bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-10 Up-Regulates Macrophage Expression of the S100 Protein S100A8
Authors: Xu Ken , Yen Tina , Geczy Carolyn L. 
Published: April 2014

AbstractThe murine calcium binding protein S100A8 (A8) is a leukocyte chemoattractant, but high levels may be protective and scavenge hypochlorite. A8 is induced by LPS, IFN-γ, and TNF in elicited macrophages. Th2 cytokines generally suppress proinflammatory gene expression, and IL-4 and IL-13 partially decreased A8 induction in macrophages and endothelial cells stimulated by LPS or IFN. In contrast, IL-10 synergized with LPS and IFN to increase mRNA levels ≥9-fold and secreted A8 levels ∼4-fold. IL-10 decreased the optimal time of mRNA expression induced by LPS from 24 to 8 h. Blocking experiments indicated that endogenous IL-10 contributes to gene induction by LPS. Cooperation between IL-10 and LPS was not due to altered mRNA stability but was dependent on de novo protein synthesis. Transfection analysis with A8 luciferase constructs confirmed that synergy was due to increased transcription. The region of the promoter involved was localized to a 178-bp fragment flanking the transcription start site of the gene. This region was also responsible for the suppressive effects of IL-4 and IL-13. Forskolin, CTP-cAMP, and PGE2 also enhanced LPS- and IFN-induced A8 mRNA, whereas indomethacin significantly reduced synergy between IL-10 and LPS. Mitogen-activated protein kinase/cyclooxygenase 2/cAMP pathways involving CCAAT-enhancing binding protein, located within the active promoter, may mediate A8 gene up-regulation in a manner mechanistically distinct to genes regulated by IL-10 via the STAT pathway. A8 exhibits pleiotropic effects, and the high levels secreted as a result of IL-10 synergy may regulate untoward inflammatory damage by virtue of its an antioxidant capacity.
Mycobacterium bovisStrain Bacillus Calmette-Guérin-Induced Liver Granulomas Contain a Diverse TCR Repertoire, but a Monoclonal T Cell Population Is Sufficient for Protective Granuloma Formation
Authors: Hogan Laura H. , Macvilay Khen , Barger Brittany , Co Dominic , Malkovska Irena , Fennelly Glenn , Sandor Matyas 
Published: April 2014

AbstractGranuloma formation is a form of delayed-type hypersensitivity requiring CD4+ T cells. Granulomas control the growth and dissemination of pathogens, preventing host inflammation from harming surrounding tissues. Using a murine model of Mycobacterium bovis strain bacillus Calmette-Guérin (BCG) infection we studied the extent of T cell heterogeneity present in liver granulomas. We demonstrate that the TCR repertoire of granuloma-infiltrating T cells is very diverse even at the single-granuloma level, suggesting that before granuloma closure, a large number of different T cells are recruited to the lesion. At the same time, the TCR repertoire is selected, because AND TCR transgenic T cells (Vα11/Vβ3 anti-pigeon cytochrome c) are preferentially excluded from granulomas of BCG-infected AND mice, and cells expressing secondary endemic Vβ-chains are enriched among AND cells homing to granulomas. Next, we addressed whether TCR heterogeneity is required for effective granuloma formation. We infected 5CC7/recombinase-activating gene 2−/− mice with recombinant BCG that express pigeon cytochrome c peptide in a mycobacterial 19-kDa bacterial surface lipoprotein. A CD4+ T cell with a single specificity in the absence of CD8+ T cells is sufficient to form granulomas and adequately control bacteria. Our study shows that expanded monoclonal T cell populations can be protective in mycobacterial infection.
Surfactant Protein A Suppresses Lipopolysaccharide-Induced IL-10 Production by Murine Macrophages
Authors: Salez Laurent , Balloy Viviane , van Rooijen Nico , Lebastard Mai , Touqui Lhousseine , McCormack Francis X. , Chignard Michel 
Published: April 2014

AbstractUpon LPS exposure, mononuclear phagocytes produce TNF-α and IL-10, two cytokines with pro- and anti-inflammatory activities, respectively. We previously described that murine resident alveolar macrophages, which play a central role in the immunosurveillance of the lung alveoli, do not synthesize IL-10 in vivo or in vitro when exposed to LPS. In the present report we demonstrate that during lung inflammation induced by the intranasal administration of LPS, bronchoalveolar cells collected between days 3 and 5 are able to synthesize IL-10 when exposed to LPS. We also show that depletion of resident alveolar macrophages by an intratracheal instillation of liposome-encapsulated clodronate is followed by subsequent replenishment of the airspaces by mononuclear phagocytes. This is accompanied by the transient competence of cells for IL-10 production. The cell capacity to produce IL-10 is evident up to 3 days and then decreases. This led us to hypothesize that the alveolar environment contains a down-regulator of LPS-induced IL-10 synthesis by recently emigrating mononuclear phagocytes. We show that the surfactant protein A, an airspace protein that has known immunomodulatory activities, dramatically inhibits LPS-induced IL-10 formation by bone marrow-derived macrophages. These data show a difference between resident and inflammatory macrophages with respect to IL-10 synthesis. Moreover, this study highlights for the first time the inhibitory role of surfactant protein A in the anti-inflammatory activity of macrophages through inhibition of IL-10 production.
Genetic Regulation of Autoimmune Disease: BALB/c Background TGF-β1-Deficient Mice Develop Necroinflammatory IFN-γ-Dependent Hepatitis
Authors: Gorham James D. , Lin Jack T. , Sung James L. , Rudner Lynnie A. , French Margaret A. 
Published: April 2014

AbstractAutoimmune hepatitis (AIH) in humans arises spontaneously in genetically susceptible individuals and is associated with the presence of Th1 cells in the liver. The understanding of AIH has advanced more slowly than that of other organ-specific autoimmune diseases, however, largely because of the lack of an appropriate animal model. We now describe a new mouse model characterized by spontaneous development of necroinflammatory hepatitis that is restricted by genetic background. Mice deficient in the immunomodulatory cytokine TGF-β1 were extensively back-bred to the BALB/c background. The BALB/c background dramatically modified the phenotype of TGF-β1−/− mice: specifically, BALB/c-TGF-β1−/− mice developed a lethal necroinflammatory hepatitis that was not observed in TGF-β1−/− mice on a different genetic background. BALB/c background TGF-β1−/− livers contained large numbers of activated CD4+ T cells that produced large quantities of IFN-γ, but little IL-4, identifying them as Th1 cells. BALB/c background TGF-β1−/−/IFN-γ−/− double knockout mice, generated by cross-breeding, did not develop necroinflammatory hepatitis, demonstrating that IFN-γ is mechanistically required for its pathogenesis. This represents the first murine model of hepatitis that develops spontaneously, is restricted by genetic background, and is dependent upon the Th1 cytokine IFN-γ, and that thus recapitulates these important aspects of AIH.
Anti-CTLA-4 Antibody Treatment Triggers Determinant Spreading and Enhances Murine Myasthenia Gravis
Authors: Wang Hua-Bing , Shi Fu-Dong , Li Hulun , Chambers Benedict J. , Link Hans , Ljunggren Hans-Gustaf 
Published: April 2014

AbstractCTLA-4 appears to be a negative regulator of T cell activation and is implicated in T cell-mediated autoimmune diseases. Experimental autoimmune myasthenia gravis (EAMG), induced by immunization of C57BL/6 mice with acetylcholine receptor (AChR) in adjuvant, is an autoantibody-mediated disease model for human myasthenia gravis (MG). The production of anti-AChR Abs in MG and EAMG is T cell dependent. In the present study, we demonstrate that anti-CTLA-4 Ab treatment enhances T cell responses to AChR, increases anti-AChR Ab production, and provokes a rapid onset and severe EAMG. To address possible mechanisms underlying the enhanced autoreactive T cell responses after anti-CTLA-4 Ab treatment, mice were immunized with the immunodominant peptide α146–162 representing an extracellular sequence of the AChR. Anti-CTLA-4 Ab, but not control Ab, treatment subsequent to peptide immunization results in clinical EAMG with diversification of the autoantibody repertoire as well as enhanced T cell proliferation against not only the immunizing α146–162 peptide, but also against other subdominant epitopes. Thus, treatment with anti-CTLA-4 Ab appears to induce determinant spreading, diversify the autoantibody repertoire, and enhance B cell-mediated autoimmune disease in this murine model of MG.
Overexpression of Bcl-2 Differentially Restores Development of Thymus-Derived CD4−8+ T Cells and Intestinal Intraepithelial T Cells in IFN-Regulatory Factor-1-Deficient Mice
Authors: Ohteki Toshiaki , Maki Chikako , Koyasu Shigeo 
Published: April 2014

AbstractMice lacking IFN-regulatory factor (IRF)-1 have reduced numbers of mature CD8+ T cells within the thymus and peripheral lymphoid organs, suggesting a critical role of IRF-1 in CD8+ T cell differentiation. Here we show that endogenous Bcl-2 expression is substantially reduced in IRF-1−/−CD8+ thymocytes and that introduction of a human Bcl-2 transgene driven by Eμ or lck promoter in IRF-1−/− mice restores the CD8+ T cell development. Restored CD8+ T cells are functionally mature in terms of allogeneic MLR and cytokine production. In contrast to thymus-derived CD8+ T cells, other lymphocyte subsets including NK, NK T, and TCR-γδ+ intestinal intraepithelial lymphocytes, which are also impaired in IRF-1−/− mice, are not rescued by expressing human Bcl-2. Our results indicate that IRF-1 differentially regulates the development of these lymphocyte subsets and that survival signals involving Bcl-2 are critical for the development of thymus-dependent CD8+ T cells.
Three Different Vaccines Based on the 140-Amino Acid MUC1 Peptide with Seven Tandemly Repeated Tumor-Specific Epitopes Elicit Distinct Immune Effector Mechanisms in Wild-Type Versus MUC1-Transgenic Mice with Different Potential for Tumor Rejection
Authors: Soares M. Melina , Mehta Vinay , Finn Olivera J. 
Published: April 2014

Abstract
Low-frequency CTL and low-titer IgM responses against tumor-associated Ag MUC1 are present in cancer patients but do not prevent cancer growth. Boosting MUC1-specific immunity with vaccines, especially effector mechanisms responsible for tumor rejection, is an important goal. We studied immunogenicity, tumor rejection potential, and safety of three vaccines: 1) MUC1 peptide admixed with murine GM-CSF as an adjuvant; 2) MUC1 peptide admixed with adjuvant SB-AS2; and 3) MUC1 peptide-pulsed dendritic cells (DC). We examined the qualitative and quantitative differences in humoral and T cell-mediated MUC1-specific immunity elicited in human MUC1-transgenic (Tg) mice compared with wild-type (WT) mice. Adjuvant-based vaccines induced MUC1-specific Abs but failed to stimulate MUC1-specific T cells. MUC1 peptide with GM-CSF induced IgG1 and IgG2b in WT mice but only IgM in MUC1-Tg mice. MUC1 peptide with SB-AS2 induced high-titer IgG1, IgG2b, and IgG3 Abs in both WT and MUC1-Tg mice. Induction of IgG responses was T cell independent and did not have any effect on tumor growth. MUC1 peptide-loaded DC induced only T cell immunity. If injected together with soluble peptide, the DC vaccine also triggered Ab production. Importantly, the DC vaccine elicited tumor rejection responses in both WT and MUC1-Tg mice. These responses correlated with the induction of MUC1-specific CD4+ and CD8+ T cells in WT mice, but only CD8+ T cells in MUC1-Tg mice. Even though MUC1-specific CD4+ T cell tolerance was not broken, the capacity of MUC1-Tg mice to reject tumor was not compromised.
Phosphatidylinositol 3′-Kinase Blocks CD95 Aggregation and Caspase-8 Cleavage at the Death-Inducing Signaling Complex by Modulating Lateral Diffusion of CD95
Authors: Varadhachary Arun S. , Edidin Michael , Hanlon Allison M. , Peter Marcus E. , Krammer Peter H. , Salgame Padmini 
Published: April 2014

AbstractActivation of phosphatidylinositol 3′-kinase (PI 3′-K) after ligation of CD3 protects Th2 cells from CD95-mediated apoptosis. Here we show that protection is achieved by inhibition of the formation of CD95 aggregates and consequent activation of caspase-8. Inhibition of aggregate formation is mediated by changes in the actin cytoskeleton, which in turn inhibit lateral diffusion of CD95, reducing its diffusion coefficient, D, 10-fold. After cytochalasin D treatment of stimulated cells, the lateral diffusion of CD95 increases to the value measured on unstimulated cells, and CD95 molecules aggregate to process caspase-8 and mediate apoptosis. Regulation of functional receptor formation by modulating lateral diffusion is a novel mechanism for controlling receptor activity.
Cyclophosphamide Induces the Development of Early Myeloid Cells Suppressing Tumor Cell Growth by a Nitric Oxide-Dependent Mechanism
Authors: Peláez Blondineth , Campillo José A. , López-Asenjo José A. , Subiza José L. 
Published: April 2014

AbstractAdoptive immunotherapy with cyclophosphamide (Cy) increases the host resistance against tumor growth. The precise mechanism(s) by which this therapy enhances tumor suppression is unclear. Cy induces the development of early myeloid cells that may be strongly antiproliferative through NO production. These cells are similar to the natural suppressor cells found in normal bone marrow with a potential antitumor effect. Here we have addressed whether the development of NO-producing cells may be involved in this tumor resistance in Cy-treated mice. The results show a synergism between Cy treatment and tumor-specific lymphocytes transferred systemically (i.v.) or locally (Winn’s assay) that results in a strong tumor suppression. Inhibition of NO production by NG-monomethyl-l-arginine at the site of tumor inoculation results in a loss of the protection achieved by the combined therapy. Cy-treated mice develop splenic early myeloid (CD11b, Gr-1, CD31 (ER-MP12), ER-MP20, ER-MP54) cells producing large amounts of NO upon T cell-derived signals (IFN-γ plus CD40 ligation) able to inhibit tumor cell growth in vitro. Early myeloid cells (ER-MP54+) and cells expressing inducible NO synthase are increased at the site of tumor challenge in mice treated with the combined therapy, but not in those treated with Cy or immune cell transfer alone. Thus, Cy induces the expansion of early myeloid cells, inhibiting tumor cell growth by a mechanism involving NO. Both the recruitment and the activation of these myeloid cells at the site of tumor challenge appear to be dependent on the presence of tumor-specific lymphocytes.
TNF-α Controls Intracellular Mycobacterial Growth by Both Inducible Nitric Oxide Synthase-Dependent and Inducible Nitric Oxide Synthase-Independent Pathways
Authors: Bekker Linda-Gail , Freeman Sherry , Murray Peter J. , Ryffel Bernard , Kaplan Gilla 
Published: April 2014

AbstractThe role of TNF-α in the control of mycobacterial growth in murine macrophages was studied in vitro. Infection of macrophages from TNF-α gene disrupted (TNF-knockout (KO)) mice with recombinant Mycobacterium bovis bacillus Calmette Guérin (BCG) expressing the vector only (BCG-vector) resulted in logarithmic growth of the intracellular bacilli. Infection with BCG-secreting murine TNF-α (BCG-TNF) led to bacillary killing. Killing of BCG-TNF was associated with rapid accumulation of inducible NO synthase (iNOS) protein and the production of nitrite. The uncontrolled growth of BCG-vector was associated with low iNOS expression but no nitrite production. Thus, iNOS expression appears to be TNF-α independent but iNOS generation of NO requires TNF-α. In cultures of TNF-KO macrophages infected with BCG-TNF, inhibition of iNOS by aminoguanidine (AMG) abolished the killing of the bacilli. However, the growth of the organisms was still inhibited, suggesting an iNOS-independent TNF-α-mediated growth inhibition. To confirm this, macrophages from iNOS-KO mice were infected with either BCG-vector or BCG-TNF. As expected, no nitrite was detected in the culture medium. TNF-α was detected only when the cells were infected with BCG-TNF. In the iNOS-KO macrophages, the growth of BCG was inhibited only in the BCG-TNF infection. These results suggest that in the absence of iNOS activity, TNF-α stimulates macrophages to control the growth of intracellular BCG. Thus, there appears to be both a TNF-α-dependent-iNOS-dependent killing pathway as well as a TNF-α-dependent-iNOS-independent growth inhibitory pathway for the control of intracellular mycobacteria in murine macrophages.
P2X7 Nucleotide Receptor Mediation of Membrane Pore Formation and Superoxide Generation in Human Promyelocytes and Neutrophils
Authors: Suh Byung-Chang , Kim Jong-So , Namgung Uk , Ha Hyunjung , Kim Kyong-Tai 
Published: April 2014

AbstractThe P2X7 receptor, which induces cation channel opening imparting significant permeability to Ca2+ and pore formation with changes in the plasma membrane potential, has been known to be rather restrictedly expressed in cells of the macrophage lineage including dendrites, mature macrophages, and microglial cells. However, we show here that the P2X7 receptor is also expressed in cells of granulocytic lineage such as HL-60 promyelocytes, granulocytic differentiated cells, and neutrophils. Exposure of these cells to 2′,3′-O-(4-benzoyl)benzoyl-ATP (BzATP) triggered intracellular Ca2+ rise through the mediation of phospholipase C-independent and suramin-sensitive pathways. BzATP also induced depolarization of the plasma membrane in the absence of extracellular Ca2+, whereas it hyperpolarized the cells in the presence of external Ca2+, probably in part through the activation of Ca2+-activated K+ channels. However, the hyperpolarization phenomenon was markedly attenuated in differentiated HL-60 cells and neutrophils. RT-PCR and Northern blot analysis revealed the presence of P2X7 receptors on both HL-60 and neutrophil-like cells. This was further confirmed by pore formation through which the uptake of Lucifer yellow and YO-PRO1 occurred on BzATP treatment. BzATP stimulated in a concentration-dependent manner the production of superoxide in differentiated HL-60 cells via a pathway partially dependent on extracellular Ca2+. Moreover, in human neutrophils, BzATP was a more effective inducer of superoxide generation than PMA. Taken together, this is a first demonstration of the expression of P2X7 receptors on neutrophils, which shows that the receptor is functionally involved in the defense mechanism by activation of the respiratory burst pathway.
Differential Involvement of Dendritic Cell Subsets During AcuteSalmonellaInfection
Authors: Kirby Alun C. , Yrlid Ulf , Svensson Mattias , Wick Mary Jo 
Published: April 2014

AbstractWithin murine CD11c+ dendritic cells (DC), CD8α+, CD8α−CD4+, and CD8α−CD4− subsets are defined. This study characterized the localization, number, and function of these subsets during acute Salmonella typhimurium infection. Immunohistochemical and flow cytometric analyses of spleens from mice orally infected with virulent S. typhimurium revealed that in situ redistribution and alteration in the absolute number and function of DC occurred in a subset-specific manner during infection. CD8α−CD4+ DC present at B cell follicle borders in the spleen of naive mice were absent 5 days post-Salmonella infection, despite no overall change in the absolute number of CD8α−CD4+ splenic DC. CD8α+ and CD8α−CD4− DC were prominently associated with the red pulp, and the frequency of these cells increased strikingly 5 days post-Salmonella infection. Significant quantitative increases in both CD8α+ and CD8α−CD4− subsets were associated with the in situ redistribution. Examination of Salmonella-infected TAP1−/−/β2-microglobulin−/− mice, which lack CD8α+ T cells, confirmed the differential subset-specific modulations in the DC populations both in situ and quantitatively. Ex vivo intracellular cytokine analysis showed significantly increased frequencies of CD8α+ DC producing TNF-α at days 2 and 5 postinfection. In contrast, CD4+ DC producing TNF-α were transiently increased followed by a significant reduction. No significant increase in IL-12p40 or IL-10 production by splenic DC was detected during the first 5 days post-S. typhimurium infection. Together these data reveal differential modulation of splenic DC subsets with regard to organization, number, and cytokine production during the course of acute Salmonella infection.
Differential Effects of Apoptotic Versus Lysed Cells on Macrophage Production of Cytokines: Role of Proteases
Authors: Fadok Valerie A. , Bratton Donna L. , Guthrie Lindsay , Henson Peter M. 
Published: April 2014

AbstractGranulocytes undergoing apoptosis are recognized and removed by phagocytes before their lysis. The release of their formidable arsenal of proteases and other toxic intracellular contents into tissues can create significant damage, prolonging the inflammatory response. Binding and/or uptake of apoptotic cells by macrophages inhibits release of proinflammatory cytokines by mechanisms that involve anti-inflammatory mediators, including TGF-β. To model the direct effects of necrotic cells on macrophage cytokine production, we added lysed or apoptotic neutrophils and lymphocytes to mouse and human macrophages in the absence of serum to avoid complement activation. The results confirmed the ability of lysed neutrophils, but not lymphocytes, to significantly stimulate production of macrophage-inflammatory protein 2 or IL-8, TNF-α, and IL-10. Concomitantly, induction of TGF-β1 by lysed neutrophils was significantly lower than that observed for apoptotic cells. The addition of selected serine protease inhibitors and anti-human elastase Ab markedly reduced the proinflammatory effects, the lysed neutrophils then behaving as an anti-inflammatory stimulus similar to intact apoptotic cells. Separation of lysed neutrophils into membrane and soluble fractions showed that the neutrophil membranes behaved like apoptotic cells. Thus, the cytokine response seen when macrophages were exposed to lysed neutrophils was largely due to liberated proteases. Therefore, we suggest that anti-inflammatory signals can be given by PtdSer-containing cell membranes, whether from early apoptotic, late apoptotic, or lysed cells, but can be overcome by proteases liberated during lysis. Therefore, the outcome of an inflammatory reaction and the potential immunogenicity of Ags within the damaged cell will be determined by which signals predominate.
Sepsis-Induced Apoptosis Causes Progressive Profound Depletion of B and CD4+ T Lymphocytes in Humans
Authors: Hotchkiss Richard S. , Tinsley Kevin W. , Swanson Paul E. , Schmieg Robert E. , Hui Jia Ji , Chang Katherine C. , Osborne Dale F. , Freeman Bradley D. , Cobb J. Perren , Buchman Timothy G. , Karl Irene E. 
Published: April 2014

Abstract
Patients with sepsis have impaired host defenses that contribute to the lethality of the disorder. Recent work implicates lymphocyte apoptosis as a potential factor in the immunosuppression of sepsis. If lymphocyte apoptosis is an important mechanism, specific subsets of lymphocytes may be more vulnerable. A prospective study of lymphocyte cell typing and apoptosis was conducted in spleens from 27 patients with sepsis and 25 patients with trauma. Spleens from 16 critically ill nonseptic (3 prospective and 13 retrospective) patients were also evaluated. Immunohistochemical staining showed a caspase-9-mediated profound progressive loss of B and CD4 T helper cells in sepsis. Interestingly, sepsis did not decrease CD8 T or NK cells. Although there was no overall effect on lymphocytes from critically ill nonseptic patients (considered as a group), certain individual patients did exhibit significant loss of B and CD4 T cells. The loss of B and CD4 T cells in sepsis is especially significant because it occurs during life-threatening infection, a state in which massive lymphocyte clonal expansion should exist. Mitochondria-dependent lymphocyte apoptosis may contribute to the immunosuppression in sepsis by decreasing the number of immune effector cells. Similar loss of lymphocytes may be occurring in critically ill patients with other disorders.