bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early B cell factor interacts with a subset of kappa promoters.
Authors: Sigvardsson M , Akerblad P , Leanderson T 
Published: December 2022

Abstract
A conserved sequence element situated between the decamer and TATA box in V kappa II and V kappa V promoters has a high homology to the binding site for early B cell factor (EBF). The kappa promoter element was shown to bind EBF specifically using both in vitro-translated protein and nuclear extract. Concomitant binding of EBF and Oct proteins to a wild-type kappa promoter template was observed at low efficiency, and such dual occupancy was dependent on an intact amino terminus of the Oct protein. When the two binding sites were separated by a 10-bp spacer, this dependency disappeared. A single kappa promoter EBF site together with a TATA box and an Ig heavy chain enhancer showed marginal transcriptional stimulatory activity. In contrast, the EBF site acted synergistically with a decamer element in EBF-negative plasmacytoma cells, but not in B cells of an earlier differentiation stage. In these cells, a distinct protein was observed that interacted with the EBF binding motif, while overexpression of EBF down-regulated the expression of a reporter construct containing Ig control elements.
Oxidative killing of Cryptococcus neoformans by human neutrophils. Evidence that fungal mannitol protects by scavenging reactive oxygen intermediates.
Authors: Chaturvedi V , Wong B , Newman S L 
Published: December 2022

Abstract
Polymorphonuclear neutrophils (PMN) kill Cryptococcus neoformans (Cn) by oxidative mechanisms, but the roles of various reactive oxygen intermediates (ROIs) are not known. We used a mannitol low-producing Cn mutant (Cn MLP) and its wild-type parent (Cn H99) to examine the role of ROIs distal to H2O2 in PMN killing and to determine whether mannitol produced by Cn protects the fungus against ROIs. At PMN:Cn cell ratios of 1:1, 10:1, and 100:1, PMN killed significantly more Cn MLP than Cn H99 cells after 2 and 4 h (p less than 0.05). Superoxide dismutase and the hydroxyl radical (OH.) scavengers mannitol and DMSO inhibited killing of both strains (p less than 0.05), but catalase did not. Cn H99 and Cn MLP stimulated PMN to produce similar amounts of O2- and H2O2. In contrast, Cn MLP stimulated greater luminol-dependent chemiluminescence than did Cn H99 (p less than 0.05). Finally, H2O2 alone killed similar numbers of Cn H99 and Cn MLP cells, but oxidants generated by FeSO4 (1 microM), H2O2 (10 microM), and iodide (1 to 3 microM) killed significantly more Cn MLP than Cn H99 cells in 1 h (p less than 0.05). Mannitol, DMSO, and catalase completely inhibited killing of both Cn strains by this cellfree system, but superoxide dismutase did not. These results suggest that 1) distal ROIs such as OH. and HOCI are key effector molecules against Cn, and 2) mannitol produced by Cn may protect against oxidative killing by scavenging distal ROIs.
Immunization with granulocyte-macrophage colony-stimulating factor-transduced, but not B7-1-transduced, lymphoma cells primes idiotype-specific T cells and generates potent systemic antitumor immunity.
Authors: Levitsky H I , Montgomery J , Ahmadzadeh M , Staveley-O'Carroll K , Guarnieri F , Longo D L , Kwak L W 
Published: December 2022

Abstract
Recently, genetically modified tumor cell vaccines have been described for nonhematopoietic cancers in which the relevant Ags are unknown. Several of these cell-based vaccine strategies have been shown to induce T cell-mediated systemic antitumor immunity, either by enhancing the processing and presentation of tumor Ags by host APCs or by facilitating effective Ag presentation by the tumor vaccine itself. These strategies were compared in a model B cell lymphoma, a tumor derived from APCs, which have the inherent capacity to activate Ag-specific T cells. Eradication of pre-established systemic lymphoma was achieved following immunization with lymphoma cells engineered to produce granulocyte-macrophage (GM)-CSF, and to a lesser extent cells producing IL-4, whereas vaccination with lymphoma cells transfected with the genes encoding IL-2 or B7-1 had no effect. The systemic immunity generated by GM-CSF- or IL-4-transfected lymphoma required both CD4+ and CD8+ T cells. Previous immunotherapeutic strategies for the treatment of lymphoma have focused on the generation of Ab responses targeted to the unique Ig Id as a tumor-specific Ag. Anti-idiotypic Abs were undetectable in animals vaccinated with GM-CSF-transduced lymphoma cells. In contrast, such immunization did result in the induction of Id-specific T cell responses. This is the first demonstration that T cell responses specific for a native tumor Ag are generated by GM-CSF-transduced tumor cell-based vaccination, suggesting that B cell lymphoma may be a suitable disease for genetically modified tumor vaccine strategies.
Acceleration of influenza virus clearance by Th1 cells in the nasal site of mice immunized intranasally with adjuvant-combined recombinant nucleoprotein.
Authors: Tamura S , Miyata K , Matsuo K , Asanuma H , Takahashi H , Nakajima K , Suzuki Y , Aizawa C , Kurata T 
Published: December 2022

Abstract
The protective roles of influenza viral nucleoprotein (NP), together with the cellular mechanism of the protection in the nasal site, were examined in BALB/c mice immunized intranasally with an adjuvant (cholera toxin B subunit containing 0.2% of the whole toxin)-combined A or B virus recombinant NP. The NP-immune mice, when challenged intranasally with a sublethal dose of the virus 3 wk after immunization, had accelerated virus clearance from the nasal site in both an influenza type-specific and a nonspecific manner, as shown by the protection from high morbidity from the second day after challenge. Both type-specific and nonspecific acceleration of recovery was confirmed by the increased survival rate after challenge with a lethal dose of virus in mice immunized and boosted with adjuvant-combined NP. The acceleration of nasal virus clearance was accompanied with acceleration of type-specific systemic delayed-type hypersensitivity (DTH) and with IFN-gamma production by nasal lymphocytes. The nasal lymphocytes from the immunized and challenged mice generated a significantly high level of DTH when transferred locally, but no class I MHC-restricted CTL response. Moreover, nasal CD4+ T cells, induced by NP immunization and increased in number by the subsequent challenge, were involved in the accelerated IFN-gamma production. These results suggest that nasal Th1 cells, capable of producing IFN-gamma and mediating DTH, are involved in the type-specific acceleration of recovery from influenza after challenge in mice immunized intranasally with adjuvant-combined NP, although the nonspecific mechanism of accelerated recovery remains to be solved.
Human herpes simplex virus (HSV)-specific CD8+ CTL clones recognize HSV-2-infected fibroblasts after treatment with IFN-gamma or when virion host shutoff functions are disabled.
Authors: Tigges M A , Leng S , Johnson D C , Burke R L 
Published: December 2022

Abstract
Herpes simplex virus (HSV)-specific CD8+ CTL cloned from individuals infected with HSV-2 efficiently lyse HSV-infected EBV-transformed B lymphoblastoid cells; however, these same CTL fail to lyse infected dermal fibroblasts. By 3 h after infection (early), class I MHC expression is reduced to less than 20% of that in uninfected fibroblasts, and expression is further reduced to less than 1% of the level in uninfected cells between 6 and 18 h after infection (late). We used an HSV-2 mutant that lacked the virion host shutoff (vhs) function to demonstrate that vhs plays a role in the loss of class I expression. While fibroblasts infected with this mutant are lysed by CTL that recognize virion proteins presented early as a consequence of introduction into the cytoplasm by the infecting virus, they are resistant to lysis by CTL that recognize viral proteins that must be synthesized de novo to be presented as class I Ags. Fibroblasts infected with a mutant that lacks the transporter-associated protein inhibitor ICP47 and is partially vhs defective are sensitive to CTL lysis. Pretreatment of fibroblasts with IFN-gamma prior to HSV infection sustained the level of class I expression for longer periods after infection, and these fibroblasts, infected with wild-type HSV-2, were partially sensitive to lysis by HSV-specific CTL. Taken together, these results suggest that the combined effects of the HSV-2 vhs and ICP47 gene products are to block Ag presentation by class I MHC. However, this effect can be transiently counteracted by IFN-gamma providing an early role for CD8+ CTL in the cellular immune response to HSV-2.
Eosinophil degranulation in the presence of bronchial epithelial cells. Effect of cytokines and role of adhesion.
Authors: Takafuji S , Ohtoshi T , Takizawa H , Tadokoro K , Ito K 
Published: December 2022

Abstract
It has been suggested that eosinophils (Eos) are responsible for damage to bronchial epithelial cells by releasing toxic eosinophil granule proteins in bronchial asthma. We examined eosinophil cationic protein (ECP) release from human Eos cultured in the presence of human bronchial epithelial cell line BEAS-2B (Ep). ECP release was potentiated only when both Eos and Ep were activated by IL-5 and TNF, respectively, while it was not potentiated when either Eos or Ep were activated. ECP release from Eos activated by IL-5 was also enhanced when Ep was stimulated by IFN-gamma. Paraformaldehyde fixation of Ep had no effect on ECP enhancement, excluding the possibility that soluble factors from Ep contribute to ECP potentiation. Coculture of Eos and Ep with cytokine treatment resulted in the enhancement of eosinophil adhesion and ECP release, and eosinophil adhesion preceded ECP release in the kinetic study. The enhancement of ECP release was partially inhibited by anti-CD18 mAb, which caused partial and comparable inhibition on the potentiation of eosinophil adhesion. These results suggest that the activation of Ep may profoundly affect the ability of cocultured Eos to release ECP and that CD18-dependent adhesion of Eos to Ep may be considered as one of the mechanisms of ECP enhancement.
CD95 (Fas/Apo-1)-induced apoptosis results in loss of glucose transporter function.
Authors: Berridge M V , Tan A S , McCoy K D , Kansara M , Rudert F 
Published: December 2022

Abstract
Treatment of activated human T cells with CD95 (Fas/Apo-1) ligand or Abs against CD95 results in apoptotic cell death. Although cellular responses to CD95 ligation have been described in some detail, the early molecular events that result in T cell death are only now beginning to be elucidated. Using Jurkat cells as a model of activated human T cells, we have investigated the effects of CD95 ligation on glucose transport and on glucose transporter function. We show that within minutes of CD95 activation, the ability to transport glucose across the plasma membrane is compromised and that transient exposure to Abs against CD95 for as little as 3 min results in reduced glucose transport and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) responses measured at 16 h. The effects of CD95 ligation on glucose transport are shown to be associated with loss of affinity of glucose transporters for glucose without altered maximum velocity and without changes in the cell surface expression of Glut 1, the predominant glucose transporter isotype on Jurkat cells. These results support a model of CD95 induced cell death that, at least in its early stages, does not depend on signaling to the nucleus or on macromolecular synthesis. Acute regulation of glucose transport is proposed to be an early effector mechanism in CD95-induced apoptotic cell death.
Adoptively transferred CD4+ lymphocytes from CD8 -/- mice are sufficient to mediate the rejection of MHC class II or class I disparate skin grafts.
Authors: Dalloul A H , Chmouzis E , Ngo K , Fung-Leung W P 
Published: December 2022

Abstract
Recent studies revealed that CD4+ cells initiate allograft rejection through direct recognition of allogeneic MHC class II Ags and indirect recognition of MHC peptides processed by self APCs. Both pathways were shown to help CD8+ cells that eventually lysed allogeneic MHC class I-presenting targets. There was little evidence, however, that CD4+ cells are sufficient for graft rejection. We studied skin graft rejection by CD8-deficient (CD8 -/-) mice. We showed that BALB/cJ(H-2d) CD8 -/- mice could reject allogeneic skin from C57BL/6J(H-2b) mice deficient in MHC class I or in MHC class II Ags. To understand the role of CD4+ cells in this process, we isolated them from CD8 -/- mice and transferred them to BALB/cJ nude mice that had been grafted with allogeneic skin (H-2b) from animals deficient in MHC class I or MHC class II. Nude mice injected with CD4+ cells rejected MHC class II and, albeit more slowly, MHC class I disparate skins. We showed in vitro evidence that CD4+ cells were not cytotoxic toward MHC class I or MHC class II disparate targets and that they recognized MHC class I allogeneic targets through indirect recognition. CD4+ cells produced Th1 cytokines, but not IL-4, following stimulation with allogeneic cells. Furthermore, intragraft TNF-alpha was elevated in skin grafted onto nude mice reconstituted with CD4+ cells compared with nonreconstituted mice. This suggests that MHC class II- or MHC class I-guided CD4+ cells alone are sufficient to induce rejection by the generation of cytokine-induced lesions.
pH dependence of MHC class I-restricted peptide presentation.
Authors: Stryhn A , Pedersen L O , Romme T , Olsen A C , Nissen M H , Thorpe C J , Buus S 
Published: December 2022

Abstract
The function of MHC class I molecules is to bind and present antigenic peptides to cytotoxic T cells. Here, we report that class I-restricted peptide presentation is strongly pH dependent. The presentation of some peptides was enhanced at acidic pH, whereas the presentation of others was inhibited. Biochemical peptide-MHC class I binding assays demonstrated that peptide-MHC class I complexes are more stable at neutral pH than at acidic pH. We suggest that acid-dependent peptide dissociation can generate empty class I molecules and that the resulting binding potential can be exploited by a subset of peptide-MHC class I combinations, in some cases leading to considerable peptide exchange. We further speculate that the relative instability of peptide-class I complexes under acidic conditions may affect the outcome of class I-restricted Ag presentation, as less stably associated peptides may dissociate from class I during passage of the acidic trans-Golgi network, and therefore may not be presented. Finally, our results may in part explain how endocytosed proteins can be presented by MHC class I molecules to cytotoxic T cells.
Rat RT6.2 and mouse Rt6 locus 1 are NAD+: arginine ADP ribosyltransferases with auto-ADP ribosylation activity.
Authors: Rigby M R , Bortell R , Stevens L A , Moss J , Kanaitsuka T , Shigeta H , Mordes J P , Greiner D L , Rossini A A 
Published: December 2022

Abstract
RT6 is a glycosylphosphatidylinositol-linked protein found on the surface of mature rat T lymphocytes. Cells that express RT6 have an immunoregulatory function and modulate the expression of autoimmune diabetes mellitus in the BioBreeding rat. A homologue of the rat RT6 gene, designated Rt6, has been identified in the mouse, but expression of mouse Rt6 protein has not been documented. Rat RT6 is known to be a nicotinamide adenine dinucleotide (NAD+) glycohydrolase. We now report that rat RT6.2 and recombinant mouse Rt6 locus 1 proteins possess auto-ADP ribosylation activity. In addition, mouse Rt6 but not rat RT6, catalyzes the ADP ribosylation of exogenous acceptors such as histones. The ADP-ribosyl-protein bonds in auto-ADP-ribosylated rat RT6.2, auto-ADP-ribosylated mouse Rt6, and ADP-ribosylhistone synthesized by Rt6 were stable to HgCl2 and HCl, but labile to NH2OH, consistent with ADP ribosylarginine linkages. To determine if these enzymatic activities could affect the function of rat T cells, the effect of substrate availability on lymphocyte proliferation was examined. An inverse correlation was observed between NAD+ concentration in the medium and the ability of rat T cells to respond to anti-CD3, ConA, and PMA plus ionomycin. The data suggest that lymphocyte surface ADP ribosyltransferases could be involved in signaling and immunoregulatory processes.
Presentation of the protective parasite antigen LACK by Leishmania-infected macrophages.
Authors: Prina E , Lang T , Glaichenhaus N , Antoine J C 
Published: December 2022

Abstract
Macrophages are apparently the only cells that in vivo allow the growth of the intracellular pathogen Leishmania. They are thus generally considered as likely candidates for the presentation of parasite Ag to CD4+ T lymphocytes known to be involved in protective and counterprotective immune responses. In the present study, we examined whether mouse macrophages infected with Leishmania were capable of stimulating T cell hybrids and a T cell clone reacting with the previously identified protective Ag LACK (Leishmania homologue of receptors for Activated C Kinase). This parasite protein is expressed in both promastigote and amastigote stages of Leishmania. We found that IFN-gamma-treated macrophages recently infected with live Leishmania promastigotes were fully competent to activate LACK-reactive T cells. However, at later times of infection, permissive macrophages infected with promastigotes were no longer able to present LACK, in spite of the presence of numerous intracellular parasites. This punctual presentation of LACK was apparently linked with the destruction, at least partial, of the intracellular parasites. In contrast, macrophages infected with live Leishmania amastigotes were always unable to stimulate the LACK-specific T cells. Amastigote-infected macrophages could, however, reactivate the T cells if LACK-delta(1), a recombinant form of LACK, was added as an exogenous protein in the culture medium. Similar results were obtained with all combinations tested involving macrophages from various origins, different activating cytokines (IFN-gamma, granulocyte-macrophage CSF, IL-4), several Leishmania species (L. amazonensis, L. major, L. donovani), and 15 different LACK-reactive T cell hybrids and clones. From these data, it is tempting to propose that the differentiation of promastigotes into amastigotes, which leads to a better survival of the parasites within macrophages, also allows them to go unnoticed by the immune system.
TNF-alpha inactivation of collagen receptors: implications for fibroblast function and fibrosis.
Authors: Chou D H , Lee W , McCulloch C A 
Published: December 2022

Abstract
TNF-alpha inhibits collagen synthesis and at high concentrations stimulates collagenase synthesis in fibroblasts. As fluid from chronic inflammatory lesions contains significant levels of TNF-alpha, it is puzzling why these lesions exhibit dense accumulations of disorganized collagen. In this study we determined if low concentrations of TNF-alpha may inhibit the collagen phagocytic pathway in fibroblasts and thereby contribute to fibrosis. Collagen phagocytosis was measured by flow cytometric assessment of internalized, fluorescent collagen beads. TNF-alpha induced a dose-dependent reduction (optimal dose: 40% at 10 ng/ml; p&lt;0.001) in the proportion of phagocytic cells and a twofold reduction of the number of internalized beads per cell but did not alter the total number of vital cells. TNF-alpha reduced by twofold the degradation of collagen films. Fluid flow shear-force assays demonstrated that TNF-alpha caused a 72% reduction (p &lt; 0.05) in strong binding of collagen-coated beads to cells indicating that TNF-alpha may inactivate receptors and inhibit collagen binding. Furthermore, TNF-alpha reduced cell contact area with collagen substrates by threefold and inhibited reattachment of trypsinized cells by fourfold. Although levels of collagen receptors were increased by TNF-alpha (53% increase in alpha(2) (beta)1 integrin; p&lt;0.001, 20% increase in alpha(1)beta(1)), the receptors were inactivated by the cytokine. The reduced phagocytic activity of TNF-alpha-treated cells was restored to control levels by treatment with the integrin-activating Abs A16G6 and JBS2. TNF-alpha inhibited focal adhesion formation and phosphotyrosine staining in focal adhesions. These effects were replicated by the tyrosine kinase inhibitor genistein, which also inhibited phagocytosis. Collectively, these data indicate that TNF-alpha inhibits adherence and phagocytosis of collagen. These effects are mediated by a reduction in the strength of alpha(2)beta(1) integrin binding to collagen, possibly through tyrosine kinases in focal adhesions. At low concentrations of TNF-alpha (10 ng/ml) that are found in the periphery of chronic inflammatory lesions, we suggest that inhibition of the collagen phagocytic pathway may contribute to fibrosis.
Activation of multiple proline-directed kinases by bacterial lipopolysaccharide in murine macrophages.
Authors: Sanghera J S , Weinstein S L , Aluwalia M , Girn J , Pelech S L 
Published: December 2022

Abstract
Bacterial LPS stimulation of murine macrophages leads to increased tyrosine phosphorylation and activation of the 42- and 44-kDa mitogen-activated protein kinases (MAPK) and the activation of stress-activated protein kinases (SAPK)/c-Jun N-terminal kinase (JNK) and p38, related to the high osmolarity glycerol protein kinase in Saccharomyces cerevisiae (HOG1). LPS caused a rapid increase (10 min) in phosphotransferase activity toward myelin basic protein (MBP), a polypeptide that encompassed the first 169 residues of c-Jun fused to gluthathione S-transferase (GST-c-Jun (1-169)) and 27-kDa heat shock protein (hsp27). MonoQ fractionation of cell extracts resolved phosphotransferase activity peaks toward MBP, GST-c-Jun (1-169), and hsp27, which contained MAPK, SAPK/JNK, and MAPKAPK2, respectively, as indicated by immunoblotting data. In RAW 264.7 macrophages, LPS stimulation of MAPKAPK2, a substrate of p38 HOG1 and MAPK, appeared to occur predominantly via p38 HOG1 and not the MAPK. PMA, which activated the MAPK as potently as LPS, did not strongly activate MAPKAPK2, as assessed by hsp27 phosphorylation. Consistent with p38 HOG1-mediating LPS activation of MAPKAPK2, treatment with LPS, but not PMA, increased the tyrosine phosphorylation of p38 HOG1, a modification known to elevate the enzymatic capacity of this kinase. In LPS-treated cells, the activity of SAPK/JNK was increased 5- to 10-fold, as measured by precipitating SAPK/JNK with Abs or immobilized GST-c-Jun and performing an in vitro kinase assay. In addition, the kinases thought to be upstream of SAPK/JNK, SAPK/ERK kinase 1 (SEK1), and MAPK/ERK kinase kinase 1 (MEKK1), were activated following LPS, but not PMA, exposure (5-fold and 2.5-fold, respectively.