bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of the IL-7 Dose-Response Threshold During Pro-B Cell Differentiation Is Dependent on Pre-B Cell Receptor Expression
Authors: Marshall Aaron J. , Fleming Heather E. , Wu Gillian E. , Paige Christopher J. 
Published: January 2023

AbstractThe IL-7R and the pre-B cell receptor (pre-BCR) each provide critical signals during differentiation of B cell precursors. In this study we examine the interplay between signals dependent upon these receptors. We demonstrate that pre-BCR-deficient pro-B cells differ significantly from controls in their ability to use the IL-7R. We show that this difference, characterized by a failure to proliferate in response to IL-7, is narrowly restricted to IL-7 concentrations in the picogram per milliliter range and can be overcome with increasing amounts of IL-7. Restoration of Ig heavy chain to recombinase-activating gene-2-deficient pro-B cells leads to a restored response to picogram per milliliter levels of IL-7, providing strong evidence that modulation of the IL-7 dose-response threshold is dependent on pre-BCR. Culture of normal pro-B cells under low IL-7 conditions leads to selective outgrowth of cells expressing μ heavy chain, suggesting that modulation of IL-7 dose-response thresholds can allow for selective expansion of pre-BCR+ cells under conditions where IL-7 is limiting. We also provide evidence that expression of pre-BCR on pro-B cells limits the duration of IL-7 responsiveness by causing differentiation to an IL-7-unresponsive pre-B cell stage. Thus, the pre-BCR-dependent modulation of IL-7 responsiveness affects both the dose-response threshold and the duration of IL-7-induced clonal expansion. Our results suggest that positive selection of pre-BCR+ pro-B cells may be achieved through the fine tuning of IL-7 responses.
Cyclosporin A Inhibits Inositol 1,4,5-Trisphosphate Binding to Its Receptors and Release of Calcium from Intracellular Stores in Peritoneal Macrophages
Authors: Misra Uma K. , Gawdi Govind , Pizzo Salvatore V. 
Published: January 2023

AbstractWe have studied the effects of the immunosuppressive drug cyclosporin A (CsA) on the generation of inositol 1,4,5-trisphosphate (IP3) and intracellular Ca2+ levels elicited upon ligation of murine macrophage receptors for α2-macroglobulin, bradykinin, epidermal growth factor, and platelet-derived growth factor. Preincubation of cells with CsA (500 ng/ml), either alone or with the various ligands, did not inhibit the synthesis of IP3. However, we observed 70–80% inhibition of the binding of [3H]IP3 to IP3 receptors on macrophage membranes isolated from CsA-treated macrophages. Preincubation of macrophages with CsA abolished IP3-mediated release of Ca2+ from intracellular stores and Ca2+ entry from the extracellular medium observed when macrophage receptors were stimulated with ligands in the absence of CsA. Preincubation of macrophages with CsA also significantly inhibited DNA synthesis induced by ligands for all four receptors studied. Thus in macrophages, as in T cells, CsA blocks receptor-activated signal transmission pathways characterized by an initial increase in intracellular Ca2+ concentration. This inhibition appears to result from a drug effect on IP3 receptors.
Antisense Oligonucleotides Targeting Protein Kinase C-α, -βI, or -δ But Not -η Inhibit Lipopolysaccharide-Induced Nitric Oxide Synthase Expression in RAW 264.7 Macrophages: Involvement of a Nuclear Factor κB-Dependent Mechanism
Authors: Chen Ching-Chow , Wang Jia-Kae , Lin Shwu-Bin 
Published: January 2023

AbstractThe signaling pathway for protein kinase C (PKC) activation and the role of PKC isoforms in LPS-induced nitric oxide (NO) release were studied in RAW 264.7 macrophages. The tyrosine kinase inhibitor genestein attenuated LPS-induced NO release and inducible nitric oxide synthase (iNOS) expression, as did the phosphoinositide-specific phospholipase C (PI-PLC) inhibitor U73122 and the phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609. LPS stimulated phosphatidylinositol (PI) hydrolysis and PKC activity in RAW cells; both were inhibited by genestein. The PKC inhibitors (staurosporine, calphostin C, Ro 31-8220, or Go 6976) or long-term 12-O-tetradecanoylphorbol 13-acetate (TPA) treatment also resulted in inhibition of LPS-induced NO release and iNOS expression. Western blot analysis showed expression of PKC-α, -βI, -δ, -η, and -ζ in RAW cells; down-regulation of PKC-α, -βI, and -δ, but not -η, was seen after long-term TPA treatment, indicating the possible involvement of one or all of PKC-α, -βI, and -δ, but not -η, in LPS-mediated effects. Treatment with antisense oligonucleotides for these isoforms further demonstrated the involvement of PKC-α, -βI, and δ, but not -η, in LPS responses. Stimulation of cells with LPS for 1 h caused activation of NF-κB in the nuclei by detection of NF-κB-specific DNA-protein binding; this was inhibited by genestein, U73122, D609, calphostin C, or antisense oligonucleotides for PKC-α, -βI, and -δ, but not -η. These data suggest that LPS activates PI-PLC and PC-PLC via an upstream tyrosine kinase to induce PKC activation, resulting in the stimulation of NF-κB DNA-protein binding, then initiated the expression of iNOS and NO release. PKC isoforms α, βI, and δ were shown to be involved in the regulation of these LPS-induced events.
Lymphotactin Gene-Modified Bone Marrow Dendritic Cells Act as More Potent Adjuvants for Peptide Delivery to Induce Specific Antitumor Immunity
Authors: Cao Xuetao , Zhang Weiping , He Long , Xie Zhifang , Ma Shihua , Tao Qun , Yu Yizhi , Hamada Hirofumi , Wang Jianli 
Published: January 2023

Abstract
Dendritic cells (DC) are regarded as attractive candidates for cancer immunotherapy. Our aim is to improve the therapeutic efficacy of DC-based tumor vaccine by augmenting DC preferential chemotaxis on T cells. Mouse bone marrow-derived DC were transduced with lymphotactin (Lptn) gene by adenovirus vector. The supernatants from Lptn gene-modified DC (Lptn-DC) were capable of attracting CD4+ and CD8+ T cells in a chemotaxis assay, whereas their mock control could not. Lptn expression of Lptn-DC was further confirmed by RT-PCR. Lptn-DC were pulsed with Mut1 peptide and used for vaccination. Immunization with the low dose (1 × 104) of Mut1 peptide-pulsed DC induced weak CTL activity, whereas the same amounts of Mut1 peptide-pulsed Lptn-DC markedly induced specific CTL against 3LL tumor cells. A single immunization with 1 × 104 Mut1 peptide-pulsed Lptn-DC could render mice resistant to a 5 × 105 3LL tumor cell challenge completely, but their counterpart could not. The protective immunity induced by Mut1 peptide-pulsed Lptn-DC depends on both CD4+ T cells and CD8+ T cells rather than NK cells in the induction phase and depends on CD8+ T cells rather than CD4+ T cells and NK cells in the effector phase. Moreover, the involvement of CD28/CTLA4 costimulation pathway and IFN-γ are also necessary. When 3LL tumor-bearing mice were treated with 1 × 104 Mut1 peptide-pulsed Lptn-DC, their pulmonary metastases were significantly reduced, whereas the same low dose of Mut1 peptide-pulsed DC had no obvious therapeutic effects. Our data suggest that Lptn-DC are more potent adjuvants for peptide delivery to induce protective and therapeutic antitumor immunity.
Neutralizing Antibodies to IFN-γ-Inducing Factor Prevent Experimental Autoimmune Encephalomyelitis
Authors: Wildbaum Gizi , Youssef Sawsan , Grabie Nir , Karin Nathan 
Published: January 2023

AbstractSpecific oligonucleotide primers were used to identify and isolate IFN-γ-inducing factor (IGIF) from the brain of rats with developing experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune disease of the central nervous system that serves as a model for multiple sclerosis. IGIF was highly transcribed in the brain at the onset and during the course of active EAE. PCR products encoding rat IGIF were used to generate the recombinant protein that was used to induce anti-IGIF neutralizing Abs. These Abs significantly reduced the production of IFN-γ by primed T cells proliferating in response to their target myelin basic protein epitope and by Con A-activated T cells from naive donors. When administered to rats during the development of either active or transferred EAE, these Abs significantly blocked the development of disease. Splenic T cells from protected rats were cultured with the encephalitogenic myelin basic protein epitope and evaluated for production of IL-4 and IFN-γ. These cells, which proliferated, exhibited a profound increase in IL-4 production that was accompanied by a significant decrease in IFN-γ and TNF-α production. Thus, we suggest that perturbation of the Th1/Th2 balance toward Th2 cells is the mechanism underlying EAE blockade by anti-IGIF immunotherapy.
A Model for the Origin of TCR-αβ+ CD4−CD8− B220+ Cells Based on High Affinity TCR Signals
Authors: Mixter Philip F. , Russell Jennifer Q. , Morrissette Gregory J. , Charland Colette , Aleman-Hoey Deborah , Budd Ralph C. 
Published: January 2023

Abstract
The origin of TCR-αβ+ CD4−CD8− cells is unclear, yet accumulating evidence suggests that they do not represent merely a default pathway of unselected thymocytes. Rather, they arise by active selection as evidenced by their absence in mice lacking expression of class I MHC. TCR-αβ+ CD4−CD8− cells also preferentially accumulate in mice lacking expression of Fas/APO-1/CD95 (lpr) or Fas-ligand (gld), suggesting that this subset might represent a subpopulation destined for apoptosis in normal mice. Findings from mice bearing a self-reactive TCR transgene support this view. In the current study we observe that in normal mice, TCR-αβ+ CD4−CD8− thymocytes contain a high proportion of cells undergoing apoptosis. The apoptotic subpopulation is further identified by its expression of B220 and IL2Rβ and the absence of surface CD2. The CD4−CD8− B220+ phenotype is also enriched in T cells that recognize endogenous retroviral superantigens, and can be induced in TCR transgenic mice using peptide/MHC complexes that bear high affinity, but not low affinity, for TCR. A model is presented whereby the TCR-αβ+ CD2− CD4−CD8− B220+ phenotype arises from high intensity TCR signals. This model is broadly applicable to developing thymocytes as well as mature peripheral T cells and may represent the phenotype of self-reactive T cells that are increased in certain autoimmune conditions.
Limiting TCR Expression Leads to Quantitative But Not Qualitative Changes in Thymic Selection
Authors: Dave Vibhuti P. , Allman David , Wiest David L. , Kappes Dietmar J. 
Published: January 2023

Abstract
Thymic selection is controlled in part by the avidity of the interaction between thymocytes and APCs. In agreement, the selective outcome can be modulated by altering the expression levels of selecting ligands on APCs. Here we test the converse proposition, i.e., whether changing TCR levels on thymocytes can alter the selective outcome. To this end, we have generated mice in which all thymocytes express two transgenic TCRs simultaneously (dual TCR-expressing (DTE) mice), the class I-restricted HY TCR and the class II-restricted AND TCR. Due to mutual dilution, surface expression levels of the two individual transgenic TCRs are diminished in DTE relative to single TCR-expressing mice. We find that thymic selection is highly sensitive to these reductions in TCR surface expression. Positive selection mediated by the AND and HY TCRs is severely impaired or abolished, respectively. Negative selection of the HY TCR in male DTE mice is also partly blocked, leading to the appearance of significant numbers of double positive thymocytes. Also, in the periphery of male, but not female, DTE mice, substantial numbers of single positive CD8bright cells accumulate, which are positively selected in the thymus but by a highly inefficient hemopoietic cell-dependent process. Overall our results favor the interpretation that the outcome of thymic selection is not determined solely by avidity and the resulting signal intensity, but is also constrained by other factors such as the nature of the ligand and/or its presentation by different subsets of APCs.
Costimulation Reverses the Defect in IL-2 But Not Effector Cytokine Production by T Cells with Impaired IκBα Degradation
Authors: Aune Thomas M. , Mora Ana L. , Kim Somee , Boothby Mark , Lichtman Andrew H. 
Published: January 2023

Abstract
Although the transcriptional basis for states of unresponsiveness in primary T cells is unclear, tolerant B lymphocytes exhibit inhibition of both c-Jun N-terminal kinase induction and IκBα (inhibitor of NF-κBα) degradation, leading to lower levels of both nuclear AP-1 and NF-κB. Expression of an IκBα mutant resistant to signal-induced degradation in transgenic T cells caused markedly deficient effector cytokine (IL-4, IFN-γ) production after primary TCR stimulation despite a detectable level of nuclear NF-κB. A TCR response element from the IFN-γ promoter, despite lacking detectable NF-κB/Rel sites, was also unresponsive to TCR ligation. Nuclear induction of AP-1 proteins in response to T cell activation was diminished in transgenic T cells. Costimulation induced by anti-CD28 mAb increased IL-2 production, but failed to reverse the defects in effector cytokine production. Taken together, these data indicate that impaired NF-κB/Rel signaling in T cells interferes with the signal transduction pathways required for efficient induction of effector cytokine production.
CTLA-4-Mediated Inhibition of Early Events of T Cell Proliferation
Authors: Brunner Monika C. , Chambers Cynthia A. , Chan Francis Ka-Ming , Hanke Jeff , Winoto Astar , Allison James P. 
Published: January 2023

AbstractCTLA-4 engagement by mAbs inhibits, while CD28 enhances, IL-2 production and proliferation upon T cell activation. Here, we have analyzed the mechanisms involved in CTLA-4-mediated inhibition of T cell activation of naive CD4+ T cells using Ab cross-linking. CTLA-4 ligation inhibited CD3/CD28-induced IL-2 mRNA accumulation by inhibiting IL-2 transcription, which appears to be mediated in part through decreasing NF-AT accumulation in the nuclei. However, CTLA-4 ligation did not appear to affect the CD28-mediated stabilization of IL-2 mRNA. Further, CTLA-4 engagement inhibited progression through the cell cycle by inhibiting the production of cyclin D3, cyclin-dependent kinase (cdk)4, and cdk6 when the T cells were stimulated with anti-CD3/CD28 and with anti-CD3 alone. These results indicate that CTLA-4 signaling inhibits events early in T cell activation both at IL-2 transcription and at the level of IL-2-independent events of the cell cycle, and does not simply oppose CD28-mediated costimulation.
Antigen-Specific T Cell Activation and Proliferation During Oral Tolerance Induction
Authors: Sun Jiaren , Dirden-Kramer Bernadette , Ito Komei , Ernst Peter B. , Van Houten Nancy 
Published: January 2023

AbstractOne of several routes of achieving immunologic tolerance is through functional inactivation of Ag-specific T cells. Oral administration of Ag can allow survival of the Ag-specific T cells that are functionally anergic. The aim of this study was to investigate whether functional inactivation of Ag-specific T cells is directed through an activation process and to further define the differentiative pathways and functional characteristics of anergic T cells. Mice were transplanted with OVA-specific TCR-transgenic T cells and either fed OVA or immunized s.c. with the OVA peptide 323–339 in CFA. OVA-specific T cells from OVA-fed mice were unresponsive to restimulation in vitro within 48–72 h after treatment. In vivo, however, T cell proliferation was detected by 5,6-carboxy-succinimidyl-fluoresceine-ester intensity changes in OVA-specific T cells. The mesenteric lymph nodes (LNs) from OVA-fed mice more frequently contained OVA-specific dividing cells in vivo than those in the peripheral LNs, and the reciprocal was observed following s.c. immunization of the OVA peptide in CFA. The induction of anergy in OVA-fed mice was accompanied by rapid up-regulation of CD69 and CTLA-4, later down-regulation of CD45RB on OVA-specific T cells, and a marked decrease in T cell secretion of IL-2, IL-10, and IFN-γ after OVA restimulation in vitro. Results from this study indicate that the inductive phase of oral tolerance is preceded by Ag-specific T cell activation in vivo, proliferation in the regional draining LNs, and differentiation into a memory-like state. These results indicate that Ag-directed differentiation occurs as a part of T cell tolerance through anergy.
Syndecan-4 Is Expressed by B Lineage Lymphocytes and Can Transmit a Signal for Formation of Dendritic Processes
Authors: Yamashita Yoshio , Oritani Kenji , Miyoshi Erina K. , Wall Randolph , Bernfield Merton , Kincade Paul W. 
Published: January 2023

Abstract
Our previous studies indicated that stromal cell-derived syndecan-4 might mediate some form of communication with pre-B cells in bone marrow. We now report additional aspects of this recognition and show that syndecan-4 is also present on pre-B cells. Indeed, the molecule is acquired at an early stage of differentiation and retained until mature B cells undergo Ig isotype switching. mAbs developed to two portions of the syndecan-4 protein core were used to probe possible functions on B lineage lymphocytes. Syndecan-4 ligation had no obvious influence on B lymphocyte formation or activation, but this treatment caused a dramatic morphological change in appropriately stimulated leukocytes. Extended filopodia appeared on transfected Ba/F3 or FDCP-1 cells, as well as activated B cell blasts that were placed on syndecan-4 Ab-coated surfaces. The dendritic processes contained polymerized actin as well as pp52(LSP1), a prominent F-actin binding protein in lymphocytes. The cytoplasmic domain of syndecan-4 was not required for this response. Shape changes of this type could facilitate interactions between B lymphocytes and other components of the immune system. Not only is syndecan-4 a useful marker for discriminating normal B lineage lymphocyte subsets, but our results suggest new ways for the syndecans to participate in immune responses.
The Substance P Receptor Is Necessary for a Normal Granulomatous Response in Murine Schistosomiasis Mansoni
Authors: Blum Arthur M. , Metwali Ahmed , Kim-Miller Mindy , Li Jie , Qadir Khurram , Elliott David E. , Lu Bao , Fabry Zsuzsa , Gerard Norma , Weinstock Joel V. 
Published: January 2023

AbstractImmune cells within the granulomas of murine schistosomiasis mansoni make the neuropeptide substance P (SP) and express neurokine 1 receptor, which is the specific receptor for substance P (SPr). It was determined if mice with deletion of the SPr (SPr−/−) would develop a normal granulomatous response to schistosome ova during the course of natural infection. Mean liver granuloma size was smaller in SPr−/− mice compared with that of wild-type control animals. Although flow analysis revealed little difference in the cellular composition of the granulomas, both splenocytes and granuloma cells from SPr−/− mice produced much less IFN-γ and IgG2a and less IgE. The expression of Th2 cytokines (IL-4/IL-5) and IgG1 was comparable to the wild-type control. The mouse with targeted disruption of its SPr had the nonmammalian gene encoding the enzyme β-galactosidase inserted in exon 1 of the SPr gene. There was β-galactosidase activity in many mononuclear cells scattered throughout the schistosome granulomas of SPr−/− mice. Also, a granuloma T cell line derived from this transgenic mouse produced β-galactosidase. These results provide further evidence that in murine schistosomiasis SPr is displayed commonly on granuloma inflammatory cells and is important for granuloma development and expression of IFN-γ circuitry in this natural infection.
Glucocorticoid Suppresses Autocrine Survival of Mast Cells by Inhibiting IL-4 Production and ICAM-1 Expression
Authors: Yoshikawa Hideshi , Nakajima Yasuo , Tasaka Kachio 
Published: January 2023

Abstract
When mast cells are activated through their high affinity IgE receptors (FcεRI), release of chemical mediators is followed by secretion of multiple cytokines. In this work, we report that IL-3-dependent mast cell line MC9 undergoes apoptosis when IL-3 is withdrawn. However, cross-linking of FcεRI prevents apoptosis of MC9 by an autocrine mechanism, producing IL-3, IL-4, and GM-CSF. Although stimulated MC9 synthesizes mRNAs and proteins of these cytokines, secretion of endogenous IL-3 and GM-CSF is not enough for cell survival, whereas IL-4 itself does not have survival effect on MC9, but it induces cell aggregation by expressing LFA-1 and makes it reactive to endogenous growth factors. Addition of dexamethazone (DXM) to MC9 results in significant down-regulation of IL-4 mRNA in activated MC9. However, mRNA levels of IL-3 and GM-CSF are not changed by DXM. DXM also directly down-regulates the expression of ICAM-1 that is the high affinity ligand of LFA-1, by which the self-aggregation of MC9 is inhibited. Thus, glucocorticoids suppress autocrine survival of mast cells by inhibiting IL-4 production and ICAM-1 expression.
Regulation of Monocyte Survival In Vitro by Deposited IgG: Role of Macrophage Colony-Stimulating Factor
Authors: Marsh Clay B. , Pomerantz Richard P. , Parker Jennifer M. , Winnard Alissa V. , Mazzaferri Ernest L. , Moldovan Nicanor , Kelley Todd W. , Beck Eric , Wewers Mark D. 
Published: January 2023

AbstractIgG deposition at tissue sites characteristically leads to macrophage accumulation and organ injury. Although the mechanism by which deposited IgG induces tissue injury is not known, we have recently demonstrated that deposited IgG stimulates the release of IL-8 and monocyte chemoattractant protein-1 from normal human monocytes, which may drive inflammation. Since IgG also induces macrophage accumulation in these diseases, we hypothesized that deposited IgG protects monocytes from apoptosis. As an in vitro model of the effect of deposited IgG on monocyte survival, monocyte apoptosis was studied after FcγR cross-linking. Monocytes cultured on immobilized IgG, which induces FcγR cross-linking, were protected from apoptosis, whereas monocytes cultured with equivalent concentrations of F(ab′)2 IgG or 50 times higher concentrations of soluble IgG, neither of which induces FcγR cross-linking, were not protected. Moreover, this protection was transferable, as supernatants from immobilized IgG-stimulated monocytes protected freshly isolated monocytes from apoptosis and contained functional M-CSF, a known monocyte survival factor. M-CSF mediated the monocyte survival induced by FcγR cross-linking, as neutralizing anti-human M-CSF Abs blocked the monocyte protection provided by either immobilized IgG or IgG-stimulated monocyte supernatants. These findings demonstrate a novel mechanism by which deposited IgG targets tissue macrophage accumulation through FcγR-mediated M-CSF release. This pathway may play an important role in promoting and potentiating IgG-mediated tissue injury.
Cutting Edge: Clonally Restricted Production of the Neurotrophins Brain-Derived Neurotrophic Factor and Neurotrophin-3 mRNA by Human Immune Cells and Th1/Th2-Polarized Expression of Their Receptors
Authors: Besser Michal , Wank Rudolf 
Published: January 2023

Abstract
Neurotrophins, such as neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF), are potent regulators of neuronal functions. Here we show that human immune cells also produce NT-3 mRNA, secrete BDNF, and express their specific receptors trkB and trkC. The truncated trkB receptor, usually expressed in sensory neurons of the central nervous system, was also constitutively expressed in unstimulated Th cells. Full-length trkB was detectable in stimulated PBMC, B cell lines, and Th1, but not in Th2 and Th0 cell clones. Clonally restricted expression was also observed for trkC, until now not detected on blood cells. The Th1 cytokine IL-2 stimulated production of trkB mRNA but not of trkC, whereas the Th2 cytokine IL-4 enhanced NT-3 but not BDNF mRNA expression. Microbial Ags, which influence the Th1/Th2 balance, could therefore modulate the neurotrophic system and thereby affect neuronal synaptic activity of the central nervous system.