bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of H4: a mouse T lymphocyte activation molecule functionally associated with the CD3/T cell receptor
Authors: Redoglia Valter , Dianzani Umberto , Rojo Josè M. , Portolés Pilàr , Bragardo Manuela , Wolff Henrik , Buonfiglio Donatella , Bonissoni Sara , Janeway Charles A. 
Published: March 2007

AbstractThe monoclonal antibody C398.4A was produced by immunizing Armenian hamsters with the mouse T cell clone D10.G4.1. It recognizes a molecule selectively expressed by activated mouse T cells and was named H4. H4 is expressed on the T cell surface about 24 h after activation and peaks at day 7. By contrast, it is not expressed by resting or activated B cells, macrophages, or fibroblasts. It is also expressed by CD4 or CD8 single‐positive mature thymocytes. Immunoprecipitation showed that H4 is a disulfide‐linked dimer, precipitating as a broad band at about 50–65 kDa under nonreducing conditions and at 25 and 29 kDa under reducing conditions. Deglycosylation of the reduced H4 by N‐glycanase gave rise to a single band of about 21 kDa, suggesting that the two chains may be differentially glycosylated forms of the same protein. The H4 expression pattern and biochemical features, together with cross‐blocking, co‐capping, co‐modulation, and immunoprecipitation preclearing experiments showed that H4 is different from other known co‐stimulatory molecules such as CD69, CD2, Ly‐6, CD25, OX‐40, Mac‐1 and LFA‐1. By in vitro kinase assay, H4 was found to co‐precipitate a tyrosine kinase activity that phosphorylated substrates of about 29 and 25 kDa. Co‐modulation and co‐capping experiments showed that H4 is physically associated with the CD3/T cell receptor. These data suggest that H4 may function as a T cell‐specific co‐stimulatory molecule and play a role in the T cell response when the activation stimulus is limited either because the antigen is only available in low concentration or has a low agonistic activity.
High‐level expression of the ER‐MP58 antigen on mouse bone marrow hematopoietic progenitor cells marks commitment to the myeloid lineage
Authors: De Bruijn Marella F. T. R. , Ploemacher Rob E. , Mayen Angelique E. M. , Voerman Jane S. A. , Slieker Walentina A. T. , van Ewijk Willem , Leenen Pieter J. M. 
Published: March 2007

AbstractStudies on the early events in the differentiation of the nonspecific immune system require the identification and isolation of myeloid‐committed progenitor cells. Using the monoclonal antibodies (mAb) ER‐MP12 and ER‐MP20, generated against immortalized macrophage precursors, we have shown previously that the earliest macrophage colony‐stimulating factor (M‐CSF)‐responsive cells in the bone marrow have the ER‐MP12hi20− phenotype. In addition, we found that the ER‐MP12hi20− subset (comprising about 2 % of total nucleated marrow) contains progenitor cells of all hematopoietic lineages. Aiming at the identification and purification of the myeloid progenitor cells within the ER‐MP12hi20− subset, we used ER‐MP58, a marker expressed at high level by all M‐CSF‐responsive bone marrow progenitors. With this marker the ER‐MP12hi20− cell population could be divided into three subfractions: one with absent or low level ER‐MP58 expression, one with intermediate, and one with high ER‐MP58 expression. These subfractions were isolated by fluorescence‐activated cell sorting and tested in vitro and in vivo for their differentiation capacities. In addition, the expression of ER‐MP58 on stem cell subsets was examined in the cobblestone area‐forming cell (CAFC) assay. Our data indicate that in the ER‐MP12hi20− subpopulation myeloid‐committed progenitors are characterized by high‐level expression of the ER‐MP58 antigen, whereas cells with other or broader differentiation capacities have an ER‐MP58 negative/low or intermediate phenotype. These myeloid‐committed progenitors have no significant repopulating ability in vivo, in contrast to the ER‐MP58 intermediate cells. Primitive CAFC‐28/35, corresponding to cells providing long‐term hematopoietic engraftment in vivo, also did not express the ER‐MP58 Ag at a high level. Thus, cells committed to the myeloid lineage can be separated from progenitor cells with other differentiation capacities by means of multiparameter cell sorting using ER‐MP58 in combination with ER‐MP12 and ER‐MP20.
Polyreactive antigen‐binding B cells in the peripheral circulation are IgD+ and B7−
Authors: Chen Zhi Jian , Shimizu Fumio , Wheeler Jim , Notkins Abner Louis 
Published: March 2007

AbstractPolyreactive antibodies are naturally occurring antibodies, primarily of the IgM isotype, that are capable of reacting with a wide variety of different self and non‐self antigens. Previously, we reported that a B cell capable of making polyreactive antibody has Ig receptors on its surface that can bind different antigens. The present investigation was initiated to characterize these polyreactive antigen‐binding B cells further. A panel of fluorescein isothiocyanate‐labeled antigens (insulin, IgG Fc fragment or β‐galactosidase) served as probes to select polyreactive antigen‐binding B cells by cell sorting. Our experiment revealed that these polyreactive antigen‐binding B cells were mainly of the IgD isotype. They expressed high levels of CD40 and major histocompatibility complex class II molecules, but little or no B7‐1, B7‐2, or Fas. In contrast to the binding of antigens to monoreactive receptors (usually high affinity), the binding of antigens to polyreactive receptors (usually moderate or low affinity) did not up‐regulate the expression of B7‐1 or B7‐2. Antigens that bound to polyreactive receptors, however, were internalized and degraded, although not as efficiently as antigens that bound to monoreactive receptors. Despite the ability of these B7− cells to process antigens, they were not able to activate T cells in a mixed leukocyte reaction. It is concluded that polyreactive antigen‐binding B cells have properties that are consistent with the ability to induce immunological tolerance.
CD66: role in the regulation of neutrophil effector function
Authors: Stocks S. Craig , Ruchaud‐Sparagano Marie‐hélène , Kerr Michael A. , Grunert Fritz , Haslett Christopher , Dransfield Ian 
Published: March 2007

AbstractNeutrophils express several heavily glycosylated carcinoembryonic antigen (CEA)‐related glycoproteins (CD66 antigens) which have been implicated in adhesion to E‐selectin and as receptors for the lectins galectin 3 and bacterial type‐1 fimbriae. The role of the CD66 antigens in neutrophil effector function was examined using non‐cross‐reacting and cross‐reacting domain‐mapped CD66 monoclonal antibody (mAb), which recognize epitopes on biliary glycoprotein (BGP; CD66a), CEA gene family member 6 (CGM6; CD66b), nonspecific cross‐reacting antigen 90 (NCA90; CD66c) or CGM1 (CD66d). We show that BGP‐specific mAb which recognize an AB‐domain epitope strongly augment adhesion to fibrinogen by an Fc receptor‐ and β2 integrin‐dependent mechanism. Co‐ligation of BGP with the glycophosphatidylinositol (GPI)‐anchored CGM6 and NCA90 also caused increased β2 integrin‐mediated adhesion, receptor clustering and priming of formyl‐Met‐Leu‐Phe (fMLP)‐induced oxidant production by neutrophils, but only a small change in expression of L‐selectin and CR3 compared to the chemotactic peptide fMLP. Ligation of CGM6 or NCA90 alone did not cause activation of the neutrophil in any of the assays used and did not cause priming of fMLP‐induced oxidant production even when a secondary cross‐linking reagent was used. We propose that specific cross‐linking of neutrophil BGP with CGM6 and NCA90 contributes significantly to the regulation of neutrophil function during neutrophil recruitment.
Reduced incidence and severity of collagen‐induced arthritis in interleukin‐12‐deficient mice
Authors: McIntyre Kim W. , Shuster David J. , Gillooly Kathleen M. , Warrier Rajeev R. , Connaughton Suzanne E. , Hall Leroy B. , Arp Lawrence H. , Gately Maurice K. , Magram Jeanne 
Published: March 2007

AbstractCollagen‐induced arthritis (CIA) is an animal model for rheumatoid arthritis. The disease is elicited by immunization of genetically susceptible DBA/1 mice with type II collagen, resulting in a debilitating arthritis characterized by inflammation and involvement of multiple joints. We investigated the role of endogenous interleukin (IL)‐12 in the pathogenesis of this disease by undertaking an analysis of IL‐12‐deficient mice on the DBA/1 genetic background after immunization with type II collagen. Both the incidence and severity of disease were significantly reduced in mice unable to produce biologically active IL‐12. Concomitant decreases were observed in serum levels of pathogenic, collagen‐specific IgG2a antibodies and collagen‐induced secretion of interferon‐γ by immune splenocytes in vitro, consistent with an impaired T helper‐1 response. There were, however, a few animals which developed severe disease in a single paw in spite of this highly diminished Th1 response. Taken together, these results demonstrate an important role for IL‐12 in the pathogenesis of CIA, although it is not absolutely required for disease development.
Heat shock increases antigenic peptide generation but decreases antigen presentation
Authors: Pépin Elsa , Villiers Christian L. , Gabert Françise M. , Serra Vincent A. , Marche Patrice N. , Colomb Maurice G. 
Published: March 2007

AbstractThe heat shock response is a universal and highly conserved cellular response to stress. We describe here the effect of elevated temperature on the capacity of B cells to present antigen. Heat shock markedly affects the ability of these cells to process and present tetanus toxin to class II‐restricted T cell clones. Inhibition of antigen presentation is due neither to a modification of antigen capture nor to a variation of major histocompatibility complex (MHC) class II molecule synthesis and cell surface expression. Stressed and nonstressed B cells are able to present peptides loaded at the cell surface with the same efficiency. Nevertheless, heat shock leads to an increase of antigen peptide generation in subcellular compartments; an enhancement of cathepsin B activity is also observed. These data suggest that such a stress induces a failure in the intracellular peptide loading onto MHC class II molecules.
Early quantitative and functional deficiency of NK1+‐like thymocytes in the NOD mouse
Authors: Gombert Jean‐Marc , Herbelin André , Tancrède‐Bohin Emmanuelle , Dy Michel , Carnaud Claude , Bach Jean‐François 
Published: March 2007

AbstractAn immunoregulatory role has recently been attributed to the discrete subset of major histocompatibility complex class I‐restricted NK1+ mature heat‐stable antigen− (HSA−) thymocytes expressing an unusual Vβ8‐biased T cell receptor repertoire. NK1+ T cells are the main interleukin (IL)‐4 producers upon priming. We have studied the size and the function of this subset in the nonobese diabetic (NOD) mouse, a model of spontaneous T cell‐mediated autoimmune insulin‐dependent diabetes. This study was complicated by the absence in this strain of the NK1.1 allele, the only one for which an antibody is available. To circumvent this difficulty, the cells, hereafter designated the NK1+‐like T subset, were characterized by the use of monoclonal antibodies which showed the Vβ8 bias in the CD44+ Ly‐49+ MEL‐14− 3G11− thymocyte subset of non‐autoimmune strains and of its absence in class I‐deficient (β2‐microglobulin−/−) mice. A clear deficit in the number of NK1+‐like cells was evidenced at 3 weeks of age in NOD mice. It was still present at 8 weeks of age in the double‐negative CD4−CD8− population. The functional anomaly was even more striking: NOD mouse NK1+‐like thymocytes virtually lacked the ability to produce IL‐4 at 3 weeks and still showed a very reduced capacity at 8 weeks. NK1+ T cell deficiency was also suggested in the periphery by the reduction of Ly‐49A+ cells in the spleen of 3‐ and 8‐week‐old NOD mice and the absence of short‐term production of IL‐4 in vitro by NOD mouse spleen cells 90 min after the administration of anti‐CD3 antibody, a response attributed to NK1+ T cells. Taken together, these data demonstrate a very early defect in NK1+‐like T cells which could be involved in the genesis of autoimmunity in NOD mice through a deficiency in Th2 cell function.
Defective antigen processing correlates with a low level of intracellular glutathione
Authors: Short Suzanna , Merkel Brian J. , Caffrey Rebecca , McCoy Kathleen L. 
Published: March 2007

AbstractPreviously, we reported that Chinese hamster ovary (CHO) cells transfected with murine mouse major histocompatibility complex class II genes, exhibit a unique antigen (Ag) processing defect whereby these cells are impaired in processing only Ag with disulfide bonds. Here, we examined various aspects of the intracellular reducing environment in the CHO cells to understand the underlying mechanism causing the defect. A cell hybrid generated by the fusion of CHO cells and L cell fibroblasts was used for comparison due to their competency in processing Ag. The transport pathway of cysteine within the CHO cells appeared normal. However, these cells had a significantly lower level of glutathione, a major physiological reducing thiol, compared to the cell hybrid. Treatment of the CHO cells with N‐acetyl‐L‐cysteine did not augment their glutathione content nor their ability to process Ag. When the cell hybrid was treated with L‐buthionine‐(S,R)‐sulfoximine (BSO), which significantly decreased their glutathione level, the hybrid poorly processed hen egg lysozyme (HEL) and ovalbumin, which have disulfide bonds. In contrast, BSO treatment did not affect the capacity of the hybrid to process pigeon cytochrome c and carboxymethylated HEL, which lack disulfide bonds. Therefore, low intracellular glutathione levels in antigen‐presenting cells correlated with defective processing of Ag with disulfide bonds, indicating that this thiol may be a critical factor in regulating productive Ag processing.
CD40‐mediated stimulation of B1 and B2 cells: implication in autoantibody production in murine lupus
Authors: Kaneko Yoriaki , Hirose Sachiko , Abe Masaaki , Yagita Hideo , Okumura Ko , Shirai Toshikazu 
Published: March 2007

AbstractB1 cells usually show preferential responses to T cell‐independent antigens. To ask whether B1 cells could respond to CD40‐mediated stimulation for proliferation and differentiation, and whether CD40‐mediated signals are involved in the production of autoantibodies by B1 cells, we compared responses to our newly established agonistic anti‐mouse CD40 monoclonal antibody (mAb) between B1 and B2 cells from autoimmune‐prone (NZB X NZW) F1 mice. Stimulation with this mAb induced a similar level of proliferative responses of both B1 and B2 cells, as well as an increase in expression of cell surface molecules I‐A, CD54, CD23, CD80, and CD86. While co‐stimulation with interleukin (IL)‐4 markedly augmented proliferative as well as IgG1 and IgE antibody responses of both B1 and B2 cells, co‐stimulation with IL‐5 augmented proliferative and IgM antibody responses of only B1 cells. Splenic B1, but not B2 cells from young (NZB X NZW) F1 mice spontaneously produced substantial amounts of IgM including IgM anti‐DNA antibodies, and the levels increased in case of stimulation with anti‐CD40 mAb alone, or to a greater extent with the mAb plus IL‐4 and IL‐5. Collectively, these results indicate that splenic B1 cells from autoimmune (NZB X NZW) F1 mice have a comparable responsiveness to the CD40‐mediated stimulation to that of B2 cells, which would be a potent regulatory mechanism involved in the spontaneous production of autoantibodies by B1 cells.
Effect of CD80 and CD86 blockade and anti‐interleukin‐12 treatment on mouse acute graftversus‐host disease
Authors: Saito Kiyoshi , Yagita Hideo , Hashimoto Hiroshi , Okumura Ko , Azuma Miyuki 
Published: March 2007

AbstractWe investigated the efficacy of a combination of anti‐CD80 and CD86 (CD80 + 86) monoclonal antibodies (mAb), anti‐interleukin (IL)‐12 mAb, or both, for prophylaxis in a mouse acute graft‐versus‐host‐disease (GVHD) model. The treatment with a combination of anti‐CD80 + 86 mAb efficiently reduced the lethality of GVHD, whereas mAb against either CD80 or CD86 alone had an effect. A delay in lymphocyte reconstitution and GVHD‐associated histological changes in organs was observed at 30 days post‐bone marrow transplantation (BMT) even in the anti‐CD80 + 86 mAb‐treated mice, although these manifestations were resolved by 100 days. In vitro, host alloantigen‐specific T cell proliferative responses and generation of CTL were significantly reduced by anti‐CD80 + 86 treatment. Furthermore, anti‐CD80 + 86 mAb preferentially inhibited the production of interferon (IFN)‐γ, but not IL‐4 and IL‐10, when cultures were assayed at 21 days. Although the anti‐IL‐12 mAb treatment alone inhibited the generation of cytotoxic T lymphocytes and IFN‐γ production in vitro, administration of anti‐IL‐12 mAb in vivo reversed the beneficial effects of anti‐CD80 + 86 treatment on host survival post‐BMT. The adverse effect of anti‐IL‐12 treatment seems to result from impairment of natural immunity and hematopoiesis, rather than as a consequence of an incomplete blockade of T helper (Th)1 responses. Our results suggest that the prevention of GVHD‐induced death results from the efficient blockade of Th1 cell activation by the anti‐CD80 + 86 treatment. However, further treatment is required for a complete prevention of GVHD, which seems to be partly mediated by Th2 cells.
RAG1, RAG2 and pre‐T cell receptor α chain expression by adult human hepatic T cells: evidence for extrathymic T cell maturation
Authors: Collins Clive , Norris Suzanne , McEntee Gerry , Traynor Oscar , Bruno Ludovica , von Boehmer Harald , Hegarty John , O'Farrelly Cliona 
Published: March 2007

AbstractFlow cytometric analysis of cell suspensions obtained from normal adult liver tissue at the time of transplantation revealed significant populations of T lymphocytes. These were examined for molecular evidence of local T cell maturation using reverse transcription‐polymerase chain reaction to detect expression of recombination activation gene 1 (RAG1), RAG2 and pre‐T cell receptor α chain (pTα), which occurs only in early thymocyte development. Four specimens of whole liver were positive for RAG1 and RAG2 expression, whereas peripheral blood mononuclear cells from the same individuals were negative. To localize RAG expression, immature (CD2+CD7+) and mature (CD45R0+) T cell subpopulations were isolated by magnetic separation from hepatic and peripheral blood mononuclear cell preparations. We detected the expression of RAG1, RAG2 and pre‐TCRα in five specimens of hepatic CD2+CD7+ but not in CD45RO+ hepatic lymphocytes. Four out of six specimens of CD2+CD7+ cells from the peripheral blood were negative for RAG1 and RAG2 while all six specimens were positive for pTα expression. These results suggest that pre‐T cells are trafficking from the bone marrow or the thymus to other tissues to continue differentiation and selection in the context of an appropriate cellular and molecular environment. The presence of immature populations of T cells in the adult liver and high levels of RAG expression suggests that the adult liver provides such an environment for extrathymic T cell maturation. These findings may have important implications for tolerance induction after liver transplantation and offer help in understanding the etiology of autoimmune liver disease.
Intracellular co‐localization of Trypanosoma cruzi and inducible nitric oxide synthase (iNOS): evidence for dual pathway of iNOS induction
Authors: Rottenberg Martín E. , Castaños‐Velez Esmeralda , De Mesquita Roberto , Laguardia Oscar Goñi , Biberfeld Peter , Örn Anders 
Published: March 2007

AbstractEvidence is presented from studies in vitro and in vivo for a dual pathway of inducible nitric oxide synthase (iNOS) induction during Trypanosoma cruzi infection, one of which is interferon (IFN)‐γ dependent and the other not. In vitro, the IFN‐γ‐dependent iNOS induction decreases parasite multiplication, and is in vivo associated with protection. iNOS induced by this pathway mediated a high NO output and showed a diffuse, cytoplasmic immunostaining in IFN‐γ‐activated macrophages in vitro as well as in cell infiltrates or infected tissues. Surprisingly, in such tissues, iNOS co‐localized with parasite nests, and by immunoelectromicroscopy, iNOS was demonstrated on the parasite surface. iNOS co‐localization with parasites was also seen in tissues from T. cruzi‐infected IFN‐γ receptor (R) knockout mice suggesting an IFN‐γ‐independent pathway of induction. However, no cytoplasmic iNOS was seen in inflammatory infiltrates of these tissues. IFN‐γR−/− mice displayed a dramatically enhanced susceptibility to infection with T. cruzi, diminished accumulation of iNOS mRNA in skeletal muscle and spleen cells, and reduced release of NO and per‐oxynitrite. Expression of iNOS around intracellular parasites was also observed after infection of peritoneal macrophages or L‐929 fibroblasts in vitro in the absence of other exogenous stimuli. A time‐dependent NO release and enhanced accumulation of iNOS mRNA also was observed in infected peritoneal cells and fibroblasts. Cultured T. cruzi amastigotes, trypomastigotes, and epimastigotes were not labeled by the anti‐iNOS antibodies and contained no iNOS mRNA, indicating that the iNOS detected actually originated from the mammalian cell. A pathogenic effect of low NO levels is suggested by the arresting effect of NOS inhibitors and the enhancing consequences of low concentrations of NO donors on intracellular parasite multiplication.
Protective major histocompatibility complex genes and the role of interleukin‐4 in collagen‐induced arthritis
Authors: Hesse Matthias , Bayrak Şinasi , Mitchison Avrion 
Published: March 2007

AbstractTo investigate the role of interleukin (IL)‐4 during the triggering of collagen‐induced arthritis, we examined the effects of the I‐Ab and I‐E protective/suppressive genes and passively administered anti‐IL‐4 monoclonal antibody. In contrast to the action of I‐E expression on its own, which has mainly a suppressive effect post‐triggering, the combination of I‐Ab and I‐E had a marked protective effect. Assuming, on the basis of previous experience with the I‐Ab allele, that it might act through suppressing early IL‐4 production, we treated mice with the 11B11 IL‐4‐neutralizing antibody around the time of initial immunization with collagen. Treatment over a period extending to 6 days post‐immunization exacerbated the arthritis, but when curtailed to 2 days post‐immunization (and tested in pristane‐primed animals), the disease was reduced. We conclude that IL‐4 plays an essential role in triggering the disease.