CD1d in Transgenic Mice Reveals Independent Roles for Thymocytes and Thymic APCs in Positive and Negative Selection of Vα14i NKT Cells
Authors: Schümann Jens , Pittoni Paola , Tonti Elena , MacDonald H. Robson , Dellabona Paolo , Casorati Giulia 
Published: April 2014

Abstract
CD1d-dependent invariant Vα14 (Vα14i) NKT cells are innate T lymphocytes expressing a conserved semi-invariant TCR, consisting, in mice, of the invariant Vα14-Jα18 TCR α-chain paired mostly with Vβ8.2 and Vβ7. The cellular requirements for thymic positive and negative selection of Vα14i NKT cells are only partially understood. Therefore, we generated transgenic mice expressing human CD1d (hCD1d) either on thymocytes, mainly CD4+ CD8+ double positive, or on APCs, the cells implicated in the selection of Vα14i NKT cells. In the absence of the endogenous mouse CD1d (mCD1d), the expression of hCD1d on thymocytes, but not on APCs, was sufficient to select Vα14i NKT cells that proved functional when activated ex vivo with the Ag α-galactosyl ceramide. Vα14i NKT cells selected by hCD1d on thymocytes, however, attained lower numbers than in control mice and expressed essentially Vβ8.2. The low number of Vβ8.2+ Vα14i NKT cells selected by hCD1d on thymocytes was not reversed by the concomitant expression of mCD1d, which, instead, restored the development of Vβ7+ Vα14i NKT cells. Vβ8.2+, but not Vβ7+, NKT cell development was impaired in mice expressing both hCD1d on APCs and mCD1d. Taken together, our data reveal that selective CD1d expression by thymocytes is sufficient for positive selection of functional Vα14i NKT cells and that both thymocytes and APCs may independently mediate negative selection.
Effects of Aryl Hydrocarbon Receptor Signaling on the Modulation of Th1/Th2 Balance
Authors: Negishi Takaaki , Kato Yutaka , Ooneda Osamu , Mimura Junsei , Takada Tomonari , Mochizuki Hidenori , Yamamoto Masayuki , Fujii-Kuriyama Yoshiaki , Furusako Shoji 
Published: April 2014

AbstractAn orally active antiallergic agent, M50367, skews the Th1/Th2 balance toward Th1 dominance by suppressing naive Th cell differentiation into Th2 cells in vitro. Administration results in the suppression of IgE synthesis and peritoneal eosinophilia in vivo. In this report, we determined that M50354 (an active metabolite of M50367) was a ligand for the aryl hydrocarbon receptor (AhR); the immunological effects of this compound on in vitro Th1/Th2 differentiation from naive Th cells and Th1/Th2 balance in vivo were manifested through binding to AhR. These effects were completely abolished in AhR-deficient mice. AhR expression in the naive Th cell was significantly up-regulated by costimulation of TCR and CD28. Suppression of naive Th cell differentiation into Th2 cells via binding of M50354 to AhR was associated with inhibition of GATA-3 expression in Th cells. In addition, forced expression of a constitutively active form of AhR or activation of AhR by the addition of representative ligands suppressed naive Th cell differentiation into Th2 cells. Based on these results, we conclude that AhR functions as a modulator of the in vivo Th1/Th2 balance through activation in naive Th cells.
Human White Blood Cells Synthesize Morphine: CYP2D6 Modulation
Authors: Zhu Wei , Cadet Patrick , Baggerman Geert , Mantione Kirk J. , Stefano George B. 
Published: April 2014

Abstract
Human plasma contains low, but physiologically significant, concentrations of morphine that can increase following trauma or exercise. We now demonstrate that normal, human white blood cells (WBC), specifically polymorphonuclear cells, contain and have the ability to synthesize morphine. We also show that WBC express CYP2D6, an enzyme capable of synthesizing morphine from tyramine, norlaudanosoline, and codeine. Significantly, we also show that morphine can be synthesized by another pathway via l-3,4-dihydroxyphenylalanine (l-DOPA). Finally, we show that WBC release morphine into their environment. These studies provide evidence that 1) the synthesis of morphine by various animal tissues is more widespread than previously thought and now includes human immune cells. 2) Moreover, another pathway for morphine synthesis exists, via l-DOPA, demonstrating an intersection between dopamine and morphine pathways. 3) WBC can release morphine into the environment to regulate themselves and other cells, suggesting involvement in autocrine signaling since these cells express the μ3 opiate receptor subtype.
Aberrant IgM Signaling Promotes Survival of Transitional T1 B Cells and Prevents Tolerance Induction in Lupus-Prone New Zealand Black Mice
Authors: Roy Valerie , Chang Nan-Hua , Cai Yongchun , Bonventi Gabriel , Wither Joan 
Published: April 2014

AbstractNew Zealand Black (NZB) mice develop a lupus-like syndrome. Although the precise immune defects leading to autoantibody production in these mice have not been characterized, they possess a number of immunologic abnormalities suggesting that B cell tolerance may be defective. In the bone marrow, immature self-reactive B cells that have failed to edit their receptors undergo apoptosis as a consequence of Ig receptor engagement. Splenic transitional T1 B cells are recent bone marrow emigrants that retain these signaling properties, ensuring that B cells recognizing self-Ags expressed only in the periphery are deleted from the naive B cell repertoire. In this study we report that this mechanism of tolerance is defective in NZB mice. We show that NZB T1 B cells are resistant to apoptosis after IgM cross-linking in vitro. Although extensive IgM cross-linking usually leads to deletion of T1 B cells, in NZB T1 B cells we found that it prevents mitochondrial membrane damage, inhibits activation of caspase-3, and promotes cell survival. Increased survival of NZB T1 B cells was associated with aberrant up-regulation of Bcl-2 after Ig receptor engagement. We also show that there is a markedly increased proportion of NZB T1 B cells that express elevated levels of Bcl-2 in vivo and provide evidence that up-regulation of Bcl-2 follows encounter with self-Ag in vivo. Thus, we propose that aberrant cell signaling in NZB T1 B cells leads to the survival of autoreactive B cells, which predisposes NZB mice to the development of autoimmunity.
Short-Interfering RNA-Mediated Lck Knockdown Results in Augmented Downstream T Cell Responses
Authors: Methi Trond , Ngai Jacob , Mahic Milada , Amarzguioui Mohammed , Vang Torkel , Tasken Kjetil 
Published: April 2014

AbstractThe Src family kinase Lck is essential for T cell Ag receptor-mediated signaling. In this study, we report the effects of acute elimination of Lck in Jurkat TAg and primary T cells using RNA interference mediated by short-interfering RNAs. In cells with Lck knockdown (kd), proximal TCR signaling was strongly suppressed as indicated by reduced ζ-chain phosphorylation and intracellular calcium mobilization. However, we observed sustained and elevated phosphorylation of ERK1/2 in Lck kd cells 30 min to 2 h after stimulation. Downstream effects on immune function as determined by activation of a NFAT-AP-1 reporter, and TCR/CD28-stimulated IL-2 secretion were strongly augmented in Jurkat and primary T cells, respectively. As expected, overexpression of SHP-1 in Jurkat cells inhibited TCR-induced NFAT-AP-1 activation, but this effect could be overcome by simultaneous kd of Lck. Furthermore, acute elimination of Lck also suppressed TCR-mediated activation of SHP-1, suggesting the possible role of SHP-1 in a negative feedback loop originating from Lck. This report underscores Lck as an important mediator of proximal TCR signaling, but also indicates a suppressive role on downstream immune function.
Developmental Changes in the Human Heavy Chain CDR3
Authors: Souto-Carneiro M. Margarida , Sims Gary P. , Girschik Hermann , Lee Jisoo , Lipsky Peter E. 
Published: April 2014

AbstractThe CDR3 of the Ig H chain (CDR3H) is significantly different in fetal and adult repertoires. To understand the mechanisms involved in the developmental changes in the CDR3H of Ig H chains, sets of nonproductive VHDJH rearrangements obtained from fetal, full-term neonates and adult single B cells were analyzed and compared with the corresponding productive repertoires. Analysis of the nonproductive repertoires was particularly informative in assessing developmental changes in the molecular mechanisms of VHDJH recombination because these rearrangements did not encode a protein and therefore their distribution was not affected by selection. Although a number of differences were noted, the major reasons that fetal B cells expressed Ig H chains with shorter CDR3H were both diminished TdT activity in the DJH junction and the preferential use of the short JH proximal D segment D7–27. The enhanced usage of D7–27 by fetal B cells appeared to relate to its position in the locus rather than its short length. The CDR3H progressively acquired a more adult phenotype during ontogeny. In fetal B cells, there was decreased recurrent DJH rearrangements before VH-DJH rearrangement and increased usage of junctional microhomologies both of which also converted to the adult pattern during ontogeny. Overall, these results indicate that the decreased length and complexity of the CDR3H of fetal B cells primarily reflect limited enzymatic modifications of the joins as well as a tendency to use proximal D and JH segments during DJH rearrangements.