bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homogeneous Escherichia coli Chaperonin 60 Induces IL-1β and IL-6 Gene Expression in Human Monocytes by a Mechanism Independent of Protein Conformation
Authors: Tabona Peter , Reddi Krisanavane , Khan Sahar , Nair Sean P. , Crean St. John V. , Meghji Sajeda , Wilson Michael , Preuss Monika , Miller Andrew D. , Poole Stephen , Carne Sandy , Henderson Brian 
Published: December 2022

Abstract
Escherichia coli chaperonin (cpn) 60 (groEL) is a protein-folding oligomer lacking tryptophan residues that copurifies with tryptophan-containing proteins and peptides. Cpn 60 is a major immunogen in infectious diseases, and evidence suggests that groEL and mycobacterial cpn 60s can induce cytokine synthesis, stimulate cytokine-dependent bone resorption, and up-regulate expression of vascular endothelial cell adhesion molecules. Whether such activities are due to the cpn 60 or to the copurifying/contaminating proteins/peptides has not been determined. Here we report a method for removing the protein contaminants of groEL and demonstrate that this, essentially homogeneous, groEL remains a potent inducer of human monocyte IL-1β and IL-6 production. Contaminating peptides had no cytokine-inducing activity and did not synergize with purified groEL. The LPS inhibitor polymyxin B and the CD14-neutralizing Ab MY4 had no inhibitory action on groEL demonstrating that activity is not due to LPS contamination. Heating groEL had no effect on its capacity to stimulate human monocytes to secrete IL-6. Proteolysis of groEL with trypsin, sufficient to produce low molecular mass peptides, also had no inhibitory effect. Thus, we conclude that groEL is a potent inducer of monocyte proinflammatory cytokine production, which acts through the binding of nonconformational peptide domains that are conserved after proteolysis. These data suggest that if groEL was released from bacteria it could induce prolonged tissue pathology by virtue of its cytokine-inducing activity and its resistance to proteolytic inhibition of bioactivity.
In Vivo Retargeting of T Cell Effector Function by Recombinant Bispecific Single Chain Fv (Anti-CD3 × Anti-Idiotype) Induces Long-Term Survival in the Murine BCL1 Lymphoma Model
Authors: De Jonge Jan , Heirman Carlo , Veerman Marijke de , Van Meirvenne Sonja , Moser Muriel , Leo Oberdan , Thielemans Kris 
Published: December 2022

AbstractAs demonstrated in several preclinical models, bispecific Abs are attractive immunotherapeutic agents for tumor treatment. We have previously reported that a bacterially produced anti-CD3 × antitumor bispecific single chain variable fragment of Ab fragment (BsscFv), which is capable of retargeting CTLs toward BCL1 tumor cells, exhibits antitumor activity in vitro. To further facilitate BsscFv production, the coding sequence was subcloned in a eukaryotic expression vector and introduced into Chinese hamster ovary cells for large-scale production. In this report, we have determined the serum stability and the clearance rate from the circulation of BsscFv. Most important, we prove here the therapeutic value of BsscFv in the treatment of BCL1 lymphoma, a murine model for human non-Hodgkin’s lymphoma. Tumor-bearing mice that were treated with rscFv in combination with staphylococcal enterotoxin B superantigen, human rIL-2, or murine rIL-12 showed long-term survival, whereas untreated mice all died. This is the first report of the successful in vivo use of BsscFv as an immunotherapeutic agent. Furthermore, long-term survival was the result of complete tumor removal and was not due to the induction of dormancy.
Fibrinogen Activates NF-κB Transcription Factors in Mononuclear Phagocytes
Authors: Sitrin Robert G. , Pan Pauline M. , Srikanth Sujata , Todd Robert F. 
Published: December 2022

AbstractAdhesion to extracellular matrices is known to modulate leukocyte activation, although the mechanisms are not fully understood. Mononuclear phagocytes are exposed to fibrinous provisional matrix throughout migration into inflammatory foci, so this study was undertaken to determine whether fibrinogen triggers activation of NF-κB transcription factors. U937 cells differentiated with PMA in nonadherent culture were shown to express two fibrinogen-binding integrins, predominately CD11b/CD18, and to a lesser extent, CD11c/CD18. Cells stimulated with fibrinogen (10–100 μg/ml)/Mn2+ (50 μM) for 2 h were examined by electrophoretic mobility shift assay. NF-κB activation, minimal in unstimulated cells, was substantially up-regulated by fibrinogen. Fibrinogen also caused activation of AP-1, but not SP1 or cAMP response element-binding protein (CREB) factors. Blocking mAbs against CD18 and CD11b abrogated fibrinogen-induced NF-κB activation. To determine the effects on transcriptional regulation, U937 cells were transfected with a plasmid containing the HIV-1 enhancer (bearing two NF-κB sites) coupled to a chloramphenicol acetyltransferase (CAT) reporter. Cells were subsequently stimulated with 1) PMA for 24 h, inducing CAT activity by 2.6-fold, 2) fibrinogen/Mn2+ for 2 h, inducing CAT activity by 3.2-fold, or 3) costimulation with fibrinogen and PMA, inducing 5.7-fold the CAT activity induced by PMA alone. We conclude that contact with fibrinogen-derived proteins may contribute to mononuclear phagocyte activation by signaling through CD11b/CD18, resulting in selective activation of transcriptional regulatory factors, including NF-κB.
Platelet-Activating Factor Synthesized by IL-12-Stimulated Polymorphonuclear Neutrophils and NK Cells Mediates Chemotaxis
Authors: Bussolati Benedetta , Mariano Filippo , Cignetti Alessandro , Guarini Anna , Cambi Vincenzo , Foà Robert , Piccoli Giuseppe , Camussi Giovanni 
Published: December 2022

AbstractIL-12 is chemotactic for NK cells and polymorphonuclear neutrophils (PMN), but not for monocytes. In the present study, we evaluated whether the chemotactic effect of IL-12 is a direct phenomenon or is dependent on the generation of secondary mediators. The results obtained indicate that IL-12 induces a dose- and time-dependent synthesis of platelet-activating factor (PAF) from PMN and NK cells and of reactive oxygen radicals (ROS) from PMN. Monocytes and CD56-negative PBMC cells did not synthesize PAF or ROS after challenge with IL-12. The production of ROS by PMN was significantly inhibited by two chemically different PAF receptor antagonists (WEB 2170 and CV 3988), suggesting an autocrine stimulation of PMN by PAF newly synthesized after the challenge with IL-12. Moreover, the IL-12-induced chemotaxis of PMN and NK cells was significantly reduced by both WEB 2170 and CV 3988, suggesting that synthesized PAF mediates the chemotactic effect of IL-12. Preincubation with superoxide dismutase, which blocks the formation of superoxide anions, also reduced the chemotactic effect of IL-12 on PMN, but not on NK cells, suggesting that superoxide anion generation is relevant only for the IL-12-induced chemotaxis of PMN. In conclusion, the results of the present study indicate that IL-12-induced PAF synthesis plays a critical role in triggering the events involved in the motogenic response of PMN and NK to IL-12.
A CD28-Associated Signaling Pathway Leading to Cytokine Gene Transcription and T Cell Proliferation Without TCR Engagement
Authors: Siefken Renate , Klein-Heßling Stefan , Serfling Edgar , Kurrle Roland , Schwinzer Reinhard 
Published: December 2022

AbstractStimulation of resting human T cells with the CD28-specific mAb BW 828 induces proliferation and cytokine synthesis without further requirement for TCR coengagement. This observation prompted us to postulate that signal 2 (costimulatory signal) alone without signal 1 (TCR signal) can activate T cells. To test whether this putative function of CD28 is mediated via a particular signaling pathway, we compared early signaling events initiated in resting T cells by the stimulatory mAb BW 828 with signals triggered by the nonstimulating CD28 mAb 9.3. Stimulation of T cells with BW 828 induced an increase in intracellular Ca2+, but did not lead to detectable activation of the protein kinases p56lck and c-Raf-1. This pathway resulted in the induction of the transcription factors NF-κB, NF-AT, and proteins binding to the CD28 response element of the IL-2 promoter. On the other hand, stimulation of T cells with mAb 9.3 increased the level of intracellular Ca2+ and triggered the activation of p56lck and c-Raf-1, but was unable to induce the binding of transcription factors to the IL-2 promoter. In contrast to the differential signaling of BW 828 and 9.3 in resting T cells, the two mAbs exhibited a similar pattern of early signaling events in activated T cells and Jurkat cells (p56lck activation, association of phosphatidylinositol 3-kinase with CD28), indicating that the signaling capacity of CD28 changes with activation. These data support the view that stimulation through CD28 can induce some effector functions in T cells and suggest that this capacity is associated with a particular pattern of early signaling events.
Requirement for Dual Signals by Anti-CD40 and IL-4 for the Induction of Nuclear Factor-κB, IL-6, and IgE in Human B Lymphocytes
Authors: Jeppson John D. , Patel Hiren R. , Sakata Naoki , Domenico Joanne , Terada Naohiro , Gelfand Erwin W. 
Published: December 2022

Abstract
Stimulation of human peripheral B cells via the CD40 receptor and IL-4R together lead to IgE synthesis and secretion, but the intracellular signaling mechanisms by which these signals lead to IgE production are unclear. Roles for the transcription factor NF-κB and IL-6 have been postulated in the induction of IgE synthesis by IL-4/CD40. We found that neither anti-CD40 Ab nor IL-4 alone was able to induce significant proliferation of human B cells. However, the combination of anti-CD40 and IL-4 was a potent inducer of B cell proliferation in addition to IgE production from purified human B cells. Furthermore, IL-4 and anti-CD40 synergized for the production of IL-6. While neither IL-4 alone nor anti-CD40 alone was able to induce significant NF-κB DNA binding activity, the combination of IL-4 and anti-CD40 induced a strong activation of NF-κB, a transcription factor that regulates IL-6 production. These data indicate that both IL-4 and anti-CD40 are required to induce NF-κB activation and IL-6 transcription and production, and implicate these events in a signaling pathway augmenting IgE production in human B lymphocytes.
New Genetic Loci That Control Susceptibility and Symptoms of Experimental Allergic Encephalomyelitis in Inbred Mice
Authors: Butterfield Russell J. , Sudweeks Jayce D. , Blankenhorn Elizabeth P. , Korngold Robert , Marini Joseph C. , Todd John A. , Roper Randall J. , Teuscher Cory 
Published: December 2022

Abstract
Experimental allergic encephalomyelitis (EAE), the principal animal model of multiple sclerosis, is a genetically determined phenotype. In this study, analyses of the cumulative disease frequencies in parental, F1 hybrid, and F2 mice, derived from the EAE-susceptible SJL/J strain and the EAE-resistant B10.S/DvTe strain, confirmed that susceptibility to EAE is not inherited as a simple Mendelian trait. Whole genome scanning, using 150 informative microsatellite markers and a panel of 291 affected and 390 unaffected F2 progeny, revealed significant linkage of EAE susceptibility to marker loci on chromosomes 7 (eae4) and 17, distal to H2 (eae5). Quantitative trait loci for EAE severity, duration, and onset were identified on chromosomes 11 (eae6, and eae7), 2 (eae8), 9 (eae9), and 3 (eae10). While each locus reported in this study is important in susceptibility or disease course, interactions between marker loci were not statistically significant in models of genetic control. One locus, eae7, colocalizes to the same region of chromosome 11 as Orch3 and Idd4, susceptibility loci in autoimmune orchitis and insulin-dependent diabetes mellitus, respectively. Importantly, eae5 and eae7 are syntenic with human chromosomes 6p21 and 17q22, respectively, two regions of potential significance recently identified in human multiple sclerosis genome scans.
Antitumor Effect of CD40 Ligand: Elicitation of Local and Systemic Antitumor Responses by IL-12 and B7
Authors: Nakajima Atsuo , Kodama Tomohiro , Morimoto Shinji , Azuma Miyuki , Takeda Kazuyoshi , Oshima Hideo , Yoshino Shin-ichi , Yagita Hideo , Okumura Ko 
Published: December 2022

Abstract
The interaction between CD40 ligand (CD40L, CD154) and its receptor CD40 has been implicated in the establishment of cell-mediated immunity as well as humoral immune responses. To examine the role of CD40L in eliciting antitumor immunity, we introduced murine CD40L gene into P815 mastocytoma (CD40L-P815). CD40L-P815 cells underwent prompt rejection when inoculated s.c. into syngenic DBA/2 mice or athymic BALB/c nu/nu mice, which was mediated by NK cells and dependent on endogenous IL-12. The primary rejection of CD40L-P815 cells in DBA/2 mice elicited CD8+ T cell-mediated protective and systemic immunity against parental tumor cells, which was induced by CD4+ T cells and endogenous B7. These results indicated a potent antitumor effect of CD40L that is mediated by potentiation of host Ag-presenting cell functions, and introduction of CD40L will be useful as a new strategy of immuno-gene therapy against tumors.
CXCR1 and CXCR2 Are Rapidly Down-Modulated by Bacterial Endotoxin Through a Unique Agonist-Independent, Tyrosine Kinase-Dependent Mechanism
Authors: Khandaker Masud H. , Xu Luoling , Rahimpour Rahbar , Mitchell Gordon , DeVries Mark E. , Pickering J. Geoffrey , Singhal Sharwan K. , Feldman Ross D. , Kelvin David J. 
Published: December 2022

AbstractThe expression of the seven-transmembrane domain chemokine receptors CXCR1 and CXCR2 modulates neutrophil responsiveness to the chemoattractant IL-8 and a number of closely related CXC chemokines. In the present study, we investigated the mechanism by which bacterial LPS induces the down-modulation of IL-8 responsiveness and CXCR1 and CXCR2 expression on human neutrophils. Treating neutrophils with LPS reduced IL-8R expression to 55 ± 5% of the control within 30 min and to 23 ± 2% within 1 h of stimulation. Furthermore, this down-modulation could not be attributed to increased concentrations of IL-8, TNF-α, or IL-1β, since ELISA studies indicated that LPS-stimulated neutrophils did not release detectable amounts of these proteins before 2 h poststimulation. The tyrosine kinase (TK) inhibitors genistein and herbimycin A attenuated the LPS-mediated down-modulation of CXCR1 and CXCR2, indicating that the activation of a TK is required for LPS to mediate its effect. The effect of LPS on receptor expression paralleled the hyperphosphorylation of the protein TK p72syk. Although IL-8 induced a comparable down-modulation of CXCR1 and CXCR2, TK inhibitors did not attenuate this effect. These studies provide the first evidence of an agonist-independent, TK-dependent pathway of chemokine receptor regulation by endotoxin.
The Role of Mast Cell Tryptase in Regulating Endothelial Cell Proliferation, Cytokine Release, and Adhesion Molecule Expression: Tryptase Induces Expression of mRNA for IL-1β and IL-8 and Stimulates the Selective Release of IL-8 from Human Umbilical Vein Endothelial Cells
Authors: Compton Steven J. , Cairns Jennifer A. , Holgate Stephen T. , Walls Andrew F. 
Published: December 2022

AbstractMast cells are found frequently in close proximity to blood vessels, and endothelial cells are likely to be exposed to high concentrations of their granule mediators. We have investigated the proinflammatory actions of the major mast cell product tryptase on HUVEC. Addition of purified tryptase was found to stimulate thymidine incorporation, but induced little alteration in cell numbers, suggesting it is not a growth factor for HUVEC. Expression of ICAM-1, VCAM-1, and E-selectin was not altered following incubation with tryptase, but the potent granulocyte chemoattractant IL-8 was released in a dose-dependent fashion in response to physiologically relevant concentrations, with maximal levels in supernatants after 24 h. The actions of tryptase on HUVEC were inhibited by heat inactivation of the enzyme, or by preincubating with the protease inhibitors leupeptin or benzamidine, suggesting a requirement for an intact catalytic site. Reverse-transcription PCR analysis indicated up-regulation of mRNA for IL-8 as well as for IL-1β in response to tryptase or TNF-α. However, tryptase was a more selective stimulus than TNF-α and did not induce increased expression of mRNA for granulocyte-macrophage CSF or stimulate the release of this cytokine. Leukocyte accumulation in response to tryptase may be mediated in part through the selective secretion of IL-8 from endothelial cells.
Activation of the Epidermal Platelet-Activating Factor Receptor Results in Cytokine and Cyclooxygenase-2 Biosynthesis
Authors: Pei Yong , Barber Lisa A. , Murphy Robert C. , Johnson Christopher A. , Kelley Susan W. , Dy Lady C. , Fertel Richard H. , Nguyen Thanh M. , Williams David A. , Travers Jeffrey B. 
Published: December 2022

Abstract
Recent studies suggest that the lipid mediator platelet-activating factor (PAF) is involved in keratinocyte function and skin inflammation. Indeed, PAF is found in association with inflammatory skin diseases, intradermal injections of PAF induce inflammation, and keratinocytes express functional PAF receptors (PAF-R). One mechanism by which the keratinocyte PAF-R could contribute to epidermal functions and inflammatory states would be through the synthesis of inflammatory regulators, such as PAF, PGs, and cytokines. The ability of the epidermal PAF-R to induce the synthesis of these immunomodulators was tested using a model system created by transduction of the PAF-R-negative human epidermal cell line KB with the PAF-R. Activation of this epidermal PAF-R resulted in arachidonic acid release, and the biosynthesis of PAF and PGE2. In addition, the KB PAF-R triggered increased levels of mRNA and protein for the inducible isozyme of cyclooxygenase (COX-2) as well as IL-6 and IL-8, both of which have been implicated in skin inflammatory processes. Studies with the human keratinocyte-derived epidermal cell line HaCaT revealed that activation of the endogenous PAF-R led to the increased accumulation of COX-2, IL-6, and IL-8 mRNA similar to that seen with the KB PAF-R model system. Finally, treatment of HaCaT keratinocytes with IL-8 resulted in PAF biosynthesis, indicating the existence of a positive feedback loop between IL-8 and PAF in epidermal cells. These studies suggest involvement of PAF and the PAF-R in the epidermal cytokine network.
IL-5 Production by NK Cells Contributes to Eosinophil Infiltration in a Mouse Model of Allergic Inflammation
Authors: Walker Christoph , Checkel James , Cammisuli Salvatore , Leibson Paul J. , Gleich Gerald J. 
Published: December 2022

AbstractIL-5 production in vivo plays a unique role in the production, activation, and localization of eosinophils in a variety of allergic conditions. The current paradigm suggests that allergen-specific Th2 cells are the main source for the IL-5 production. The experiments outlined in this work, however, suggest that in vivo production of IL-5 by NK cells can separately influence eosinophil-associated inflammatory responses. Specifically, a mouse model of allergic inflammation was used in which C57BL/6 mice were immunized and challenged with a short ragweed Ag extract, known to induce a selective eosinophilia within the peritoneal cavity. Peritoneal lavage fluids from these mice also contained increased numbers of T cells and NK cells, as well as significantly elevated levels of IL-4, IL-5, and IFN-γ. Flow-cytometric analysis of cytokine-producing cells in peritoneal lavage fluid revealed increased numbers of IL-5-producing cells in both T cell and NK cell populations following allergen exposure. Depletion of NK cells by treatment with NK1.1 Abs selectively reduced the number of infiltrating eosinophils by more than 50%. Moreover, the inhibition of the infiltration of eosinophils was accompanied by a complete loss of IL-5-producing NK cells and significantly reduced levels of peritoneal lavage fluid IL-5, whereas the number of IL-5-producing T cells was not affected. Thus, the results presented in this study provide clear evidence for a novel immunoregulatory function of NK cells in vivo, promoting allergen-induced eosinophilic inflammatory responses by the production of IL-5.
Cutting Edge: CXCR4 Is a Functional Coreceptor for Infection of Human Macrophages by CXCR4-Dependent Primary HIV-1 Isolates
Authors: Verani Alessia , Pesenti Elena , Polo Simona , Tresoldi Eleonora , Scarlatti Gabriella , Lusso Paolo , Siccardi Antonio G. , Vercelli Donata 
Published: December 2022

Abstract
The identification of HIV-1 coreceptors has provided a molecular basis for the tropism of different HIV-1 strains. CXC chemokine receptor-4 (CXCR4) mediates the entry of both primary and T cell line-adapted (TCLA) syncytia-inducing strains. Although macrophages (Mφ) express CXCR4, this coreceptor is assumed to be nonfunctional for HIV-1 infection. We addressed this apparent paradox by infecting human monocyte-derived Mφ with primary and TCLA isolates that were rigorously characterized for coreceptor usage and by adding the natural CXCR4 ligand, stem cell differentiation factor-1, to specifically block CXCR4-mediated entry. Our results show that primary HIV-1 isolates that selectively use CXCR4 productively infected both normal and C-C chemokine receptor-5-null Mφ. By contrast, Mφ supported the entry of CXCR4-dependent TCLA strains with variable efficiency but were not productively infected. Thus, the tropism of HIV isolates results from complex virus/host cell interactions both at the entry and postentry levels.
Cutting Edge: Human Anaphylatoxin C4a Is a Potent Agonist of the Guinea Pig But Not the Human C3a Receptor
Authors: Lienenklaus Stefan , Ames Robert S. , Tornetta Mark A. , Sarau Henry M. , Foley James J. , Crass Torsten , Sohns Bettina , Raffetseder Ute , Grove Melanie , Hölzer Anja , Klos Andreas , Köhl Jörg , Bautsch Wilfried 
Published: December 2022

Abstract
The interaction of human anaphylatoxin C4a with the guinea pig (gp) and human (hu) C3a receptors (C3aR) was analyzed using human rC4a, which exhibited C4a-specific activity on guinea pig platelets. A gpC3aR of 475 residues with a large second extracellular loop and a peptide sequence ∼60% identical to the huC3aR was isolated from a genomic DNA library and found to be expressed in guinea pig heart, lung, and spleen. HEK-293 cells cotransfected with this clone, and a cDNA encoding Gα-16 specifically bound (Kd = 1.6 ± 0.7 nM) and responded functionally to C3a with an intracellular calcium mobilization (ED50 = 0.18 ± 0.02 nM). Human rC4a weakly bound to both the hu- and gpC3aR (IC50 &gt; 1 μM). However, only HEK-293 cells expressing the gpC3aR responded functionally to rC4a (ED50 = 8.7 ± 0.52 nM), while cells expressing the huC3aR did not (c ≤ 1 μM). Thus, through an interaction with the C3aR, huC4a may elicit anaphylatoxic effects in guinea pigs but not in man.