bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Apoptotic Pathway Contributing to the Deletion of Naive CD8 T Cells during the Induction of Peripheral Tolerance to a Cross-Presented Self-Antigen
Authors: Redmond William L. , Wei Cheng-Hong , Kreuwel Huub T. C. , Sherman Linda A. 
Published: April 2014

AbstractThe maintenance of T cell tolerance in the periphery proceeds through several mechanisms, including anergy, immuno-regulation, and deletion via apoptosis. We examined the mechanism underlying the induction of CD8 T cell peripheral tolerance to a self-Ag expressed on pancreatic islet β-cells. Following adoptive transfer, Ag-specific clone 4 T cells underwent deletion independently of extrinsic death receptors, including Fas, TNFR1, or TNFR2. Additional experiments revealed that the induction of clone 4 T cell apoptosis during peripheral tolerance occurred via an intrinsic death pathway that could be inhibited by overexpression of Bcl-2 or targeted deletion of the proapoptotic molecule, Bim, thereby resulting in accumulation of activated clone 4 T cells. Over-expression of Bcl-2 in clone 4 T cells promoted the development of effector function and insulitis whereas Bim−/− clone 4 cells were not autoaggressive. Examination of the upstream molecular mechanisms contributing to clone 4 T cell apoptosis revealed that it proceeded in a p53, E2F1, and E2F2-independent manner. Taken together, these data reveal that initiation of clone 4 T cell apoptosis during the induction of peripheral tolerance to a cross-presented self-Ag occurs through a Bcl-2-sensitive and at least partially Bim-dependent mechanism.
MyD88-Dependent Pathway in T Cells Directly Modulates the Expansion of Colitogenic CD4+ T Cells in Chronic Colitis
Authors: Tomita Takayuki , Kanai Takanori , Fujii Toshimitsu , Nemoto Yasuhiro , Okamoto Ryuichi , Tsuchiya Kiichiro , Totsuka Teruji , Sakamoto Naoya , Akira Shizuo , Watanabe Mamoru 
Published: April 2014

Abstract
TLRs that mediate the recognition of pathogen-associated molecular patterns are widely expressed on/in cells of the innate immune system. However, recent findings demonstrate that certain TLRs are also expressed in conventional TCRαβ+ T cells that are critically involved in the acquired immune system, suggesting that TLR ligands can directly modulate T cell function in addition to various innate immune cells. In this study, we report that in a murine model of chronic colitis induced in RAG-2−/− mice by adoptive transfer of CD4+CD45RBhigh T cells, both CD4+CD45RBhigh donor cells and the expanding colitogenic lamina propria CD4+CD44high memory cells expresses a wide variety of TLRs along with MyD88, a key adaptor molecule required for signal transduction through TLRs. Although RAG-2−/− mice transferred with MyD88−/−CD4+CD45RBhigh cells developed colitis, the severity was reduced with the delayed kinetics of clinical course, and the expansion of colitogenic CD4+ T cells was significantly impaired as compared with control mice transferred with MyD88+/+CD4+CD45RBhigh cells. When RAG-2−/− mice were transferred with the same number of MyD88+/+ (Ly5.1+) and MyD88−/− (Ly5.2+) CD4+CD45RBhigh cells, MyD88−/−CD4+ T cells showed significantly lower proliferative responses assessed by in vivo CFSE division assay, and also lower expression of antiapoptotic Bcl-2/Bcl-xL molecules and less production of IFN-γ and IL-17, compared with the paired MyD88+/+CD4+ T cells. Collectively, the MyD88-dependent pathway that controls TLR signaling in T cells may directly promote the proliferation and survival of colitogenic CD4+ T cells to sustain chronic colitis.
Formation of IL-7Rαhigh and IL-7Rαlow CD8 T Cells during Infection Is Regulated by the Opposing Functions of GABPα and Gfi-1
Authors: Chandele Anmol , Joshi Nikhil S. , Zhu Jinfang , Paul William E. , Leonard Warren J. , Kaech Susan M. 
Published: April 2014

Abstract
IL-7 is essential for the survival of naive and memory T cells, and IL-7 receptor α-chain (IL-7Rα) expression is dynamically regulated in activated CD8 T cells during acute viral and bacterial infections. Most virus-specific CD8 T cells become IL-7Rαlow and are relatively short-lived, but some escape IL-7Rα repression (referred to as IL-7Rαhigh memory precursor effector cells) and preferentially enter the memory CD8 T cell pool. How antiviral effector CD8 T cells regulate IL-7Rα expression in an “on and off” fashion remains to be characterized. During lymphocytic choriomeningitis virus infection, we found that opposing actions of the transcription factors GABPα (GA binding protein α) and Gfi-1 (growth factor independence 1) control IL-7Rα expression in effector CD8 T cells. Specifically, GABPα was required for IL-7Rα expression in memory precursor effector cells, and this correlated with hyperacetylation of the Il7ra promoter. In contrast, Gfi-1 was required for stable IL-7Rα repression in effector CD8 T cells and acted by antagonizing GABPα binding and recruiting histone deacetylase 1, which deacetylated the Il7ra promoter. Thus, Il7ra promoter acetylation and activity was dependent on the reciprocal binding of GABPα and Gfi-1, and these data provide a biochemical mechanism for the generation of stable IL-7Rαhigh and IL-7Rαlow states in virus-specific effector CD8 T cells.
Effector Memory αβ T Lymphocytes Can Express FcγRIIIa and Mediate Antibody-Dependent Cellular Cytotoxicity
Authors: Clémenceau Béatrice , Vivien Régine , Berthomé Mathilde , Robillard Nelly , Garand Richard , Gallot Géraldine , Vollant Solène , Vié Henri 
Published: April 2014

AbstractHuman memory T cells are comprised of distinct populations with different homing potential and effector functions: central memory T cells that mount recall responses to Ags in secondary lymphoid organs, and effector memory T cells that confer immediate protection in peripheral tissues. In the present study we demonstrate that a proportion of effector memory T cells express FcγRIIIa (CD16), are perforin positive, and directly mediate Ab-dependent cytotoxicity ex vivo. This particular αβ T lymphocyte subset has the morphology of large granular lymphocytes, increases proportionately in vivo during reactive lymphocytosis, and can be detected in vitro among EBV-specific T lymphocytes after stimulation with EBV Ags. Consequently, during a normal immune response, amplification of these effector memory T lymphocytes that are capable of Ab-dependent cytotoxicity may have beneficial or harmful consequences depending on the presence of pathogen- or tissue-specific Abs, respectively.
Sphingosine 1-Phosphate Regulates the Egress of IgA Plasmablasts from Peyer’s Patches for Intestinal IgA Responses
Authors: Gohda Masashi , Kunisawa Jun , Miura Fumi , Kagiyama Yuki , Kurashima Yosuke , Higuchi Morio , Ishikawa Izumi , Ogahara Ikuko , Kiyono Hiroshi 
Published: April 2014

AbstractIt is well established that Peyer’s patches (PPs) are sites for the differentiation of IgA plasma cell precursors, but molecular and cellular mechanisms in their trafficking remain to be elucidated. In this study, we show that alterations in type 1 sphingosine 1-phosphate (S1P) receptor expression during B cell differentiation in the PPs control the emigration of IgA plasma cell precursors. Type 1 S1P receptor expression decreased during the differentiation of IgM+B220+ B cells to IgA+B220+ B cells, but recovered on IgA+B220− plasmablasts for their emigration from the PPs. Thus, IgA+B220− plasmablasts migrated in response to S1P in vitro. Additionally, IgA+ plasmablasts selectively accumulated in lymphatic regions of PPs when S1P-mediated signaling was disrupted by FTY720 treatment. This accumulation of IgA+ plasmablasts in the PPs led to their reduction in the intestinal lamina propria and simultaneous impairment of Ag-specific intestinal IgA production against orally administered Ag. These findings suggest that S1P regulates the retention and emigration of PP B cells and plays key roles in the induction of intestinal IgA production.
Inter-Strain Tissue-Infiltrating T Cell Responses to Minor Histocompatibility Antigens Involved in Graft-Versus-Host Disease as Determined by Vβ Spectratype Analysis
Authors: Zilberberg Jenny , McElhaugh Danielle , Gichuru Loise N. , Korngold Robert , Friedman Thea M. 
Published: April 2014

AbstractLethal graft-vs-host disease (GVHD) can be induced between MHC-matched murine strains expressing multiple minor histocompatibility Ag differences. In the B6–&gt;BALB.B model, both CD4+ and CD8+ donor T cells can mediate lethal GVHD, whereas in the B6–&gt;CXB-2 model, only CD8+ T cells are lethal. TCR Vβ CDR3-size spectratyping was previously used to analyze CD8+ and CD4+ T cell responses in lethally irradiated BALB.B and CXB-2 recipients, which showed significant overlap in the reacting repertoires. However, CD4+ T cells exhibited unique skewing of the Vβ2 and 11 families in only BALB.B recipients. These Vβ family reactivities were confirmed by immunohistochemical staining of lingual epithelial infiltrates, and by positive and negative selection Vβ family transfer experiments for GVHD induction in BALB.B recipients. We have now extended these studies to examine the T cell repertoire responses involved in target tissue damage. Infiltrating B6 host-presensitized CD8+ and CD4+ T cells were isolated 8–10 days post-transplant from the spleens, intestines and livers of CXB-2 and BALB.B transplant recipients. For both T cell subsets, the results indicated overlapping tissue skewings between the recipients, also between the tissues sampled within the respective recipients as well as tissue specific responses unique to both the BALB.B and CXB-2 infiltrates. Most notably, the CD4+ Vβ 11+ family was skewed in the intestines of BALB.B but not CXB-2 recipients. Taken together, these data suggest that there are likely to be target tissue-related anti-multiple minor histocompatibility Ag-specific responses in each of the strain recipients, which may also differ from those found in peripheral lymphoid organs.
The Lymphotoxin Pathway Regulates Aire-Independent Expression of Ectopic Genes and Chemokines in Thymic Stromal Cells
Authors: Seach Natalie , Ueno Tomoo , Fletcher Anne L. , Lowen Tamara , Mattesich Monika , Engwerda Christian R. , Scott Hamish S. , Ware Carl F. , Chidgey Ann P. , Gray Daniel H. D. , Boyd Richard L. 
Published: April 2014

Abstract
Medullary thymic epithelial cells (mTEC) play an important and unique role in central tolerance, expressing tissue-restricted Ags (TRA) which delete thymocytes autoreactive to peripheral organs. Since deficiencies in this cell type or activity can lead to devastating autoimmune diseases, it is important to understand the factors which regulate mTEC differentiation and function. Lymphotoxin (LT) ligands and the LTβR have been recently shown to be important regulators of mTEC biology; however, the precise role of this pathway in the thymus is not clear. In this study, we have investigated the impact of this signaling pathway in greater detail, focusing not only on mTEC but also on other thymic stromal cell subsets. LTβR expression was found in all TEC subsets, but the highest levels were detected in MTS-15+ thymic fibroblasts. Rather than directing the expression of the autoimmune regulator Aire in mTEC, we found LTβR signals were important for TRA expression in a distinct population of mTEC characterized by low levels of MHC class II (mTEClow), as well as maintenance of MTS-15+ fibroblasts. In addition, thymic stromal cell subsets from LT-deficient mice exhibit defects in chemokine production similar to that found in peripheral lymphoid organs of Lta−/− and Ltbr−/− mice. Thus, we propose a broader role for LTα1β2-LTβR signaling in the maintenance of the thymic microenvironments, specifically by regulating TRA and chemokine expression in mTEClow for efficient induction of central tolerance.
Release from Regulatory T Cell-Mediated Suppression during the Onset of Tissue-Specific Autoimmunity Is Associated with Elevated IL-21
Authors: Clough Louise E. , Wang Chun Jing , Schmidt Emily M. , Booth George , Hou Tie Zheng , Ryan Gemma A. , Walker Lucy S. K. 
Published: April 2014

Abstract
The activity of regulatory T cells (Treg) is widely accepted to play a central role in preventing pathogenic immune responses against self-Ags. However, it is not clear why such regulation breaks down during the onset of autoimmunity. We have studied self-Ag-specific Treg during the induction of spontaneous diabetes. Our data reveal a shift in the balance between regulatory and pathogenic islet-reactive T cells in the pancreas-draining lymph nodes during disease onset. Treg function was not compromised during disease initiation, but instead conventional T cells showed reduced susceptibility to Treg-mediated suppression. Release from Treg suppression was associated with elevated levels of IL-21 in vivo, and provision of this cytokine abrogated Treg suppression in vitro and in vivo. These data suggest that immunological protection of a peripheral tissue by Treg can be subverted by IL-21, suggesting new strategies for intervention in autoimmunity.
The Adjuvants Aluminum Hydroxide and MF59 Induce Monocyte and Granulocyte Chemoattractants and Enhance Monocyte Differentiation toward Dendritic Cells
Authors: Seubert Anja , Monaci Elisabetta , Pizza Mariagrazia , O’Hagan Derek T. , Wack Andreas 
Published: April 2014

AbstractAluminum hydroxide (alum) and the oil-in-water emulsion MF59 are widely used, safe and effective adjuvants, yet their mechanism of action is poorly understood. We assessed the effects of alum and MF59 on human immune cells and found that both induce secretion of chemokines, such as CCL2 (MCP-1), CCL3 (MIP-1α), CCL4 (MIP-1β), and CXCL8 (IL-8), all involved in cell recruitment from blood into peripheral tissue. Alum appears to act mainly on macrophages and monocytes, whereas MF59 additionally targets granulocytes. Accordingly, monocytes and granulocytes migrate toward MF59-conditioned culture supernatants. In monocytes, both adjuvants lead to increased endocytosis, enhanced surface expression of MHC class II and CD86, and down-regulation of the monocyte marker CD14, which are all phenotypic changes consistent with a differentiation toward dendritic cells (DCs). When monocyte differentiation into DCs is induced by addition of cytokines, these adjuvants enhanced the acquisition of a mature DC phenotype and lead to an earlier and higher expression of MHC class II and CD86. In addition, MF59 induces further up-regulation of the maturation marker CD83 and the lymph node-homing receptor CCR7 on differentiating monocytes. Alum induces a similar but not identical pattern that clearly differs from the response to LPS. This model suggests a common adjuvant mechanism that is distinct from that mediated by danger signals. We conclude that during vaccination, adjuvants such as MF59 may increase recruitment of immune cells into the injection site, accelerate and enhance monocyte differentiation into DCs, augment Ag uptake, and facilitate migration of DCs into tissue-draining lymph nodes to prime adaptive immune responses.
Nonoverlapping Expression of IL10, IL12p40, and IFNγ mRNA in the Marginal Zone and T Cell Zone of the Spleen after Antigenic Stimulation
Authors: Kalies Kathrin , König Peter , Zhang Yong-Ming , Deierling Maria , Barthelmann Julia , Stamm Claudia , Westermann Jürgen 
Published: April 2014

Abstract
The differentiation of CD4+ T cells is regulated by cytokines locally within the compartments of secondary lymphoid organs during adaptive immune responses. Quantitative data about the expression of cytokine mRNAs within the T and B cell zones of lymphoid organs are lacking. In this study, we assessed the expression of multiple cytokine genes within the lymphoid compartments of the spleen of rats after two types of stimulation. First, the spleen was stimulated directly by a blood-derived Ag. Second, the spleen was stimulated indirectly by incoming lymphocytes that had been activated and released during a proceeding immune response at a distant tissue site. Using laser microdissection, we show that the expression of cytokine mRNAs was compartment specific, transient, and preceded cell proliferation after the direct antigenic stimulation. Surprisingly, the indirect stimulation by incoming activated lymphocytes induced similar cytokines in the T cell zone. However, the nonoverlapping expression was lost and IL10 appeared as the major cytokine in all compartments. Thus, tracking two types of immune activation without disturbing the integrity of structures reveals distinct and overlapping events in the compartments of the spleen. This information adds a new dimension to the understanding of immune responses in vivo.
A Conserved IFN-α Receptor Tyrosine Motif Directs the Biological Response to Type I IFNs
Authors: Zhao Wenli , Lee Carolyn , Piganis Rebecca , Plumlee Courtney , de Weerd Nicole , Hertzog Paul J. , Schindler Christian 
Published: April 2014

Abstract
Mammalian type I IFNs (IFN-Is) mediate their potent biological activities through an evolutionarily conserved IFN-α receptor (IFNAR), consisting of IFNAR1 and IFNAR2. These two chains direct the rapid activation of two founding members of the STAT family of transcription factors, STAT1 and STAT2. To understand how IFN-Is direct the recruitment and activation of STATs, a series of mutant murine IFNAR1 and IFNAR2 receptors were generated and evaluated in IFNAR1 and IFNAR2 knockout cells. These studies reveal that a single conserved IFNAR2 tyrosine, Y510, plays a critical role in directing the IFN-I-dependent activation of STAT1 and STAT2, both in murine fibroblasts and macrophages. A second IFNAR2 tyrosine, Y335, plays a more minor role. Likewise, Y510 &gt; Y335 play a critical role in the induction of genes and antiviral activity traditionally associated with IFN-Is.
Immunoproteomic Identification and Serological Responses to Novel Chlamydia pneumoniae Antigens That Are Associated with Persistent C. pneumoniae Infections
Authors: Bunk Sebastian , Susnea Iuliana , Rupp Jan , Summersgill James T. , Maass Matthias , Stegmann Werner , Schrattenholz André , Wendel Albrecht , Przybylski Michael , Hermann Corinna 
Published: April 2014

Abstract
The controversial discussion about the role of Chlamydia pneumoniae in atherosclerosis cannot be solved without a reliable diagnosis that allows discrimination between past and persistent infections. Using a proteomic approach and immunoblotting with human sera, we identified 31 major C. pneumoniae Ags originating from 27 different C. pneumoniae proteins. More than half of the proteins represent Chlamydia Ags not described previously. Using a comparative analysis of spot reactivity Pmp6, OMP2, GroEL, DnaK, RpoA, EF-Tu, as well as CpB0704 and CpB0837, were found to be immunodominant. The comparison of Ab-response patterns of sera from subjects with and without evidence for persisting C. pneumoniae, determined by multiple PCR analysis of PBMC and vasculatory samples, resulted in differential reactivity for 12 proteins, which is not reflected by reactivity of the sera in the microimmunofluorescence test, the current gold standard for serodiagnosis. Although reactivity of sera from PCR-positive donors was increased toward RpoA, MOMP, YscC, Pmp10, PorB, Pmp21, GroEL, and Cpaf, the reactivity toward YscL, Rho, LCrE, and CpB0837 was decreased, reflecting the altered protein expression of persisting C. pneumoniae in vitro. Our data provide the first evidence of a unique Ab-response pattern associated with persistent C. pneumoniae infections, which is a prerequisite for the serological determination of persistently infected patients.
The Long Isoform of Cellular FLIP Is Essential for T Lymphocyte Proliferation through an NF-κB-Independent Pathway
Authors: Zhang Nu , Hopkins Kaycie , He You-Wen 
Published: April 2014

Abstract
Although the long isoform of cellular FLIP (c-FLIPL) has been implicated in TCR-mediated signaling, its role in T cell proliferation remains controversial. Some studies have demonstrated that overexpression of c-FLIPL promotes T cell proliferation and NF-κB activation, whereas others have reported that c-FLIPL overexpression has no effect or even inhibits T cell proliferation. To establish the role of c-FLIPL in T lymphocyte proliferation, we have generated a conditional knockout mouse strain specifically lacking c-FLIPL in T lymphocytes. c-FLIPL−/− mice exhibit severely impaired effector T cell development after Listeria monocytogenes infection in vivo and c-FLIPL-deficient T cells display defective TCR-mediated proliferation in vitro. However, c-FLIPL−/− T cells exhibit normal NF-κB activity upon TCR stimulation. These results demonstrate that c-FLIPL is essential for T lymphocyte proliferation through an NF-κB-independent pathway.
Comparison of Proteins Expressed on Secretory Vesicle Membranes and Plasma Membranes of Human Neutrophils
Authors: Uriarte Silvia M. , Powell David W. , Luerman Gregory C. , Merchant Michael L. , Cummins Timothy D. , Jog Neelakshi R. , Ward Richard A. , McLeish Kenneth R. 
Published: April 2014

Abstract
Secretory vesicles are neutrophil intracellular storage granules formed by endocytosis. Understanding the functional consequences of secretory vesicle exocytosis requires knowledge of their membrane proteins. The current study was designed to use proteomic technologies to develop a more complete catalog of secretory vesicle membrane proteins and to compare the proteomes of secretory vesicle and plasma membranes. A total of 1118 proteins were identified, 573 (51%) were present only in plasma membrane-enriched fractions, 418 (37%) only in secretory vesicle-enriched membrane fractions, and 127 (11%) in both fractions. Gene Ontology categorized 373 of these proteins as integral membrane proteins. Proteins typically associated with other intracellular organelles, including nuclei, mitochondria, and ribosomes, were identified in both membrane fractions. Ingenuity Pathway Knowledge Base analysis determined that the majority of canonical and functional pathways were significantly associated with proteins from both plasma membrane-enriched and secretory vesicle-enriched fractions. There were, however, some canonical signaling pathways that involved proteins only from plasma membranes or secretory vesicles. In conclusion, a number of proteins were identified that may elucidate mechanisms and functional consequences of secretory vesicle exocytosis. The small number of common proteins suggests that the hypothesis that secretory vesicles are formed from plasma membranes by endocytosis requires more critical evaluation.
Pneumocystis Infection Enhances Antibody-Mediated Resistance to a Subsequent Influenza Infection
Authors: Wiley James A. , Harmsen Allen G. 
Published: April 2014

Abstract
In contrast to the detrimental outcomes most often associated with the resolution of coinfections, the model presented here involving a localized Pneumocystis infection of the lung, followed 2 wk later by an influenza virus infection, results in a significant beneficial outcome for the host. In the week following the influenza infection, immunocompetent coinfected animals exhibited an accelerated rate of virus clearance, an accelerated appearance of higher influenza-specific neutralizing Ab titers in their serum and bronchoalveolar lavage fluid (BALF), significantly reduced inflammatory cytokine levels in their BALF, and reduced levels of morbidity relative to animals infected only with influenza virus. The beneficial outcome observed in coinfected immunocompetent animals was dependent on the ongoing resolution of a viable Pneumocystis infection. No differences in viral clearance were detected between coinfected and influenza-only-infected μMT mice or likewise for SCID mice. The accelerated anti-influenza response did not appear to be associated with influenza-specific CD8 T cell-mediated responses or NK cell responses in the lung. Rather, the increased rate of viral clearance was due to the enhancement of the influenza-specific Ab response, which in turn was transiently dependent upon the resolution of the ongoing Pneumocystis infection.