bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the human C6 promoter: requirement of the CCAAT enhancer binding protein binding site for C6 gene promoter activity.
Authors: González S , López-Larrea C 
Published: December 2022

Abstract
The sixth complement component (C6) is a late-acting complement protein that participates in the assembly of the membrane attack complex. C6 and most of the complement proteins are mainly synthesized in the liver. However, the human hepatoma-derived cell line Hep-G2, which produces the majority of complement proteins, synthesizes traces of C6. Here, we have isolated and characterized the human C6 promoter. Approximately 1 kb of C6 upstream sequence is shown to be sufficient to achieve tissue-specific expression of a luciferase reporter gene in two hepatic (Hep-G2 and Hep-3B) and two extrahepatic cell lines (fibroblast M1 and HeLa) in a manner similar to endogenous C6. There are wide differences in C6 mRNA expression among the four cell lines, whereas Hep-3B expresses high levels of C6, Hep-G2 and M1 poorly synthesize C6, and HeLa completely lacks C6 expression. Deletional and mutational analysis demonstrates that a C/EBP (CCAAT/enhancer binding protein) site located at -67 is required for C6 expression in Hep-3B cells, but it has little effect in M1 and Hep-G2 cells. Electrophoretic mobility shift assays show that this sequence binds to a C/EBP alpha using Hep-3B nuclear extract, but a negligible activity is detected using a Hep-G2 extract. To further investigate whether C/EBP alpha is the limiting factor for C6 expression, we have transfected a C/EBP alpha expression vector into Hep-G2 and Ml cells. C/EBP alpha expression vector dramatically trans-activates the luciferase reporter gene controlled by the C6 promoter, and it partially restores C6 mRNA expression in Hep-G2 cells.
T cell-mediated terminal maturation of dendritic cells: loss of adhesive and phagocytotic capacities.
Authors: Kitajima T , Caceres-Dittmar G , Tapia F J , Jester J , Bergstresser P R , Takashima A 
Published: December 2022

Abstract
Dendritic cells (DC) are a specific subset of APC characterized by the potent ability to activate immunologically naive T cells. We have observed previously that the murine epidermis-derived DC line XS52 undergoes a set of profound changes upon Ag-specific interaction with T cells, including IL-1 beta secretion acquired expression of CD86, and lost expression of CD115 (CSF-1 receptor) and proliferative responsiveness to CSF-1. These changes, which appear to reflect a critical transition during Ag presentation, have been termed T cell-mediated "terminal maturation" of DC, Here we report that XS52 cells also lose their adhesive and phagocytotic capacities during this event. XS52 cells, ordinarily adhere to petri dishes and phagocytose latex heads, as has been reported for DC freshly procured from spleen and skin. Importantly, XS52 cells lose both capacities after 3 to 24 h of incubation with HDK-1 T cells (keyhole limpet hemocyanin-specific TH1 clone) or with 5S8 T cells (dinitrobenzene sulfonate specific Th0 clone) in the presence of Ag. By contrast, incubation with T cells alone or with Ag alone has minimal effects, indicating that this regulation required both T cells and Ag. With respect to mechanisms, several lines of evidence suggest this IFN-gamma, which is secreted by T cells, serves as the primary mediator in down-regulating both capacities. Our observations illustrate a unique mechanism by which responding T cells upon Ag-specific activation by DC, suppress the machinery of Ag uptake through the elaboration of IFN-gamma.
Role of reactive oxygen intermediates in TCR-induced death of T cell blasts and hybridomas.
Authors: Williams M S , Henkart P A 
Published: December 2022

Abstract
The functional role of reactive oxygen intermediates (ROI) in activation-induced death of mature T lymphocytes and hybridomas was tested using antioxidants and inhibitors of enzymes that generate oxidants. These agents were shown to inhibit TCR-triggered death in a concentration-dependent manner, suggesting a possible role of ROI in this death. Since the TCR-induced death of both human T blasts and the murine T cell hybridoma 2B4 involve an initial step of TCR-induced Fas ligand (FasL) up-regulation followed by a lethal step induced by Fas cross-linking, both steps were examined separately for ROI dependence. The thiol antioxidants N-acetyl cysteine and glutathione blocked Fas-induced death triggered via cross-linking either by IgM anti-Fas or cell-bound FasL, while the other inhibitors of activation-induced death did not block this late lethal step. None of the agents used blocked early events after TCR ligation, as seen by the lack of inhibition of IL-2 secretion or CD69 up-regulation. However, the nonthiol agents that blocked activation-induced death all blocked FasL up-regulation induced by TCR signals in the hybridoma, as measured by a functional assay. Agents inhibiting FasL up-regulation also inhibited activation-induced ROI generation in the hybridoma, as detected by flow cytometry using dihydrorhodamine oxidation. Furthermore, a good correlation was found between the extent of ROI generation and functional FasL expression in 2B4 cells. Thus, while ROI do not appear to act as downstream mediators of apoptotic death induced by steroid or Fas cross-linking in T cells, they are generated by TCR signaling and appear to participate in FasL up-regulation.
Differential activation of the nuclear factor-kappa B by TNF muteins specific for the p60 and p80 TNF receptors.
Authors: Chainy G B , Singh S , Raju U , Aggarwal B B 
Published: December 2022

Abstract
Human TNF is a highly pleiotropic cytokine that mediates its effects by binding to two distinct receptors, viz p60 and p80, which transmit their signals independently of each other. Activation of the transcription factor NF-kappa B is one of the earliest events induced by TNF, but whether it is mediated through one or both forms of the TNF receptor is controversial. in the present studies, we examined the role of each receptor in the activation of NF-kappa B by using TNFs that has been designed by site-specific mutagenesis to bind either the p60 (R32W; S86T) or the p80 (D143N; A145R) form of the receptor. Human myelogenous leukemic ML-1 a cells known to express almost equal amounts of the two receptors were used. The binding of TNF to these cell could be inhibited equally by either TNF(p60) or TNF(p80) mutein. Treatment of these cells with TNF(p60) mutein activate NF-kappa B within 30 min, whereas TNF(p80) mutein, even at a 1000-fold excess, had no effect, suggesting that the activation of NF-kappa B is differentially regulated through the p60 receptor. Consistent with these results, treatment with either anti-p80 monoclonal or polygonal Abs blocked the binding of TNF to the p80 receptor without affecting TNF-mediated activation of NF-kappa B TNF(p60) mutein was also effective in cell killing, but the TNF(p80) mutein was totally ineffective. The effect was not cell type-specific, since other p80-expressing cell lines were also unresponsive. Overall, our results clearly demonstrate that the activation of NF-kappa B and cytotoxicity by TNF is differentially regulated through the p60 receptor.
Characterization of three promoter elements and cognate DNA binding protein(s) necessary for IFN-gamma induction of gp91-phox transcription.
Authors: Eklund E A , Luo W , Skalnik D G 
Published: December 2022

Abstract
The cytochrome b558 heavy chain (gp9l-phox) is expressed in terminally differentiated myelomonocytic cells. Three cis-elements located between -450 and -100 bp of the gp91-phox promoter are required for IFN-gamma induced transcription. Mutations that disrupt individual cis-elements incrementally decrease gp9l-phox promoter activity, and one of the two proximal elements must be present for an IFN-gamma response. The DNA-binding activities that interact with each of the cis-elements exhibit similar gel mobility and binding site specificity, although a consensus binding site common to the three elements is not apparent. An increased level of each DNA/protein complex is observed in myeloid cells following treatment with PMA, retinoic acid/dimethylformamide, or IFN-gamma, but not in similarly treated HeLa cells. The myeloid-specific increase in the intensity of each complex is delayed 12 to 24 h following IFN-gamma treatment, and the complexes are not immunoreactive with antisera directed against IFN-responsive factors such as IRF-1, IRF-2, IFN consensus sequence binding protein, Stat1, and IFN-stimulated gene factor-3 gamma, although IRF-2 is additionally detected as binding to the middle cis-element. These results reveal cis-elements and a DNA-binding factor(s) that participate in a common pathway in response to various stimuli that induce gp9l-phox transcription.
Use of phage surface expression to analyze regions of human V4-34(VH4-21)-encoded IgG autoantibody required for recognition of DNA: no involvement of the 9G4 idiotope.
Authors: Mockridge C I , Chapman C J , Spellerberg M B , Isenberg D A , Stevenson F K 
Published: December 2022

Abstract
The V4-34 gene encodes the majority of autoanti-red cell Abs of I/i specificity. It also encodes a proportion of autoanti-DNA Abs found in patients with systemic lupus erythematosus. Nucleotide sequence analysis of mAbs that use this gene has indicated a role for CDR3 in discrimination between these autoantigens. Specifically, anti-DNA activity may require basic amino acids, such as arginine, found in this region. To investigate this requirement, we have expressed VH and VL sequences from a patient's IgG anti-DNA mAb, as Fab molecules at the surface of phage. Expressed Fab bound strongly to DNA, whereas control VH and VL pairs from an anti-red cell mAb did not. Replacement of the homologous mutated V4-34 sequence by germ-line sequence did not affect binding, indicating that somatic mutations in VH did not contribute significantly. In contrast, replacement of the basic CDR3 by an anti-red cell CDR3 abrogated anti-DNA activity, confirming its major role. However, an influence of VL was revealed by replacing homologous mutated V kappa IIIb by an unmutated V kappa IIIb sequence, reducing binding by approximately 50%. This influence was apparent only with homologous VH since the mutated V kappa was unable to generate anti-DNA activity when combined with anti-red cell VH. The 9G4 idiotope, which arises from FWR1, was expressed by all constructs. Substitution of Trp by Ser at position 7 in FWR11 caused complete loss of idiotope expression, with no effect on recognition of DNA, indicating no influence of idiotope expression on anti-DNA activity. Phage surface expression provides a powerful and rapid technique for assessing sequences relevant for Ab specificity or idiotope expression.
Interval mapping of quantitative trait loci controlling humoral immunity to exogenous antigens: evidence that non-MHC immune response genes may also influence susceptibility to autoimmunity.
Authors: Wu J , Longmate J A , Adamus G , Hargrave P A , Wakeland E K 
Published: December 2022

Abstract
IgG Ab titers elicited to bovine rhodopsin in CFA differ 8- to 10-fold between H2s identical inbred strains A.SW/snJ (high responder) and SJL/snJ (low responder). This variation in IgG Ab titer resulted from a dramatic difference in the rise in Ab titer occurring during the maturation of the T-dependent humoral immune response. To determine the positions of non-MHC genes controlling this quantitative variation in T-dependent humoral immune responsiveness, 206 reciprocal (A.SW/snJ x SJL/snJ)F2 female progeny were immunized and assayed for anti-rhodopsin responsiveness. The genomes of these progeny were screened with 115 polymorphic simple sequence repeat markers covering &gt;90% of the mouse genome. interval mapping analysis localized the positions of these non-MHC immune response genes to genomic intervals on chromosomes 1, 5, and 13. Interestingly, these three intervals coincide exactly with three intervals recently shown to contain genes contributing to susceptibility to systemic lupus erythematosus and/or the production of autoimmune anti-dsDNA Abs. These results suggest that some genes affecting levels of humoral immune responsiveness to exogenous Ag may also play a role in genetic susceptibility to humoral autoimmune diseases. Analyses of the modes of inheritance demonstrated that high responder alleles were inherited from both parental genomes, indicative of epistatic interactions among genes influencing humoral immune responsiveness.
Respiratory syncytial virus infection of human respiratory epithelial cells up-regulates class I MHC expression through the induction of IFN-beta and IL-1 alpha.
Authors: Garofalo R , Mei F , Espejo R , Ye G , Haeberle H , Baron S , Ogra P L , Reyes V E 
Published: December 2022

Abstract
CD8+ T cells mediate some of the damage to the lung epithelium following respiratory syncytial virus (RSV) infection. Since CD8+ T cells recognize antigen-laden class I MHC molecules on the target cells, we examined in this study the expression of class I MHC by RSV-infected respiratory epithelial cells. Respiratory epithelial cell lines and bronchial epithelial cells from normal human tissue responded to RSV infection with an increased expression of class I MHC as determined by flow cytometry and immunoprecipitation of class I MHC from metabolically radiolabeled cells. The increase in class I MHC expression was dependent on infectious, replicating virus. UV-irradiated culture supernatants from RSV-infected A549 cells, when added to fresh A549 cell cultures, induced an increase in class I MHC expression by those cells. The class I MHC increasing activity within supernatants from A549 cells was due, in large part, to IFN-beta, and to a lesser extent to IL-1 alpha. The addition of neutralizing Abs to both cytokines completely blocked the increase in class I MHC expression by cells treated with the above-mentioned supernatants. These results demonstrate that RSV infection elicits IFN-beta production by respiratory epithelial cells, which in turn leads to an increase in their synthesis of class I MHC, which would facilitate their recognition and lysis by RSV-specific CD8+ T cells.
In vivo fate of the inflammatory macrophage during the resolution of inflammation: inflammatory macrophages do not die locally, but emigrate to the draining lymph nodes.
Authors: Bellingan G J , Caldwell H , Howie S E , Dransfield I , Haslett C 
Published: December 2022

Abstract
The resolution of acute inflammation requires bulk clearance of extravasated inflammatory cells in an ordered manner. Neutrophils undergo apoptosis and are ingested by macrophages (M psi) via a novel recognition mechanism that fails to provoke proinflammatory responses. Thereafter, the fate of inflammatory M psi themselves remains unclear. We investigated this in vivo, developing a semiallogeneic adoptive transfer system to track the fate of inflammatory M psi in a murine model of resolving peritonitis. Fluorescently labeled M psi from H-2k/d mice were transferred into the peritoneal cavity of H-2k mice at the same stage of resolving inflammation as the donor mice. Dual color flow cytometry permitted discrimination among donor cells, recipient cells, and donor cells that had been phagocytosed by recipient M psi. Despite the absence of significant local phagocytosis, the number of transferred M psi free in the peritoneum of recipient mice declined rapidly, being undetectable by 96 h. These data suggest that inflammatory M psi normally emigrate rapidly from the peritoneal cavity during the resolution of inflammation, contrasting with resident M psi, which persist in the noninflamed peritoneum for weeks. Accordingly, labeled nonphagocytosed cells were detected in the draining lymph nodes, but not in a variety of other tissues. Thus, unlike the polymorphonuclear leukocyte, which dies by apoptosis and is ingested by M psi, the inflammatory M psi itself does not die locally. Having performed its acute inflammatory and scavenging roles, it emigrates in a nonrandom fashion to the draining lymph node, where it may play an important part in the presentation of Ags from the inflamed site.
p161, a murine membrane protein expressed on mast cells and some macrophages, is mouse CD13/aminopeptidase N.
Authors: Chen H , Kinzer C A , Paul W E 
Published: December 2022

Abstract
pl6l is a membrane glycoprotein expressed on mast cells and on activated macrophages but on few if any other cells of hematopoietic lineages. Its lack of expression on basophils makes it useful to distinguish mast cells from basophils and aids in the analysis of mast cells and their precursors. p161 was purified from the mast cell line CFTL-12 by affinity chromatography and subjected to limited proteolysis. The sequences of the resultant peptides indicated that p161 is homologous with rat and human CD13/aminopeptidase N. Using oligonucleotide primers derived from rat CD13 cDNA, a mouse cDNA was obtained. Its deduced amino acid sequence displays 87% identity with rat CD13 and 76 % identity with human CD13. Expression of the mouse cDNA in M12 cells, which are p161 negative, renders these cells positive for staining with the monoclonal anti-p161 Ab, K-1. Furthermore, a mAb raised against partially purified mouse intestinal aminopeptidase N specifically blocked the binding of K-1 to both CFTL-12 cells and the transfected M12 cells. These results strongly indicate that mouse p161 is CD13/aminopeptidase N. Northern blot analysis shows that p161 mRNA is most abundantly expressed in the intestinal tract and kidney and is present in liver, lymph node, spleen, and brain.
IL-6 is an in vitro and in vivo autocrine growth factor for middle T antigen-transformed endothelial cells.
Authors: Giraudo E , Arese M , Toniatti C , Strasly M , Primo L , Mantovani A , Ciliberto G , Bussolini F 
Published: December 2022

Abstract
Murine endothelial cells immortalized with the middle-size Ag of polyomavirus (PmT) cause vascular tumors in syngenic mice by recruitment of host normal endothelial cells. This pathogenic process is similar to that occurring in Kaposi's sarcoma, in which the core of the lesion is constituted by "spindle cells," which recruit normal vascular mesenchymal cells. In murine endothelial cells, PmT induces modification of the expression of genes, including that of IL-6. Since IL-6 is a pleiotrophic cytokine that also regulates endothelial cell functions related to angiogenesis, we studied the relevance of IL-6 in the tumorigenicity of PmT-endothelial cells. In vitro studies demonstrated that the spontaneous PmT-endothelial cell proliferation rate was slow during the first 6 days of culture and then increased rapidly and paralleled the IL-6 release. The addition of recombinant IL-6 during the first days of culture induced a marked proliferation in a dose-dependent manner. PmT-endothelial cells expressed on their surface a high-affinity binding site for IL-6 constituted by both IL-6Ralpha and gp130 transmembrane receptors. The growth-promoting effect of exogenous IL-6 or that released by PmT-endothelial cells was abrogated by mAbs anti-IL-6Ralpha, whereas a mAb recognizing the endothelial cell CD31 molecule was inactive. 15A7 mAb anti-murine IL-6Ralpha was also active in vivo, reducing the number of metastases forming after transplantation of PmT-endothelial cells in DBA/2 mice. 15A7 mAb also increased the survival of mice bearing vascular tumors. We conclude that IL-6 is involved in the progression of vascular tumors induced by PmT, and that the blockage of IL-6-mediated intercellular circuits could be useful in the management of human vascular tumors, including Kaposi's sarcoma.
Induction of the TNF-alpha promoter in the murine dendritic cell line 18 and the murine mast cell line CPII is differently regulated.
Authors: Preischl E E , Pendl G G , Elbe A , Serfling E , Harrer N E , Stingl G , Baumruker T 
Published: December 2022

Abstract
While it was recently shown that activation of dendritic cells (DC) results in the production of a number of cytokines, the signal pathways and transcription factors involved in this process have not been described. To address this issue we compared the events resulting in the activation of the human TNF-alpha promoter occurring in the fetal dendritic cell line 18 (DC18) with those in the well-characterized murine mast cell line CPII. As stimuli we employed the protein kinase C inducer, PMA, and the Ca2+ ionophore, ionomycin, both of which are known to activate a large variety of intracellular signaling pathways. In the DC18 cells, PMA alone induces the TNF-alpha promoter in a macrolide-insensitive manner. In contrast, in the mast cell line CPII, both stimuli (PMA plus ionomycin) are necessary for promoter activation which, in addition, is sensitive to immunosuppressive drugs. Mapping of the TNF-alpha promoter showed that in both cell types the so-called kappa factor binding site is the crucial promoter element for the induction. We show that in DC18 cells, this sequence is bound to and controlled by NF-kappaB proteins p50 (NF-kappaB1) and p65 (ReIA), whereas in CPII mast cells, NF-AT and AN factors are the predominant proteins that bind to and control the kappaB element of the TNF-alpha promoter. These and further experimental data indicate that in DC, NF-kappaB factors play a predominant role in the activation of the TNF-alpha promoter and, possibly, of other cytokine promoters.
T helper 2 cytokines differently regulate monocyte chemoattractant protein-1 production by human peripheral blood monocytes and alveolar macrophages.
Authors: Yano S , Yanagawa H , Nishioka Y , Mukaida N , Matsushima K , Sone S 
Published: December 2022

Abstract
Th2 cytokines, such as IL-4, IL-10, and IL-13, suppress proinflammatory cytokine production by monocytes/macrophages. Since monocyte chemoattractant protein-1 (MCP-1) is presumed to play an important role in monocyte recruitment and activation during inflammatory and immune responses, we examined here the effects of these Th2 cytokines on MCP-1 production by human blood monocytes and alveolar macrophages. Unstimulated, highly purified blood monocytes did not produce MCP-1 spontaneously, while LPS treatment induced the production of MCP-1 and its mRNA expression. All Th2 cytokines tested suppressed LPS-induced MCP-1 production and its mRNA expression, although the suppressive effect of IL-13 was weaker than that of IL-4 or IL-10. In contrast, IL-10, but neither IL-4 nor IL-13, induced unstimulated peripheral blood monocytes to produce biologically active MCP-1 protein within 4 h, reaching a maximal level at 12 h. IL-10-induced MCP-1 production was reduced by pretreatment of IL-10 with anti-IL-10 Ab, negating the involvement of contaminated endotoxin. Moreover, IL-10 induced MCP-1 mRNA expression in unstimulated monocytes, independent of de novo protein synthesis. Furthermore, human alveolar macrophages produced MCP-1 spontaneously, and the production was inhibited by IL-4 or IL-13, but was augmented by IL-10. These findings suggest that IL-10 regulates MCP-1 production by monocytes/macrophages in a different way from other Th2 cytokines, such as IL-4 and IL-13, and contributes to host defense responses.