bluuebunny/crossref_metadata_2025_split huggingface dataset:
TNF-α Blockade Down-Regulates the CD40/CD40L Pathway in the Mucosal Microcirculation: A Novel Anti-Inflammatory Mechanism of Infliximab in Crohn’s Disease
Authors: Danese Silvio , Sans Miquel , Scaldaferri Franco , Sgambato Alessandro , Rutella Sergio , Cittadini Achille , Piqué Josep M. , Panes Julian , Katz Jeffry A. , Gasbarrini Antonio , Fiocchi Claudio 
Published: April 2014

AbstractThe CD40/CD40 ligand (CD40L) pathway is involved in Crohn’s disease (CD) pathogenesis. In the patients’ circulation, soluble CD40L (sCD40L) levels are elevated and surface CD40L is increased in platelets and T cells, whereas in the intestine CD40 is overexpressed in the microvasculature and CD40L in platelets and T cells. The therapeutic effects of infliximab in CD are attributed to its systemic anti-TNF-α action, but because TNF-α modulates both CD40 and CD40L, we investigated whether infliximab affects the CD40/CD40L pathway in the intestine. Eighteen CD patients were evaluated before and after infliximab therapy. Plasma sCD40L was measured by ELISA and platelet and peripheral blood T cell (PBT) CD40L expression by flow cytometry. Microvascular CD40 and VCAM-1 expression were assessed in mucosal biopsies by immunohistochemistry and by flow cytometry in human intestinal microvascular endothelial cells (HIMEC). Cell cultures were performed in the presence and absence of infliximab. Infliximab treatment significantly reduced plasma sCD40L levels and eliminated CD40 and VCAM-1 from mucosal microvessels. In vitro infliximab prevented TNF-α-induced CD40 and VCAM-1 expression by HIMEC, and reduced PBT, but not platelet, surface CD40L expression and sCD40L release. In addition, infliximab decreased T cell-induced VCAM-1 expression in HIMEC by down-regulating CD40L in T cells and promoting T cells apoptosis. These findings point to a novel mechanism of action of infliximab, i.e., the disruption of CD40/CD40L-dependent cognate interactions between intestinal microvessels and T cells. Thus, in addition to neutralizing TNF-α and inducing T cell death, the therapeutic effects of infliximab in CD appear to be also mediated by inhibition of vascular inflammation in the gut.
Persistent Cytomegalovirus-Specific Memory Responses in the Lung Allograft and Blood following Primary Infection in Lung Transplant Recipients
Authors: Shlobin Oksana A. , West Erin E. , Lechtzin Noah , Miller Susan M. , Borja Marvin , Orens Jonathan B. , Dropulic Lesia K. , McDyer John F. 
Published: April 2014

Abstract
Primary CMV infection in lung transplant recipients (LTRs) is associated with increased mortality. We studied 22 donor CMV-positive, recipient-negative (D+R−) LTRs for the development of posttransplant CMV-specific immunity. We found that 13 of 22 D+R− LTRs (59.1%) seroconverted (CMV IgG Ab+). Using pooled peptides of the immunodominant CMV Ags pp65 and IE1, we detected CMV-specific CD8+IFN-γ+ T cells in the PBMC of 90% of seroconverted individuals following primary infection by intracellular cytokine staining. In contrast, few seroconverters had detectable CMV-specific CD4+IFN-γ+ T cells during viral latency. However, the majority of IgG+ LTRs demonstrated CMV-specific CD4+ and CD8+ T cell proliferative responses from PBMC, with CD4+IFN-γ+ T cells detectable upon re-expansion. Examination of lung allograft mononuclear cells obtained by bronchoalveolar lavage revealed both CMV-specific CD4+ and CD8+IFN-γ+ T cells, including patients from whom CD4+IFN-γ+ T cells were simultaneously undetectable in the PBMC, suggesting differential effector memory populations between these compartments. Moreover, both responses in the PBMC and lung allograft were found to persist, despite substantial immunosuppression, long after primary infection. Clinical correlation in this cohort demonstrated that the acquisition of CMV immunity was associated with freedom from CMV disease (p ≤ 0.009) and preservation of allograft function (p ≤ 0.02) compared with those who failed to develop CMV immunity. Together, our data reveal immunologic heterogeneity in D+R− LTRs, with the development and persistence of primary CMV responses that may provide clinical benefit.
B Cells Are Crucial for Determinant Spreading of T Cell Autoimmunity among β Cell Antigens in Diabetes-Prone Nonobese Diabetic Mice
Authors: Tian Jide , Zekzer Dan , Lu Yuxin , Dang Hoa , Kaufman Daniel L. 
Published: April 2014

Abstract
The determinant spreading of T cell autoimmunity plays an important role in the pathogenesis of type 1 diabetes and in the protective mechanism of Ag-based immunotherapy in NOD mice. However, little is known about the role of APCs, particularly B cells, in the spreading of T cell autoimmunity. We studied determinant spreading in NOD/scid or Igμ−/− NOD mice reconstituted with NOD T and/or B cells and found that mice with mature B cells (TB NOD/scid and BMB Igμ−/− NOD), but not mice that lacked mature B cells (T NOD/scid and BM Igμ−/− NOD), spontaneously developed Th1 autoimmunity, which spread sequentially among different β cell Ags. Immunization of T NOD/scid and BM Igμ−/− NOD mice with a β cell Ag could prime Ag-specific Th1 or Th2 responses, but those T cell responses did not spread to other β cell Ags. In contrast, immunization of TB NOD/scid and BMB Igμ−/− NOD mice with a β cell Ag in IFA induced Th2 responses, which spread to other β cell Ags. Furthermore, we found that while macrophages and dendritic cells could evoke memory and effector T cell responses in vitro, B cells significantly enhanced the detection of spontaneously primed and induced Th1 responses to β cell Ags. Our data suggest that B cells, but not other APCs, mediate the spreading of T cell responses during the type 1 diabetes process and following Ag-based immunotherapy. Conceivably, the modulation of the capacity of B cells to present Ag may provide new interventions for enhancing Ag-based immunotherapy and controlling autoimmune diseases.
The P2X7 Receptor: A Key Player in IL-1 Processing and Release
Authors: Ferrari Davide , Pizzirani Cinzia , Adinolfi Elena , Lemoli Roberto M. , Curti Antonio , Idzko Marco , Panther Elisabeth , Di Virgilio Francesco 
Published: April 2014

Abstract
Human IL-1 family proteins are key mediators of the host response to infections, injury, and immunologic challenges. The mechanism by which IL-1 activates proinflammatory responses in target cells, and the plasma membrane receptors involved, is fairly well known. This has led to the development of innovative drugs that block IL-1 downstream to its synthesis and secretion. On the contrary, the mechanism of IL-1 and other IL-1 family members (e.g., IL-18) maturation and release is incompletely understood. Accruing evidence points to a plasma membrane receptor for extracellular ATP, the P2X7 receptor, as a key player in both processes. A deeper understanding of the mechanism by which the P2X7 receptor triggers IL-1 maturation and exteriorization may suggest novel avenues for the treatment of inflammatory diseases and provide a deeper insight in the fundamental mechanism of protease activation and cellular export of proteins lacking a leader sequence.
Cutting Edge: Itk-Dependent Signals Required for CD4+ T Cells to Exert, but Not Gain, Th2 Effector Function
Authors: Au-Yeung Byron B. , Katzman Shoshana D. , Fowell Deborah J. 
Published: April 2014

Abstract
The TCR signals for the release of CD4 effector function are poorly understood. Itk plays an essential role in Th2, but not Th1, responses. However, when Itk is required during Th2 development is unclear. We followed the fate of Itk-deficient T cells during Th2 development in vitro and in vivo using an IL-4/GFP reporter. Surprisingly, a similar frequency of itk−/− CD4+ cells differentiated and committed to the Th2 lineage as wild-type cells. However, Itk-deficient Th2 cells failed to exert effector function upon TCR triggering. Loss of function was marked by defective transcriptional enhancement of Th2 cytokines and GATA3. IL-4 production in itk−/− Th2s could be rescued by the expression of kinase-active Itk. Thus, Itk is necessary for the release, but not gain, of Th2 function. We suggest that the liberation of effector function is tightly controlled through qualitative changes in TCR signals, facilitating postdifferentiation regulation of cytokine responses.
Nitric Oxide Promotes Resistance to Tumor Suppression by CTLs
Authors: Su Zhanhai , Kuball Jürgen , Barreiros Ana-Paula , Gottfried Daniela , Ferreira Edite Antunes , Theobald Matthias , Galle Peter R. , Strand Dennis , Strand Susanne 
Published: April 2014

Abstract
Many human tumors express inducible NO synthetase (NOS2), but the roles of NO in tumor development are not fully elucidated. An important step during tumor development is the acquisition of apoptosis resistance. We investigated the dose-dependent effects of endogenously produced NO on apoptosis using ecdysone-inducible NOS2 cell lines. Our results show that short-term NOS2 expression enhances CD95-mediated apoptosis and T cell cytotoxicity dose dependently. Furthermore, we could show that during chronic exposure to NO, besides the primary cytotoxic NO effect, there is selection of cell clones resistant to NO that show cross-resistance to CD95-induced apoptosis and the killing by CTLs. We propose that NO production could initially act as an autocrine suicide or paracrine killing mechanism in cells undergoing malignant transformation. However, once failed, the outcome is fatal. NO promotes tumor formation by enhancing the selection of cells that can evade immune attack by acquiring apoptosis resistance.
Desiccating Stress Induces T Cell-Mediated Sjögren’s Syndrome-Like Lacrimal Keratoconjunctivitis
Authors: Niederkorn Jerry Y. , Stern Michael E. , Pflugfelder Stephen C. , De Paiva Cintia S. , Corrales Rosa M. , Gao Jianping , Siemasko Karyn 
Published: April 2014

Abstract
Chronic dry eye syndrome affects over 10 million people in the United States; it is associated with inflammation of the lacrimal gland (LG) and in some cases involves T cell infiltration of the conjunctiva. We demonstrate that environmental desiccating stress (DS) elicits T cell-mediated inflammation of the cornea, conjunctiva, and LG, but not other organs in mice. The lacrimal keratoconjunctivitis (LKC) was mediated by CD4+ T cells, which, when adoptively transferred to T cell-deficient nude mice, produced inflammation in the LG, cornea, and conjunctiva, but not in any other organ. Adoptively transferred CD4+ T cells produced LKC even though recipients were not exposed to DS. LKC was exacerbated in euthymic mice depleted of CD4+CD25+forkhead/winged helix transcription factor+ regulatory T cells. The results suggest that DS exposes shared epitopes in the cornea, conjunctiva, and LG that induce pathogenic CD4+ T cells that produce LKC, which under normal circumstances is restrained by CD4+CD25+forkhead/winged helix transcription factor+ regulatory T cells.
Essential Role of IκB Kinase α in Thymic Organogenesis Required for the Establishment of Self-Tolerance
Authors: Kinoshita Dan , Hirota Fumiko , Kaisho Tsuneyasu , Kasai Michiyuki , Izumi Keisuke , Bando Yoshimi , Mouri Yasuhiro , Matsushima Akemi , Niki Shino , Han Hongwei , Oshikawa Kiyotaka , Kuroda Noriyuki , Maegawa Masahiko , Irahara Minoru , Takeda Kiyoshi , Akira Shizuo , Matsumoto Mitsuru 
Published: April 2014

Abstract
IκB kinase (IKK) α exhibits diverse biological activities through protein kinase-dependent and -independent functions, the former mediated predominantly through a noncanonical NF-κB activation pathway. The in vivo function of IKKα, however, still remains elusive. Because a natural strain of mice with mutant NF-κB-inducing kinase (NIK) manifests autoimmunity as a result of disorganized thymic structure with abnormal expression of Rel proteins in the thymic stroma, we speculated that the NIK-IKKα axis might constitute an essential step in the thymic organogenesis that is required for the establishment of self-tolerance. An autoimmune disease phenotype was induced in athymic nude mice by grafting embryonic thymus from IKKα-deficient mice. The thymic microenvironment that caused autoimmunity in an IKKα-dependent manner was associated with defective processing of NF-κB2, resulting in the impaired development of thymic epithelial cells. Thus, our results demonstrate a novel function for IKKα in thymic organogenesis for the establishment of central tolerance that depends on its protein kinase activity in cooperation with NIK.
Induction of Peripheral T Cell Tolerance by Antigen-Presenting B Cells. I. Relevance of Antigen Presentation Persistence
Authors: Raimondi Giorgio , Zanoni Ivan , Citterio Stefania , Ricciardi-Castagnoli Paola , Granucci Francesca 
Published: April 2014

Abstract
Various mechanisms of peripheral T cell tolerization have evolved to avoid responses mediated by autoreactive T cells that have not been eliminated in the thymus. In this study, we investigated the peripheral conditions of Ag presentation required to induce T cell tolerance when the predominant APCs are B cells. We show that transient Ag presentation, in absence of inflammation and in a self-context, induces CD4+ T cell activation and memory formation. In contrast, chronic Ag presentation leads to CD4+ T cell tolerance. The importance of long-lasting Ag presentation in inducing tolerance was also confirmed in the herpes stromal keratitis autoimmune disease model. Keratogenic T cells could be activated or tolerized depending on the APC short or long persistence. Thus, when APCs are B cells, the persistence of the Ag presentation itself is one of the main conditions to have peripheral T cell tolerance.
Induction of Peripheral T Cell Tolerance by Antigen-Presenting B Cells. II. Chronic Antigen Presentation Overrules Antigen-Presenting B Cell Activation
Authors: Raimondi Giorgio , Zanoni Ivan , Citterio Stefania , Ricciardi-Castagnoli Paola , Granucci Francesca 
Published: April 2014

Abstract
Ag presentation in the absence of danger signals and Ag persistence are the inductive processes of peripheral T cell tolerization proposed so far. Nevertheless, it has never been definitively shown that chronic Ag presentation per se can induce T cell tolerance independent of the state of activation of APCs. In the present work, we investigated whether chronic Ag presentation by either resting or activated B cells can induce tolerance of peripheral Ag-specific T cells. We show that CD4+ T cells that re-encounter the Ag for a prolonged period, presented either by resting or activated Ag-presenting B cells, become nonfunctional and lose any autoimmune reactivity. Thus, when the main APCs are B cells, the major mechanism responsible for peripheral T cell tolerization is persistent Ag exposure, independent of the B cell activation state.
Suppressor of Cytokine Signaling 1 Stringently Regulates Distinct Functions of IL-7 and IL-15 In Vivo during T Lymphocyte Development and Homeostasis
Authors: Ramanathan Sheela , Gagnon Julien , Leblanc Chantal , Rottapel Robert , Ilangumaran Subburaj 
Published: April 2014

Abstract
SOCS1 −/− mice accumulate within the thymus and periphery CD8+ lymphocytes that express memory cell markers and display heightened in vitro responses to common γ-chain cytokines. To investigate whether dysregulated homeostasis of T lymphocytes and acquisition of memory phenotype by CD8+ cells in SOCS1−/− mice were mediated by IL-7 and/or IL-15 in vivo, we have generated SOCS1−/−IL-7−/−, SOCS1−/−IL-15−/− and SOCS1−/−IL-7−/−IL-15−/− mice. We observed that in mice lacking SOCS1, either IL-7 or IL-15 skewed thymocyte development toward CD8 lineage, whereas IL-15 is the principal mediator of dysregulated homeostasis in the periphery. Homeostatic proliferation of SOCS1−/− CD8+ lymphocytes in Rag1−/−, Rag1−/−IL-7−/−, Rag1−/−IL-15−/−, and Rag1−/−IL-7−/−IL-15−/− mice showed that SOCS1 deficiency did not overcome the requirement for IL-7 and IL-15 to sustain homeostatic expansion. Differential expression of memory phenotype markers CD44, CD122, and Ly6C by SOCS1−/−IL-15−/− CD8+ lymphocytes suggest that multiple signals contributed to the memory cell differentiation program. To address whether increased IL-15 responsiveness of SOCS1−/− CD8+ lymphocytes required prior TCR sensitization, we generated SOCS1−/− H-Y TCR transgenic (Tg) mice. Using female SOCS1−/− H-Y TCRtg mice in Rag1+/+ and Rag1−/− backgrounds, we show that acquisition of the memory phenotype by SOCS1-deficient CD8+ lymphocytes did not require prior antigenic stimulation, but required the presence of activated T cells. SOCS1 deficiency accelerated the maturation of CD8 single-positive thymocytes expressing Tg TCR, but did not compromise negative selection in HY-TCRtg males. Our findings illustrate distinct functions for IL-7 and IL-15 in T lymphocyte development and homeostasis, and stringent regulation of these processes by SOCS1.
Immunization-Induced Perturbation of Human Blood Plasma Cell Pool: Progressive Maturation, IL-6 Responsiveness, and High PRDI-BF1/BLIMP1 Expression Are Critical Distinctions between Antigen-Specific and Nonspecific Plasma Cells
Authors: González-García Inés , Ocaña Esther , Jiménez-Gómez Gema , Campos-Caro Antonio , Brieva José A. 
Published: April 2014

Abstract
The present study shows that reimmunization with tetanus toxoid (tet) caused a transient increase of the human blood plasma cell (PC) pool, detectable from 6th to 15th day postboost, as well as the temporal alteration of several PC features. Labeling of specific PC with FITC-tet C fragment (tetC) allowed kinetics analysis of the tetC+ and tetC− PC, and revealed remarkable differences between them: 1) the kinetics of tetC+ PC occurrence was exponential, and most of them appeared in a narrow time frame (5th to 8th day postboost), whereas the tetC− PC increase was lower (three to five times) and more prolonged (4th to 15th day postboost). 2) The tetC+ PC subset contained a fraction of cycling cells, expressed high levels of DR, CD138, and CD126, and responded to IL-6 by improving their survival and Ig secretion; in contrast, the tetC− PC showed higher CXCR4 and lower DR and CD138, did not respond to IL-6, and contained a fraction of apoptotic cells. 3) Sequential phenotypic analysis revealed maturational changes within the tetC+, but not tetC−, PC subset; sequencing of tetC+ PC IgVH genes showed clear features of Ag selection. 4) The tetC+ PC expressed several times more positive regulatory domain I- binding factor 1/B lymphocyte-induced maturation protein 1 transcription factor than the tetC− PC. 5) The tetC− PC and bone marrow resident PC similarly expressed low DR and high CXCR4, but differed in that the latter exhibited higher levels of CD31, CD138, and positive regulatory domain I- binding factor 1/B lymphocyte-induced maturation protein 1. These findings support the view that tetC+ PC contain bone marrow PC precursors, and tetC− PC probably belong to a removable compartment of aged PC.
Effector T Cell Differentiation and Memory T Cell Maintenance Outside Secondary Lymphoid Organs
Authors: Obhrai Jagdeep S. , Oberbarnscheidt Martin H. , Hand Timothy W. , Diggs Lonnette , Chalasani Geetha , Lakkis Fadi G. 
Published: April 2014

Abstract
Naive T cell circulation is restricted to secondary lymphoid organs. Effector and memory T cells, in contrast, acquire the ability to migrate to nonlymphoid tissues. In this study we examined whether nonlymphoid tissues contribute to the differentiation of effector T cells to memory cells and the long-term maintenance of memory T cells. We found that CD4, but not CD8, effector T cell differentiation to memory cells is impaired in adoptive hosts that lack secondary lymphoid organs. In contrast, established CD4 and CD8 memory T cells underwent basal homeostatic proliferation in the liver, lungs, and bone marrow, were maintained long-term, and functioned in the absence of secondary lymphoid organs. CD8 memory T cells found in nonlymphoid tissues expressed both central and effector memory phenotypes, whereas CD4 memory T cells displayed predominantly an effector memory phenotype. These findings indicate that secondary lymphoid organs are not necessary for the maintenance and function of memory T cell populations, whereas the optimal differentiation of CD4 effectors to memory T cells is dependent on these organs. The ability of memory T cells to persist and respond to foreign Ag independently of secondary lymphoid tissues supports the existence of nonlymphoid memory T cell pools that provide essential immune surveillance in the periphery.
Impact of HLA-B Alleles, Epitope Binding Affinity, Functional Avidity, and Viral Coinfection on the Immunodominance of Virus-Specific CTL Responses
Authors: Bihl Florian , Frahm Nicole , Di Giammarino Loriana , Sidney John , John Mina , Yusim Karina , Woodberry Tonia , Sango Kaori , Hewitt Hannah S. , Henry Leah , Linde Caitlyn H. , Chisholm John V. , Zaman Tauheed M. , Pae Eunice , Mallal Simon , Walker Bruce D. , Sette Alessandro , Korber Bette T. , Heckerman David , Brander Christian 
Published: April 2014

Abstract
Immunodominance is variably used to describe either the most frequently detectable response among tested individuals or the strongest response within a single individual, yet factors determining either inter- or intraindividual immunodominance are still poorly understood. More than 90 individuals were tested against 184 HIV- and 92 EBV-derived, previously defined CTL epitopes. The data show that HLA-B-restricted epitopes were significantly more frequently recognized than HLA-A- or HLA-C-restricted epitopes. HLA-B-restricted epitopes also induced responses of higher magnitude than did either HLA-A- or HLA-C-restricted epitopes, although this comparison only reached statistical significance for EBV epitopes. For both viruses, the magnitude and frequency of recognition were correlated with each other, but not with the epitope binding affinity to the restricting HLA allele. The presence or absence of HIV coinfection did not impact EBV epitope immunodominance patterns significantly. Peptide titration studies showed that the magnitude of responses was associated with high functional avidity, requiring low concentration of cognate peptide to respond in in vitro assays. The data support the important role of HLA-B alleles in antiviral immunity and afford a better understanding of the factors contributing to inter- and intraindividual immunodominance.
Mast Cell-Associated TNF Promotes Dendritic Cell Migration
Authors: Suto Hajime , Nakae Susumu , Kakurai Maki , Sedgwick Jonathon D. , Tsai Mindy , Galli Stephen J. 
Published: April 2014

Abstract
Mast cells represent a potential source of TNF, a mediator which can enhance dendritic cell (DC) migration. Although the importance of mast cell-associated TNF in regulating DC migration in vivo is not clear, mast cells and mast cell-derived TNF can contribute to the expression of certain models of contact hypersensitivity (CHS). We found that CHS to FITC was significantly impaired in mast cell-deficient KitW-sh/W-sh or TNF−/− mice. The reduced expression of CHS in KitW-sh/W-sh mice was fully repaired by local transfer of wild-type bone marrow-derived cultured mast cells (BMCMCs), but was only partially repaired by transfer of TNF−/− BMCMCs. Thus, mast cells, and mast cell-derived TNF, were required for optimal expression of CHS to FITC. We found that the migration of FITC-bearing skin DCs into draining lymph nodes (LNs) 24 h after epicutaneous administration of FITC in naive mice was significantly reduced in mast cell-deficient or TNF−/− mice, but levels of DC migration in these mutant mice increased to greater than wild-type levels by 48 h after FITC sensitization. Mast cell-deficient or TNF−/− mice also exhibited significantly reduced migration of airway DCs to local LNs at 24 h after intranasal challenge with FITC-OVA. Migration of FITC-bearing DCs to LNs draining the skin or airways 24 h after sensitization was repaired in KitW-sh/W-sh mice which had been engrafted with wild-type but not TNF−/− BMCMCs. Our findings indicate that mast cell-associated TNF can contribute significantly to the initial stages of FITC-induced migration of cutaneous or airway DCs.