bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adoptively Transferred γδ T Cells Indirectly Regulate Murine Graft-Versus-Host Reactivity Following Donor Leukocyte Infusion Therapy in Mice
Authors: Drobyski William R. , Vodanovic-Jankovic Sanja , Klein John 
Published: April 2014

AbstractThe purpose of this study was to determine whether γδ T cells were able to regulate graft-vs-host (GVH) reactivity mediated by αβ T cells in murine recipients transplanted with MHC-mismatched marrow grafts. Studies were conducted using ex vivo-activated γδ T cells because this was a more clinically relevant strategy, and these cells have been shown to be capable of facilitating alloengraftment without causing GVH disease (GVHD). Coadministration of activated γδ T cells and naive αβ T cells at the time of bone marrow transplantation (BMT) significantly exacerbated GVHD when compared with naive αβ T cells alone. In contrast, when the administration of naive αβ T cells was delayed for 2 wk post-BMT, survival was significantly enhanced in mice transplanted with BM plus activated γδ T cells vs those given marrow cells alone. Mitigation of GVHD by activated γδ T cells occurred only at high doses (150 × 106) and was a unique property of γδ T cells, as activated αβ T cells were incapable of ameliorating the subsequent development of GVHD. Protection from GVHD was not due to the direct inhibition of naive αβ T cells by γδ T cells. Rather, γδ T cells mediated this effect indirectly through donor BM-derived αβ T cells that acted as the proximate regulatory population responsible for the decrease in GVH reactivity. Collectively, these data demonstrate that activated γδ T cells are capable of modulating the ability of MHC-incompatible nontolerant αβ T cells to cause GVHD after allogeneic BMT.
The Effect of a T Cell-Specific NF-κB Inhibitor on In Vitro Cytokine Production and Collagen-Induced Arthritis
Authors: Gerlag Danielle M. , Ransone Lynn , Tak Paul P. , Han Zuoning , Palanki Moorthy , Barbosa Miguel S. , Boyle David , Manning Anthony M. , Firestein Gary S. 
Published: April 2014

AbstractNF-κB plays a key role in the production of cytokines in inflammatory diseases. The effects of a novel T cell-specific NF-κB inhibitor, SP100030, were evaluated in cultured Jurkat cells and in murine collagen-induced arthritis (CIA). Chemical libraries were screened for NF-κB-inhibitory activity. SP100030, a compound identified in this process, inhibited NF-κB activation in PMA/PHA-activated Jurkat cells by EMSA at a concentration of 1 μM. Jurkat cells and the monocytic cell line THP-1 were transfected with an NF-κB promotor/luciferase construct and activated. SP100030 inhibited luciferase production in the Jurkat cells (IC50 = 30 nM). ELISA and RT-PCR confirmed that IL-2, IL-8, and TNF-α production by activated Jurkat and other T cell lines were inhibited by SP100030. However, cytokine expression was not blocked by the compound in THP-1 cells, fibroblasts, endothelial cells, or epithelial cells. Subsequently, DBA/1J mice were immunized with type II collagen. Treatment with SP100030 (10 mg/kg/day i.p. beginning on day 21) significantly decreased arthritis severity from onset of clinical signs to the end of the study on day 34 (arthritis score, 5.6 ± 1.7 for SP100030 and 9.8 ± 1.5 for control; p &lt; 0.001). Histologic evaluation demonstrated a trend toward improvement in SP100030-treated animals. EMSA of arthritic mouse ankles in CIA showed that synovial NF-κB binding was suppressed in the SP100030-treated mice. SP100030 inhibits NF-κB activation in T cells, resulting in reduced NF-κB-regulated gene expression and decreased CIA. Its selectivity for T cells could provide potent immunosuppression with less toxicity than other NF-κB inhibitors.
α-Glycosylceramides Enhance the Antitumor Cytotoxicity of Hepatic Lymphocytes Obtained from Cancer Patients by Activating CD3−CD56+ NK Cells In Vitro
Authors: Ishihara Soichiro , Nieda Mie , Kitayama Joji , Osada Takuya , Yabe Toshio , Kikuchi Akiko , Koezuka Yasuhiko , Porcelli Steven A. , Tadokoro Kenji , Nagawa Hirokazu , Juji Takeo 
Published: April 2014

Abstractα-Glycosylceramides, such as α-galactosylceramide and α-glucosylceramide, induce antitumor immunity in various murine cancer models. In the murine hepatic metastasis model, Vα14 TCR+NK1.1+ T cells, which accumulate preferentially in the liver, are considered to play a key role in the induction of antitumor immunity by α-glycosylceramides. We recently reported that Vα24 TCR+ NKT cells, the human homologues of murine Vα14 TCR+NK1.1+cells, are rarely seen among freshly isolated human hepatic lymphocytes. Therefore, it is important to examine whether α-glycosylceramides also enhance the antitumor cytotoxicity of human hepatic lymphocytes, as they have been shown to do in murine systems, to determine the usefulness of α-glycosylceramides in cancer immunotherapy in humans. Here, we show that α-glycosylceramides greatly enhance the cytotoxicity of human hepatic lymphocytes obtained from cancer patients against the tumor cell lines, K562 and Colo201, in vitro. The direct effector cells of the elicited cytotoxicity were CD3−CD56+ NK cells. Even though Vα24 TCR+NKT cells proliferated remarkably in response to α-glycosylceramides, they did not contribute directly to the cytotoxicity. Our observations strongly suggest the potential usefulness of α-glycosylceramides for immunotherapy of liver cancer in humans based on their ability to activate CD3−CD56+ NK cells in the liver.
Genetic Control of Glycoprotein 70 Autoantigen Production and Its Influence on Immune Complex Levels and Nephritis in Murine Lupus
Authors: Tucker Rebecca M. , Vyse Timothy J. , Rozzo Stephen , Roark Christina L. , Izui Shozo , Kotzin Brian L. 
Published: April 2014

AbstractThe F1 hybrids of New Zealand Black (NZB) and New Zealand White (NZW) mice spontaneously develop an autoimmune disease that serves as a model for human systemic lupus erythematosus. Autoimmunity in (NZB × NZW)F1 mice includes the production of autoantibodies to the endogenous retroviral envelope glycoprotein, gp70, and gp70-anti-gp70 immune complexes (gp70 IC) have been implicated in the development of lupus nephritis in these animals. We used backcross and intercross combinations of C57BL/6 (B6; low gp70 levels) and NZB mice (high gp70 levels) to examine the contribution of serum gp70 Ag levels to the development of gp70 IC and nephritis. Analysis of (B6.H2z × NZB)F1 × NZB backcross mice and (NZB × B6)F2 mice showed a much stronger association of gp70 IC with kidney disease compared with IgG anti-chromatin autoantibodies in both populations of mice. Serum levels of gp70 correlated with production of gp70 IC in mice producing autoantibodies, although the overall effect on nephritis appeared to be small. Genetic mapping revealed three NZB-derived regions on chromosomes 2, 4, and 13 that were strongly linked with increased gp70 levels, and together, accounted for over 80% of the variance for this trait. However, additional linkage analyses of these crosses showed that loci controlling autoantibody production rather than gp70 levels were most important in the development of nephritogenic immune complexes. Together, these studies characterize a set of lupus-susceptibility loci distinct from those that control autoantibody production and provide new insight into the components involved in the strong association of gp70 IC with murine lupus nephritis.
Dynamics of HIV-Specific CD8+ T Lymphocytes with Changes in Viral Load
Authors: Mollet Lucile , Li Tai-Sheng , Samri Assia , Tournay Claire , Tubiana Roland , Calvez Vincent , Debré Patrice , Katlama Christine , Autran Brigitte ,   the RESTIM and COMET Study Groups
Published: April 2014

AbstractThe influence of HIV burden variations on the frequencies of Ag-specific CD8+ T cell responses was evaluated before and during highly active antiretroviral therapy by analyzing the number, diversity, and function of these cells. The frequencies of HLA-A2-restricted CD8+ PBL binding HLA-A2/HIV-epitope tetramers or producing IFN-γ were below 1%. A panel of 16 CTL epitopes covering 15 HLA class I molecules in 14 patients allowed us to test 3.8 epitopes/patient and to detect 2.2 ± 1.8 HIV epitope-specific CD8+ subsets per patient with a median frequency of 0.24% (0.11–4.79%). During the first month of treatment, viral load rapidly decreased and frequencies of HIV-specific CD8 PBL tripled, eight new HIV specificities appeared of 11 undetectable at entry, while CMV-specific CD8+ PBL also appeared. With efficient HIV load control, all HIV specificities decayed involving a reduction of the CD8+CD27+CD11ahigh HIV-specific effector subset. Virus rebounds triggered by scheduled drug interruptions or transient therapeutic failures induced four patterns of epitope-specific CD8+ lymphocyte dynamics, i.e., peaks or disappearance of preexisting specificities, emergence of new specificities, or lack of changes. The HIV load rebounds mobilized both effector/memory HIV- and CMV-specific CD8+ lymphocytes. Therefore, frequencies of virus-specific CD8 T cells appear to be positively correlated to HIV production in most cases during highly active antiretroviral therapy, but an inverse correlation can also be observed with rapid virus changes that might involve redistribution, sequestration, or expansion of these Ag-specific CD8 T cells. Future strategies of therapeutic interruptions should take into account these various HIV-specific cell dynamics during HIV rebounds.
Fusions of Human Ovarian Carcinoma Cells with Autologous or Allogeneic Dendritic Cells Induce Antitumor Immunity
Authors: Gong Jianlin , Nikrui Najmosama , Chen Dongshu , Koido Shigeo , Wu Zekui , Tanaka Yasuhiro , Cannistra Stephen , Avigan David , Kufe Donald 
Published: April 2014

Abstract
Human ovarian carcinomas express the CA-125, HER2/neu, and MUC1 tumor-associated Ags as potential targets for the induction of active specific immunotherapy. In the present studies, human ovarian cancer cells were fused to human dendritic cells (DC) as an alternative strategy to induce immunity against known and unidentified tumor Ags. Fusions of ovarian cancer cells to autologous DC resulted in the formation of heterokaryons that express the CA-125 Ag and DC-derived costimulatory and adhesion molecules. Similar findings were obtained with ovarian cancer cells fused to allogeneic DC. The fusion cells were functional in stimulating the proliferation of autologous T cells. The results also demonstrate that fusions of ovarian cancer cells to autologous or allogeneic DC induce cytolytic T cell activity and lysis of autologous tumor cells by a MHC class I-restricted mechanism. These findings demonstrate that fusions of ovarian carcinoma cells and DC activate T cell responses against autologous tumor and that the fusions are functional when generated with either autologous or allogeneic DC.
Cutting Edge: The T Cell Chemoattractant IFN-Inducible Protein 10 Is Essential in Host Defense Against Viral-Induced Neurologic Disease
Authors: Liu Michael T. , Chen Benjamin P. , Oertel Patricia , Buchmeier Michael J. , Armstrong David , Hamilton Thomas A. , Lane Thomas E. 
Published: April 2014

AbstractThe contribution of the T cell chemoattractant chemokine IFN-inducible protein 10 (IP-10) in host defense following viral infection of the CNS was examined. IP-10 is expressed by astrocytes during acute encephalomyelitis in mouse hepatitis virus-infected mice, and the majority of T lymphocytes infiltrating into the CNS expressed the IP-10 receptor CXCR3. Treatment of mice with anti-IP-10 antisera led to increased mortality and delayed viral clearance from the CNS as compared with control mice. Further, administration of anti-IP-10 led to a &gt;70% reduction (p ≤ 0.001) in CD4+ and CD8+ T lymphocyte infiltration into the CNS, which correlated with decreased (p ≤ 0.01) levels of IFN-γ. These data indicate that IP-10 functions as a sentinel molecule in host defense and is essential in the development of a protective Th1 response against viral infection of the CNS.
Cutting Edge: CD7 Delivers a Pro-Apoptotic Signal During Galectin-1-Induced T Cell Death
Authors: Pace Karen E. , Hahn Hejin P. , Pang Mabel , Nguyen Julie T. , Baum Linda G. 
Published: April 2014

AbstractGalectin-1, an endogenous lectin expressed in lymphoid organs and immune-privileged sites, induces death of human and murine thymocytes and T cells. Galectin-1 binds to several glycoproteins on the T cell surface, including CD7. However, the T cell surface glycoprotein receptors responsible for delivering the galectin-1 death signal have not been identified. We show that CD7 is required for galectin-1-mediated death. This demonstrates a novel function for CD7 as a death trigger and identifies galectin-1/CD7 as a new biologic death signaling pair.
Cutting Edge: Outer Membrane Protein A (OmpA) Binds to and Activates Human Macrophages
Authors: Soulas Caroline , Baussant Thierry , Aubry Jean-Pierre , Delneste Yves , Barillat Nicolas , Caron Gersende , Renno Toufic , Bonnefoy Jean-Yves , Jeannin Pascale 
Published: April 2014

AbstractOuter membrane protein (Omp)A is highly represented and conserved in the Enterobacteriaceae family. Using a recombinant OmpA from Klebsiella pneumoniae (P40), we have analyzed the interaction between OmpA and macrophages. We report that Alexa488-labeled P40 binds (at 4°C) to murine and human macrophages in a dose-dependent manner and is rapidly internalized (at 37°C). No binding or internalization of the Alexa488-labeled glycophorin A control protein is observed under the same conditions. Furthermore, P40 up-regulates the production of IL-1β, IL-8, IL-10, IL-12, and TNF-α by human macrophages and of NO by the RAW 264.7 murine macrophage cell line. P40 also synergizes with IFN-γ and suboptimal concentrations of LPS to up-regulate the production of these mediators. In conclusion, P40 binds to and activates macrophages. These data suggest that recognition of OmpA by macrophages may be an initiating event in the antibacterial host response.
Stress Renders T Cell Blasts Sensitive to Killing by Activated Syngeneic NK Cells
Authors: Rabinovich Brian A. , Shannon John , Su Ruey-Chyi , Miller Richard G. 
Published: April 2014

AbstractExposure of primary T cell blasts to stress in the forms of heat, hydrogen peroxide, or high-density growth conditions resulted in a state of enhanced susceptibility to killing by syngeneic IL-2-activated NK cells or lymphokine-activated killer cells, but not to killing by CTL. Cytotoxicity was perforin mediated and was not due to decreased target expression of total MHC class I. The levels of stress used had little effect on cell viability. For thermal stress, sensitization increased with temperature, required a minimum exposure time, and disappeared when cells were given a long enough recovery time. Our data support a model that predicts that activated NK cells play a role in the immunosurveillance of nontransformed stressed cells in normal animals.
Break of T Cell Ignorance to a Viral Antigen in the Liver Induces Hepatitis
Authors: Voehringer David , Blaser Claudine , Grawitz Andrea Busse , Chisari Francis V. , Buerki Kurt , Pircher Hanspeter 
Published: April 2014

AbstractTo study peripheral tolerance of CD8 T cells to a classically MHC-restricted peptide Ag expressed in hepatocytes, ALB1 transgenic (tg) mice expressing the CTL epitope GP33 of the lymphocytic choriomeningitis virus glycoprotein under control of the mouse albumin promoter were generated. ALB1 mice exclusively expressed the GP33 transgene in the liver and, at a 100- to 1000-fold lower level, in the thymus. TCR-tg mice specific for the GP33 epitope were used to directly follow GP33-specific T cells in vivo. These experiments revealed that 1) thymic expression of the GP33 transgene led to incomplete central deletion of TCR-tg cells; and 2) peripheral TCR-tg cells in ALB1 mice ignored the GP33 transgene expressed in hepatocytes. Ignorance of adoptively transferred TCR-tg cells in ALB1 mice was broken by infection with lymphocytic choriomeningitis virus, leading to induction of hepatitis in ALB1, but not in control, mice. Taken together, we have established a novel model of virus-induced CD8 T cell-mediated autoimmune hepatitis in mice and demonstrate that naive CD8 T cells may ignore Ags expressed in the liver.
Activation Via Multiple Signaling Pathways Induces Down-Regulation of Platelet-Activating Factor Receptors on Human B Lymphocytes
Authors: Zhuang Qianli , Bastien Yolande , Mazer Bruce D. 
Published: April 2014

AbstractPlatelet-activating factor receptor (PAFR) has been identified in B cell lines and primary human B cells, but the regulation of PAFR during B cell activation has not been completely elucidated. In the present study, we have investigated the effects of B cell activation on PAFR binding parameters, PAFR mRNA and PAF-triggered intracellular calcium mobilization. The human B lymphoid cell line LA350 was shown to exhibit high levels of PAFR (48,550 ± 4,310 sites/cell) as determined by radio-ligand binding assay with PAFR antagonist [3H]WEB2086. Treatment with phorbol 12,13-dibutyrate caused a biphasic reduction of PAFR binding. The early phase was inhibited by the protein kinase C inhibitor bisindolylmaleimide I (BIM), whereas the late phase was not blocked by BIM, protein tyrosine kinase inhibitor genistein, or the mitogen-activated protein kinase/extracellular signal-related kinase inhibitor PD98059. However, staurosporine, a broad-spectrum protein kinase inhibitor, completely inhibited the late phase down-regulation. Ionomycin also decreased [3H]WEB2086 binding sites, whereas the combination of PDB and ionomycin induced a greater reduction than either agent alone. Cross-linking of B cell receptor by anti-IgM Ab also induced down-regulation of PAFR, which was abolished by genistein or PD98059, but not by BIM or staurosporine. The decrease in surface PAFR number was closely paralleled by the reduction in PAFR mRNA both in LA350 cells and human tonsillar B cells, and was associated with decreased response to PAF indicated by decreased intracellular calcium mobilization. These data show that multiple signaling pathways are involved in down-regulating PAFR expression during B cell activation and development.
Survival and Homeostatic Proliferation of Naive Peripheral CD4+ T Cells in the Absence of Self Peptide:MHC Complexes
Authors: Clarke Sally R. M. , Rudensky Alexander Y. 
Published: April 2014

AbstractTCR-self peptide:MHC interactions play a critical role in thymic positive selection, yet relatively little is known of their function in the periphery. It has been suggested that continued contact with selecting MHC molecules is necessary for long-term peripheral maintenance of naive T cells. More recent studies have also demonstrated a role for specific self peptide:MHC complexes in the homeostatic expansion of naive T cells in lymphopenic mice. Our examination of these processes revealed that, whereas self class II MHC molecules do have a modest effect on long-term survival of individual CD4+ T cells, interactions with specific TCR ligands are not required for peripheral naive CD4+ T cell maintenance. In contrast, selective engagement of TCRs by self-peptide:MHC complexes does promote proliferation of CD4+ T cells under severe lymphopenic conditions, and this division is associated with an activation marker phenotype that is different from that induced by antigenic stimulation. Importantly, however, the ability of naive T cells to divide in response to homeostatic stimuli does not appear to be stringently dependent on TCR-self peptide:MHC interactions. Therefore, these results show that the factors regulating survival and homeostatic expansion of naive T cells in the periphery are not identical. In addition, we provide evidence for a novel form of T cell proliferation that can occur independently of TCR signaling and suggest that this reflects another mechanism regulating homeostatic T cell expansion.
Binding Kinetics, Structure-Activity Relationship, and Biotransformation of the Complement Inhibitor Compstatin
Authors: Sahu Arvind , Soulika Athena M. , Morikis Dimitrios , Spruce Lynn , Moore William T. , Lambris John D. 
Published: April 2014

Abstract
We have previously identified a 13-residue cyclic peptide, Compstatin, that binds to complement component C3 and inhibits complement activation. Herein, we describe the binding kinetics, structure-activity relationship, and biotransformation of Compstatin. Biomolecular interaction analysis using surface-plasmon resonance showed that Compstatin bound to native C3 and its fragments C3b and C3c, but not C3d. While binding of Compstatin to native C3 was biphasic, binding to C3b and C3c followed the 1:1 Langmuir binding model; the affinities of Compstatin for C3b and C3c were 22- and 74-fold lower, respectively, than that of native C3. Analysis of Compstatin analogs synthesized for structure-function studies indicated that 1) the 11-membered ring between disulfide-linked Cys2-Cys12 constitutes a minimal structure required for optimal activity; 2) retro-inverso isomerization results in loss of inhibitory activity; and 3) some residues of the type I β-turn segment also interact with C3. In vitro studies of Compstatin in human blood indicated that a major pathway of biotransformation was the removal of Ile1, which could be blocked by N-acetylation of the peptide. These findings indicate that acetylated Compstatin is stable against enzymatic degradation and that the type I β-turn segment is not only critical for preservation of the conformational stability, but also involved in intermolecular recognition.
Apoptosis Induced by TGF-β1 in Burkitt’s Lymphoma Cells Is Caspase 8 Dependent But Is Death Receptor Independent
Authors: Inman Gareth J. , Allday Martin J. 
Published: April 2014

AbstractTGF-β is a potent inducer of apoptosis in many Burkitt’s lymphoma (BL) cell lines. In this study, we characterize this apoptotic process in the EBV-negative BL41 cell line. Induction of apoptosis was detected as early as 8 h after TGF-β treatment, as assayed by TUNEL and poly(ADP-ribose) polymerase cleavage. FACS analysis demonstrates that this proceeds predominately from the G1, but also from the G2/M phases of the cell cycle. We observed no early detectable changes in the steady-state levels of Bcl-2 and several of its family members after TGF-β treatment. We detected cleavage of caspases 2, 3, 7, 8, and 9 into their active subunits. Consistent with the involvement of these enzymes in TGF-β-mediated apoptosis, the broad spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(Ome)-flouromethylketone (ZVAD-fmk) blocked TGF-β-induced apoptosis and revealed a G1 arrest in treated cells. Use of specific caspase inhibitors revealed that the induction of apoptosis is caspase 8 dependent, but caspase 3 independent. Activation of caspase 8 has been shown to be a critical event in death receptor-mediated apoptosis. However, TGF-β treatment of BL41 cells was found not to affect the cell surface expression of Fas, TNF-R1, DR3, DR4, or DR5, or the steady-state expression levels of Fas ligand, TNF-R1, DR3, DR4, and DR5. Furthermore, blocking experiments indicated that TGF-β-mediated apoptosis is not dependent on Fas ligand, TNF-α, tumor necrosis-like apoptosis-inducing ligand, or TNF-like weak inducer of apoptosis signaling. Therefore, it appears that TGF-β induces apoptosis in BL cell lines via caspase 8 in a death receptor-independent fashion.