bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and Characterization of a Variant HL60 Cell Line Defective in the Activation of the NADPH Oxidase by Phorbol Myristate Acetate
Authors: Tardif Marianne , Rabiet Marie-Josèphe , Christophe Thierry , Milcent Marie-Danielle , Boulay François 
Published: December 2022

AbstractPromyelocytic human leukemia HL60 cells can be differentiated into neutrophil-like cells that exhibit an NADPH oxidase activity through direct stimulation of protein kinase C (PKC) with PMA or through formyl peptide receptor activation. We have isolated a variant HL60 clone that exhibited a conditional PMA-induced oxidative response depending on the agent used for the differentiation. While cells differentiated with DMSO responded to either PMA or N-formyl peptide (N-formyl-Met-Leu-Phe-Lys or fMLFK), cells differentiated with dibutyryl-cAMP (Bt2cAMP) responded to fMLFK but very poorly to PMA. However, in Bt2cAMP-differentiated cells, the expression of the different PKC isoforms was similar to that observed in DMSO-differentiated cells. Moreover, PMA was able to induce a normal phosphorylation of the cytosolic factor p47phox and to fully activate extracellular signal-regulated kinases (Erk1/2). Interestingly, Bt2cAMP-differentiated cells exhibited a strong and sustained O2− production when costimulated with PMA and suboptimal concentrations of fMLFK which were, per se, ineffective. This sustained response was only slightly reduced by the conjunction of the mitogen-activated protein (MAP) kinase kinase (MEK) inhibitor PD98059 and wortmannin, a phosphatidylinositol-3 kinase (PI3K) inhibitor. Variant HL60 cells that were stably transfected with a constitutively active form of Rac1 were able, when differentiated with Bt2cAMP, to secrete oxidant following PMA stimulation. Altogether, the results suggest that, in addition to the phosphorylation of p47phox, the activation of NADPH oxidase requires the activation of a Rac protein through a pathway that diverges at a point upstream of MEK and that is independent of the activation of wortmannin sensitive PI3K.
Persistent Expression of Experimental Autoimmune Encephalomyelitis (EAE)-Specific Vβ8.2 TCR Spectratype in the Central Nervous System of Rats with Chronic Relapsing EAE
Authors: Kim Giok , Kohyama Kuniko , Tanuma Naoyuki , Arimito Hirohiko , Matsumoto Yoh 
Published: December 2022

AbstractMonitoring the TCR repertoire is indispensable for the assessment of T cell-associated autoimmune diseases and subsequent TCR-based immunotherapy. In the present study, we examined the TCR repertoire of spinal cord T cells of Lewis rats by CDR3 spectratyping during chronic relapsing experimental autoimmune encephalomyelitis (EAE) induced by immunization with spinal cord homogenate. It was found that Vβ8.2 spectratype with the shortest CDR3 expanded oligoclonally throughout the course of the disease. In addition, Vβ12 spectratype expansion was observed at the first and second attacks of EAE. Sequence analysis revealed that clones with the DSSYEQYF sequence, which is a representative sequence of myelin basic protein (MBP)-reactive T cell clones, constituted the predominant population in the Vβ8.2 family. Surprisingly, Vβ12 also used the identical amino acid sequence in the CDR3 region. These findings indicate that although infiltrating T cells in the central nervous system are activated polyclonally, the TCR repertoire remains unchanged throughout the course. Moreover, the finding that the predominant CDR3 amino acid sequence of Vβ8.2 and Vβ12 spectratypes is identical with that of MBP-induced EAE suggests that a single Ag in spinal cord homogenate, possibly MBP, is involved in disease development.
Characterization of the Pathogenic Autoreactive T Cells in Cyclosporine-Induced Syngeneic Graft-Versus-Host Disease
Authors: Chen Weiran , Thoburn Christopher , Hess Allan D. 
Published: December 2022

AbstractAdministration of the immunosuppressive drug cyclosporine after syngeneic bone marrow transplantation paradoxically elicits a systemic autoimmune syndrome resembling graft-vs-host disease (GVHD). This syndrome, termed syngeneic GVHD, is associated with the development of CD8+ cytolytic T lymphocytes that promiscuously recognize MHC class II molecules in association with a peptide from the invariant chain (CLIP). Clonal analysis reveals a major subset of cells that are pathogenic and require the N-terminal flanking region of CLIP for activation, while there is a minor subset of nonpathogenic T cells that require the C-terminal flanking region. The present studies show that pathogenic T cells produce type 1 cytokines (IL-2; IFN-γ), while the nonpathogenic clones produce type 2 cytokines (IL-4; IL-10). Moreover, the repertoire of the pathogenic T cells is highly conserved with respect to Vβ and Vα TCR gene expression. The vast majority of clones express Vβ8.5 (12/12) and Vα11 (11/12). Although a limited number was evaluated, the nonpathogenic clones have only a Vα restriction. Sequence analysis of the pathogenic T cell clones reveals a marked heterogeneity in the complementarity-determining region 3 domain and differential J region gene expression for both TCR α- and β-chains. Evaluation of the specificity of these clones suggests that the functional interaction between the N-terminal flanking region of CLIP (defined by the amino acid sequence -KPVSP-) and the V region of the TCR is critical, allowing effective target cell recognition and tissue destruction in syngeneic GVHD.
CD16 Cross-Linking Blocks Rearrangement of the TCRβ Locus and Development of αβ T Cells and Induces Development of NK Cells from Thymic Progenitors
Authors: Durum Scott K. , Lee Chong-Kil , Geiman Theresa M. , Murphy William J. , Muegge Kathrin 
Published: December 2022

AbstractMouse thymocytes normally develop into T lymphocytes, but the embryonic thymus also contains precursor cells capable of developing into NK cells. Here, we describe conditions that induce pro-T cells to develop into NK cells. CD16 is expressed on thymic pro-T cells. We observed that CD16 cross-linking during culture of embryonic thymic organs suppressed rearrangement of the TCRβ locus (but did not inhibit TCRγ locus rearrangement). Rearrangement of the TCRβ locus is normally required for development to the CD4+CD8+, and this development was also suppressed by CD16 cross-linking. The ability of CD16 cross-linking to block αβT cell development was not attributable to toxic effects, but rather was accompanied by promotion of development into NK cells, identified based on molecular and functional criteria. These results suggest that common lymphoid precursors can respond to environmental signals to commit to the αβT vs NK developmental pathways.
Epidermal Growth Factor (EGF) Modulates Fetal Thymocyte Growth and Differentiation: Partial Reversal by Insulin, Mimicking by Specific Inhibitors of EGF Receptor Tyrosine Kinase Activity, and Differential Expression of CD45 Phosphatase Isotypes
Authors: Freitas Claudia S. , Dalmau Sergio R. , Savino Wilson 
Published: December 2022

AbstractWe have recently reported that epidermal growth factor (EGF) modulates thymocyte development in fetal thymus organ cultures. Exogenously added EGF arrested thymocyte growth and differentiation, acting at the transition from the CD4−CD8− (double-negative (DN)) to the CD4+CD8+ (double-positive (DP)) phenotype. In this study, we further investigate some molecular aspects of this blockade. This inhibitory effect could be mimicked by tyrphostins, which are selective inhibitors of EGF receptor kinase activity. An attempt to use insulin (INS) as a synergizing effector resulted in partial restoration of lobe cellularity, leading to expansion of the CD44−CD25+ DN subset. However, INS did not overcome the EGF-driven blockade of the thymocyte DN → DP transition. Analysis of CD45 phosphatase showed that this transition was preceded by a rise in CD45RB isotype expression. At the end of a 7-day culture, the remaining DN cells from both EGF- and EGF+INS-treated fetal thymus organ cultures showed a CD45RB− phenotype and were negative for the EGF-immunoreactive molecule described previously on the fetal thymocyte surface. This finding implies that neither molecule is related to the growth capability of cells at this early developmental stage; it is more likely that the molecules are related to subsequent events in the thymocyte pathway to the DP phenotype. Thus, our data support the concept that EGF receptor-related circuitry may be relevant in thymus ontogeny. Additionally, evidence is provided for the duality between growth and differentiation at this particular early stage of thymocyte development.
IL-12 Up-Regulates IL-18 Receptor Expression on T Cells, Th1 Cells, and B Cells: Synergism with IL-18 for IFN-γ Production
Authors: Yoshimoto Tomohiro , Takeda Kiyoshi , Tanaka Takashi , Ohkusu Kazunobu , Kashiwamura Shin-ichiro , Okamura Haruki , Akira Shizuo , Nakanishi Kenji 
Published: December 2022

AbstractIL-18 is a product of macrophages and with IL-12 strikingly induces IFN-γ production from T, B, and NK cells. Furthermore, IL-18 and IL-12 synergize for IFN-γ production from Th1 cells, although this combination fails to affect Th2 cells. In this study, we show that IL-12 and IL-18 promptly and synergistically induce T and B cells to develop into IFN-γ-producing cells without engaging their Ag receptors. We also studied the mechanism underlying differences in IL-18 responsiveness between Th1 and Th2 cells. Pretreatment of T or B cells with IL-12 rendered them responsive to IL-18, which induces cell proliferation and IFN-γ production. These IL-12-stimulated cells had both high and low affinity IL-18R and an increased IL-18R mRNA expression. In particular, IL-12-stimulated T cells strongly and continuously expressed IL-18R mRNA. However, when T cells developed into Th1 cells after stimulation with anti-CD3 and IL-12, they lowered this IL-12-induced-IL-18R mRNA expression. Then, such T cells showed a dominant response to anti-CD3 by IFN-γ production when they were subsequently stimulated with anti-CD3 and IL-18. In contrast, Th2 cells did not express IL-18R mRNA and failed to produce IFN-γ in response to anti-CD3 and IL-18, although they produced a substantial amount of IFN-γ in response to anti-CD3 and IL-12. However, when Th1 and Th2 cells were stimulated with anti-CD3, IL-12, and IL-18, only the Th1 cells markedly augmented IFN-γ production in response to IL-18, suggesting that IL-18 responsiveness between Th1 and Th2 cells resulted from their differential expression of IL-18R.
Impaired TCR-Mediated Apoptosis and Bcl-XL Expression in T Cells Lacking the Stress Kinase Activator SEK1/MKK4
Authors: Nishina Hiroshi , Radvanyi Laszlo , Raju Kaliannan , Sasaki Takehiko , Kozieradzki Ivona , Penninger Josef M. 
Published: December 2022

AbstractThe dual specificity kinase SEK1 (MKK4) is a direct activator of stress-activated protein kinases (SAPK/JNK) in response to environmental stresses or mitogenic factors. We show in Sek1−/−Rag−/− chimeric mice that a Sek1 null mutation augments the susceptibility of peripheral T cells to TCR/CD3 religation-induced apoptosis. Sek1−/− T cells failed to induce expression of the death suppressor Bcl-XL in response to Ag receptor activation. The Sek1 mutation did not alter the induction of apoptosis in response to etoposide, cisplatinum, Adriamycin, and γ-irradiation. Moreover, we show that CD3ε activation alone leads to SEK1 activation in Sek1+/+ T cells. These results suggest that SEK1 transduces cellular survival signals during T cell stimulation.
Carboxyl-Terminal 15-Amino Acid Sequence of NFATx1 Is Possibly Created by Tissue-Specific Splicing and Is Essential for Transactivation Activity in T Cells
Authors: Imamura Ryu , Masuda Esteban S. , Naito Yoshiyuki , Imai Shin-ichiro , Fujino Tadahiro , Takano Toshiya , Arai Ken-ichi , Arai Naoko 
Published: December 2022

Abstract
NFAT regulates transcription of a number of cytokine and other immunoregulatory genes. We have isolated NFATx, which is one of four members of the NFAT family of transcription factors and is preferentially expressed in the thymus and peripheral blood leukocytes, and an isoform of NFATx, NFATx1. Here we provide evidence showing that 15 amino acids in the carboxyl-terminal end of NFATx1 are required for its maximum transactivation activity in Jurkat T cells. A fusion between these 15 amino acids and the GAL4 DNA binding domain was capable of transactivating reporters driven by the GAL4 DNA binding site. Interestingly, this 15-amino acid transactivation sequence is well conserved in NFAT family proteins, although the sequences contiguous to the carboxyl-terminal regions of the NFAT family are much less conserved. We also report three additional isoforms of NFATx, designated NFATx2, NFATx3, and NFATx4. This transactivation sequence is altered by tissue-specific alternative splicing in newly isolated NFATx isoforms, resulting in lower transactivation activity in Jurkat T cells. NFATx1 is expressed predominantly in the thymus and peripheral blood leukocyte, while the skeletal muscle expressed primarily NFATx2. In Jurkat cells, transcription from the NFAT site of the IL-2 promoter is activated strongly by NFATx1 but only weakly by NFATx2. These data demonstrate that the 15-amino acid sequence of NFATx1 is a major transactivation sequence required for induction of genes by NFATx1 in T cells and possibly regulates NFAT activity through tissue-specific alternative splicing.
Identification of Two NF-κB Sites in Mouse CD95 Ligand (Fas Ligand) Promoter: Functional Analysis in T Cell Hybridoma
Authors: Matsui Ken , Fine Alan , Zhu Bangmin , Marshak-Rothstein Ann , Ju Shyr-Te 
Published: December 2022

AbstractFas ligand (FasL) gene expression is critically involved in peripheral T cell tolerance and lymphocyte homeostasis. Previous studies have suggested that nuclear translocation of NF-κB during T cell activation is a critical event for FasL gene activation. In the present study we have identified two NF-κB sites (designated FasL-κB1 and FasL-κB2) on the promoter (∼700 bp) of FasL. The NF-κB sites were identified by electrophoretic mobility shift assay. Transient transfection reporter analyses showed that the FasL promoter activity was comparable between a construct that contains both sites and a shorter construct (433 bp) that contains only the FasL-κB1 site. Furthermore, elimination of FasL-κB1 by site-directed mutagenesis significantly inhibited FasL promoter activity. These observations provide strong evidence that NF-κB directly binds to the FasL-κB1 site and up-regulates FasL gene expression.
lck-Independent Inhibition of T Cell Antigen Response by the HIV gp120
Authors: Gratton Sophie , Julius Michael , Sékaly Rafick-Pierre 
Published: December 2022

AbstractBinding of the HIV envelope glycoprotein gp120 to CD4 inhibits T cell activation. We have used a murine T cell clone transfected with either wild-type human CD4 or mutated forms of CD4 to characterize the pathways involved in this inhibitory effect of gp120. Ag-induced proliferation of T cell clones transfected with human CD4 was completely inhibited in the presence of gp120, even though stimulation of this clone is independent of a CD4/MHC class II interaction. In addition, our results demonstrate that the inhibition by gp120 is not due to the sequestration of lck from TCR and does not require activation of lck by gp120. This suggests that CD4 can regulate the initiation of T cell activation independently of its interaction with lck. Moreover, we demonstrate that the nonresponsiveness induced by gp120 can be reversed by soluble CD4 when added early after onset of stimulation and that gp120 exerts its inhibitory effect when cells are in the G0 ≥ 1 phase of the cell cycle.
In Vivo and In Vitro Activities of the gp130-Stimulating Designer Cytokine Hyper-IL-6
Authors: Peters Malte , Blinn Guido , Solem Fian , Fischer Martina , zum Büschenfelde Karl-Hermann Meyer , Rose-John Stefan 
Published: December 2022

Abstract
IL-6 is a multifactorial cytokine mediating acute inflammatory responses in the liver. When IL-6 binds to a specific receptor (IL-6R), the IL-6/IL-6R complex associates with the signal transducer gp130, initiating intracellular signaling. A soluble form of the IL-6R (sIL-6R) renders target cells sensitive to IL-6 that do not express the IL-6R on their surfaces. A designer cytokine, termed Hyper-IL-6, consisting of IL-6 covalently linked to the sIL-6R was fully active on gp130-expressing cells at 100- to 1000-fold lower concentrations than unlinked IL-6 and IL-6R. Mice were injected i.p. with Hyper-IL-6 or IL-6. Upon injection of Hyper-IL-6 into mice, the acute phase response, as measured by haptoglobin mRNA expression in the liver, was markedly increased and lasted significantly longer compared with that in mice injected with a 10-fold higher dose of IL-6 alone. On human hepatoma cells, Hyper-IL-6 caused similar effects, indicating that the longer lasting response to the fusion protein could not only be explained by the longer plasma half-life of the fusion protein. Experiments using iodinated IL-6 and Hyper-IL-6 revealed that Hyper-IL-6 bound with high affinity to gp130 and was less efficiently internalized. This effect might explain the longer lasting activity of this protein on cells. The highly active IL-6/sIL-6R designer protein might be of significant clinical importance for the stimulation of cells that are more responsive to the IL-6/sIL-6R complex than to IL-6 alone. Such cells include hemopoietic progenitor cells and hepatocytes.
Soluble ICAM-1 Activates Lung Macrophages and Enhances Lung Injury
Authors: Schmal Hagen , Czermak Boris J. , Lentsch Alex B. , Bless Nicolas M. , Beck-Schimmer Beatrice , Friedl Hans P. , Ward Peter A. 
Published: December 2022

AbstractBecause of the important role of rat ICAM-1 in the development of lung inflammatory injury, soluble recombinant rat ICAM-1 (sICAM-1) was expressed in bacteria, and its biologic activities were evaluated. Purified sICAM-1 did bind to rat alveolar macrophages in a dose-dependent manner and induced production of TNF-α and the CXC chemokine, macrophage inflammatory protein-2 (MIP-2). Alveolar macrophages exhibited cytokine responses to both sICAM-1 and immobilized sICAM-1, while rat PBMCs failed to demonstrate similar responses. Exposure of alveolar macrophages to sICAM-1 resulted in NFκB activation (which was blocked by the presence of the aldehyde peptide inhibitor of 28S proteosome and by genistein, a tyrosine kinase inhibitor). As expected, cross-linking of CD18 on macrophages with Ab resulted in generation of TNF-α and MIP-2. This response was also inhibited in the presence of the proteosome inhibitor and by genistein. Alveolar macrophages showed adherence to immobilized sICAM-1 in a CD18-dependent manner. Finally, airway instillation of sICAM-1 intensified lung injury produced by intrapulmonary deposition of IgG immune complexes in a manner associated with enhanced lung production of TNF-α and MIP-2 and increased neutrophil recruitment. Therefore, through engagement of β2 integrins, sICAM-1 enhances alveolar macrophage production of MIP-2 and TNF-α, the result of which is intensified lung injury after intrapulmonary disposition of immune complexes.
A RANTES-Antibody Fusion Protein Retains Antigen Specificity and Chemokine Function
Authors: Challita-Eid Pia M. , Abboud Camille N. , Morrison Sherie L. , Penichet Manuel L. , Rosell Karen E. , Poles Tina , Hilchey Shannon P. , Planelles Vicente , Rosenblatt Joseph D. 
Published: December 2022

AbstractThe successful eradication of cancer cells in the setting of minimal residual disease may require targeting of metastatic tumor deposits that evade the immune system. We combined the targeting flexibility and specificity of mAbs with the immune effector function of the chemokine RANTES to target established tumor deposits. We describe the construction of an Ab fusion molecule with variable domains directed against the tumor-associated Ag HER2/neu, linked to sequences encoding the chemokine RANTES (RANTES.her2.IgG3). RANTES is a potent chemoattractant of T cells, NK cells, monocytes, and dendritic cells, and expression of RANTES has been shown to enhance immune responses against tumors in murine models. RANTES.her2.IgG3 fusion protein bound specifically to HER2/neu Ag expressed on EL4 cells and on SKBR3 breast cancer cells as assayed by flow cytometry. RANTES.her2.IgG3 could elicit actin polymerization of THP-1 cells and transendothelial migration of primary T lymphocytes. RANTES.her2.IgG3 prebound to SKBR3 cells also facilitated migration of T cells. RANTES.her2.IgG3 bound specifically to the CCR5 chemokine receptor, as demonstrated by flow cytometry, and inhibited HIV-1 infection via the CCR5 coreceptor. RANTES.her2.IgG3, alone or in combination with other chemokine or cytokine fusion Abs, may be a suitable reagent for recruitment and activation of an expanded repertoire of effector cells to tumor deposits.
Cytokine-Induced Protein Kinase B Activation and Bad Phosphorylation Do Not Correlate with Cell Survival of Hemopoietic Cells
Authors: Hinton Heather J. , Welham Melanie J. 
Published: December 2022

AbstractActivation of phosphoinositide-3 kinases (PI3Ks), their downstream target protein kinase B (PKB), and phosphorylation of Bad have all been implicated in survival signaling in many systems. However, it is not known whether these events are sufficient or necessary to universally prevent apoptosis. To address this issue, we have used three different factor-dependent hemopoietic cell lines, MC/9, BaF/3, and factor-dependent (FD)-6, which respond to a range of cytokines, to investigate the relationship between PI3K, PKB, and Bad activity with survival. The cytokines IL-3, IL-4, stem cell factor (SCF), GM-CSF, and insulin all induced the rapid and transient activation of PKB in responsive cell lines. In all cases, cytokine-induced PKB activation was sensitive to inhibition by the PI3K inhibitor, LY294002. However, dual phosphorylation of the proapoptotic protein Bad was found not to correlate with PKB activation. In addition, we observed cell-type-specific differences in the ability of the same cytokine to induce Bad phosphorylation. Whereas IL-4 induced low levels of dual phosphorylation of Bad in FD-6, it was unable to in MC/9 or BaF/3. Insulin, which was the most potent inducer of PKB in FD-6, induced barely detectable Bad phosphorylation. In addition, the ability of a particular cytokine to induce PKB activity did not correlate with its ability to promote cell survival and/or proliferation. These data demonstrate that, in hemopoietic cells, activation of PKB does not automatically confer a survival signal or result in phosphorylation of Bad, implying that other survival pathways must be involved.