bluuebunny/crossref_metadata_2025_split huggingface dataset:
Th1/Th2-Regulated Expression of Arginase Isoforms in Murine Macrophages and Dendritic Cells
Authors: Munder Markus , Eichmann Klaus , Morán José M. , Centeno Francisco , Soler Germán , Modolell Manuel 
Published: January 2023

AbstractActivated murine macrophages metabolize arginine by two alternative pathways involving the enzymes inducible NO synthase (iNOS) or arginase. The balance between the two enzymes is competitively regulated by Th1 and Th2 T helper cells via their secreted cytokines: Th1 cells induce iNOS, whereas Th2 cells induce arginase. Whereas the role of macrophages expressing iNOS as inflammatory cells is well established, the functional competence of macrophages expressing arginase remains a matter of speculation. Two isoforms of mammalian arginases exist, hepatic arginase I and extrahepatic arginase II. We investigated the regulation of arginase isoforms in murine bone marrow-derived macrophages (BMMΦ) in the context of Th1 and Th2 stimulation. Surprisingly, in the presence of either Th2 cytokines or Th2 cells, we observe a specific induction of the hepatic isoform arginase I in BMMΦ. Induction of arginase I was shown on the mRNA and protein levels and obeyed the recently demonstrated synergism among the Th2 cytokines IL-4 and IL-10. Arginase II was detectable in unstimulated BMMΦ and was not significantly modulated by Th1 or Th2 stimulation. Similar to murine BMMΦ, murine bone marrow-derived dendritic cells, as well as a dendritic cell line, up-regulated arginase I expression and arginase activity upon Th2 stimulation, whereas arginase II was never detected. In addition to revealing the unexpected expression of arginase I in the macrophage/monocyte lineage, these results uncover a further intriguing parallelism between iNOS and arginase: both have a constitutive and an inducible isoform, the latter regulated by the Th1/Th2 balance.
ADP-Ribosylation of Rho by C3 Ribosyltransferase Inhibits IL-2 Production and Sustained Calcium Influx in Activated T Cells
Authors: Angkachatchai Vachras , Finkel Terri H. 
Published: January 2023

Abstract
Activation of the T lymphocyte induces dramatic cytoskeletal changes, and there is increasing evidence that disruption of the cytoskeleton inhibits early and late events of T cell signal transduction. However, relatively little is known about the signaling molecules involved in activation-induced cytoskeletal rearrangement. The rho family of small GTP-binding proteins, which include rho, rac, and cdc42, regulates the cytoskeleton and coordinates various cellular functions via their many effector targets. In prior studies, the Clostridium botulinum toxin C3 exoenzyme has been used to ADP-ribosylate and inactivate rho. In this study, we demonstrate that treatment of T cells with C3 exoenzyme inhibits IL-2 transcription following ligation of the TCR. Inhibition of IL-2 expression correlated with loss of sustained increase in [Ca+2]i and mitogen activated protein kinase (MAPK/Erk) activity, but not with activation of the tyrosine kinase, lck. These findings are the first to show that ADP-ribosylation of rho by C3 ribosyltransferase (exoenzyme) inhibits IL-2 production due, in part, to the requirement for sustained calcium influx and MAPK activation after Ag receptor ligation.
IFN-α Activates Stat6 and Leads to the Formation of Stat2:Stat6 Complexes in B Cells
Authors: Gupta Sanjay , Jiang Man , Pernis Alessandra B. 
Published: January 2023

Abstract
IFN-α consists of a family of highly homologous proteins, which exert pleiotropic effects on a wide variety of cell types. The biologic activities of IFN-α are mediated by its binding to a multicomponent receptor complex resulting in the activation of the Janus kinase-STAT signaling pathway. In most cell types, activation of Stat1 and Stat2 by IFN-α leads to the formation of either STAT homo-/heterodimers or of the IFN-stimulated gene factor 3 complex composed of Stat1, Stat2, and p48, a non-STAT protein. These distinct transcriptional complexes then target two different sets of cis-elements, γ-activated sites and IFN-stimulated response elements. Here, we report that IFN-α can activate complexes containing Stat6, which, until now, has been primarily associated with signaling by two cytokines with biologic overlap, IL-4 and IL-13. Induction of Stat6 complexes by IFN-α appears to be cell type specific, given that tyrosine phosphorylation of Stat6 in response to IFN-α is predominantly detected in B cells. Activation of Stat6 by IFN-α in B cells is accompanied by the formation of novel Stat2:Stat6 complexes, including an IFN-stimulated gene factor 3-like complex containing Stat2, Stat6, and p48. B cell lines resistant to the antiproliferative effects of IFN-α display a decrease in the IFN-α-mediated activation of Stat6. Activation of Stat6 as well as of Stat2:Stat6 complexes by IFN-α in B cells may allow modulation of target genes in a cell type-specific manner.
Mapping the Major Interaction Between Binding Protein and Ig Light Chains to Sites Within the Variable Domain
Authors: Davis David P. , Khurana Ritu , Meredith Stephen , Stevens Fred J. , Argon Yair 
Published: January 2023

Abstract
Newly synthesized Ig chains are known to interact in vivo with the binding protein (BiP), a major peptide-binding chaperone in the endoplasmic reticulum. The predominant interactions between the light chain and BiP are observed early in the folding pathway, when the light chain is either completely reduced, or has only one disulfide bond. In this study, we describe the in vitro reconstitution of BiP binding to the variable domain of light chains (VL). Binding of deliberately unfolded VL was dramatically more avid than that of folded VL, mimicking the interaction in vivo. Furthermore, VL binding was inhibited by addition of ATP, was competed with excess unlabeled VL, and was demonstrated with several different VL proteins. Using this assay, peptides derived from the VL sequence were tested experimentally for their ability to bind BiP. Four peptides from both β sheets of VL were shown to bind BiP specifically, two with significantly higher affinity. As few as these two peptide sites, one from each β sheet of VL, are sufficient to explain the association of BiP with the entire light chain. These results suggest how BiP directs the folding of Ig in vivo and how it may be used in shaping the B cell repertoire.
Characterization of an Avian (Gallus gallus domesticus) TCR αδ Gene Locus
Authors: Kubota Takayuki , Wang Jin-yi , Göbel Thomas W. F. , Hockett Richard D. , Cooper Max D. , Chen Chen-lo H. 
Published: January 2023

Abstract
Mammalian TCRδ genes are located in the midst of the TCRα gene locus. In the chicken, one large Vδ gene family, two Dδ gene segments, two Jδ gene segments, and one Cδ gene have been identified. The TCRδ genes were deleted on both alleles in αβ T cell lines, thereby indicating conservation of the combined TCRαδ locus in birds. Vα and Vδ gene segments were found to rearrange with one, both or neither of the Dδ segments and either of the two Jδ segments. Exonuclease activity, P-addition, and N-addition during VDJδ rearrangement contributed to TCRδ repertoire diversification in the first embryonic wave of T cells. An unbiased Vδ1 repertoire was observed at all ages, but an acquired Jδ1 usage bias occurred in the TCRδ repertoire. The unrestricted combinatorial diversity of relatively complex TCRγ and δ loci may contribute to the remarkable abundance of γδ T cells in this avian representative.
TNF Receptor p55 Is Required for Elimination of Inflammatory Cells Following Control of Intracellular Pathogens
Authors: Kanaly Suzanne T. , Nashleanas Michelle , Hondowicz Brian , Scott Phillip 
Published: January 2023

Abstract
The elimination of lymphocytes within inflammatory lesions is a critical component in the resolution of disease once pathogens have been cleared. We report here that signaling through the TNF receptor p55 (TNFRp55) is required to eliminate lymphocytes from lesions associated with intracellular pathogens. Thus, TNFRp55−/− mice, but not Fas-deficient mice, maintained inflammatory lesions associated with either Leishmania major or Rhodococcus equi infection, although they developed a Th1 response and controlled the pathogens. Inflammatory cells from either L. major- or R. equi-infected C57BL/6 mice were sensitive to TNF-induced apoptosis, and conversely the number of apoptotic cells in the lesions from TNFRp55−/− mice was dramatically reduced compared with wild-type mice. Furthermore, in vivo depletion of TNF in wild-type mice blocked lesion regression following R. equi infection. Taken together, our results suggest that signaling through the TNFRp55, but not Fas, is required to induce apoptosis of T cells within inflammatory lesions once pathogens are eliminated, and that in its absence lesions fail to regress.
Monocyte-Driven Activation-Induced Apoptotic Cell Death of Human T-Lymphotropic Virus Type I-Infected T Cells
Authors: Wakamatsu Shin-ichi , Makino Masahiko , Tei Chuuwa , Baba Masanori 
Published: January 2023

Abstract
We attempted apoptotic cell death induction of T cells infected with human T lymphotropic virus type I (HTLV-I) which induces HTLV-I-associated myelopathy/tropical spastic paraparesis and adult T cell leukemia. T cells acutely infected and expressing HTLV-Igag Ags were killed by cross-linking their TCR with anti-CD3 mAb. Cells in apoptotic process were found by staining with annexin V. The apoptosis was not affected by costimulation through CD28 molecules and was resistant to ligation of Fas molecules. Whereas the virus-infected T cells expressed higher levels of HLA-DR, CD25, CD80, and CD86 Ags than apoptosis-resistant PHA-blasts, the T cell apoptosis was enhanced by addition of exogenous IL-2. Furthermore, in this apoptosis, monocytes played an important role because T cells infected in the absence of monocytes were resistant to the death signals. The apoptosis-sensitive T cells responded to TCR signaling more strongly by proliferating than those apoptosis-resistant cells. Monocytes weakly affected the expression levels of viral Ags on T cells. However, HTLV-I-infected monocytes primed T cells to die by subsequent TCR signaling. T cells primed with the monocytes, subsequently infected in the absence of monocytes, were killed by TCR signaling. These observations suggest that primed and infected T cells could be killed by activation-induced cell death.
The Inhibitory Action of Mycobacterium ulcerans Soluble Factor on Monocyte/T Cell Cytokine Production and NF-κB Function
Authors: Pahlevan Ali A. , Wright David J. M. , Andrews Caroline , George Kathleen M. , Small Pamela L. C. , Foxwell Brian M. 
Published: January 2023

Abstract
Buruli ulcer is a chronic and progressive necrotizing ulcer for which there is no medical treatment. Historically, a soluble toxin (factor) derived from the causative Mycobacterium ulcerans was found to induce the massive necrosis of skin and s.c. tissue seen in this condition. However, the persistence of the disease is thought to be caused by a lack of any immune response. We therefore investigated whether the factor was related to immunosuppression. A protocol to partially purify the factor was developed, and its effects on immune competent cells were tested. The factor produced &gt;95% inhibition of LPS-induced release of TNF and IL-10 from human monocytes and caused a loss of adherence of these cells without cell death. The factor also blocked the production of IL-2 from activated T lymphocytes. The factor had no effect on TNF-induced cytotoxicity, but abrogated TNF-induced NF-κB activation. Surprisingly, a synergy was observed between the factor and phorbol ester-directed NF-κB activation. The factor had no effect on IL-1- or LPS-induced NF-κB activity, indicating selective activity of the factor. The factor did not inhibit the degradation of IκBα induced by TNF, indicating that the target for its activity lies within an undefined part of the TNF signaling mechanism. The data indicate that the localized immunosuppression associated with Buruli ulcer relates to the activity of the released factor, and this may provide a target for future therapeutic strategies for this intractable disease.
Pulmonary Epithelial Cells are a Source of IL-8 in the Response to Mycobacterium tuberculosis: Essential Role of IL-1 from Infected Monocytes in a NF-κB-Dependent Network
Authors: Wickremasinghe Melissa I. , Thomas Lynette H. , Friedland Jon S. 
Published: January 2023

Abstract
Pulmonary epithelial cells, covering a 70-m2 surface area, have not previously been considered an important source of chemokines in pulmonary tuberculosis. We analyzed IL-8 secretion from A549 cells and primary normal human bronchial epithelial cells (NHBE) infected by Mycobacterium tuberculosis. Direct infection of A549 cells by M. tuberculosis caused IL-8 secretion of 7720 ± 1610 pg/106 cells, but no IL-8 secretion from NHBE after 24 h. In contrast, conditioned media from M. tuberculosis-infected human monocytes (CoMTB) induced a much greater IL-8 secretion of 92,635 ± 13,180 pg/106 A549 cells and 13,416 ± 3,529 pg/106 NHBE after 24 h. CoMTB induced rapid IL-8 mRNA accumulation, which was stable over 24 h, compared with TNF-α-induced transcripts. CoMTB stimulated nuclear binding of p65, p50, and c-Rel subunits of NF-κB to IL-8 promoter sequences. Transient transfections with IL-8 promoter reporter constructs showed NF-κB binding-site mutations abolished IL-8 promoter activity while NF-IL-6 binding-site mutations decreased promoter activity to 50.2 ± 6.3% of wild-type activity. IL-1R antagonist but not neutralizing anti-TNF-α inhibited epithelial cell IL-8 secretion, mRNA accumulation, and NF-κB binding. Recombinant IL-1β (2 ng/ml) induced similar levels of IL-8 secretion to CoMTB in both A549 cells and NHBE. Pulmonary epithelial cells are a major source of IL-8 in the initial host response to pulmonary tuberculosis. Such IL-8 secretion is NF-κB dependent, NF-IL-6 requiring, and activated by an IL-1-mediated pathway as a consequence of phagocytosis of M. tuberculosis by monocytes.
Regulation of Complement Activation by C-Reactive Protein: Targeting the Complement Inhibitory Activity of Factor H by an Interaction with Short Consensus Repeat Domains 7 and 8–11
Authors: Jarva Hanna , Jokiranta T. Sakari , Hellwage Jens , Zipfel Peter F. , Meri Seppo 
Published: January 2023

Abstract
C-reactive protein (CRP) is a major acute phase protein whose functions are not totally clear. In this study, we examined the interaction of CRP with factor H (FH), a key regulator of the alternative pathway (AP) of complement. Using the surface plasmon resonance technique and a panel of recombinantly expressed FH constructs, we observed that CRP binds to two closely located regions on short consensus repeat (SCR) domains 7 and 8–11 of FH. Also FH-like protein 1 (FHL-1), an alternatively spliced product of the FH gene, bound to CRP with its most C-terminal domain (SCR 7). The binding reactions were calcium-dependent and partially inhibited by heparin. In accordance with the finding that CRP binding sites on FH were distinct from the C3b binding sites, CRP preserved the ability of FH to promote factor I-mediated cleavage of C3b. We propose that the function of CRP is to target functionally active FH and FHL-1 to injured self tissues. Thereby, CRP could restrict excessive complement attack in tissues while allowing a temporarily enhanced AP activity against invading microbes in blood.
TNF-α and IL-1 Sequentially Induce Endothelial ICAM-1 and VCAM-1 Expression in MRL/lprLupus-Prone Mice
Authors: McHale Julie F. , Harari Olivier A. , Marshall Diane , Haskard Dorian O. 
Published: January 2023

AbstractDysfunctional leukocyte-endothelial interactions are thought to play a key role in systemic lupus erythematosus pathogenesis. We questioned the importance of TNF-α and IL-1 for endothelial activation in MRL/lpr lupus-prone mice. Endothelial ICAM-1 and VCAM-1 expression increased significantly with disease evolution in kidney, heart, and brain, as shown by i.v. injected radiolabeled Ab uptake. Lung endothelial VCAM-1 also increased, while lung endothelial ICAM-1 did not rise above a high basal level. Immunoassays showed a significantly raised circulating level of TNF-α by 14 wk, with levels of circulating IL-1α and IL-1β being additionally raised by 20 wk. With 14-wk-old MRL/lpr, anti-TNF-α antiserum inhibited expression of ICAM-1 and VCAM-1 by endothelial cells cultured with sera in vitro, and uptake of anti-ICAM-1 and anti-VCAM-1 mAb in lung, kidney, brain, and heart in vivo. In contrast, both anti-TNF-α and anti-IL-1 antisera were required for maximal inhibition in vitro and in vivo at 20 wk. These data indicate that TNF-α is largely responsible for the early up-regulation of endothelial ICAM-1 and VCAM-1, but that IL-1 enhances expression in late disease. Our observations provide novel insights of possible relevance to understanding endothelial activation in systemic lupus erythematosus, and highlight an approach that can be extended to dissecting other chronic inflammatory diseases.
Inhibition of Bacterial Cell Wall-Induced Leukocyte Recruitment and Hepatic Granuloma Formation by TGF-β Gene Transfer
Authors: Song Xiao-yu , Zeng Li , Pilo Carey M. , Zagorski John , Wahl Sharon M. 
Published: January 2023

Abstract
Intraperitoneal injection of streptococcal cell walls (SCW) into Lewis rats results in dissemination of SCW to the liver, spleen, bone marrow, and peripheral joints. The uptake of SCW by Kupffer cells in the liver initiates a chain of events largely mediated by T lymphocytes and macrophages. Local synthesis and secretion of cytokines and growth factors in response to the persistent SCW lead to the evolution and maintenance of a chronic T cell-dependent granulomatous response and result in granuloma formation and irreversible hepatic fibrosis. In an attempt to impede the development of the chronic granulomatous lesions in the liver, we injected a plasmid DNA encoding TGF-β1 i.m. to the SCW animals to determine the effect of TGF-β1 gene transfer on the course of liver inflammation and fibrosis. A single injection of plasmid DNA encoding TGF-β1 resulted in virtual abolition of the development of the SCW-induced hepatic granuloma formation and matrix expansion. TGF-β1 DNA not only reduced key proinflammatory cytokines including TNF-α, IL-1β, IFN-γ, and IL-18, but also inhibited both CXC and CC chemokine production, thereby blocking inflammatory cell recruitment and accumulation in the liver. Moreover, TGF-β1 gene delivery inhibited its own expression in the liver tissue, which is otherwise up-regulated in SCW-injected animals. Our study suggests that TGF-β1 gene transfer suppresses hepatic granuloma formation by blocking the recruitment of inflammatory cells to the liver, and thus may provide a new approach to the control of hepatic granulomatous and fibrotic diseases.
Protection from Radiation-Induced Colitis Requires MHC Class II Antigen Expression by Cells of Hemopoietic Origin
Authors: Marguerat Samuel , MacDonald H. Robson , Kraehenbuhl Jean-Pierre , van Meerwijk Joost P. M. 
Published: January 2023

Abstract
Ulcerative colitis, an inflammatory bowel disease, is believed to result from a breakdown of dominant tolerance mechanisms that normally control intestinal immunity. Although CD4+ T lymphocyte subpopulations and expression of MHC class II molecules have been shown to play a role in the pathogenesis of the disease, the nature of the responsible mechanisms remains unclear. In this paper we describe a novel mouse model for inflammatory bowel disease, radiation-induced colitis, that occurs with complete penetrance 6–8 wk postinduction. A combination of high dose gamma-irradiation and lack of MHC class II expression on cells of hemopoietic origin results in development of colitis in C57BL/6 mice. Because of its versatility (due to susceptibility of mice of the widely genetically manipulated C57BL/6 background), high reproducibility, and 100% penetrance, radiation-induced colitis will be a useful mouse model for colitis and a significant tool to study dominant immunological tolerance mechanisms. Moreover, our data imply that tolerization to enteric Ags requires MHC class II mediated presentation by APC of hemopoietic origin.
IL-2 Receptor-Targeted Cytolytic IL-2/Fc Fusion Protein Treatment Blocks Diabetogenic Autoimmunity in Nonobese Diabetic Mice
Authors: Zheng Xin Xiao , Steele Alan W. , Hancock Wayne W. , Kawamoto Kensaku , Li Xian Chang , Nickerson Peter W. , Li Yongsheng , Tian Yan , Strom Terry B. 
Published: January 2023

Abstract
High affinity IL-2R5 is present on recently activated but not on resting or memory T cells. Selective targeting of T cells bearing high affinity IL-2R is an attractive therapy for many T cell-dependent cytopathic disease processes. A variety of rodent mAbs directed against the α-chain of the IL-2R, as well as IL-2 fusion toxins, have been used in animals and humans to achieve selective immunosuppression. Here we report on the development of a novel IL-2R targeting agent, a cytolytic chimeric IL-2/Fc fusion protein. This immunoligand binds specifically and with high affinity to IL-2R and is structurally capable of recruiting host Ab-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity activities. The Ig component ensures an extended circulating t1/2 of 25 h following systemic administration. To subsequently explore the mechanisms of the antidiabetogenic effects of IL-2/Fc, we have mutated the FcR binding and complement C1q binding (Fc−/−) domains of the Fc fragment to render the Fc unable to direct Ab-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity activities. In a model of passive transfer of diabetes in nonobese diabetic mice, lytic IL-2/Fc, but not nonlytic IL-2/Fc−/−, exhibited striking antidiabetogenic effects. Together with the negligible potential of IL-2/Fc for immunogenicity, this finding forecasts that cytolytic IL-2/Fc may offer a new therapeutic approach for selective targeting of auto and alloimmune T cells.
Hyperexpression of CD40 Ligand (CD154) in Inflammatory Bowel Disease and Its Contribution to Pathogenic Cytokine Production
Authors: Liu Zhanju , Colpaert Stefaan , D’Haens Geert R. , Kasran Ahmad , Boer Mark de , Rutgeerts Paul , Geboes Karel , Ceuppens Jan L. 
Published: January 2023

Abstract
CD40 ligand (CD40L or CD154), a type II membrane protein with homology to TNF, is transiently expressed on activated T cells and known to be important for B cell Ig production and for activation and differentiation of monocytes and dendritic cells. Both Crohn’s disease and ulcerative colitis are characterized by local production of cytokines such as TNF and by an influx of activated lymphocytes into inflamed mucosa. Herein, we investigated whether CD40L signaling participates in immune responses in these diseases. Our results demonstrated that CD40L was expressed on freshly isolated lamina propria T cells from these patients and was functional to induce IL-12 and TNF production by normal monocytes, especially after IFN-γ priming. The inclusion of a blocking mAb to CD40L or CD40 in such cocultures significantly decreased monocyte IL-12 and TNF production. Moreover, lamina propria and peripheral blood T cells from these patients, after in vitro activation with anti-CD3, showed increased and prolonged expression of CD40L as compared with controls. Immunohistochemical analyses indicated that the number of CD40+ and CD40L+ cells was significantly increased in inflamed mucosa, being B cells/macrophages and CD4+ T cells, respectively. These findings suggest that CD40L up-regulation is involved in pathogenic cytokine production in inflammatory bowel disease and that blockade of CD40-CD40L interactions may have therapeutic effects for these patients.