bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phorbol ester-stimulated adherence of neutrophils to endothelial cells is reduced by adenosine A2 receptor agonists.
Authors: Felsch A , Stöcker K , Borchard U 
Published: December 2022

Abstract
In this study we investigated the effect of adenosine receptor agonists on the adherence of PMA-stimulated human neutrophils to cultured porcine aortic endothelial cells. Additionally, we studied the influence of adenosine analogues on the second messenger cAMP in neutrophils and cultured endothelial cells. In the presence of 10 ng/ml PMA, there was a rapid and stable increase on adherence of neutrophils to the endothelial layer. The adenosine A2 receptor agonists, 2-(p-(2-carboxylethyl)phenethylamino)-5' N-ethylcarboxamido-adenosine (CGS 21680) (0.01 to 1 microM) and 5' N-ethylcarboxamidoadenosine (NECA) (0.01 to 1 microM) decreased the adherence of PMA-stimulated neutrophils maximally by 43% and 34%, respectively. In contrast the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (0.01 to 1 microM) showed a 30% increase in PMA-stimulated adherence of neutrophils to endothelial cells. CGS 21680 (0.01 to 1 microM) and NECA (0.01 to 1 microM) were without detectable effect on the formation of cAMP in neutrophils and endothelial cells; however, in the presence of the phosphodiesterase inhibitor Ro 20-1724 (70 microM), CGS 21680 and NECA maximally increased cAMP level 20-fold and 10-fold, respectively, in neutrophils, and 1.8-fold and 2-fold, respectively, in cultured endothelial cells. However, addition of 70 microM Ro 20-1724 to the adherence assay did not potentiate the inhibitory effects of CGS 21680 and NECA on PMA-stimulated neutrophil adherence. On the other hand, 2-chloro-N6-cyclopentyladenosine (0.01 to 1 microM) did not significantly alter cAMP level in neutrophils and endothelial cells in the presence of 4(3-butoxy-4-methoxyphenyl)methyl)-2-imidazolidinone (Ro 20-1724). Our results indicate that adenosine A2 receptor agonists decrease phorbol ester-stimulated adherence of neutrophils to cultured endothelial cells. This effect is possibly independent of adenosine A2 receptor-mediated stimulation of adenylate cyclase in neutrophils and cultured endothelial cells.
Inhibitors of protein tyrosine kinase suppress TNF-stimulated induction of endothelial cell adhesion molecules.
Authors: Weber C , Negrescu E , Erl W , Pietsch A , Frankenberger M , Ziegler-Heitbrock H W , Siess W , Weber P C 
Published: December 2022

Abstract
We studied the role of tyrosine phosphorylation in the induction of vascular cell adhesion molecule 1 (VCAM-1), endothelial leukocyte adhesion molecule 1 (ELAM-1), and intercellular adhesion molecule 1 (ICAM-1) in HUVEC. Induction of VCAM-1 and ELAM-1 surface expression by TNF was dose-dependently reduced by pretreatment with the protein tyrosine kinase inhibitors herbimycin A (HMA, IC50 300 nM) or genistein (IC50 30 microM). Only genistein attenuated ICAM-1 induction. Genistein or HMA did not affect adhesion molecule up-regulation by PMA. U937 monocyte adhesion to TNF-stimulated HUVEC was markedly inhibited by a combination of anti-VCAM-1 and anti-ELAM-1 mAb, as well as by HMA or genistein, probably due to suppression of VCAM-1 and ELAM-1 up-regulation. HMA appeared to prevent VCAM-1 transcription, since it reduced induction of VCAM-1 mRNA by TNF. Gelshift analysis demonstrated inhibition of TNF-induced nuclear factor-kappa B (NF-kappa B) mobilization by HMA. TNF rapidly enhanced tyrosine phosphorylation of a protein migrating with an apparent molecular mass of 35 kDa. HMA and genistein suppressed constitutive tyrosine phosphorylation of all detectable proteins and prevented TNF-induced tyrosine phosphorylation of the 35 kDa protein with an IC50 and dose range, similar to inhibition of VCAM-1 and ELAM-1 induction. Our data suggest that specific phosphorylation following protein tyrosine kinase activation may be required for NF-kappa B mobilization and induction of VCAM-1 and ELAM-1 by TNF.
Costimulatory requirements of naive CD4+ T cells. ICAM-1 or B7-1 can costimulate naive CD4 T cell activation but both are required for optimum response.
Authors: Dubey C , Croft M , Swain S L 
Published: December 2022

Abstract
Efficient initiation of a CD4 T cell response requires both activation through the TCR and costimulation provided by molecules on APC with counterreceptors on the T cell. We investigated the relative contribution of the ICAM-1:LFA-1 and B7:CD28/CTLA-4 costimulatory pathways in naive T cell activation, using either anti-CD28 Ab or fibroblast cell lines transfected with I-Ek, which express either no costimulatory molecules, ICAM-1 alone, B7-1 alone, or ICAM-1 and B7-1 together. Peptide Ag or immobilized anti-CD3 was used to provide the TCR signal. CD4 T cells from mice transgenic for the V beta 3/V alpha 11 TCR, which recognize a peptide of pigeon cytochrome c complexed to I-Ek, were used as a source of naive T cells. Naive T cells stimulated with Ag or anti-CD3 responded well to high numbers of APC expressing either ICAM-1 alone or B7-1 alone. However, APC expressing both ICAM-1 and B7-1 were much better stimulators of proliferation and IL-2 secretion at low cell numbers, and were far superior inducers of IL-2 at higher numbers, indicating a synergy between the two pathways. Stimulation provided by ICAM-1 could not be solely attributed to adhesive strengthening of other pathways, since costimulation was seen when immobilized anti-CD3 was used and when ICAM-1 only APC were added, indicating that ICAM-1 was in fact acting as a classic costimulatory molecule. Both the magnitude of the response and the amount of costimulation required for response were dependent on the intensity of TCR interaction. These results suggest that an efficient naive T cell response requires both a strong TCR signal and more than one costimulatory signal that will synergize with the TCR signal. This offers an explanation as to why APC such as dendritic cells and activated B cells, which express high levels of multiple costimulatory/adhesion molecules, are the only APC that elicit naive T cell responses.
IL-12 regulation of parasite antigen-driven IgE production in human helminth infections.
Authors: King C L , Hakimi J , Shata M T , Medhat A 
Published: December 2022

Abstract
Recombinant IL-12 inhibits IgE synthesis by IL-4-stimulated lymphocytes from healthy persons and influences the development of Th subset selection involved in Ig isotype selection. Whether endogenous IL-12 production modulates IgE synthesis in patients with elevated serum IgE is unknown. To examine this question we studied the effects of neutralizing anti-IL-12 or recombinant IL-12 on parasite Ag-driven polyclonal IgE production and corresponding IFN-gamma and IL-4 synthesis by PBMC from helminth-infected individuals. The addition of neutralizing anti-IL-12 Ab significantly inhibited parasite Ag-driven IgE production in 11 of 12 individuals (p &lt; 0.001). Recombinant IL-12 (1-10 U/ml) suppressed Ag-driven IgE production in a dose-dependent fashion up to 94% relative to untreated cultures. The effect of endogenous IL-12 on IgE production occurred, in part, by suppressing Ag-induced IL-4 and augmenting IFN-gamma production. IL-12 did not suppress IgE synthesis by purified B cells. An IFN-gamma-independent effect of IL-12 on Ag-driven IgE production was suggested by the ability of human rIL-12 to suppress IgE synthesis in the presence of neutralizing anti-IFN-gamma. This study demonstrates that IL-12 modulates helminth Ag-driven IgE production, in part, by regulating the relative quantities of IFN-gamma and IL-4 generated by Ag-specific lymphocytes.
Functional glucocorticoid receptor expression is required for cAMP-mediated apoptosis in a human leukemic T cell line.
Authors: Kiefer J , Okret S , Jondal M , McConkey D J 
Published: December 2022

Abstract
The involvement of the glucocorticoid receptor (GR) in cAMP-induced apoptosis in a GR-deficient derivative of the CEM.C7 human T-ALL line was investigated. Incubation of the parental CEM.C7 cells with agents that elevate cAMP levels (dibutyryl cAMP and forskolin) resulted in DNA fragmentation characteristic of apoptotic cell death, whereas the GR-deficient ICR.27 cells were insensitive to the cytolytic effects of cAMP. Reconstitution of GR expression by transfection not only restored glucocorticoid sensitivity to the ICR.27 cells, but also promoted sensitivity to induction of apoptosis by cAMP. Thus, cAMP-induced apoptosis in T cells appears to occur via ligand-independent stimulation of at least some aspects of glucocorticoid receptor function.
Disturbed MHC regulation in the IFN-gamma knockout mouse. Evidence for three states of MHC expression with distinct roles for IFN-gamma.
Authors: Goes N , Sims T , Urmson J , Vincent D , Ramassar V , Halloran P F 
Published: December 2022

Abstract
We compared the expression of MHC class I and II products in tissues of IFN-gamma knockout (GKO) vs normal (wild-type) BALB/c mice. We studied expression in the basal state, after local tissue injury, after stimuli that induce systemic MHC expression (allogeneic cells, oxazolone skin painting, or LPS), and after rIFN-gamma. Basal class II expression in interstitial cells was not reduced in GKO mice. However, GKO mice had less basal class I expression in kidney, liver, heart, and arterial endothelium than wild-type mice. Local renal ischemic injury increased class I and II expression in kidney tubules of both GKO and wild-type mice, but induction in GKO was less than in wild-type. Potent inflammatory stimuli increased systemic MHC class I and II markedly in kidney, liver, and heart of wild-type mice, but induced no increase in GKO mice. rIFN-gamma induced class I and II equally in GKO and wild-type mice. Thus, three states of MHC expression can be defined that differ in their dependencies on IFN-gamma: basal, locally induced, and systemically induced. Basal class II expression in interstitial cells is IFN-gamma independent, but basal class I expression, particularly in arterial endothelium, is partially dependent on IFN-gamma. The local increase in MHC class I and II in parenchymal cells in response to injury reflects both IFN-gamma and a non-IFN-gamma factor. Systemic MHC class I and II induction is almost exclusively due to IFN-gamma.
Regulation of IkB alpha phosphorylation by PKC- and Ca(2+)-dependent signal transduction pathways.
Authors: Steffan N M , Bren G D , Frantz B , Tocci M J , O'Neill E A , Paya C V 
Published: December 2022

Abstract
The Ca(2+)-dependent phosphatase calcineurin, a target of FK506 and CsA, synergizes with PKC-induced activation of nuclear factor (NF)-kappa B in T cell lines. We have investigated whether this synergy is present in other cell types and the mechanism(s) by which these two pathways lead to NF-kappa B activation. While this synergy is present in other cell types, in the monocytic cell line U937 calcineurin is also sufficient to activate NF-kappa B. Having previously shown that Ca(2+)- and PKC-dependent pathways synergize by accelerating the degradation of IkB alpha, we focused on the regulation of IkB alpha phosphorylation. While PKC-dependent pathways sequentially result in the phosphorylation and in an incomplete degradation of IkB alpha in T cell lines, co-activation of Ca(2+)-dependent pathways accelerates the rate of IkB alpha phosphorylation and results in its complete degradation. Activation of Ca(2+)-dependent pathways alone do not result in the phosphorylation and/or degradation of IkB alpha in Jurkat T or in U937 cells. Treatment of T cells with the selective PKC inhibitor GF109203X abrogates the PMA-induced IkB alpha phosphorylation/degradation irrespective of activation of Ca(2+)-dependent pathways, but not the phosphorylation and degradation of IkB alpha induced by TNF-alpha, a PKC-independent stimulus. Contrary to the interaction with PKC, Ca(2+)-dependent pathways synergize with TNF-alpha not at the level of IkB alpha phosphorylation, but at the level of its degradation. These results indicate that Ca(2+)-dependent pathways, including the phosphatase calcineurin, participate in the regulation of NF-kappa B in a cell specific fashion and synergize with PKC-dependent and -independent pathways at the level of IkB alpha phosphorylation and degradation.
Triggering of complement receptors CR1 (CD35) and CR3 (CD11b/CD18) induces nuclear translocation of NF-kappa B (p50/p65) in human monocytes and enhances viral replication in HIV-infected monocytic cells.
Authors: Thieblemont N , Haeffner-Cavaillon N , Haeffner A , Cholley B , Weiss L , Kazatchkine M D 
Published: December 2022

Abstract
Monocyte/macrophages may harbor HIV in a nonproductive fashion for prolonged periods of time. Viral gene expression may be reactivated by stimulation of the cells with LPS or cytokines such as TNF-alpha in vitro. The effect of LPS and TNF-alpha is mediated by their ability to induce nuclear translocation of the DNA-binding heterodimer NF-kappa B (p50/p65), which binds to a specific sequence in the HIV-long terminal repeat. The present study demonstrates that triggering of complement receptors CR1 (CD35) and CR3 (CD11b/CD18) enhances viral replication in HIV-infected human monocytic cells. Monocytic cell lines and normal peripheral blood monocytes were infected with HIV-1 in vitro and cultured in the presence or absence of F(ab')2 fragments of monoclonal anti-CR1 or anti-CR3 Abs or with C3 fragments. Stimulation of CR1 or CR3 induces a two- to fourfold increase in the amount of cell-associated and released p24 Ag in cell cultures that was equivalent to that observed in control cultures triggered with LPS. We further observed that stimulation of CR1 or CR3 induces the nuclear translocation of NF-kappa B p50/p65 in infected cells. Translocation of NF-kappa B p50/p65 was also observed following stimulation of CR1 or CR3 of uninfected peripheral blood monocytes from HIV-seronegative donors. The amount of protein translocated was similar to that observed when cells were stimulated with rhTNF-alpha. TNF-alpha did not mediate the translocation of NF-kappa B p50/p65 induced by triggering of complement receptors. Taken together, these observations suggest that HIV gene expression may be activated in infected monocytes through interaction of the cells with complement-opsonized particles and that enhanced viral replication is associated with C3 receptor-mediated nuclear translocation of the NF-kappa B complex.
A central role for IL-1 beta in the in vitro and in vivo regulation of hepatic inducible nitric oxide synthase. IL-1 beta induces hepatic nitric oxide synthesis.
Authors: Geller D A , de Vera M E , Russell D A , Shapiro R A , Nussler A K , Simmons R L , Billiar T R 
Published: December 2022

Abstract
We have previously demonstrated that high levels of inducible nitric oxide synthase (iNOS) expression in hepatocytes required a combination of LPS and TNF-alpha, IL-1 beta, and IFN-gamma. The need for such a complex regulatory system seemed unwarranted based on the importance of NO in the liver. Therefore, we investigated whether individual cytokines could induce NO synthesis in hepatocytes and characterized some of the mechanisms involved. Rat hepatocytes were stimulated in vitro with escalating doses of TNF-alpha, IL-1 beta, or IFN-gamma. Only IL-1 beta induced high levels of iNOS mRNA and corresponding NO2- + NO3- production, and dexamethasone and cycloheximide blocked a majority of this response. Nuclear run-on experiments revealed that IL-1 beta upregulated iNOS gene transcription. IL-1 receptor antagonist protein (IL-1ra) competitively inhibited IL-1 beta-stimulated NO synthesis, implying activation through a cell-specific receptor. Rats injected with both LPS and IL-1ra showed decreased hepatic iNOS mRNA and plasma NO2- + NO3- compared with rats given LPS alone, indicating that IL-1 beta plays a role in regulating iNOS expression within the liver in vivo during endotoxemia. The soluble TNF receptor antagonist, PEG-(rsTNF-RI)2, also suppressed hepatic iNOS mRNA levels and plasma NO2- + NO3- increases, supporting a role for this cytokine in LPS-induced iNOS expression. Finally, IL-1 beta at high doses also induced iNOS mRNA and significant NO2- + NO3- production in cultures of primary human hepatocytes. These data indicate an important role for IL-1 beta in the regulation of hepatic NO synthesis.
Construction and characterization of a humanized anti-gamma-Ig receptor type I (Fc gamma RI) monoclonal antibody.
Authors: Graziano R F , Tempest P R , White P , Keler T , Deo Y , Ghebremariam H , Coleman K , Pfefferkorn L C , Fanger M W , Guyre P M 
Published: December 2022

Abstract
The murine mAb 22 (M22) binds to the human high affinity receptor for the Fc portion of IgG (Fc gamma RI). This mAb recognizes an epitope on Fc gamma RI that is distinct from the natural ligand (Fc) binding site, and, therefore, can bind to Fc gamma RI in the presence of saturating levels of IgG found in vivo. Fc gamma RI is expressed only on cytotoxic effector cells and it acts as an efficient mediator (trigger molecule) of effector functions. Directing tumor cells or other pathogens to Fc gamma RI utilizing M22 conjugated to an anti-tumor- or to an anti-pathogen-specific mAb may represent an effective method to enhance their removal and destruction under physiologic conditions. Humanization of M22 may improve the therapeutic potential of the mAb since murine mAbs normally elicit a human anti-mouse Ab response. In this report we describe the humanization of M22 by CDR-grafting onto human V region frameworks based on KOL VH and REI V kappa attached to human IgG1 and kappa constant domains. This humanized mAb, H22, displays equivalent binding specificity and affinity as its murine counterpart. In addition, H22 is able to trigger superoxide release from Fc gamma RI-bearing cells, a finding that demonstrates that H22 triggers Fc gamma RI functions. The successful humanization of mAb 22 is an important step in the development of Fc gamma RI-directed immunotherapy.
Immobilized antibodies to CD45 induce rapid morphologic changes and increased tyrosine phosphorylation of p56lck-associated proteins in T cells.
Authors: Arendt C W , Hsi G , Ostergaard H L 
Published: December 2022

Abstract
CD45 is a transmembrane protein tyrosine phosphatase required for signal transduction through the Ag receptor complexes of T and B lymphocytes. Herein, we demonstrate that immobilized mAbs to the external domain of CD45 induce rapid and dramatic morphologic changes in a variety of T cell lines, including CD8+ cytotoxic clones. CD45-induced morphologic changes can be inhibited by the cytoskeletal inhibitors cytochalasin D and E and by the protein tyrosine kinase inhibitor herbimycin A. Consistent with the requirement for tyrosine kinase activity, tyrosine phosphorylation of proteins at about 60 to 75 kDa and 115 to 130 kDa is increased upon engagement with immobilized anti-CD45 mAb with kinetics paralleling the observed changes in morphology. The phosphorylation of these proteins is inhibited by tyrosine kinase inhibitors at concentrations that also inhibit changes in morphology. The phosphoproteins induced when cells are added to immobilized anti-CD45 are co-immunoprecipitated with p56lck, suggesting that this tyrosine kinase might play a role in the phosphorylation of these proteins. Consistent with this, there is no increase in the phosphorylation of these proteins in p56lck-deficient CTLL-2 cells in response to immobilized anti-CD45 mAb. An important role for p56lck in the morphologic pathway is further supported by the observation that p56lck-deficient human J.CAM1.6 cells, in contrast to the parental Jurkat line, cannot be induced to undergo morphologic changes. Taken together, these results suggest a possible role for CD45 in coordinating a cytoskeletal remodeling cascade that may be important in cell activation.
Oxygen radical production and thiol depletion are required for Ca(2+)-mediated endogenous endonuclease activation in apoptotic thymocytes.
Authors: Fernandez A , Kiefer J , Fosdick L , McConkey D J 
Published: December 2022

Abstract
Glucocorticoid hormones stimulate apoptosis in thymocytes via a mechanism that involves changes in intracellular Ca2+, and exogenous Ca2+ can also directly promote the nuclear alterations of apoptosis (lamin degradation and chromatin cleavage) in isolated nuclei. Here we report that glucocorticoid treatment resulted in the production of reactive oxygen species and the depletion of reduced glutathione. Separation of apoptotic cells on Percoll gradients demonstrated that both effects selectively occurred in thymocytes undergoing apoptosis. Moreover, glucocorticoid-induced endonuclease activation was partially blocked by the antioxidant N-acetyl-L-cysteine. Although abrogation of methylprednisolone-induced Ca2+ increases using the intracellular Ca2+ buffer 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid resulted in inhibition of endonuclease activation, it failed to prevent GSH depletion. However, N-acetyl-L-cysteine almost completely blocked methylprednisolone-induced elevations in cytosolic calcium levels, indicating that oxidative stress was playing a role in the Ca2+ response. Our results support the idea that oxidative stress is a key component of the apoptotic effector pathway in thymocytes, and that it interacts, at least in part, with the Ca2+ response.
Evidence for immunologic immaturity of cord blood T cells. Cord blood T cells are susceptible to tolerance induction to in vitro stimulation with a superantigen.
Authors: Takahashi N , Imanishi K , Nishida H , Uchiyama T 
Published: December 2022

Abstract
T cell blasts resulting from stimulating human cord blood (CB) mononuclear cells (MC) and adult peripheral blood (APB) MC with a bacterial superantigen, toxic shock syndrome toxin-1 (TSST-1), and then with human rIL-2 were investigated for their reactions to restimulation with TSST-1. Expression of TCR V beta 2, which determines the potential reactivity to TSST-1 and of CD45RO, was increased in both TSST-1-induced CB and APB T cell blasts. Most preparations of the TSST-1-induced CB T cell blasts exhibited low or no production of IL-2 and IL-4 in response to restimulation with TSST-1, while the APB T cell blasts showed high responses. TSST-1-induced T cell blasts derived from APB T cells depleted of both CD45RO+ T cells and HLA class II+ T cells showed high IL-2 production in response to restimulation with TSST-1. TSST-1-induced CB T cell blasts generated in the presence of DR+ L cells with high accessory cell activity still showed a low response to restimulation with TSST-1. These results indicate that CB T cells are inherently highly susceptible to tolerance induction by bacterial superantigens, suggesting the immunologic immaturity of CB T cells.