bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction of Myeloid-Derived Suppressor Cells and Induction of M1 Macrophages Facilitate the Rejection of Established Metastatic Disease
Authors: Sinha Pratima , Clements Virginia K. , Ostrand-Rosenberg Suzanne 
Published: April 2014

AbstractMore than 60% of STAT6−/− mice immunologically reject spontaneous metastatic mammary carcinoma and survive indefinitely if their primary tumors are removed, whereas 95% of STAT6-competent BALB/c mice succumb to metastatic disease. BALB/c and STAT6-deficient mice with primary tumors have elevated levels of Gr1+CD11b+ myeloid suppressor cells (MSCs), which inhibit T cell activation. After removal of primary tumor, MSC levels revert to baseline in STAT6-deficient mice, but remain elevated in BALB/c mice. The decrease is IFN-γ dependent, as is the reduction in metastatic disease. Neither BALB/c nor STAT6-deficient MSCs produce inducible NO synthase; however, both produce arginase and reactive oxygen species. STAT6-deficient mice produce M1 macrophages, which contain high levels of NO and are tumoricidal, whereas BALB/c mice produce M2 macrophages, which make arginase and are not tumoricidal. Immunity in STAT6-deficient mice requires the activation of NO-producing M1 macrophages that are tumoricidal, the reduction in MSC levels to baseline after surgical removal of primary tumor, and the activation of tumor-specific T cells. These mechanisms occur in STAT6−/− mice because STAT6 deficiency prevents signaling through the type 2 IL-4Rα, thereby blocking the production of arginase and promoting the synthesis of NO.
IL-10 Diminishes CTLA-4 Expression on Islet-Resident T Cells and Sustains Their Activation Rather Than Tolerance
Authors: Gregg Randal K. , Bell J. Jeremiah , Lee Hyun-Hee , Jain Renu , Schoenleber Scott J. , Divekar Rohit , Zaghouani Habib 
Published: April 2014

Abstract
IL-10, a powerful anti-Th1 cytokine, has shown paradoxical effects against diabetes. The mechanism underlying such variable function remains largely undefined. An approach for controlled mobilization of endogenous IL-10 was applied to the NOD mouse and indicated that IL-10 encounter with diabetogenic T cells within the islets sustains activation, while encounter occurring peripheral to the islets induces tolerance. Insulin β-chain (INSβ) 9-23 peptide was expressed on an Ig, and the aggregated (agg) form of the resulting Ig-INSβ triggered IL-10 production by APCs, and expanded IL-10-producing T regulatory cells. Consequently, agg Ig-INSβ delayed diabetes effectively in young NOD mice whose pathogenic T cells remain peripheral to the islets. However, agg Ig-INSβ was unable to suppress the disease in 10-wk-old insulitis-positive animals whose diabetogenic T cells have populated the islets. This is not due to irreversibility of the disease because soluble Ig-INSβ did delay diabetes in these older mice. Evidence is provided indicating that upon migration to the islet, T cells were activated and up-regulated CTLA-4 expression. IL-10, however, reverses such up-regulation, abolishing CTLA-4-inhibitory functions and sustaining activation of the islet T lymphocytes. Therefore, IL-10 supports T cell tolerance in the periphery, but its interplay with CTLA-4 sustains activation within the islets. As a result, IL-10 displays opposite functions against diabetes in young vs older insulitis-positive mice.
Negative Regulation of T Cell Homeostasis by Lymphocyte Activation Gene-3 (CD223)
Authors: Workman Creg J. , Vignali Dario A. A. 
Published: April 2014

Abstract
Lymphocyte homeostasis is a central biological process that is tightly regulated. However, its molecular and cellular control is poorly understood. We show that aged mice deficient in lymphocyte activation gene 3 (LAG-3), an MHC class II binding CD4 homologue, have twice as many T cells as wild-type controls. CD4+ and CD8+ LAG-3-deficient T cells showed enhanced homeostatic expansion in lymphopenic hosts, which was abrogated by ectopic expression of wild-type LAG-3, but not by a signaling-defective mutant. In addition, in vivo treatment with anti-LAG-3 mAb resulted in enhanced T cell expansion to a level comparable to that in LAG-3-deficient cells. This deregulation of T cell homeostasis also resulted in the expansion of multiple cell types, including B cells, macrophages, granulocytes, and dendritic cells. Lastly, regulatory T cells were dependent on LAG-3 for their optimal control of T cell homeostasis. Our data suggest that LAG-3 negatively regulates T cell homeostasis by regulatory T cell-dependent and independent mechanisms.
Induction of CD70 on Dendritic Cells through CD40 or TLR Stimulation Contributes to the Development of CD8+ T Cell Responses in the Absence of CD4+ T Cells
Authors: Bullock Timothy N. J. , Yagita Hideo 
Published: April 2014

Abstract
The expansion of CD8+ T cells in response to Ag can be characterized as either dependent or independent of CD4+ T cells. The factors that influence this dichotomy are poorly understood but may be dependent upon the degree of inflammation associated with the Ag. Using dendritic cells derived from MHC class II-deficient mice to avoid interaction with CD4+ T cells in vivo, we have compared the immunogenicity of peptide-pulsed dendritic cells stimulated with molecules associated with infection to those stimulated via CD40. In the absence of CD4+ T cell help, the expansion of primary CD8+ T cells after immunization with TNF-α- or poly(I:C)-stimulated dendritic cells was minimal. In comparison, LPS- or CpG-stimulated dendritic cells elicited substantial primary CD8+ T cell responses, though not to the same magnitude generated by immunization with CD40L-stimulated dendritic cells. Remarkably, mice immunized with any stimulated dendritic cell population generated fully functional recall CD8+ T cells without the aid of CD4+ T cell help. The observed hierarchy of immunogenicity was closely correlated with the expression of CD70 (CD27L) on the stimulated dendritic cells, and Ab-mediated blockade of CD70 substantially prevented the CD4+ T cell-independent expansion of primary CD8+ T cells. These results indicate that the expression of CD70 on dendritic cells is an important determinant for helper-dependence of primary CD8+ T cell expansion and provide an explanation for the ability of a variety of pathogens to stimulate primary CD8+ T cell responses in the absence of CD4+ T cells.
The Reciprocal Interaction of NK Cells with Plasmacytoid or Myeloid Dendritic Cells Profoundly Affects Innate Resistance Functions
Authors: Gerosa Franca , Gobbi Andrea , Zorzi Penelope , Burg Stephanie , Briere Francine , Carra Giuseppe , Trinchieri Giorgio 
Published: April 2014

Abstract
A reciprocal activating interaction between NK cells and dendritic cells (DC) has been suggested to play a role in the functional regulation of these cells in immunity, but it has been studied only using in vitro generated bone marrow- or monocyte-derived DC. We report that human peripheral blood plasmacytoid DC (pDC) and myeloid DC are necessary to induce NK cell function depending on the type of microbial stimulus. pDC and myeloid DC are required for strongly increased NK cytolytic activity and CD69 expression, in response to inactivated influenza virus or CpG-containing oligonucleotides and poly(I:C), respectively. Secreted type I IFN is required and sufficient for the augmentation of NK cell cytolytic activity in the coculture with pDC or myeloid DC, whereas CD69 expression is dependent on both type I IFN and TNF. In addition, in response to poly(I:C), myeloid DC induce NK cells to produce IFN-γ through a mechanism dependent on both IL-12 secretion and cell contact between NK cells and myeloid DC, but independent of type I IFN. IL-2-activated NK cells have little to no cytolytic activity for immature myeloid DC and pDC, but are able to induce maturation of these cells. Moreover, IL-2-activated NK cells induce, in the presence of a suboptimal concentration of CpG-containing oligonucleotides, a strong IFN-α and TNF production. These data suggest that the reciprocal functional interaction between NK cells and either pDC or myeloid DC may play an important physiological role in the regulation of both innate resistance and adaptive immunity to infections.
Dendritic Cells and NK Cells Stimulate Bystander T Cell Activation in Response to TLR Agonists through Secretion of IFN-αβ and IFN-γ
Authors: Kamath Arun T. , Sheasby Christopher E. , Tough David F. 
Published: April 2014

Abstract
Recognition of conserved features of infectious agents by innate pathogen receptors plays an important role in initiating the adaptive immune response. We have investigated early changes occurring among T cells after injection of TLR agonists into mice. Widespread, transient phenotypic activation of both naive and memory T cells was observed rapidly after injection of molecules acting through TLR3, -4, -7, and -9, but not TLR2. T cell activation was shown to be mediated by a combination of IFN-αβ, secreted by dendritic cells (DCs), and IFN-γ, secreted by NK cells; notably, IFN-γ-secreting NK cells expressed CD11c and copurified with DCs. Production of IFN-γ by NK cells could be stimulated by DCs from TLR agonist-injected mice, and although soluble factors secreted by LPS-stimulated DCs were sufficient to induce IFN-γ, maximal IFN-γ production required both direct contact of NK cells with DCs and DC-secreted cytokines. In vitro, IFN-αβ, IL-18, and IL-12 all contributed to DC stimulation of NK cell IFN-γ, whereas IFN-αβ was shown to be important for induction of T cell bystander activation and NK cell IFN-γ production in vivo. The results delineate a pathway involving innate immune mediators through which TLR agonists trigger bystander activation of T cells.
Importance of Cellular Microenvironment and Circulatory Dynamics in B Cell Immunotherapy
Authors: Gong Qian , Ou Qinglin , Ye Shiming , Lee Wyne P. , Cornelius Jennine , Diehl Lauri , Lin Wei Yu , Hu Zhilan , Lu Yanmei , Chen Yongmei , Wu Yan , Meng Y. Gloria , Gribling Peter , Lin Zhonghua , Nguyen Kathy , Tran Thanhvien , Zhang Yifan , Rosen Hugh , Martin Flavius , Chan Andrew C. 
Published: April 2014

Abstract
B cell immunotherapy has emerged as a mainstay in the treatment of lymphomas and autoimmune diseases. Although the microenvironment has recently been demonstrated to play critical roles in B cell homeostasis, its contribution to immunotherapy is unknown. To analyze the in vivo factors that regulate mechanisms involved in B cell immunotherapy, we used a murine model for human CD20 (hCD20) expression in which treatment of hCD20+ mice with anti-hCD20 mAbs mimics B cell depletion observed in humans. We demonstrate in this study that factors derived from the microenvironment, including signals from the B cell-activating factor belonging to the TNF family/BLyS survival factor, integrin-regulated homeostasis, and circulatory dynamics of B cells define distinct in vivo mechanism(s) and sensitivities of cells in anti-hCD20 mAb-directed therapies. These findings provide new insights into the mechanisms of immunotherapy and define new opportunities in the treatment of cancers and autoimmune diseases.
Matrix Metalloproteinase-9 in Macrophages Induces Thymic Neovascularization following Thymocyte Apoptosis
Authors: Odaka Chikako , Tanioka Masatoshi , Itoh Takeshi 
Published: April 2014

Abstract
Matrix metalloproteinase-9 (MMP-9) has been implicated in the degradation of the extracellular matrix in a variety of physiological and pathological processes. We found that MMP-9 expression in thymuses of BALB/c mice that had been injected with anti-CD3 Ab to induce thymocyte apoptosis was increased both at mRNA and protein levels. Macrophages are shown to be the principal stromal cells responsible for phagocytosis of dying thymocytes, and macrophages were found to constitutively express MMP-9. The activity of plasmin, which is known as one of the activators for MMP-9, was increased in the thymuses with MMP-9 activation. Binding of Ab HUIV26, which recognizes a cryptic epitope on collagen type IV following proteolytic cleavage, was found to be reduced in MMP-9 knockout mice, suggesting that collagen type IV is a substrate of MMP-9. Although the formation of thymic neovessels was found following thymocyte apoptosis, it was diminished in anti-CD3 Ab-injected MMP-9 knockout mice. In vivo administration of Ab HUIV26 resulted in a reduction of thymic neovascularization. After clearance of apoptotic thymocytes, the number of macrophages in the thymuses was decreased, and this decrease was delayed by blocking of HUIV26 epitope. Taken together, our results suggest that MMP-9 expression in macrophages mediates degradation of collagen type IV and facilitates their migration from the thymus after clearance of apoptotic thymocytes. These studies demonstrate a potential role of macrophage MMP-9 in the remodeling of thymic extracellular matrix following thymocyte apoptosis.
p53 Potentiation of Tumor Cell Susceptibility to CTL Involves Fas and Mitochondrial Pathways
Authors: Thiery Jérôme , Abouzahr Soraya , Dorothee Guillaume , Jalil Abdelali , Richon Catherine , Vergnon Isabelle , Mami-Chouaib Fathia , Chouaib Salem 
Published: April 2014

Abstract
In this study, we have investigated the mechanisms used by wild-type p53 (wtp53) to potentiate tumor cell susceptibility to CTL-mediated cell death. We report that wtp53 restoration in a human lung carcinoma cell line Institut Gustave Roussy (IGR)-Heu, displaying a mutated p53, resulted in up-regulation of Fas/CD95 receptor expression associated with an increase of tumor cell sensitivity to the autologous CTL clone, Heu127. However, when IGR-Heu cells were transfected with Fas cDNA, no potentiation to Heu127-mediated lysis was observed, indicating that induction of CD95 is not sufficient to sensitize target cells to CTL killing. Importantly, our data indicate that the effect of wtp53 on the Fas-mediated pathway involves a degradation of short cellular FLICE inhibitory protein resulting in subsequent caspase 8 activation. Furthermore, we demonstrate that wtp53 restoration also resulted in CTL-induced Bid translocation into mitochondria and a subsequent mitochondrial membrane permeabilization leading to cytochrome c release. These results indicate that tumor cell killing by autologous CTL can be enhanced by targeting degranulation-independent mechanisms via restoration of wtp53, a key determinant of apoptotic machinery regulation.
Different MHC Class I Heavy Chains Compete with Each Other for Folding Independently of β2-Microglobulin and Peptide
Authors: Tourdot Sophie , Nejmeddine Mohamed , Powis Simon J. , Gould Keith G. 
Published: April 2014

Abstract
We reported previously that different MHC class I molecules can compete with each other for cell surface expression in F1 hybrid and MHC class I transgenic mice. In this study, we show that the competition also occurs in transfected cell lines, and investigate the mechanism. Cell surface expression of an endogenous class I molecule in Chinese hamster ovary (CHO) cells was strongly down-regulated when the mouse Kd class I H chain was introduced by transfection. The competition occurred only after Kd protein translation, not at the level of RNA, and localization studies of a CHO class I-GFP fusion showed that the presence of Kd caused retention of the hamster class I molecule in the endoplasmic reticulum. The competition was not for β2-microglobulin, because a single chain version of Kd that included mouse β2-microglobulin also had a similar effect. The competition was not for association with TAP and loading with peptide, because a mutant form of the Kd class I H chain, not able to associate with TAP, caused the same down-regulation of hamster class I expression. Moreover, Kd expression led to a similar level of competition in TAP2-negative CHO cells. Competition for cell surface expression was also found between different mouse class I H chains in transfected mouse cells, and this competition prevented association of the H chain with β2-microglobulin. These unexpected new findings show that different class I H chains compete with each other at an early stage of the intracellular assembly pathway, independently of β2-microglobulin and peptide.
The Rat Expresses Two Complement Factor C4 Proteins, but Only One Isotype Is Expressed in the Liver
Authors: Roos Christian , Dressel Ralf , Schmidt Bernhard , Günther Eberhard , Walter Lutz 
Published: April 2014

Abstract
The complement component C4 is well known for its complex genetics in human and mouse where it is part of a tandemly duplicated module. For the rat, no such information had been available until recently. A C4 gene duplication could be identified also in the rat, but the duplicated module maps ∼200 kb centromerically from the canonical C4-1 gene. In this study, we present the genomic organization of the two C4 gene-containing modules and the expression of the two C4 genes in the rat (Rattus norvegicus). The duplicated module contains an intact C4 gene as well as Cyp21 and Stk19 pseudogenes. Quantitative mRNA expression analyses revealed that both C4 genes are transcribed in various organs and tissues, but displaying ample differences of C4-1 and C4-2 expression. Most notably, C4-2 is not expressed in the liver. At variance to the mouse, the expression of the rat C4 genes does not exhibit any sex dependency. By using two-dimensional gel electrophoresis and mass spectrometry, products of both C4 genes could be identified in rat serum samples. These two rat C4 isotypes are nearly identical, but differ in a functionally important amino acid residue that is known to influence the functional properties of the C4 isotypes in human.
Vaccination with a Human High Molecular Weight Melanoma-Associated Antigen Mimotope Induces a Humoral Response Inhibiting Melanoma Cell Growth In Vitro
Authors: Wagner Stefan , Hafner Christine , Allwardt Dorothee , Jasinska Joanna , Ferrone Soldano , Zielinski Christoph C. , Scheiner Otto , Wiedermann Ursula , Pehamberger Hubert , Breiteneder Heimo 
Published: April 2014

Abstract
Peptide mimics of a conformational epitope that is recognized by a mAb with antitumor activity are promising candidates for formulations of anticancer vaccines. These mimotope vaccines are able to induce a polyclonal Ab response focused to the determinant of the mAb. Such attempts at cancer immunotherapy are of special interest for malignant melanoma that is highly resistant to chemotherapy and radiotherapy. In this study, we describe for the first time the design and immunogenicity of a vaccine containing a mimotope of the human high m.w. melanoma-associated Ag (HMW-MAA) and the biological potential of the induced Abs. Mimotopes were selected from a pVIII-9mer phage display peptide library with the anti-HMW-MAA mAb 225.28S. The mimotope vaccine was then generated by coupling the most suitable candidate mimotope to tetanus toxoid as an immunogenic carrier. Immunization of rabbits with this vaccine induced a specific humoral immune response directed toward the epitope recognized by the mAb 225.28S on the native HMW-MAA. The induced Abs inhibited the in vitro growth of the melanoma cell line 518A2 up to 62%. In addition, the Abs mediated 26% lysis of 518A2 cells in Ab-dependent cellular cytotoxicity. Our results indicate a possible application of this mimotope vaccine as a novel immunotherapeutic agent for the treatment of malignant melanoma.
Enhanced Production of IL-10 by Dendritic Cells Deficient in CIITA
Authors: Yee Christina S. K. , Yao Yongxue , Xu Qi , McCarthy Brian , Sun-Lin Deqin , Tone Masahide , Waldmann Herman , Chang Cheong-Hee 
Published: April 2014

Abstract
Dendritic cells (DC) are professional APCs that play a critical role in regulating immunity. In DC, maturation-induced changes in MHC class II expression and Ag presentation require transcriptional regulation by CIITA. To study the role of CIITA in DC, we evaluated key cell functions in DC from CIITA-deficient (CIITA−/−) mice. The ability to take up Ag, measured by fluid phase endocytosis, was comparable between CIITA−/− and control DC. Although CIITA−/− DC lack MHC class II, they maintained normal expression of costimulatory molecules CD80, CD86, and CD40. In contrast, CIITA−/− DC activated with LPS or CpG expressed increased IL-10 levels, but normal levels of TNF-α and IL-12 relative to control. Enhanced IL-10 was due to greater IL-10 mRNA in CIITA−/− DC. Aβ−/− DC, which lack MHC class II but express CIITA normally, had exhibited no difference in IL-10 compared with control. When CIITA was cotransfected with an IL-10 promoter-reporter into a mouse monocyte cell line, RAW 264.7, IL-10 promoter activity was decreased. In addition, reintroducing CIITA into CIITA−/− DC reduced production of IL-10. In all, these data suggest that CIITA negatively regulates expression of IL-10, and that CIITA may direct DC function in ways that extend beyond control of MHC class II.
The Role of p53 and Fas in a Model of Acute Murine Graft-versus-Host Disease
Authors: Yada Shinichiro , Takamura Noriaki , Inagaki-Ohara Kyoko , O’Leary Melissa K. , Wasem Christoph , Brunner Thomas , Green Douglas R. , Lin Tesu , Pinkoski Michael J. 
Published: April 2014

Abstract
Graft-vs-host disease (GVHD) is a devastating, frequently fatal, pathological condition associated with lesions in specific target organs, including the intestine, liver, lung, and skin, as well as pancytopenia and alopecia. Bone marrow (BM) atrophy is observed in acutely diseased animals, but the underlying mechanisms of hemopoietic stem cell depletion remained to be established. We used an experimental mouse model of acute GVHD in which parental cells were injected into F1 hosts preconditioned by sublethal irradiation. The resulting graft-vs-host response was kinetically consistent, resulting in lethality within 3 wk. We observed disease pathology in the liver and small intestine, and consistent with previous observations, we found BM atrophy to be a factor in the onset of acute disease. The product of the protooncogene, p53, is known to be a key player in many physiological examples of apoptosis. We investigated the role of p53 in the apoptosis of BM cells (BMC) during the development of acute disease and found that at least one copy of the p53 gene is necessary for depletion of BM and subsequent lethality in host animals. BM depletion was preceded by induction of the death receptor, Fas, on the surface of host stem cells, and induction of Fas was coincidental with the sensitization of BMC to Fas-mediated apoptosis. Our data indicate that BM depletion in acute GVHD is mediated by p53-dependent up-regulation of Fas on BMC, which leads to Fas-dependent depletion and subsequent disease.