bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulation through CD40 on Mouse and Human Renal Cell Carcinomas Triggers Cytokine Production, Leukocyte Recruitment, and Antitumor Responses that Can Be Independent of Host CD40 Expression
Authors: Shorts Lynnette , Weiss Jonathan M. , Lee Jong-Keuk , Welniak Lisbeth A. , Subleski Jeffrey , Back Timothy , Murphy William J. , Wiltrout Robert H. 
Published: April 2014

AbstractCD40, a member of the TNFR superfamily, is expressed on a variety of host immune cells, as well as some tumors. In this study, we show that stimulation of CD40 expressed on both mouse and human renal carcinoma cells (RCCs) triggers biological effects in vitro and in vivo. Treatment of the CD40+ Renca mouse RCC tumor cells in vitro with an agonistic anti-CD40 Ab induced strong expression of the genes and proteins for GM-CSF and MCP-1, and induced potent chemotactic activity. Similarly, administration of αCD40 to both wild-type and CD40−/− mice bearing Renca tumors resulted in substantial amounts of TNF-α and MCP-1 in the serum, increased the number of total splenocytes and MHC class II+ CD11c+ leukocytes, and when combined with IFN-γ, inhibited the progression of established Renca tumors in vivo in both wild-type and CD40−/− mice. Similarly, treatment of CD40+ A704 and ACHN human RCC lines with mouse anti-human CD40 Ab induced strong expression of genes and proteins for MCP-1, IL-8, and GM-CSF in vitro and in vivo. Finally, in SCID mice, the numbers of ACHN pulmonary metastases were dramatically reduced by treatment with species-specific human CD40 Ab. These results show that CD40 stimulation of CD40+ tumor cells can enhance immune responses and result in antitumor activity.
TCRγδ Intraepithelial Lymphocytes Are Required for Self-Tolerance
Authors: Locke Natasha R. , Stankovic Sanda , Funda David P. , Harrison Leonard C. 
Published: April 2014

AbstractNeonatal thymectomy (NTX) impairs T cell regulation and leads to organ-specific autoimmune disease in susceptible mouse strains. In the NOD mouse model of spontaneous type 1 diabetes, we observed that NTX dramatically accelerated autoimmune pancreatic β cell destruction and diabetes. NTX had only a minor effect in NOD mice protected from diabetes by transgenic expression of the β cell autoantigen proinsulin in APCs, inferring that accelerated diabetes after NTX is largely due to failure to regulate proinsulin-specific T cells. NTX markedly impaired the development of intraepithelial lymphocytes (IEL), the number of which was already reduced in euthymic NOD mice compared with control strains. IEL purified from euthymic NOD mice, specifically CD8αα TCRγδ IEL, when transferred into NTX-NOD mice, trafficked to the small intestinal epithelium and prevented diabetes. Transfer of prototypic CD4+CD25+ regulatory T cells also prevented diabetes in NTX-NOD mice; however, the induction of these cells by oral insulin in euthymic mice depended on the integrity of TCRγδ IEL. We conclude that TCRγδ IEL at the mucosal interface between self and nonself play a key role in maintaining peripheral tolerance both physiologically and during oral tolerance induction.
Impact of Orthologous Melan-A Peptide Immunizations on the Anti-Self Melan-A/HLA-A2 T Cell Cross-Reactivity
Authors: Colombetti Sara , Fagerberg Theres , Baumgärtner Petra , Chapatte Laurence , Speiser Daniel E. , Rufer Nathalie , Michielin Olivier , Lévy Frédéric 
Published: April 2014

AbstractIn HLA-A2 individuals, the CD8 T cell response against the differentiation Ag Melan-A is mainly directed toward the peptide Melan-A26–35. The murine Melan-A24–33 sequence encodes a peptide that is identical with the human Melan-A26–35 decamer, except for a Thr-to-Ile substitution at the penultimate position. Here, we show that the murine Melan-A24–33 is naturally processed and presented by HLA-A2 molecules. Based on these findings, we compared the CD8 T cell response to human and murine Melan-A peptide by immunizing HLA-A2 transgenic mice. Even though the magnitude of the CTL response elicited by the murine Melan-A peptide was lower than the one elicited by the human Melan-A peptide, both populations of CTL recognized the corresponding immunizing peptide with the same functional avidity. Interestingly, CTL specific for the murine Melan-A peptide were completely cross-reactive against the orthologous human peptide, whereas anti-human Melan-A CTL recognized the murine Melan-A peptide with lower avidity. Structurally, this discrepancy could be explained by the fact that Ile32 of murine Melan-A24–33 created a larger TCR contact area than Thr34 of human Melan-A26–35. These data indicate that, even if immunizations with orthologous peptides can induce strong specific T cell responses, the quality of this response against syngeneic targets might be suboptimal due to the structure of the peptide-TCR contact surface.
Abrogation of Functional Selectin-Ligand Expression Reduces Migration of Pathogenic CD8+ T Cells into Heart
Authors: Cai Yi Hong , Alvarez Angeles , Alcaide Pilar , Duramad Paurene , Lim Yaw-Chin , Jarolim Petr , Lowe John B. , Luscinskas Francis W. , Lichtman Andrew H. 
Published: April 2014

AbstractCD8+ T cells are involved in autoimmune and infectious myocarditis and cardiac allograft rejection. The role of selectins in cardiac recruitment of CD8+ T cells is not understood. In this study, the contribution of T cell selectin ligands to effector CD8+ T cell recruitment into the heart was examined using a model of myocarditis, which depends on transfer of OVA peptide-specific CD8+ T cells (OT-I) into mice (CMy-mOva) that express OVA in the heart. α-(1,3)-Fucosyltransferase (FucT)-VII-deficient OT-I cells displayed over a 95% reduction in their ability to interact with P-selectin under flow conditions in vitro, compared with wild-type OT-I cells. Interaction of FucT-VII-deficient OT-I cells with E-selectin was reduced ∼50%. FucT-VII-deficient OT-I cells were also less efficiently recruited into a dermal site of Ag and adjuvant injection. Significantly, FucT-VII-deficient OT-I cells were also impaired in their ability to migrate into CMy-mOva hearts, compared with wild-type OT-I cells. Transfer of FucT-VII-deficient T cells caused less severe early myocarditis and myocyte damage than transfer of wild-type T cells. Combined FucT-IV/VII-deficient OT-I cells displayed a more profound reduction in E-selectin interactions in vitro compared with FucT-VII-deficient T cells, and the FucT-IV/VII-deficient T cells also showed less early recruitment and pathogenicity in the CMy-mOva myocarditis model. These results identify a prominent role for selectin ligands in contributing to effector CD8+ T cell recruitment into the myocardium and indicate that selectin-dependent T cell recruitment is relevant to other tissues besides the skin.
A Complex of Wiskott-Aldrich Syndrome Protein with Mammalian Verprolins Plays an Important Role in Monocyte Chemotaxis
Authors: Tsuboi Shigeru 
Published: April 2014

AbstractThe Wiskott-Aldrich syndrome protein (WASP) is a product of the gene defective in an Xid disorder, Wiskott-Aldrich syndrome. WASP expression is limited to hemopoietic cells, and WASP regulates the actin cytoskeleton. It has been reported that monocytes/macrophages from WASP-deficient Wiskott-Aldrich syndrome patients are severely defective in chemotaxis, resulting in recurrent infection. However, the molecular basis of such chemotactic defects is not understood. Recently, the WASP N-terminal region was found to bind to the three mammalian verprolin homologs: WASP interacting protein (WIP); WIP and CR16 homologous protein (WICH)/WIP-related protein (WIRE); and CR16. Verprolin was originally found to play an important role in the regulation of actin cytoskeleton in yeast. We have shown that WASP, WIP, and WICH/WIRE are expressed predominantly in the human monocyte cell line THP-1 and that WIP and WICH/WIRE are involved in monocyte chemotaxis. When WASP binding to verprolins was blocked, chemotactic migration of monocytes was impaired in both THP-1 cells and primary human monocytes. Increased expression of WASP and WIP enhanced monocyte chemotaxis. Blocking WASP binding to verprolins impaired cell polarization but not actin polymerization. These results indicate that a complex of WASP with mammalian verprolins plays an important role in chemotaxis of monocytes. Our results suggest that WASP and mammalian verprolins function as a unit in monocyte chemotaxis and that the activity of this unit is critical to establish cell polarization. In addition, our results also indicate that the WASP-verprolin complex is involved in other functions such as podosome formation and phagocytosis.
CD4+CD25+Foxp3+ T Cells and CD4+CD25−Foxp3+ T Cells in Aged Mice
Authors: Nishioka Tomohisa , Shimizu Jun , Iida Ryuji , Yamazaki Sayuri , Sakaguchi Shimon 
Published: April 2014

Abstract
Aging is associated with a progressive decline in T cell-mediated immune responses. However, it has been unknown whether regulatory/suppressive CD4 T cells are involved in this decline. Our in vitro analyses revealed that CD4+CD25+ T cells, the well-characterized naturally occurring regulatory/suppressive CD4 T cells, in aged mice are functionally comparable to those in young mice (i.e., anergic and suppressive), although slightly increased in number. In contrast, functional changes to whole CD4+CD25− T cells were pronounced in aged mice, i.e., the majority of aged CD4+CD25− T cells exhibited a significant hyporesponsiveness, and the remaining cells maintained a normal responsiveness. Furthermore, we identified Foxp3 (a transcription factor critical in conferring the regulatory/suppressive function to CD4 T cells)-positive suppressive CD4 T cells among aged hyporesponsive CD4+CD25− T cells. These results suggest that the age-related decline in T cell-mediated immune responses is ascribable to changes in the CD4+CD25− T cell population and not to a functional augmentation of suppressive CD4+CD25+ T cells.
Macrophage-Colony-Stimulating Factor-Induced Proliferation and Lipopolysaccharide-Dependent Activation of Macrophages Requires Raf-1 Phosphorylation to Induce Mitogen Kinase Phosphatase-1 Expression
Authors: Sánchez-Tilló Ester , Comalada Mónica , Farrera Consol , Valledor Annabel F. , Lloberas Jorge , Celada Antonio 
Published: April 2014

AbstractMacrophages are key regulators of immune responses. In the absence of an activating signal, murine bone marrow-derived macrophages undergo proliferation in response to their specific growth factor, namely M-CSF. The addition of bacterial LPS results in macrophage growth arrest and their engagement in a proinflammatory response. Although participation of ERKs is required for both macrophage proliferation and activation, ERK phosphorylation follows a more delayed pattern in response to activating agents. In primary macrophages, mitogen kinase phosphatase-1 (MKP-1) is a key regulator of the time course of MAPK activity. Here we showed that MKP-1 expression is dependent on Raf-1 activation. The time course of Raf-1 activation correlated with that of ERK-1/2. However, whereas ERK phosphorylation in response to M-CSF is Raf-1 dependent, in response to LPS, an alternative pathway directs the activation of these kinases. Inhibition of Raf-1 activity increased the expression of cyclin-dependent kinase inhibitors and growth arrest. In contrast, no effect was observed in the expression of proinflammatory cytokines and inducible NO synthase following LPS stimulation. The data reported here reveal new insights into how signaling determines opposing macrophage functions.
B and T Lymphocyte Attenuator-Mediated Signal Transduction Provides a Potent Inhibitory Signal to Primary Human CD4 T Cells That Can Be Initiated by Multiple Phosphotyrosine Motifs
Authors: Chemnitz Jens M. , Lanfranco Anthony R. , Braunstein Inbal , Riley James L. 
Published: April 2014

AbstractThe B and T lymphocyte attenuator (BTLA) is a recently identified member of the CD28 family of cell receptors. Initial reports demonstrated that mice deficient in BTLA expression were more susceptible to experimental autoimmune encephalomyelitis, indicating that BTLA was likely to function as a negative regulator of T cell activation. However, cross-linking of BTLA only resulted in a 2-fold reduction of IL-2 production, questioning the potency with which BTLA engagement blocks T cell activation. We established a model in which BTLA signaling could be studied in primary human CD4 T cells. We observed that cross-linking of a chimeric receptor consisting of the murine CD28 extracellular domain and human BTLA cytoplasmic tail potently inhibits IL-2 production and completely suppresses T cell expansion. Mutation of any BTLA tyrosine motifs had no effect on the ability of BTLA to block T cell activation. Only mutation of all four tyrosines rendered the BTLA cytoplasmic tail nonfunctional. We performed structure-function studies to determine which factors recruited to the BTLA cytoplasmic tail correlated with BTLA function. Using pervanadate as a means to phosphorylate the BTLA cytoplasmic tail, we observed both Src homology protein (SHP)-1 and SHP-2 recruitment. However, upon receptor engagement, we observed only SHP-1 recruitment, and mutations that abrogated SHP-1 recruitment did not impair BTLA function. These studies question whether SHP-1 or SHP-2 have any role in BTLA function and caution against the use of pervanadate as means to initiate signal transduction cascades in primary cells.
Regulation of Ly49D/DAP12 Signal Transduction by Src-Family Kinases and CD45
Authors: Mason Llewellyn H. , Willette-Brown Jami , Taylor Lynn S. , McVicar Daniel W. 
Published: April 2014

AbstractActivating, DAP12-coupled members of the Ly-49 family of NK cell receptors help control viral infections in mice. However, the kinases and/or phosphatases mediating tyrosine phosphorylation of Ly-49D-associated DAP12 have not been elucidated. In this study, we show for the first time that Src family tyrosine kinases are physically and functionally associated with Ly-49D/DAP12 signaling in murine NK cells. Specifically, we demonstrate the following: 1) inhibition of Src family kinases suppresses DAP12 phosphorylation and downstream DAP12 signals; 2) both Fyn and Lck are capable of phosphorylating DAP12; and 3) both kinases coimmunoprecipitate with the Ly-49D/DAP12 complex in NK cells. Although we detect enhanced phosphorylation of Fyn upon Ly-49D cross-linking in NK cells, Ly-49D-mediated events in both Fyn−/− and Fyn/Lck−/− mice appear normal, reinforcing the theme of redundancy in the ability of Src family kinases to initiate activation events. In contrast to disruption of specific Src family enzymes, Ly-49D/DAP12-mediated calcium mobilization and cytokine production by CD45 null NK cells are defective. Although others have ascribed the effects of CD45 mutation solely on the suppression of Src family activity, we demonstrate in this study that DAP12 is hyperphosphorylated in CD45 null NK cells, resulting in uncoordinated tyrosine-mediated signaling upon Ly-49D ligation. Therefore, although our data are consistent with a Src kinase activity proximally within DAP12 signaling, DAP12 also appears to be a substrate of CD45, suggesting a more complex role for this phosphatase than has been reported previously.
Antitumor Activity of the TLR-5 Ligand Flagellin in Mouse Models of Cancer
Authors: Sfondrini Lucia , Rossini Anna , Besusso Dario , Merlo Andrea , Tagliabue Elda , Mènard Sylvie , Balsari Andrea 
Published: April 2014

Abstract
Flagellin, the structural protein subunit of the bacterial flagellum, is specifically recognized by TLR-5 and has potent immunomodulatory effects. The antitumor effects of purified Salmonella typhimurium flagellin were evaluated in mice transplanted s.c. with a weakly immunogenic murine tumor or with its variant stably transfected to express the highly antigenic human HER-2 oncoprotein. Peritumoral administration of flagellin 8–10 days after tumor implantation did not affect the growth rate of the weakly immunogenic tumor but significantly inhibited growth of the antigenic variant tumor. In contrast, flagellin administered at the time of implantation of the antigenic tumor led to accelerated tumor growth. These contrasting effects of flagellin on tumor growth correlated with the type of immune response induced; i.e., late flagellin administration was associated with an increased IFN-γ:IL-4 ratio and the decreased frequency of CD4+CD25+ T regulatory cells, whereas flagellin treatment at the time of tumor implantation decreased the IFN-γ:IL-4 ratio and increased CD4+CD25+ T cell frequency. When the early flagellin treatment was combined with administration of CpG-containing oligodeoxynucleotides, tumor growth was completely suppressed, indicating synergy between flagellin and CpG-containing oligodeoxynucleotides. Together, these data provide evidence that flagellin can have contrasting effects on tumor growth.
Functional Regulatory T Cells Are Collected in Stem Cell Autografts by Mobilization with High-Dose Cyclophosphamide and Granulocyte Colony-Stimulating Factor
Authors: Condomines Maud , Quittet Philippe , Lu Zhao-Yang , Nadal Laure , Latry Pascal , Lopez Ernesto , Baudard Marion , Requirand Guilhem , Duperray Christophe , Schved Jean-François , Rossi Jean-François , Tarte Karin , Klein Bernard 
Published: April 2014

Abstract
High-dose cyclophosphamide (Cy) and G-CSF are widely used to mobilize hemopoietic stem cells for treating patients with high-dose chemotherapy and autologous stem cell transplantation (ASCT). Because lymphocyte count in the graft collected after Cy-G-CSF treatment is an independent survival factor after ASCT for patients with multiple myeloma, our purpose was to study how Cy-G-CSF treatment affects the phenotype and function of T cells in patients with multiple myeloma. Cy induced a 3-fold decrease of T cell counts with a slow and partial T cell recovery of one-third at the time of hemopoietic stem cell collection. Cy-G-CSF treatment did not affect the relative ratios of central memory, effector memory, and late effector CD4+ or CD8+ T cells, but a decrease in the percentage of naive CD4+ cells was observed. The percentages of CD25+ cells increased 2- to 3-fold in CD4+ and CD8+ T cells, the former including both activated CD25low and CD25high cells. CD4+CD25high cells were regulatory T cells (Treg) that expressed high levels of FOXP3, CTLA-4, and GITR and displayed in vitro suppressive properties. The recovery of Treg absolute counts after Cy-G-CSF treatment was higher than the recovery of other lymphocyte subpopulations. In conclusion, Cy-G-CSF treatment induces a severe T cell count decrease without deleting Treg, which are potent inhibitors of antitumor response. The present data encourage novel therapeutic strategies to improve T cell recovery following ASCT while limiting Treg expansion.
Differential Signaling of T Cell Generation of IL-4 by Wild-Type and Short-Deletion Variant of Type 2 G Protein-Coupled Receptor for Vasoactive Intestinal Peptide (VPAC2)
Authors: Huang Mei-Chuan , Miller Allison L. , Wang Wengang , Kong Yvonne , Paul Sudhir , Goetzl Edward J. 
Published: April 2014

Abstract
Vasoactive intestinal peptide (VIP) released from some neurons and T cells affects T cell migration, cytokine generation, and other functions by binding to constitutively expressed type 1 G protein-coupled receptor (VPAC1) or activation-induced type 2 G protein-coupled receptor (VPAC2). Recently, a short-deletion (SD) splice variant of mouse VPAC2 that lacks 14 amino acids at the end of the last transmembrane domain has been identified in T cells and shown to resemble wild-type (WT) VPAC2 in affinity of VIP binding but to differ by lack of signaling of T cell adenylyl cyclase, migration, and IL-2 secretion. As Th2 cells are the principal source of immune VIP and have the greatest functional responses to VIP, the differences in signals transduced by WT and SD VPAC2 were studied in VPAC2–low D10G4.1 model Th2 cell transfectants individually expressing the respective types of VPAC2 equally. WT and SD VPAC2 Th2 cell transfectants secreted equal amounts of VIP. WT VPAC2 transfectants generated more IL-4 than did SD VPAC2 transfectants, and this increment was dependent on endogenous VIP. Exogenous VIP further increased IL-4 production by WT VPAC2 transfectants but decreased IL-4 production by SD VPAC2 transfectants. Cotransfection of the two constructs diminished VIP enhancement of IL-4 production seen with WT VPAC2 alone by preventing increases in nuclear levels of the requisite transcription factors c-Maf and Jun B. Thus the ratio of two forms of T cell VPAC2 determines the net effect of VIP on IL-4 generation by activated Th2 cells.
Lipopolysaccharide-Induced IL-1β Production by Human Uterine Macrophages Up-Regulates Uterine Epithelial Cell Expression of Human β-Defensin 2
Authors: Pioli Patricia A. , Weaver Lehn K. , Schaefer Todd M. , Wright Jacqueline A. , Wira Charles R. , Guyre Paul M. 
Published: April 2014

AbstractThe uterine endometrium coordinates a wide spectrum of physiologic and immunologic functions, including endometrial receptivity and implantation as well as defense against sexually transmitted pathogens. Macrophages and epithelial cells cooperatively mediate innate host defense against bacterial invasion through the generation of immunologic effectors, including cytokines and antimicrobial peptides. In this study, we demonstrate that stimulation of peripheral blood monocytes and uterine macrophages with bacterial LPS induces the production of biologically active proinflammatory IL-1β. High doses of estradiol enhance LPS-induced IL-1β expression in an estrogen receptor-dependent manner. Furthermore, both peripheral blood monocyte- and uterine macrophage-derived IL-1β induce secretion of antimicrobial human β-defensin 2 by uterine epithelial cells. These data indicate dynamic immunologic interaction between uterine macrophages and epithelial cells and implicate a role for estradiol in the modulation of the immune response.
Macrophages Induce Neutrophil Apoptosis through Membrane TNF, a Process Amplified byLeishmania major
Authors: Allenbach Cindy , Zufferey Christel , Perez Cynthia , Launois Pascal , Mueller Christoph , Tacchini-Cottier Fabienne 
Published: April 2014

AbstractNeutrophils are recruited to the site of parasite inoculation within a few hours of infection with the protozoan parasite Leishmania major. In C57BL/6 mice, which are resistant to infection, neutrophils are cleared from the site of s.c. infection within 3 days, whereas they persist for at least 10 days in susceptible BALB/c mice. In the present study, we investigated the role of macrophages (MΦ) in regulating neutrophil number. Inflammatory cells were recruited by i.p. injection of either 2% starch or L. major promastigotes. Neutrophils were isolated and cultured in the presence of increasing numbers of MΦ. Extent of neutrophil apoptosis positively correlated with the number of MΦ added. This process was strictly dependent on TNF because MΦ from TNF-deficient mice failed to induce neutrophil apoptosis. Assays using MΦ derived from membrane TNF knock-in mice or cultures in Transwell chambers revealed that contact with MΦ was necessary to induce neutrophil apoptosis, a process requiring expression of membrane TNF. L. major was shown to exacerbate MΦ-induced apoptosis of neutrophils, but BALB/c MΦ were not as potent as C57BL/6 MΦ in this induction. Our results emphasize the importance of MΦ-induced neutrophil apoptosis, and membrane TNF in the early control of inflammation.