bluuebunny/crossref_metadata_2025_split huggingface dataset:
TNF-α Regulates Corneal Langerhans Cell Migration
Authors: Dekaris Iva , Zhu Su-Ning , Dana M. Reza 
Published: January 2023

AbstractLangerhans cells (LC) belong to the dendritic cell family and mediate Ag presentation in the cornea and ocular surface. Under normal physiological conditions, the central cornea is devoid of LC. Centripetal migration of LC plays a critical role in promoting immunoinflammatory responses in the eye including allograft rejection and herpetic keratitis. The molecular mechanisms responsible for ocular LC migration are poorly understood. To examine whether TNF-α mediates corneal LC migration and to establish the interaction of IL-1 and TNF-α in regulating LC migratory capacity, we utilized gene-targeted knockout mice lacking IL-1 receptor I (IL-1RI−/−), TNF receptor I (p55−/−), TNF receptor II (p75−/−), or both (p55−/−p75−/−). LC migration was induced by thermal cautery or cytokine injection and enumerated by an immunofluorescence assay. Migration of LC after cauterization and TNF-α injection was significantly depressed in both p55−/− and p75−/− mice. Similarly, in the first 72 h after intracorneal injection of IL-1α, LC migration was reduced in p55−/−, p75−/−, and p55−/−p75−/− mice. In contrast, injection of TNF-α in IL-1RI−/− mice led to normal migration of corneal LC indistinguishable from wild-type controls. These results suggest that the IL-1 induction of corneal LC migration is largely mediated by TNFR function, whereas TNF-α induction of LC migration is independent of IL-1RI activity. Moreover, the data suggest that both p55 and p75 signaling pathways are important in mediating LC migration in the cornea.
Endocytosis of Heparin-Binding Protein (CAP37) Is Essential for the Enhancement of Lipopolysaccharide-Induced TNF-α Production in Human Monocytes
Authors: Heinzelmann Michael , Platz Andreas , Flodgaard Hans , Polk Hiram C. , Miller Frederick N. 
Published: January 2023

AbstractHeparin-binding protein (HBP), also known as CAP37, is a proteolytically inactive serine protease homologue that is released from activated granulocytes. However, HBP is not a biologically inactive molecule but rather a multifunctional protein with properties that include the enhancement of LPS-induced TNF-α production from monocytes. We have previously demonstrated that HBP is internalized in monocytes. In the current study, we hypothesize that HBP is internalized in monocytes via endocytosis, and this internalization is an important mechanism by which HBP enhances LPS-induced TNF-α release. Using whole blood from healthy donors and flow cytometry, we found that colchicine (0.1–10 mM), cytochalasin D (1000 μM), NH4Cl (10–50 mM), and bafilomycin A1 (0.1–3 μM) significantly reduced the affinity of FITC-HBP for CD14-positive monocytes. Using isolated human monocytes and ELISA, we found that colchicine (0.1 mM), cytochalasin D (30 and 300 μM), NH4Cl (30 mM), and bafilomycin A1 (1 μM) significantly reduced the effect of HBP (10 μg/ml) to enhance LPS (10 ng/ml)-induced TNF-α release after 24 h. These findings demonstrate that internalization of HBP in monocytes is essential for the enhancement of LPS-induced TNF-α release. Transport of HBP to an activating compartment depends on intact F-actin polymerization and endosomal acidification, an important mechanism for endosomal protein sorting and trafficking.
Golli-Induced Paralysis: A Study in Anergy and Disease
Authors: Clark Lise , Otvos Laszlo , Stein Paul L. , Zhang Xiang-Ming , Skorupa Annette F. , Lesh Georgia E. , McMorris F. Arthur , Heber-Katz Ellen 
Published: January 2023

AbstractThe Golli-MBP transcription unit contains three Golli-specific exons as well as the seven exons of the classical myelin basic protein (MBP) gene and encodes alternatively spliced proteins that share amino acid sequence with MBP. Unlike MBP, which is a late Ag expressed only in the nervous system, Golli exon-containing gene products are expressed both pre- and postnatally at many sites, including lymphoid tissue, as well as in the central nervous system. To investigate whether Golli-MBP peptides unique to Golli would result in neurological disease, we immunized rats and observed a novel neurological disease characterized by mild paralysis and the presence of groups of lymphocytes in the subarachnoid space but not in the parenchyma of the brain. Disease was induced by Th1-type T cells that displayed an unusual activation phenotype. Primary stimulation in vitro induced T cell proliferation with increased surface CD45RC that did not become down-regulated as it did in other Ag-stimulated cultures. Secondary stimulation of this CD45RChigh population with Ag, however, did not induce proliferation or IL-2 production, although an IFN-γ-producing population resulted. Proliferation could be induced by secondary stimulation with IL-2 or PMA-ionomycin, suggesting an anergic T cell population. Cells could adoptively transfer disease after secondary stimulation with IL-2, but not with Ag alone. These responses are suggestive of a chronically stimulated, anergic population that can be transiently activated to cause disease, fall back into an anergic state, and reactivated to cause disease again. Such a scenario may be important in chronic human disease.
The Role of the Human Fc Receptor FcγRIIA in the Immune Clearance of Platelets: A Transgenic Mouse Model
Authors: McKenzie Steven E. , Taylor Scott M. , Malladi Padmini , Yuhan Heena , Cassel Diana L. , Chien Paul , Schwartz Elias , Schreiber Alan D. , Surrey Saul , Reilly Michael P. 
Published: January 2023

AbstractIn humans, the Fc receptor for IgG, FcγRIIA, is expressed on macrophages and platelets and may play an important role in the pathophysiology of immune-mediated thrombocytopenia. Mice lack the genetic equivalent of human FcγRIIA. To better understand the role of FcγRIIA in vivo, FcγRIIA transgenic mice were generated and characterized. One transgenic mouse line expressed FcγRIIA on platelets and macrophages at levels equivalent to human cells, and cross-linking FcγRIIA on these platelets induced platelet aggregation. Immune-mediated thrombocytopenia in this transgenic line was studied using i.v. and i.p. administration of anti-mouse platelet Ab. In comparison with matched wild-type littermates that are negative for the FcγRIIA transgene, Ab-mediated thrombocytopenia was significantly more severe in the FcγRIIA transgenic mice. In contrast, FcR γ-chain knockout mice that lack functional expression of the Fc receptors FcγRI and FcγRIII on splenic macrophages did not demonstrate Ab-mediated thrombocytopenia. We generated FcγRIIA transgenic × FcR γ-chain knockout mice to examine the role of FcγRIIA in immune clearance in the absence of functional FcγRI and FcγRIII. In FcγRIIA transgenic × FcR γ-chain knockout mice, severe immune thrombocytopenia mediated by FcγRIIA was observed. These results demonstrate that FcγRIIA does not require the FcR γ-chain for expression or function in vivo. Furthermore, taken together, the data suggest that the human Fc receptor FcγRIIA plays a significant role in the immune clearance of platelets in vivo.
Cutting Edge: Sustained Expansion of CD8+ T Cells Requires CD154 Expression by Th Cells in Acute Graft Versus Host Disease
Authors: Buhlmann Janet E. , Gonzalez Mercedes , Ginther Brigit , Panoskaltsis-Mortari Angela , Blazar Bruce R. , Greiner Dale L. , Rossini Aldo A. , Flavell Richard , Noelle Randolph J. 
Published: January 2023

Abstract
Brief treatment with αCD154 Ab has been shown to prevent acute graft versus host disease (aGvHD). We extend these data to show that in the absence of CD154 function, donor T cells are unable to expand or generate high level anti-host CTL activity. Using transgenic (Tg) alloreactive CD8+ T cells adoptively transferred into allogeneic recipients, we show that short-term expansion of the CD8+ Tg T cells occurred in the absence of Th cells, and this short-term expansion could be facilitated with an agonistic αCD40. While CD40 agonism could enhance short-term expansion, sustained expansion of CD8+ Tg T cells required bona fide CD154-expressing CD4+ alloreactive Th cells. While CD154 was necessary for CD8+ Tg T cell sustained expansion, IL-2 was also implicated as essential. These observations suggest αCD154 therapy in GvHD is effective because the treatment causes an abortive CD8 alloresponse leading to the exhaustion or deletion of alloreactive CD8+ clones preventing the development of disease.
Cutting Edge: Recruitment of the CD19/CD21 Coreceptor to B Cell Antigen Receptor Is Required for Antigen-Mediated Expression of Bcl-2 by Resting and Cycling Hen Egg Lysozyme Transgenic B Cells
Authors: Roberts Teresa , Snow E. Charles 
Published: January 2023

Abstract
Recruitment of the CD19/CD21 coreceptor is thought to lower the threshold for effective signaling through the B cell Ag receptor. We provide evidence supporting a second role for coreceptor recruitment, and that is to enhance the survival/proliferative potential of the responding B cells. We show that B cell Ag receptor signaling in the absence of coreceptor recruitment induces cellular accumulation of the anti-apoptotic protein Bcl-xL, whereas CD19-mediated signals are required for Bcl-2 accumulation. The expression of both anti-apoptotic proteins correlates with the enhanced responsiveness of both resting and cycling B cells to growth-promoting signals delivered through CD40. These results provide further evidence for the necessity of coreceptor recruitment during Ag-dependent B cell activation and indicate that Ags derived from inflammatory sites function as better thymus-dependent Ags than their counterparts not coated with complement fragments.
MHC Class I-Restricted Presentation of Maleylated Protein Binding to Scavenger Receptors
Authors: Bansal Pratima , Mukherjee Paushali , Basu Sandip K. , George Anna , Bal Vineeta , Rath Satyajit 
Published: January 2023

Abstract
Pathways for loading exogenous protein-derived peptides on MHC class I are thought to be present mainly in monocyte-lineage cells and to involve phagocytosis- or macropinocytosis-mediated antigenic leakage into either cytosol or extracellular milieu to give peptide access to MHC class I. We show that maleylation of OVA enhanced its presentation to an OVA-specific MHC class I-restricted T cell line by both macrophages and B cells. This enhanced presentation involved uptake through receptors of scavenger receptor (SR)-like ligand specificity, was TAP-1-independent, and was inhibited by low levels (2 mM) of ammonium chloride. No peptide loading of bystander APCs by maleylated (maleyl) OVA-pulsed macrophages was detected. Demaleylated maleyl-OVA showed enhanced MHC class I-restricted presentation through receptor-mediated uptake and remained highly sensitive to 2 mM ammonium chloride. However, if receptor binding of maleyl-OVA was inhibited by maleylated BSA, the residual presentation was relatively resistant to 2 mM ammonium chloride. Maleyl-OVA directly introduced into the cytosol via osmotic lysis of pinosomes was poorly presented, confirming that receptor-mediated presentation of exogenous maleyl-OVA was unlikely to involve a cytosolic pathway. Demaleylated maleyl-OVA was well presented as a cytosolic Ag, consistent with the dependence of cytosolic processing on protein ubiquitination. Thus, receptor-specific delivery of exogenous protein Ags to APCs can result in enhanced MHC class I-restricted presentation, suggesting that the exogenous pathway of peptide loading for MHC class I may be a constitutive property dependent mainly on the quantity of Ag taken up by APCs.
Aberrant CD3- and CD28-Mediated Signaling Events in Cord Blood T Cells Are Associated with Dysfunctional Regulation of Fas Ligand-Mediated Cytotoxicity
Authors: Sato Katsuaki , Nagayama Hitomi , Takahashi Tsuneo A. 
Published: January 2023

AbstractThere have been numerous reports of decreased acute and chronic graft-vs-host disease (GVHD) in patients receiving HLA-matched or HLA-disparate umbilical cord transplants. However, little is known about the mechanisms underlying the low incidence of GVHD in umbilical cord blood transplantation (CBT). In this study, we examined CD3- and CD28-mediated functional properties and signaling events in CB T cells (CBTCs). Dual stimulation of peripheral blood TCs (PBTCs) and bone marrow TCs (BMTCs) with mAbs to CD3- and CD28-induced expressions of Fas ligand (FasL), as well as CD25 and CD154 (CD40L), whereas defective induction of these activation-associated cell surface molecules were observed in CBTCs. Engagement of both CD3 and CD28 induced FasL-mediated cytotoxicity in peripheral blood TCs (PBTCs) but not CBTCs; however, both of these tissue sources possess intrinsically similar proliferative responsiveness. Analysis of CD3- and CD28-induced signal transduction revealed a deficiency in signaling events that involved repressed tyrosine phosphorylation and enzymatic activities of a family of mitogen-activated protein kinases, extracellular signal-regulated kinase 2, stress-activated protein kinase/c-jun N-terminal kinase (SAPK/JNK), and p38mapk, as well as p56lck and ZAP-70 in CBTCs compared with those in PBTCs. These results suggest that CD3- and CD28-mediated signaling events blockage in CBTCs may be responsible for dysfunction of FasL-mediated cytotoxicity and lead to the low incidence of severe GVHD in CBT.
Diesel Exhaust Particles Induce NF-κB Activation in Human Bronchial Epithelial Cells In Vitro: Importance in Cytokine Transcription
Authors: Takizawa Hajime , Ohtoshi Takayuki , Kawasaki Shin , Kohyama Tadashi , Desaki Masashi , Kasama Tsuyoshi , Kobayashi Kazuo , Nakahara Kazuhiko , Yamamoto Kazuhiko , Matsushima Kouji , Kudoh Shoji 
Published: January 2023

Abstract
Fine particles derived from diesel engines (diesel exhaust particles, DEP) have attracted attention, since their density in industrial countries seems related to the increased prevalence of pulmonary diseases. Previous studies have suggested that DEP have a potential to directly activate airway epithelial cells to produce and release inflammatory cytokines and mediators, and thus facilitate inflammatory responses in the lung. To elucidate the molecular mechanisms of their action, we studied here IL-8 gene expression, one of the important cytokines in inflammatory responses, by Northern blot analysis and run-on transcription assay. Suspended DEP (1–50 μg/ml) increased the steady state levels of IL-8 mRNA, which was suggested to be largely due to increased transcriptional rates. Electrophoretic mobility shift assay demonstrated that DEP induced increased binding to the specific motif of NF-κB, but not of transcription factor AP-1. The luciferase reporter gene assay using wild-type and mutated NF-κB-binding sequences showed that DEP-induced NF-κB activation was involved in IL-8 transcription. Finally, both N-acetylcysteine and pyrrolidine dithiocarbamate attenuated the action of DEP on IL-8 mRNA expression, suggesting that oxidant-mediated pathway might be involved in its processes. These results suggested that DEP activate NF-κB, which might be an important mechanism of its potential to increase the expression of inflammatory cytokines in vitro.
A Novel β1 Integrin-Dependent Mechanism of Leukocyte Adherence to Apoptotic Cells
Authors: Schwartz Barbara R. , Karsan Aly , Bombeli Thomas , Harlan John M. 
Published: January 2023

Abstract
Adherence of leukocytes to cells undergoing apoptosis has been reported to be dependent on a variety of recognition pathways. These include αVβ3 (CD51/CD61, vitronectin receptor), CD36 (thrombospondin receptor), macrophage class A scavenger receptor, phosphatidylserine translocated to the outer leaflet of apoptotic cell membranes, and CD14 (LPS-binding protein). We investigated the mechanism by which leukocytes adhere to apoptotic endothelial cells (EC). Peripheral blood mononuclear leukocytes and U937 monocytic cells adhered to human or bovine aortic EC induced to undergo apoptosis by withdrawal of growth factors, treatment with the promiscuous protein kinase inhibitor staurosporine, with the protein synthesis inhibitor and protein kinase activator anisomycin, or with the combination of cycloheximide and TNF-α. Expression of endothelial adherence molecules such as CD62E (E-selectin), CD54 (ICAM-1), and CD106 (VCAM-1) was not induced or increased by these treatments. A mAb to αVβ3, exogenous thrombospondin, or blockade of phosphatidylserine by annexin V did not inhibit leukocyte adherence. Further, leukocyte binding to apoptotic EC was completely blocked by treatment of leukocytes but not EC with mAb to β1 integrin. These results define a novel pathway for the recognition of apoptotic cells.
Extracellular Acidification Induces Human Neutrophil Activation
Authors: Trevani Analía S. , Andonegui Graciela , Giordano Mirta , López Daniel H. , Gamberale Romina , Minucci Fernando , Geffner Jorge R. 
Published: January 2023

Abstract
In the current work, we evaluated the effect of extracellular acidification on neutrophil physiology. Neutrophils suspended in bicarbonate-buffered RPMI 1640 medium adjusted to acidic pH values (pH 6.5–7.0) underwent: 1) a rapid transient increase in intracellular free calcium concentration levels; 2) an increase in the forward light scattering properties; and 3) the up-regulation of surface expression of CD18. By contrast, extracellular acidosis was unable to induce neither the production of H2O2 nor the release of myeloperoxidase. Acidic extracellular pH also modulated the functional profile of neutrophils in response to conventional agonists such as FMLP, precipiting immune complexes, and opsonized zymosan. It was found that not only calcium mobilization, shape change response, and up-regulation of CD18 expression but also production of H2O2 and release of myeloperoxidase were markedly enhanced in neutrophils stimulated in acidic pH medium. Moreover, extracellular acidosis significantly delayed neutrophil apoptosis and concomitantly extended neutrophil functional lifespan. Extracellular acidification induced an immediate and abrupt fall in the intracellular pH, which persisted over the 240-s analyzed. A similar abrupt drop in the intracellular pH was detected in cells suspended in bicarbonate-supplemented PBS but not in those suspended in bicarbonate-free PBS. A role for intracellular acidification in neutrophil activation is suggested by the fact that only neutrophils suspended in bicarbonate-buffered media (i.e., RPMI 1640 and bicarbonate-supplemented PBS) underwent significant shape changes in response to extracellular acidification. Together, our results support the notion that extracellular acidosis may intensify acute inflammatory responses by inducing neutrophil activation as well as by delaying spontaneous apoptosis and extending neutrophil functional lifespan.
Soluble Murine IL-1 Receptor Type I Induces Release of Constitutive IL-1α
Authors: Netea Mihai G. , Jan Kullberg Bart , Boerman Otto C. , Verschueren Ineke , Dinarello Charles A. , Van der Meer Jos W. M. 
Published: January 2023

Abstract
IL-1α and IL-1β are proinflammatory cytokines involved in the pathogenesis of many infectious and noninfectious inflammatory diseases. To reduce IL-1 toxicity, extracellular domains of the soluble (s) IL-1R are shed from cell membranes and prevent triggering of cell-bound receptors. We investigated to what extent murine sIL-1RI can neutralize the IL-1 produced by LPS-stimulated macrophages. When mouse peritoneal macrophages were incubated with LPS, addition of sIL-1RI significantly inhibited the bioactivity of IL-1. Stimulation of cells with sIL-1RI alone induced no bioactive IL-1. When immunoreactive cytokine concentrations were measured with specific radioimmunoassays, sIL-1RI alone appeared to induce a significant release of IL-1α in a concentration-dependent manner. This effect was independent of new protein synthesis. The production of IL-1β or TNF-α was not influenced by sIL-1RI. There was no interference of sIL-1RI with the IL-1α radioimmunoassay. In mice, an i.v. injection of sIL-RI alone induced a rapid release of IL-1α, but not of TNF-α or IL-1β. Treatment of mice with sIL-1RI improved the survival during a lethal infection with Candida albicans. In conclusion, sIL-1RI induces a rapid release of IL-1α from cells, as well as into the systemic circulation. Although this IL-1α may be inactivated in circulation by the same sIL-1RI, this phenomenon probably has immunostimulatory effects at local levels where the sIL-1RI-induced IL-1α acts in a paracrine or autocrine manner.
Extracellular-Regulated Kinase 1/2, Jun N-Terminal Kinase, and c-Jun Are Involved in NF-κB-Dependent IL-6 Expression in Human Monocytes
Authors: Tuyt Leonore M. L. , Dokter Wim H. A. , Birkenkamp Kim , Koopmans Sicco B. , Lummen Chantal , Kruijer Wiebe , Vellenga Edo 
Published: January 2023

Abstract
In the present study we investigated the possible involvement of the mitogen-activated protein kinase family members extracellular-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) in mediating IL-6 gene expression in human monocytes, in particular their role in enhancing NF-κB activity. Freshly isolated monocytes treated with the protein phosphatase inhibitor okadaic acid secreted high levels of IL-6 protein, which coincided with enhanced binding activity of NF-κB as well as with phosphorylation and activation of the ERK1/2 and JNK proteins. The ERK pathway-specific inhibitor PD98059 inhibited IL-6 secretion from monocytes. Transient overexpression of inactive mutants of either Raf-1 or JNK1 showed that both pathways were involved in κB-dependent IL-6 promoter activity. By using PD98059, we demonstrated that the Raf1/MEK1/ERK1/2 pathway did not affect the DNA binding of NF-κB but, rather, acted at the level of transcriptional activity of NF-κB. Interestingly, it was shown that NF-κB-mediated gene transcription, both in the context of the IL-6 promoter as well as on its own, was dependent on both serine kinase activity and interaction with c-Jun protein. We conclude that okadaic acid-induced IL-6 gene expression is at least partly mediated through the ERK1/2 and JNK pathway-dependent activation of NF-κB transcriptional capacity. Our results suggest that the JNK pathway may regulate NF-κB-mediated gene transcription through its phosphorylation and activation of c-Jun.
CD26/Dipeptidyl-Peptidase IV Down-Regulates the Eosinophil Chemotactic Potency, But Not the Anti-HIV Activity of Human Eotaxin by Affecting Its Interaction with CC Chemokine Receptor 3
Authors: Struyf Sofie , Proost Paul , Schols Dominique , De Clercq Erik , Opdenakker Ghislain , Lenaerts Jean-Pierre , Detheux Michel , Parmentier Marc , De Meester Ingrid , Scharpé Simon , Van Damme Jo 
Published: January 2023

AbstractChemokines attract and activate distinct sets of leukocytes. The CC chemokine eotaxin has been characterized as an important mediator in allergic reactions because it selectively attracts eosinophils, Th2 lymphocytes, and basophils. Human eotaxin has a penultimate proline, indicating that it might be a substrate for dipeptidyl-peptidase IV (CD26/DPP IV). In this study we demonstrate that eotaxin is efficiently cleaved by CD26/DPP IV and that the NH2-terminal truncation affects its biological activity. CD26/DPP IV-truncated eotaxin(3–74) showed reduced chemotactic activity for eosinophils and impaired binding and signaling properties through the CC chemokine receptor 3. Moreover, eotaxin(3–74) desensitized calcium signaling and inhibited chemotaxis toward intact eotaxin. In addition, HIV-2 infection of CC chemokine receptor 3-transfected cells was inhibited to a similar extent by eotaxin and eotaxin(3–74). Thus, CD26/DPP IV differently regulates the chemotactic and antiviral potencies of eotaxin by the removal of two NH2-terminal residues. This physiological processing may be an important down-regulatory mechanism, limiting eotaxin-mediated inflammatory responses.