bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peroxynitrite Mediates IL-8 Gene Expression and Production in Lipopolysaccharide-Stimulated Human Whole Blood
Authors: Filep János G. , Beauchamp Micheline , Baron Chantal , Paquette Yves 
Published: December 2022

AbstractRecent evidence indicates that free oxygen radicals, in particular hydroxyl radicals, may act as intracellular second messengers for the induction of IL-8, a potent chemoattractant and activator of neutrophil granulocytes. Here we report that peroxynitrite (ONOO−), formed by a reaction of nitric oxide (NO) with superoxide, mediates IL-8 gene expression and IL-8 production in LPS-stimulated human whole blood. The NO synthase inhibitors aminoguanidine and NG-nitro-l-arginine methyl ester (L-NAME) blocked IL-8 release by ∼90% in response to LPS (1 μg/ml), but did not affect the production of IL-1β or TNF-α. Both aminoguanidine and L-NAME blocked the induction of IL-8 mRNA by LPS. Authentic ONOO− (2.5–80 μM) augmented IL-8 mRNA expression and stimulated IL-8 release in a concentration-dependent manner, whereas the NO-releasing compounds, S-nitroso-N-acetyl-dl-penicillamine and sodium nitroprusside failed to induce cytokine production. Combination of the NO-generating chemicals with a superoxide-generating system (xanthine/xanthine oxidase) markedly increased IL-8 release. Enhanced ONOO− formation was detected in granulocytes, monocytes, lymphocytes, and plasma after challenge with LPS. Furthermore, pyrrolidine dithiocarbamate, an inhibitor of activation of nuclear factor-κB, markedly attenuated the induction of IL-8 mRNA expression and IL-8 release by either LPS or ONOO−. Our study identifies ONOO− as a novel signaling mechanism for IL-8 gene expression and suggests that inhibition of ONOO− formation or scavenging ONOO− may represent a novel therapeutic approach to inhibit IL-8 production that could lead to reduction of neutrophil accumulation and activation.
Inhibition of MAP Kinase Kinase Prevents Cytokine and Prostaglandin E2 Production in Lipopolysaccharide-Stimulated Monocytes
Authors: Scherle Peggy A. , Jones Elizabeth A. , Favata Margaret F. , Daulerio Andrea J. , Covington Maryanne B. , Nurnberg Sherrill A. , Magolda Ronald L. , Trzaskos James M. 
Published: December 2022

AbstractActivation of the extracellular signal-regulated kinase (ERK) pathway has been shown to occur in monocytes following stimulation with LPS. However, the importance of this event for monocyte function is not clear. To address this issue, we used the novel MAP/ERK kinase (MEK) inhibitor, U0126. Stimulation of monocytes with LPS resulted in activation of the mitogen-activated protein kinase (MAPK) family members ERK, Jun NH2-terminal kinase (JNK), and p38. Treatment of monocytes with LPS in the presence of U0126 blocked the activation of ERK1 and ERK2. However, the activation of Jun NH2-terminal kinase and p38 family members was not affected by the compound, confirming the selectivity of U0126. To examine the effects of MEK inhibition on monocyte function, we measured production of the cytokines IL-1, IL-8, and TNF, as well as PGE2. Monocytes treated with LPS in the presence of U0126 failed to release IL-1, IL-8, TNF, or PGE2. The failure to secrete IL-1 and TNF was due to decreased levels of mRNA. These results demonstrate that activation of MEK/ERK is critical for cytokine and PGE2 production by monocytes in response to LPS.
Lyme Arthritis Synovial γδ T Cells Respond toBorrelia burgdorferiLipoproteins and Lipidated Hexapeptides
Authors: Vincent Michael S. , Roessner Karen , Sellati Timothy , Huston Christopher D. , Sigal Leonard H. , Behar Samuel M. , Radolf Justin D. , Budd Ralph C. 
Published: December 2022

AbstractLyme arthritis synovial fluid contains a large proportion of γδ T cells that proliferates upon stimulation with the causative spirochete, Borrelia burgdorferi. A panel of Borrelia-reactive γδ T cell clones was derived from synovial fluid of two patients with Lyme arthritis. Each of six γδ clones from one patient used the Vδ1 TCR segment but had otherwise unique CDR3 sequences and diverse Vγ segment usage. Stimulation of the Vδ1 clones was optimal in the presence of Borrelia, dendritic cells, and exogenous IL-2, which was reflected by proliferation, TCR down-modulation, as well as induction of CD25 and Fas ligand expression. Stimulation by B. burgdorferi-pulsed dendritic cells withstood chemical fixation and was not restricted to class I or class II MHC, CD1a, CD1b, or CD1c. In contrast, anti-γδ antibody potently inhibited proliferation. Extraction of B. burgdorferi lipoproteins with Triton X-114 enriched for the stimulatory component. This was confirmed using lipidated vs nonlipidated hexapeptides of Borrelia outer surface proteins. These observations suggest that synovial Vδ1 T cells may mediate an innate immune response to common lipoprotein products of spirochetes.
Respiratory Syncytial Virus-Induced RANTES Production from Human Bronchial Epithelial Cells Is Dependent on Nuclear Factor-κB Nuclear Binding and Is Inhibited by Adenovirus-Mediated Expression of Inhibitor of κBα
Authors: Thomas L. H. , Friedland J. S. , Sharland M. , Becker S. 
Published: December 2022

Abstract
Respiratory syncytial virus (RSV) infection is an important cause of lower respiratory tract illness, the severity of which may be partly due to cellular recruitment. RSV infection activates chemokine secretion from airway epithelial cells by largely unknown mechanisms. We investigated the regulation of RSV-induced activation of the chemokine RANTES in the bronchial epithelial cell line BEAS-2B and primary normal human tracheobronchial epithelial cultures. RANTES protein and mRNA were detected at 24 h and up until 72 h from cultures of BEAS-2B infected with replicating virus, but not with UV-inactivated RSV. RSV infection of BEAS-2B or normal human tracheobronchial epithelial cells stimulated NF-κB translocation to the nucleus and binding to the RANTES-specific κB-binding sequences within 2 h, with levels peaking at 24 h. Supershift assays indicated that binding was due to p50/p65 heterodimers. BEAS-2B cells were transfected with a replication-deficient adenoviral vector, expressing a mutated, nondegradable form of IκBα. IκBα overexpression specifically blocked NF-κB translocation and inhibited mRNA accumulation and secretion of RANTES induced by RSV or TNF-α plus IFN-γ. Adenoviral transfection did not interfere with RSV replication or significantly induce apoptosis. Further, a control adenovirus, expressing the β-galactosidase gene, did not alter cellular functions. Thus, NF-κB nuclear translocation is a critical step in RSV induction of RANTES secretion. Elucidating the mechanisms of cellular activation by RSV and targeting specific areas may lead to novel therapeutic approaches in the treatment of RSV.
Murine Graft-Versus-Host Disease in an F1-Hybrid Model Using IFN-γ Gene Knockout Donors
Authors: Ellison Cynthia A. , Fischer Jacqie M. M. , HayGlass Kent T. , Gartner John G. 
Published: December 2022

AbstractThese experiments were performed to determine whether the absence of donor-derived IFN-γ would influence the outcome of acute graft-vs-host disease (GVHD). Graft-vs-host reactions were induced in B6D2F1 hybrids using grafts from either IFN-γ gene knockout (gko) or wild-type, C57BL/6J, parental strain donors. GVHD was equally lethal in both groups, but IFN-γ gko graft recipients developed a more protracted form of the disease. These mice developed early wasting that persisted until death. IFN-γ was present in spleen cell cultures from wild-type graft recipients, but was absent in cultures from IFN-γ gko graft recipients. Both recipient groups showed macrophage priming for LPS-induced TNF-α release. Engraftment of donor-derived CD4+ and CD8+ cells was greater in IFN-γ gko graft recipients. Pathologic changes in IFN-γ gko graft recipients were different from those typically seen in acute GVHD. The syndrome developing in IFN-γ gko recipients consisted of patchy alopecia, corneal dryness and clouding, and lymphocytic infiltration of the liver, pancreas, salivary gland, lung, and kidney. Lymphocytic infiltrates were also present in the epidermis and the epithelium of both bile and salivary gland ducts. Some of the lesions closely resembled those seen in the “sicca”/Sjogren’s-like syndrome associated with chronic GVHD; however, there was no evidence of immune complex deposition in the kidney. These results indicate that GVHD in IFN-γ gko graft recipients shares many features with acute GVHD, but both the duration of the disease and its pathologic manifestations are different. Our results suggest that IFN-γ plays a significant role in the pathogenesis of acute GVHD by increasing the rate at which mortality develops.
Inhibition of CD28/CD3-Mediated Costimulation of Naive and Memory Human T Lymphocytes by Intracellular Incorporation of Polyclonal Antibodies Specific for the Activator Protein-1 Transcriptional Complex
Authors: Woodside Darren G. , McIntyre Bradley W. 
Published: December 2022

Abstract
A number of indirect methods have been utilized in demonstrating activator protein-1 transcription factor function in IL-2 promoter activity. However, there has been no direct demonstration that activator protein-1 is involved in CD28-dependent costimulation of IL-2 gene transcription in freshly isolated naive and memory human T lymphocytes. To address this issue, the method of scrape loading was applied to purified peripheral blood T lymphocytes. Since scrape loading relies on adherent cells, peripheral blood human T (PB-T) cells were immobilized on the nonspecific cell attachment factor poly-l-lysine. Cells scraped off poly-l-lysine in the presence of Ig FITC efficiently incorporated Ig, with relatively uniform fluorescence. T cells retained their physical parameters as measured by forward and side light scatter, and functional activity as measured by costimulation of proliferation and IL-2 production after being scraped off this substrate. CD28/CD3-costimulated T cells produced intracellular IL-2 from all subsets measured (CD4+, CD4−, CD45RO+, and CD45RO−). IL-2 production and intracellular accumulation in nonscraped PB-T cells activated with CD28/CD3 coligation were skewed favoring CD45RO+ and CD4+ subsets, as was IL-2 production in scraped PB-T cells. The intracellular incorporation of Abs specific for c-Fos and c-Jun family members by scrape loading inhibited the production and intracellular accumulation of IL-2 within 6 h of costimulation with PMA/ionomycin, or costimulation by CD28 and CD3 ligation. Scrape loading thus provides an efficient mechanism for intracellular incorporation of macromolecules, and the first direct evidence that c-Fos and c-Jun are involved in transcription of the IL-2 gene within its correct chromosomal context, in resting human T lymphocyte subpopulations.
B Cell Antigen Receptor (BCR)-Mediated Formation of a SHP-2-pp120 Complex and Its Inhibition by FeγRIIB1-BCR Coligation
Authors: Nakamura Kazuhiro , Cambier John C. 
Published: December 2022

AbstractAccumulating evidence indicates that the Src homology 2-containing tyrosine phosphatase 2 (SHP-2) plays an important role in signal transduction through receptor tyrosine kinase and cytokine receptors. In most models, SHP-2 appears to be a positive mediator of signaling. However, coligation of FcγRIIB1 with B cell Ag receptors (BCR) inhibits BCR-mediated signaling by a mechanism that may involve recruitment of phosphatases SHP-1, SHP-2, and the SH2 containing inositol 5′phosphatase (SHIP) to the phosphorylated FcγRIIB1 immunoreceptor tyrosine-based inhibitory motif. The role of SHP-2 in BCR-mediated cell activation and in FcγRIIB1-mediated inhibitory signaling is unclear. In this study we assessed the association of SHP-2 with phosphotyrosine-containing cellular protein(s) before and after stimulation through these receptors. BCR stimulation induced the association of SHP-2 with a single major tyrosyl-phosphorylated molecule (pp120) that had an apparent molecular mass of 120 kDa. Coligation of FcγRIIB1 with BCR led to a rapid decrease in SHP-2 association with pp120. Analysis of the subcellular localization of pp120 showed that the complex of SHP-2 and tyrosyl-phosphorylated p120 occurs predominantly in the cytosol. Furthermore, the binding of the two molecules was mediated by the interaction of tyrosyl-phosphorylated p120 with the SHP-2 N-terminal SH2 domain. These findings indicate that SHP-2 and pp120 function in BCR signaling, and this function may be inhibited by FcγRIIB1 signaling.
Antigen-Dependent Intrathecal Antibody Synthesis in the Normal Rat Brain: Tissue Entry and Local Retention of Antigen-Specific B Cells
Authors: Knopf Paul M. , Harling-Berg Christine J. , Cserr Helen F. , Basu Devraj , Sirulnick Erik J. , Nolan Scott C. , Park Joel T. , Keir Geoffrey , Thompson Edward J. , Hickey William F. 
Published: December 2022

Abstract
The intrathecal Ab response to Ag introduced into the normal brain has not been fully explored. Involvement of Ag-specific, peripheral B cells in an intrathecal response was studied using a normal rat model of Ag infusion through an indwelling cannula into defined brain sites, while maintaining a functionally intact blood-brain barrier. Specific Ab was detected in serum and cerebrospinal fluid. The intrathecal response is first detectable at day 14. Isoelectric focusing of cerebrospinal fluid reveals banding patterns consistent with local Ab production. To increase Ag-specific, circulating peripheral lymphocytes available for trafficking to Ag-stimulated brain and for enhancing intrathecal Ab synthesis, rats were preimmunized peripherally. Subsequently, Ag or saline (control) was infused through the cannula. Under this protocol, intrathecal synthesis is detectable earlier (day 5 postinfusion). Immunohistochemical studies at the infusion site assessed Ag-specific B cells, T cells, and activated APCs. Rats receiving peripheral preimmunization followed by Ag into caudate nucleus have far greater numbers of these cells, including plasma cells, within the infusion site compared with saline controls. Results confirm previous indirect evidence of intrathecal Ab synthesis in normal rat brain and provide the first direct evidence for B cell trafficking across normal brain barriers plus retention at the Ag deposition site. Our studies indicate that the normal brain microenvironment supports development of Ag-directed humoral immunity. We propose that immune privilege in normal brain is characterized by down-regulation of cell-mediated but not Ab immune responses within the central nervous system.
NK Cells Can Recognize Different Forms of Class I MHC
Authors: Su Ruey-Chyi , Kung Sam K. P. , Gariépy Jean , Barber Brian H. , Miller Richard G. 
Published: December 2022

AbstractNK recognition and lysis of targets are mediated by activation receptor(s) whose effects may be over-ridden by inhibitory receptors recognizing class I MHC on the target. Incubation of normal lymphoblasts with a peptide that can bind to their class I MHC renders them sensitive to lysis by syngeneic NK cells. By binding to class I MHC, the peptide alters or masks the target structure recognized by an inhibitory NK receptor(s). This target structure is most likely an “empty” dimer of class I heavy chain and β2m as opposed to a “full” class I trimer formed by binding of specific peptide that is recognized by CTL.
Macrophage Activation by Polycyclic Aromatic Hydrocarbons: Evidence for the Involvement of Stress-Activated Protein Kinases, Activator Protein-1, and Antioxidant Response Elements
Authors: Ng David , Kokot Niels , Hiura Timothy , Faris Mary , Saxon Andrew , Nel Andre 
Published: December 2022

Abstract
Polycyclic aromatic hydrocarbons (PAH) contained in fossil fuel combustion particles enhance the allergic response to common environmental Ags. A key question is: what are molecular pathways in the immune system by which PAH and conversion products drive allergic inflammation? Circumstantial evidence suggests that macrophages are involved in PAH-induced responses. We demonstrate that a representative PAH, β-napthoflavone (BNF), and a representative quinone metabolite, tert-butylhydroxyquinone (tBHQ), induce Jun kinase and p38 mitogen-activated protein kinase activities in parallel with the generation of activator protein-1 (AP-1) mobility shift complexes in THP-1 and RAW264.7 macrophage cell lines. Activation of mitogen-activated protein kinases was dependent on generation of oxidative stress, and could be inhibited by N-acetylcysteine. Another genetic response pathway linked to PAH is the antioxidant response element (ARE), which regulates expression of detoxifying enzymes. BNF and tBHQ activated a human ARE (hARE) reporter gene in RAW264.7 cells. Interestingly, bacterial lipopolysaccharide also induced hARE/chloramphenicol acetyltransferase activity. While the hARE core, GTGACTCAGC, contains a consensus AP-1 sequence (underlined), AP-1 was not required for hARE activation. This suggests that PAH and their conversion products operate via ARE-specific transcription factors in the immune system. BNF and tBHQ did, however, induce AP-1 binding to the hARE, while constitutively active Jun kinase interfered in hARE/chloramphenicol acetyltransferase activation. This suggests that AP-1 proteins negatively regulate the hARE. These data establish important activation pathways for PAH in the immune system and provide us with targets to modulate the effect of environmental pollutants on allergic inflammation.
Serine 16 of Stathmin as a Cytosolic Target for Ca2+/Calmodulin-Dependent Kinase II After CD2 Triggering of Human T Lymphocytes
Authors: le Gouvello Sabine , Manceau Valérie , Sobel André 
Published: December 2022

AbstractWe investigated specific signaling events initiated after T cell triggering through the costimulatory surface receptors CD2 and CD28 as compared with activation via the Ag receptor (TCR/CD3). We therefore followed the phosphorylation of stathmin, a ubiquitous cytoplasmic phosphoprotein proposed as a general relay integrating diverse intracellular signaling pathways through the combinatorial phosphorylation of serines 16, 25, 38, and 63, the likely physiologic substrates for Ca2+/calmodulin (CaM)-dependent kinases, mitogen-activated protein (MAP) kinase, cyclin-dependent kinases (cdks), and protein kinase A, respectively. We addressed the specific protein kinase systems involved in the CD2 pathway of T cell activation through the analysis of stathmin phosphorylation patterns in exponentially growing Jurkat T cells, as revealed by phosphopeptide mapping. Stimulation via CD2 activated multiple signal transduction pathways, resulting in phosphorylation of distinct sites of stathmin, the combination of which only partially overlaps the CD3- and CD28-induced patterns. The partial redundancy of the three T cell activation pathways was evidenced by the phosphorylation of Ser25 and Ser38, substrates of MAP kinases and of the cdk family kinase(s), respectively. Conversely, the phosphorylation of Ser16 of stathmin was observed in response to both CD2 and CD28 triggering, but not CD3 triggering, with a kinetics compatible with the lasting activation of CaM kinase II in response to CD2 triggering. In vitro, Ser16 of recombinant human stathmin was phosphorylated also by purified CaM kinase II, and in vivo, CaM kinase II activity was indeed stimulated in CD2-triggered Jurkat cells. Altogether, our results favor an association of CaM kinase II activity with costimulatory signals of T lymphocyte activation and phosphorylation of stathmin on Ser16.
IL-12 Promotes the Adhesion of NK Cells to Endothelial Selectins Under Flow Conditions
Authors: Yago Tadayuki , Tsukuda Mamoru , Fukushima Hirofumi , Yamaoka Hideyuki , Kurata-Miura Kazumi , Nishi Tatsunari , Minami Mutsuhiko 
Published: December 2022

Abstract
This study examined the adhesive interactions of peripheral blood NK cells with P- and E-selectin and analyzed the effect of IL-12 on the binding of NK cells to these selectins. P-selectin glycoprotein ligand-1 (PSGL-1) is expressed on most resting and IL-12-activated NK cells. However, the percentage of resting NK cells bound to P-selectin-IgG was 15%, and that of activated NK cells bound to P-selectin-IgG was 65%. Furthermore, the number of IL-12-activated NK cells bound to P-selectin-transfected Chinese hamster ovary cells was significantly higher than that of resting NK cells under flow conditions. These interactions were abolished by the incubation of these NK cells with anti-PSGL-1 (PL-1) mAb. Thus, PSGL-1/P-selectin interaction is important in the binding of resting and activated NK cells to P-selectin. NK cells express sialyl-Lewisx (sLex) structure recognized by anti-sLex mAb (KM-93), and IL-12 activation of NK cells increased the mean fluorescence intensity of KM-93-reactive NK cells. Adhesion of IL-12-activated NK cells to E-selectin-transfected Chinese hamster ovary cells was stronger than that of resting NK cells under flow conditions. These interactions were reduced markedly by incubation with anti-sLex mAb. Thus, sLex is the major ligand of resting and activated NK cells for E-selectin. These findings indicate that IL-12 stimulation of NK cells promotes their adhesion activity to endothelial selectins.
B Lymphocytes Are Crucial Antigen-Presenting Cells in the Pathogenic Autoimmune Response to GAD65 Antigen in Nonobese Diabetic Mice
Authors: Falcone Marika , Lee Jae , Patstone Gail , Yeung Brian , Sarvetnick Nora 
Published: December 2022

AbstractRecent reports have shown that B cells play a key role in the pathogenesis of T cell-mediated autoimmune diseases such as insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic mice (NOD). We have investigated the role of B lymphocytes as APCs in the generation of autoreactive T cell responses by comparing spontaneous responses to self Ags in B cell-deficient and wild-type NOD mice. We determined that B cell-deficient mice had no spontaneous responses to 65-kDa glutamate decarboxylase (GAD65), its immunodominant peptides, and the 60-kDa heat shock protein. In contrast, these Ags are able to induce proliferative responses in the splenocyte cultures of B cell-positive NOD mice. However, T cells from B-deficient mice conserved the ability to respond to nonself Ags and mitogens. The Ag-presenting function of B cells was pivotal in the autoimmune response, since the proliferation of wild-type splenocytes to GAD65 was completely inhibited by blocking the surface Ig-mediated capture of the protein Ag by B cells. Responses to immunodominant GAD65 peptides were also absent in B cell-deficient NOD mice, suggesting that B cells are crucial with regard to the diversification of the autoimmune response to various self epitopes. We believe our results represent strong evidence that B cells are required as APCs to generate pathogenic autoimmune T cell responses and provide a direct correlation between the protection from autoimmune diabetes previously reported in B cell-deficient NOD mice and the lack of anti-GAD65 and anti-heat shock protein 60 T cell responses in these mice.
Dendritic Cells Interact Directly with Naive B Lymphocytes to Transfer Antigen and Initiate Class Switching in a Primary T-Dependent Response
Authors: Wykes Michelle , Pombo Ana , Jenkins Chris , MacPherson G. Gordon 
Published: December 2022

AbstractDendritic cells (DC) are thought to initiate Ab synthesis by activation of T cells, which then provide cytokine and cell-bound “help” to B cells. Here, we provide evidence that DC can capture and retain unprocessed Ag in vitro and in vivo, and can transfer this Ag to naive B cells to initiate a specific Ab response. The response is skewed with 4- to 13-fold higher titers of IgG than IgM, and the predominant subclasses of Ab produced in naive animals are those associated with Th2-type responses. Ag retention and the skew in class switching is a physiologic phenomenon because DC loaded with Ag in vivo and isolated 24 h later initiated a class-switched, Ag-specific Ab response in naive animals. In vitro studies confirmed that DC provide naive B cells with signals that are essential for the synthesis of class-switched Ab. Taken together, these observations show that DC have an important role in the initiation of Ab synthesis by direct interaction with B cells.