bluuebunny/crossref_metadata_2025_split huggingface dataset:
IFN-gamma-inducing factor up-regulates Fas ligand-mediated cytotoxic activity of murine natural killer cell clones.
Authors: Tsutsui H , Nakanishi K , Matsui K , Higashino K , Okamura H , Miyazawa Y , Kaneda K 
Published: December 2022

Abstract
NK cells, non-T non-B immune effector lymphocytes, are localized in many organs, including liver, as well as in the circulation. To investigate the regulatory mechanism of killing apparatus in hepatic NK cells, we established IL-2-dependent NK cell clones from liver lymphocytes of BALB/c nude mice. To generate the NK cell clones, we incubated liver lymphocytes with a high dose of IL-2 in the presence of irradiated Kupffer cells, as feeder cells and as the source of IL-12, originally identified as NK cell stimulatory factor. Unless liver lymphocytes were incubated with both IL-2 and Kupffer cells, no cell growth was observed. Hepatic NK cell clones were established from this cell line by limiting dilution. The surface phenotypes of cloned NK cells were IL-2R beta-chain+ CD16+ CD3- IgM-. The clones did not express NK2.1, which is expressed by a half of NK-enriched spleen cells of BALB/c mice. Although the cells contained dense granules reactive to mAb against perforin, they exerted no conventional cytolytic activity against YAC-1. They constitutively expressed Fas ligand (FasL) and specifically killed Fas-positive target cells by fragmenting DNA. This Fas-FasL-mediated killing activity was enhanced by IFN-gamma-inducing factor, a recently identified novel cytokine produced by activated Kupffer cells, but was not affected by other Kupffer cell-produced cytokines, such as IL-12, IL-1beta, and TNF-alpha. Taken together, these findings suggest that hepatic NK cells participate in the immune response as effector cells through the Fas-FasL system in collaboration with cytokines from Kupffer cells.
The listerial exotoxins listeriolysin and phosphatidylinositol-specific phospholipase C synergize to elicit endothelial cell phosphoinositide metabolism.
Authors: Sibelius U , Chakraborty T , Krögel B , Wolf J , Rose F , Schmidt R , Wehland J , Seeger W , Grimminger F 
Published: December 2022

Abstract
Exotoxins such as listeriolysin (LLO) and phosphatidylinositol-specific phospholipase C (PIcA) have been implicated in listerial infection and sepsis. Employing different Listeria strains, mutated in individually known virulence genes, we examined exotoxin-related induction of endothelial cell signaling. Listeria monocytogenes was a potent inductor of phosphatidylinositol (PtdIns) metabolism in HUVEC. This effect was completely absent in a LLO-negative strain. Using a recombinant Listeria innocua strain, engineered to produce high levels of LLO, PtdIns metabolism was restored to approximately 30% of that produced by the parental L. monocytogenes strain. A recombinant L. innocua strain expressing only PIcA did not induce any PtdIns metabolism. Even higher than wild-type levels of PtdIns hydrolysis products were, however, evoked when engineered bacteria secreted both LLO and PIcA. These effects occurred in the absence of bacterial uptake by the endothelial cells. Corresponding results were observed with regard to endothelial diacylglycerol (DAG) generation. The amplification of endothelial cell signaling could be reproduced by engaging purified LLO and PIcA in the absence of bacteria. In these experiments, the unrelated pore-forming agent staphylococcal alpha-toxin, a very weak stimulus for endothelial phosphoinositide metabolism by itself, substituted for LLO to allow marked PtdIns hydrolysis when co-applied with PIcA. We conclude that the listerial exotoxins LLO and PIcA cooperate to provoke potent second messenger synthesis in endothelial cells, in the absence of cell invasion by the bacteria. This is an impressive example of synergism between a pore-forming and an enzymatic bacterial exotoxin in provoking cell signaling and inflammatory events.
Increased heat shock protein 90 (hsp90) expression leads to increased apoptosis in the monoblastoid cell line U937 following induction with TNF-alpha and cycloheximide: a possible role in immunopathology.
Authors: Galea-Lauri J , Richardson A J , Latchman D S , Katz D R 
Published: December 2022

Abstract
In this study, we examined the hypothesis that heat shock proteins (hsp) (such as hsp72 and hsp90) are implicated in the regulation of forms of cell injury that lead to programmed cell death. The monoblastoid cell line U937 has been used as a model system. For hsp90, which is not heat inducible in this cell line, we used stable U937 transfectants that either hyperexpress or hypoexpress the protein. For hsp72 (which is reproducibly induced in all three cell lines to relatively high levels of expression), we studied U937 cells before and after heat shock. We showed that apoptosis does occur in the monoblast/mononuclear phagocyte lineage, and that it could be induced in vitro by serum deprivation, UV light, or TNF-alpha in combination with cycloheximide (cx). However, an excess of hsp90 is associated with increased apoptosis when the cells are treated with a combination of TNF-alpha and cx but not when they are exposed to UV B radiation. This was complemented by the finding that reduced hsp90 levels correlate with protection against apoptosis in the TNF-alpha- and cx-treated cells. Furthermore, new synthesis of hsp72 does not protect against apoptosis. Thus, hsp90 levels may play a role in controlling the part played by mononuclear phagocytes in immunopathology.
The loss of recombinant human granulocyte colony-stimulating factor and recombinant human TNF-alpha priming effects on the superoxide-generating response in exudated neutrophils is associated with a decrease in their receptor affinities.
Authors: Niwa M , Yousif A E , Kohno K , Kanamori Y , Matsuno M , Abe A , Uematsu T 
Published: December 2022

Abstract
Several cytokines are known to enhance FMLP-stimulated superoxide generation in human circulating blood neutrophils through binding to their specific receptors, a process referred to as the priming effect. The priming effects produced by recombinant human granulocyte CSF (rhGCSF) and TNF-alpha (rhTNF-alpha) on FMLP-stimulated superoxide production in human and rabbit blood neutrophils were compared with their effects in their respective tissue neutrophils, i.e., human salivary and rabbit peritoneal neutrophils. The receptor binding characteristics of rhGCSF and rhTNF-alpha were also compared between the two types of neutrophils. Both rhGCSF and rhTNF-alpha produced dose-dependent priming effects on FMLP-stimulated superoxide production in human blood neutrophils, whereas they failed to produce any priming effects in human salivary neutrophils. Similar results were obtained for the priming effects by rhGCSF in rabbit blood and peritoneal neutrophils. A decrease in receptor binding affinity, but not in receptor density, in tissue neutrophils was demonstrated by analyzing the binding of [125I]rhGCSF and [125I]rhTNF-alpha. These findings suggest that tissue neutrophils are less responsive to rhGCSF and rhTNF-alpha in the modulation of FMLP-stimulated superoxide generation. This is due at least in part to the lower affinities of GCSF and TNF-alpha to their receptors in tissue neutrophils. This marked difference in priming effects by cytokines between blood and tissue neutrophils may represent an early step in the defensive responses against invading microorganisms or Ags.
Receptor-mediated endocytosis of antigens overcomes the requirement for HLA-DM in class II-restricted antigen presentation.
Authors: Ma C , Blum J S 
Published: December 2022

Abstract
HLA-DM- APC are unable to present soluble Ags to T cells in the context of class II DR molecules. This defect in DM- APC can be overcome by receptor-mediated delivery of Ag into cells. Ag conjugated to ligands for cell surface receptors, such as transferrin or goat anti-human Ig, was processed and presented by DM- T2.DR4 cells. Intracellular processing of Ag conjugates was required, as receptor cross-linking alone did not restore presentation by DM- APC. Ag conjugates targeted by transferrin receptors to endosomes or via surface Ig to endosomal and lysosomal compartments, were each efficiently presented by DM- cells. These Ag conjugates were predominantly localized in light density endosomes in T2.DR4 cells. This study demonstrates that the facilitated uptake and sorting of exogenous Ag by cell surface receptors allow efficient class II-restricted presentation even in the absence of HLA-DM.
Immunoregulatory role of IL-10 during superantigen-induced hyporesponsiveness in vivo.
Authors: Sundstedt A , Höiden I , Rosendahl A , Kalland T , van Rooijen N , Dohlsten M 
Published: December 2022

Abstract
Injection of the superantigen staphylococcal enterotoxin A (SEA) to mice rapidly elicits production of the Th1-related pro-inflammatory cytokines IL-2, TNF, and IFN-gamma, while repeated SEA challenges transduce a hyporesponsive state characterized by T cell deletions and anergy in the remaining SEA-reactive T cells. In the present study we show that exposure to SEA promotes the development of immunoregulatory IL-10-producing Th cells. Serum IL-10 was undetectable in mice given a priming injection of SEA, but rose to considerable levels when a SEA challenge was administered 4 days later. This coincided with maintained IL-2 production and superinduction of TNF, IFN-gamma, and IL-4. Interestingly, administration of a second SEA challenge resulted in high serum levels of IL-10, but the production of all other studied cytokines (IL-2, TNF, IFN-gamma, and IL-4) was impaired. The IL-10 production was sustained after a third and a fourth SEA challenge in the complete absence of IL-2, IFN-gamma, and IL-4. Pretreatment of mice with neutralizing anti-lL-10 mAb before the SEA challenges substantially enhanced IFN-gamma and TNF serum levels, but failed to rescue IL-2 production. Depletion of T cells with anti-CD4 or anti-CD8 mAb indicated that CD4+ T cells were crucial for SEA-induced IL-10 production. This finding was confirmed using CD4- and CD8- knockout mice. We conclude that repeated SEA challenges promote an IL-10-producing Th cell subset ("Th10" profile), which exerts an immunoregulatory effect by suppressing IFN-gamma and TNF production.
Analysis of the promoter elements necessary for IL-4 and anti-CD40 antibody induction of murine Fc epsilon RII (CD23): comparison with the germline epsilon promoter.
Authors: Richards M L , Katz D H 
Published: December 2022

Abstract
IL-4 and CD40 ligand stimulate transcription of CD23 (Fc epsilonRII) in B cells and are necessary for the expression of germline epsilon mRNA and production of IgE. Because in vivo studies have shown that the Fc epsilonRII is involved in the regulation of IgE, a study was initiated to compare how IL-4 and engagement of CD40 up-regulate the Fc epsilonRII and epsilon genes. Herein, we describe the preparation of a series of linker-scanning mutants that cover the IL-4 response region in the murine Fc epsilonRII promoter, and their function when transfected into M12.4.5 and M12.4.1 B lymphoma cell lines. Several discrete elements were found to be necessary for IL-4 induction of the Fc epsilonRII gene, some of which have homology with the binding sites of known transcription factors, including NF-IL-4 and NF-kappaB. In contrast, the response element for anti-CD40 (plus IL-4) mapped to a single discrete sequence, a NF-kappaB-like site. Aligning the Fc epsilonRII and germline epsilon promoters in the region that is highly conserved between the human and mouse homologues of both genes reveals a high degree of identity, particularly within discrete clusters. Comparing the function of linker-scanning mutants of the Fc epsilonRII promoter with a similar report for germline epsilon shows that both genes require at least two homologous and similarly located DNA elements in their promoters for a full IL-4 induction. Moreover, the similar response of Fc epsilonRII and epsilon promoter-driven chloramphenicol acetyl transferase plasmids to several cytokines and other agents suggests that the two proximal promoter regions are activated by a similar cassette of factors.
Down-regulation of IL-12, not a shift from a T helper-1 to a T helper-2 phenotype, is responsible for impaired IFN-gamma production in mammary tumor-bearing mice.
Authors: Handel-Fernandez M E , Cheng X , Herbert L M , Lopez D M 
Published: December 2022

Abstract
Altered cytokine production has been implicated in the down-regulation of cell-mediated immunity in mice bearing large mammary tumors. In several diseases, an imbalance between helper T lymphocytes Th1 and Th2 and their cytokines has been suggested as a contributing factor. In this study, although IFN-gamma from splenic T cells of D1-DMBA-3 mammary tumor-bearing mice was greatly diminished, other cytokine levels remained unchanged, indicating no clear shift between the Th1, Th2, or Th3 phenotypes. The IFN-gamma levels can be restored in vitro by addition of rIL-12 to cultured splenocytes from tumor bearers. Furthermore, IL-12 production is greatly down-regulated in macrophages from tumor-bearing mice as detected by ELISA, and this correlates with diminished expression of IL-12 p40 chain RNA. The mammary tumor used in our studies produces several factors, including granulocyte macrophage-CSF, PGE2, and phosphatidyl serine, that can affect the immune system. Addition of these tumor-derived factors in vitro to macrophages from normal mice resulted in decreased levels of IL-12 protein in cultures treated with PGE2 or phosphatidyl serine. These results indicate that the down-regulation of T cell-produced IFN-gamma in this tumor model is the result of decreased IL-12 production caused by tumor-derived factors and not a shift from the Th1 to the Th2 phenotype.
IL-10 exerts suppressive and enhancing effects on antifungal activity of mononuclear phagocytes against Aspergillus fumigatus.
Authors: Roilides E , Dimitriadou A , Kadiltsoglou I , Sein T , Karpouzas J , Pizzo P A , Walsh T J 
Published: December 2022

Abstract
Invasive aspergillosis has emerged as a frequent and serious infection in immunocompromised patients. We studied the effects of human IL-10 on antifungal activity of monocytes (MNCs) from healthy adults against Aspergillus fumigatus after incubation with IL-10 at 37 degrees C for 2 to 4 days. IL-10 (2-20 ng/ml)-pretreated MNCs exhibited approximately 40% suppression of superoxide anion (02-) production in response to PMA and FMLP (p &lt; or = 0.003), and anti-IL-10 containing supernatant neutralized the IL-10 effect. IL-10 (20 ng/ml)-pretreated MNCs exhibited decreased damage of Aspergillus hyphae after 2 to 4 days (55-98% decrease, p &lt; or = 0.04). The MNC phagocytic activity against conidia, as assessed by microscopy (percentage of phagocytosing MNCs and number of intracellular conidia per MNC) as well as by colony counting (colonies grown from intracellular conidia), was enhanced by 127% (p = 0.006), 14% (p = 0.03), and 23% (p = 0.009), respectively. MNC capacity to inhibit intracellular germination was marginally enhanced (p = 0.04) and intracellular conidiocidal activity was unaffected by IL-10. IL-4 (5 ng/ml) did not change the up-regulatory IL-10 effect on phagocytosis. IFN-gamma (25 ng/ml) and granulocyte-macrophage CSF (20 ng/ml), but not macrophage CSF (15 ng/ml), appeared to counteract suppressive IL-10 effects. Thus, IL-10 suppresses oxidative burst and antifungal activity of MNCs against Aspergillus hyphae, while increasing their phagocytic activity. These findings further elucidate a potential role of IL-10 in the pathogenesis of invasive aspergillosis, which may lead to new treatment strategies.
Monocyte chemoattractant protein-1 is sufficient for the chemotaxis of monocytes and lymphocytes in transgenic mice but requires an additional stimulus for inflammatory activation.
Authors: Gunn M D , Nelken N A , Liao X , Williams L T 
Published: December 2022

Abstract
Monocyte chemoattractant protein-1 (MCP-1), a chemotactic cytokine, acts in vitro as a chemotactic and activating factor for multiple types of leukocytes. To determine the chemotactic and activating effects of MCP-1 in vivo, we constructed transgenic mice that express human MCP-1 in type II alveolar epithelial cells and secrete it into the bronchoalveolar space. We found that MCP-1 overexpression led to a marked increase in the numbers of both monocytes and lymphocytes that could be recovered by bronchoalveolar lavage. This accumulation of mononuclear leukocytes could be reversed by the administration of an MCP-1-blocking Ab. In spite of its chemotactic effect, MCP-1 expression did not cause the inflammatory activation of accumulated leukocytes. Lungs of MCP-1 transgenic mice also showed no morphologic evidence of inflammation. However, MCP-1 mice had an increased sensitivity to other inflammatory stimuli. MCP-1 mice treated with either i.p. LPS or i.v. yeast wall glucan developed consolidated pulmonary infiltrates consisting predominantly of macrophages. Nontransgenic mice developed no such infiltrates. These results demonstrate that MCP-1 is chemotactic for monocytes and lymphocytes in vivo and that MCP-1 expression alone does not cause inflammatory activation of cells, but leads to an enhanced inflammatory response upon treatment with other stimuli.
Acute phase proteins in salmonids: evolutionary analyses and acute phase response.
Authors: Jensen L E , Hiney M P , Shields D C , Uhlar C M , Lindsay A J , Whitehead A S 
Published: December 2022

Abstract
Inflammation induces dramatic changes in the biosynthetic profile of the liver, leading to increased serum concentrations of positive acute phase (AP) proteins and decreased concentrations of negative AP proteins. Serum amyloid A (SAA) and the pentraxins C-reactive protein (CRP) and serum amyloid P component (SAP) are major AP proteins: their serum levels can rise by 1000-fold, indicating that they play a critical role in defense and/or the restoration of homeostasis. We have cloned SAA and a SAP-like pentraxin from salmonid fish species. The salmonid SAA shares approximately 70% amino acid identity with mammalian AP SAA. When salmonids are challenged with an AP stimulus, i.e., Aeromonas salmonicida, SAA responds dramatically as a major AP reactant. The salmonid pentraxin shows approximately 40% amino acid identity to both mammalian SAP and CRP. Evolutionary analysis suggests the presence of only a single such protein in teleosts and lower animal species. Surprisingly, the salmonid pentraxin behaves as a negative AP reactant, reminiscent of the SAP-like Syrian hamster female protein, in that hepatic mRNA concentrations decline to 50% of prestimulus levels. This study reinforces the hypothesis that SAA induction is an essential and universal feature of the vertebrate AP response and that it represents part of an ancient host defense system. Conversely, the species-dependent heterogeneity of pentraxin expression during the vertebrate AP response supports the possibility that its most important ancestral (and perhaps present) function is not related to its AP behavior.
The faster kinetics of L-selectin than of E-selectin and P-selectin rolling at comparable binding strength.
Authors: Puri K D , Finger E B , Springer T A 
Published: December 2022

Abstract
Selectins are a family of lectins that mediate tethering and rolling of leukocytes on endothelium in vascular shear flow. To test the hypothesis that the kinetics and the strength of rolling interactions can be independently varied for different selectin:ligand pairs, we have directly compared all three selectins with regard to distinct measures of selectin-mediated interactions in shear flow: tethering, rolling velocity, and strength of rolling adhesions. At comparable site densities of E-selectin, P-selectin, and the L-selectin counter-receptor CD34, neutrophils tethered with similar efficiency and developed rolling adhesions of similar strength as measured by resistance to detachment. Under the same conditions, neutrophils rolled 7.5- to 10.5-fold faster on CD34 than on E-selectin and P-selectin. These findings suggest that the kinetics of bond dissociation and bond formation are faster for L-selectin than for E- and P-selectin. We also compared the behavior of neutrophils and lymphocytes on the same selectin. Both cell types showed comparable strength of binding to CD34; however, neutrophils rolled with faster velocities than lymphocytes.
Effect of estradiol on cytokine secretion by proteolipid protein-specific T cell clones isolated from multiple sclerosis patients and normal control subjects.
Authors: Gilmore W , Weiner L P , Correale J 
Published: December 2022

Abstract
The ability of estradiol (E2) to modulate the secretion of cytokines by CD4+ T cells was investigated using neuroantigen-specific T cell clones isolated from normal control subjects and patients with the demyelinating disease, multiple sclerosis. In the presence of E2, the majority of the tested clones showed a dose-dependent enhancement of Ag-stimulated IL-10 secretion. The secretion of IFN-gamma was also enhanced, although the peak enhancement occurred at lower E2 concentrations and at lower magnitude than observed for IL-10. By contrast, the effect of E2 on Ag-stimulated secretion of TNF-alphabeta was biphasic, with enhancement occurring at low doses, and inhibition present at high concentrations. E2 had no effect on the secretion of IL-4 or TGF-beta. These data indicate that E2 is capable of modulating both pro- and anti-inflammatory activities of CD4+ T cells and thus has the potential to influence the outcome of CD4+ T cell-mediated immune responsiveness.
Humanized antibodies against the alpha-chain of the IL-2 receptor and against the beta-chain shared by the IL-2 and IL-15 receptors in a monkey uveitis model of autoimmune diseases.
Authors: Guex-Crosier Y , Raber J , Chan C C , Kriete M S , Benichou J , Pilson R S , Kerwin J A , Waldmann T A , Hakimi J , Roberge F G 
Published: December 2022

Abstract
We studied the efficacy and tolerance of humanized Ab interfering with the signal of the IL-2 and IL-15 receptors in a primate model of experimental autoimmune uveoretinitis. The inhibitory effects of humanized anti-Tac (HAT), an anti-IL-2R alpha-chain Ab, and HuMik beta1, an Ab directed at the beta-chain shared by the receptors of IL-2 and IL-15, were tested in culture on the proliferative response of monkey Con A-blast lymphocytes stimulated with IL-2 or IL-15. Uveitis was induced in cynomolgus monkeys by immunization with human recombinant retinal S-antigen. Treatment was initiated at the first sign of disease and consisted of HAT and HuMik beta1, alone or in combination, or vehicle control given by i.v. injection twice a week for 4 wk. Disease was evaluated by ocular funduscopy. The results in culture showed a significant dose-dependent inhibition of the IL-2-driven proliferation of lymphocytes by HAT. HuMik beta1 alone was ineffective against IL-2 stimulation, but had a marked potentiating effect in combination with HAT, independent of IL-15 signaling. IL-15-driven proliferation was inhibited by HuMik beta1, but not by HAT alone or in combination. In monkeys, experimental autoimmune uveoretinitis evolution was significantly inhibited by HAT treatment. HuMik beta1 alone had no effect on the disease. However, when used in combination, the two Ab markedly reduced the severity of ocular inflammation. The Ab were well tolerated. Only three monkeys, treated with HAT alone, made an Ab response against the injected Ab.