bluuebunny/crossref_metadata_2025 huggingface dataset:
IFN-α and IL-18 exert opposite regulatory effects on the IL-12 receptor expression and IL-12-induced IFN-γ production in mouse macrophages: novel pathways in the regulation of the inflammatory response of macrophages
Authors: Fantuzzi Laura , Puddu Patrizia , Varano Barbara , Del Cornò Manuela , Belardelli Filippo , Gessani Sandra
Published: September 2022

We characterized the IL-12 response of mouse macrophages in terms of modulation of IFN-γ production by cytokines (IFN-α and IL-18) and regulation of IL-12 receptor expression. β1 and β2 IL-12R chain mRNA expression increased with time in culture in the absence of exogenous stimulation, with concomitant acquisition of responsiveness to IL-12 for IFN-γ production. Expression of the IL-12R β1 chain mRNA was increased further following IL-12 treatment as a consequence of IFN-γ expression. IL-12 response was regulated differentially by IFN-α and IL-18. Neutralization of endogenous type I IFN increased IFN-γ secretion, whereas exogenous IFN-α reduced it. In contrast, IL-18 enhanced IFN-γ mRNA accumulation and IFN-γ secretion in IL-12-stimulated, but not -untreated, cultures. The opposite effects exerted by IFN-α and IL-18 mirror their mutual capacity of regulating—in a negative or positive manner, respectively—the expression of the IL-12R β1 chain. We suggest that differential regulation of IL-12 response by IFN-α and IL-18 can represent previously unrecognized regulatory mechanisms for maintaining suitable levels of differentiation/activation in macrophages.
Fibronectin-bound TNF-α stimulates monocyte matrix metalloproteinase-9 expression and regulates chemotaxis
Authors: Vaday Gayle G , Hershkoviz Rami , Rahat Michal A , Lahat Nitza , Cahalon Liora , Lider Ofer
Published: September 2022

Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine implicated in the stimulation of matrix metalloproteinase (MMP) production by several cell types. Our previous studies demonstrated that TNF-α avidly binds fibronectin (FN) and laminin, major adhesive glycoproteins of extracellular matrix (ECM) and basement membranes. These findings suggested that TNF-α complexing to insoluble ECM components may serve to concentrate its activities to distinct inflamed sites. Herein, we explored the bioactivity and possible function of ECM-bound TNF-α by examining its effects on MMP-9 secretion by monocytes. Immunofluorescent staining indicated that LPS-activated monocytes deposited newly synthesized TNF-α into ECM-FN. FN-bound TNF-α (FN/TNF-α) significantly up-regulated MMP-9 expression and secretion by the human monocytic cell line MonoMac-6 and peripheral blood monocytes. Such secretion could be inhibited by antibodies that block TNF-α activity and binding to its receptors TNF RI (p55) and TNF RII (p75). Chemotaxis through ECM gels in the presence of soluble or bound TNF-α was inhibited by a hydroxamic acid inhibitor of MMPs (GM6001). It is interesting that, although the adhesion of MonoMac-6 cells to FN/TNF-α required functional activated β1 integrins, FN/TNF-α-induced MMP-9 secretion was independent of binding to β1 integrins, since MMP-9 secretion was unaffected by: (1) neutralizing mAb to α4, α5, and β1 subunits, which blocked cell adhesion; (2) a mAb that stimulated β1 integrin-mediated adhesion; and (3) binding TNF-α to the 30-kDa amino-terminal fragment of FN, which lacks the major cell adhesive binding sites. Thus, in addition to their cell-adhesive roles, ECM glycoproteins, such as FN, may play a pivotal role in presenting proinflammatory cytokines to leukocytes within the actual inflamed tissue, thereby affecting their capacities to secrete ECM-degrading enzymes. These TNF-α-ECM interactions may serve to limit the cytokine’s availability and bioactivity to target areas of inflammation.
Activating Ly-49D NK receptors: expression and function in relation to ontogeny and Ly-49 inhibitor receptors
Authors: Ortaldo John R , Winkler-Pickett Robin , Wiegand Gordon
Published: September 2022

Developmental changes in the repertoire of activating Ly-49 family members have not been examined previously. In the present study, we have examined the expression and function of the activating Ly-49s (D and H) from birth through 8 weeks of age. We demonstrate that 1) activating Ly-49s are expressed early, 2) their expression intensity is not different from adult NK cells, and 3) activating receptors are functional. Examination of the inhibitory Ly-49s also demonstrated functional capacity immediately upon expression. To examine the kinetics of expression of the repertoire of activating Ly-49 members, we utilized five- and six-color flow cytometric analyses of NK cells from birth through adulthood. Previous studies examining the inhibitory Ly-49 repertoire have proposed that expression is regulated by the product rule. Our results indicated that Ly-49D, which recognizes H-2Dd, had a discordantly high coexpression of the inhibitory Ly-49s that recognized H-2Dd (Ly-49A and Ly-49G2). The product rule of Ly-49 expression does not explain the coexpression of selected activating and inhibitory receptors. This high level of coexpression of H-2Dd recognizing activating and inhibitory Ly- 49s suggests an in vivo selection or regulated coexpression.
Expression of mammalian defensin genes
Authors: Kaiser Vicki , Diamond Gill
Published: September 2022

Antimicrobial peptides are a prevalent mechanism of host defense found throughout nature. In mammals, defensins are among the most abundant of these broad-spectrum antibiotics, and are expressed in epithelial and hematopoietic cells. The defensin peptides are especially abundant in neutrophils; however, gene expression is limited to the promyelocyte stage. In epithelial cells, defensin genes are found as both constitutively expressed and inducible. Induction has been observedin vitro by stimulation with bacterial lipopolysaccharide as well as inflammatory mediators. In vivo, up-regulation of several defensin genes occurs in both infectious and inflammatory states. Gene regulation occurs via signal transduction pathways common to other innate immune responses, utilizing transcription factors such as nuclear factor (NF)-κB and NF interleukin-6. Together, the data suggest a broad-based innate host defense whereby potent antimicrobial peptides are present to prevent initial colonization by pathogenic microorganisms. In addition, the recognition of bacteria coupled with a nascent inflammatory response can bolster this defense by a coordinated up-regulation of the peptides.
Expression of α4β7 and E-selectin ligand by circulating memory B cells: implications for targeted trafficking to mucosal and systemic sites
Authors: Rott Lusijah S , Briskin Michael J , Butcher Eugene C
Published: September 2022

We have examined the expression of homing receptors on circulating memory B cells subsets. Blood IgD+ (naive) B cells homogeneously express a high level of intestinal homing receptor, α4β7, but IgD− (putative memory) B cells comprise distinct α4β7+ and α4β7− subsets. Naive and α4β7+ memory B cells but not α4β7− cells bind MAdCAM-1, suggesting that α4β7 expression may predict B cell intestinal homing. In contrast, α4β7+ and α4β7− B cells bind well to VCAM-1, possibly allowing recruitment of both subsets to extra-intestinal sites, including those tissues of the “common mucosal immune system” characterized by vascular VCAM-1 expression. sIgA+ B cells, which are associated with mucosal immunity in the gut and elsewhere, are heterogeneous in homing receptor expression—with discrete subsets expressing α4β7, L-selectin, and cutaneous lymphocyte antigen (CLA). sIgA+ CLA+ B cells are enriched by binding to E-selectin, suggesting that CLA may participate in B cell homing to nonintestinal mucosal tissues characterized by vascular E-selectin expression, such as chronically inflamed bronchial or oral mucosal. We conclude that circulating human peripheral blood memory B cells, like T cells, consist of discrete homing receptor-defined subsets. This diversity in homing phenotypes is apparent even among sIgA (presumptive mucosal) memory B cells, implying heterogeneity in trafficking mechanisms to different target mucosal surfaces.
Regulatory effects of fever-range whole-body hyperthermia on the LPS-induced acute inflammatory response
Authors: Ostberg Julie R , Taylor Shannon L , Baumann Heinz , Repasky Elizabeth A
Published: September 2022

The thermal component of fever is one of the most poorly understood aspects of inflammation. To evaluate the role of fever-range hyperthermia on acute inflammation, BALB/c and C57BL/6 mice were exposed to mild, long-duration whole-body hyperthermia (WBH), and serum concentrations of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), IL-1β, and the acute phase proteins (APPs) α1-acid glycoprotein and haptoglobin were analyzed. WBH alone did not affect serum concentrations of these cytokines or APPs when compared with controls. In contrast, when WBH was applied just after intraperitoneal administration of lipopolysaccharide (LPS), serum concentrations of TNF-α and IL-6 were greater than or equal to threefold higher in BALB/c mice compared with LPS-treated controls. LPS-induced IL-6 levels were also enhanced in WBH-treated C57BL/6 mice. However, APP levels were prolonged only in WBH-treated BALB/c mice. It is interesting thatin vitro hyperthermia treatment of LPS-stimulated peritoneal cells resulted in decreased cytokine production compared with controls. These results suggest that fever-range hyperthermia regulates acute inflammation in a mouse strain-specific manner that is more complex than that observed in vitro.
Neutrophil migration stimulates rat intestinal epithelial cell cytokine expression during helminth infection
Authors: Stadnyk Andrew W , Dollard Cheryl D , Issekutz Andrew C
Published: September 2022

We are interested in understanding the role of epithelial cells during inflammation, and we previously reported that rat small intestinal epithelial cells express interleukin-1β (IL-1β) during infection byTrichinella spiralis. We now report that the epithelium also produces the potent neutrophil chemotactic factor, macrophage inflammatory protein-2 (MIP-2), and an IL-1 antagonist: the type II IL-1 receptor. Consequently we investigated the pattern of neutrophil infiltration into the infected intestine, which closely paralleled the epithelial cytokine expression. Speculating that neutrophil infiltration may provoke epithelial cytokine expression, neutrophil migration into the infected gut was reduced by depleting circulating cells through the use of a specific antibody, or by preventing migration through the use of a function-blocking anti-CD18 monoclonal antibody. Either treatment reduced the number of neutrophils recoverable from the small intestinal epithelium and was paralleled by reduced mRNA levels for epithelial cytokines. These results demonstrate that neutrophil infiltration of the small intestinal epithelium contributes to the stimulation of epithelial cell cytokines.
Human lymphocytes stimulate prostacyclin synthesis in human umbilical vein endothelial cells. Involvement of endothelial cPLA2
Authors: Merhi-Soussi Faten , Dominguez Zury , Macovschi Olga , Dubois Madeleine , Savany Alain , Lagarde Michel , Prigent Annie-France
Published: September 2022

Prostacyclin (PGI2) contributes to the maintenance of a nonadhesive luminal surface in blood vessels due to its anti-platelet and vasodilatory properties. Here, we sought to determine whether peripheral blood lymphocytes (PBL) may regulate the PGI2 production of human umbilical vein endothelial cells (HUVEC). Cell-cell contact between HUVEC and lymphocytes markedly enhanced PGI2 synthesis as a function of the number of lymphocytes added. This stimulated synthesis was totally suppressed when lymphocytes and HUVEC were separated by a microporous insert. It was not due to prostaglandin H synthase up-regulation. The pretreatment of lymphocytes with the PGI2 synthase inhibitor tranylcypromine partially inhibited PGI2 synthesis (47%), suggesting a transcellular metabolism of the endothelial prostaglandin endoperoxide PGH2 by the lymphocyte PGI2 synthase. Experiments using [14C]arachidonate-labeled lymphocytes coincubated with unlabeled HUVEC, and [14C]arachidonate-labeled HUVEC coincubated with unlabeled lymphocytes showed that the arachidonic acid used for PGI2 synthesis was totally of endothelial origin. Furthermore, the PGI2 synthesis was strongly inhibited by the cytosolic phospholipase A2 inhibitor, MAFP and totally suppressed by the combination of the calcium chelators, BAPTA and EGTA. Collectively, these results suggest that lymphocytes trigger an outside-in signaling in endothelial cells involving cPLA2 activation. Overall, the switch-on for PGI2 synthesis induced by lymphocytes might serve as a protection against atherothrombogenesis.
Mechanisms mediating the effects of IL-3 gene expression on tumor growth
Authors: Wu Yuan-Zhau , Hong Ji-Hong , Huang Hsin-Hong , Dougherty Graeme J , McBride William H , Chiang Chi-Shiun
Published: September 2022

IL-3 gene expression within tumors leads to host-cell infiltration, particularly by macrophages, slower tumor growth, and enhanced immunogenicity. Surprisingly, tumor-associated macrophages (TAMs) from within FSAN-JmIL3 tumors had decreased expression of TNF-α and iNOS. On short-term culture, TAMs from FSAN-JmIL3 tumors regained their capacity to produce TNF-α and NO, indicating that they were primedin vivo. In vitro experiments were unable to demonstrate differences between FSAN-JmIL3 and FSAN tumor cells in their ability to stimulate TNF-α production by TAMs. In the absence of evidence that TAM activation was responsible for the slower growth of FSAN-JmIL3 tumors, the response of tumor cells to these effector molecules was studied. TNF-α and NO were cytotoxic for FSAN-JmIL3 cells but growth stimulatory for FSAN. These tumor-related phenotypic changes may contribute as much if not more than functional changes in host infiltrating cells to the slower growth of FSAN-JmIL3 tumorsin vivo.
Differential chemokine response of human monocytes to yeast and hyphal forms ofCandida albicansand its relation to the β-1,6 glucan of the fungal cell wall
Authors: Torosantucci Antonella , Chiani Paola , Cassone Antonio
Published: September 2022

Hyphae formation from yeast cells is a virulence trait enabling the human opportunistic pathogen Candida albicans to invade host tissues. Hyphal cells proved to be much less efficient than yeast cells in stimulating production of macrophage inflammatory protein-1α (MIP-1α), MIP-1β, interleukin-8 (IL-8), and particularly, monocyte chemotactic protein-1 (MCP-1) by human monocyte. This different stimulation did not depend on the monocyte inability to ingest the hyphae nor did it imply hyphal resistance to the extracellular killing by the monocytes. Purified hyphal and yeast cell walls reproduced the differences shown by the intact cells, and chemical-enzymatic dissection of cell wall components suggested that cell wall β-1,6 rather than β-1,3 glucan was the main chemokine inducer. Coherently, immunofluorescence studies with an anti β-1,6 glucan serum showed that the surface expression of this polysaccharide was much lower on hyphae than on yeast cells. By minimizing chemokine induction, the formation of hyphal filaments might facilitate C. albicans escaping from host immunity.
Pivotal role of 5-lipoxygenase in the activation of human eosinophils: platelet-activating factor and interleukin-5 induce CD69 on eosinophils through the 5-lipoxygenase pathway
Authors: Urasaki Tetsuya , Takasaki Jun , Nagasawa Toshiro , Ninomiya Haruhiko
Published: September 2022

CD69 is an activation-related cell surface molecule on human eosinophils. It has been reported that interleukin (IL)-5, but not platelet-activating factor (PAF), can induce CD69 on human eosinophils in vitro. In this study, PAF induced CD69 intensely on eosinophils from patients with hypereosinophilic syndrome (HES), while only weakly on those from normal donors. Because HES eosinophils contain abundant cytosolic phospholipase A2 (cPLA2) and 5-lipoxygenase (5-LO), we examined the roles of several enzymes involved in the metabolism of arachidonic acid in the PAF- or IL-5-induced CD69 expression on eosinophils. The CD69 expression induced by PAF and IL-5 on HES eosinophils and that by IL-5 on normal eosinophils were both inhibited by AA861 and MK-886, inhibitors of 5-LO activity. In addition, AACOCF3, a selective cPLA2 inhibitor, inhibited IL-5-induced CD69 expression on normal eosinophils, although it hardly affected either IL-5- or PAF-induced CD69 expression on HES eosinophils. Moreover, PAF alone induced CD69 only weakly on normal eosinophils, but exogenous arachidonic acid remarkably enhanced PAF-induced CD69 expression on them. These findings suggest that IL-5 activates both cPLA2 and 5-LO but PAF activates only 5-LO. It is suggested that 5-LO plays a critical role in the induction of CD69 on eosinophils.
Interleukin-12 can replace CD28-dependent T-cell costimulation during nonspecific cytotoxic T lymphocyte induction by anti-CD3 antibody
Authors: Makrigiannis Andrew P , Musgrave Bruce L , Haeryfar S M Mansour , Hoskin David W
Published: September 2022

Cytotoxic T lymphocyte (CTL) development is regulated closely by an intricate series of signals provided by the T-cell receptor/CD3 complex, cytokines, and costimulatory ligand/receptor systems. In this study, we have explored the role of interleukin (IL)-12 and CD28 in mouse CTL development. Activation of T cells with anti-CD3 monoclonal antibody (mAb) in the presence of anti-CD86 mAb, which prevents CD28-CD86 interaction, led to decreased production of type 1 (IL-2, interferon-γ) and type 2 (IL-4, IL-6, IL-10) cytokines, as well as diminished expression of granzyme B (Gzm B) and reduced cytotoxic effector function. Cytolytic activity in T-cell cultures that were activated in the presence of anti-CD86-blocking mAb alone or in combination with anti-CD80 mAb could be restored by the addition of exogenous IL-12 at initiation of culture. The ability of IL-12 to substitute for CD28-costimulatory signaling during CTL development was found to be dependent on the presence of IL-2 rather than interferon-γ. IL-2 is required for IL-12Rβ2 expression by T cells activated in the presence of anti-CD86 mAb. Moreover, IL-12Rβ2 expression by T cells activated in the presence of anti-CD86 mAb is enhanced by IL-12. We, therefore, conclude that the ability of IL-12 to substitute for CD28-costimulatory signaling during CTL development is a result of the interaction of IL-12 with IL-12Rβ2 induced by low levels of IL-2 synthesized by T cells activated in a CD28-independent manner.
Role of mast cells in zymosan-induced peritoneal inflammation in Balb/c and mast cell-deficient WBB6F1 mice
Authors: Kolaczkowska Elzbieta , Seljelid Rolf , Plytycz Barbara
Published: September 2022

Zymosan-induced peritonitis was investigated in mast cell-deficient WBB6F1 mice and in Balb/c mice pretreated with mast cell stabilizer (cromolyn) or antagonists of histamine receptors (mepyramine, triprolidine, cimetidine, or ranitidine). The inherited mast cell deficiency in W/Wv knockouts of WBB6F1 mice impaired significantly the level of histamine and plasma exudation (measured 30 min after stimulation) as well as the influx of exudatory leukocytes, accumulation of plasma and exudate chemoattractants, and the release of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) measured at 6 h of inflammation. All of those factors were fully restored after selective intraperitoneal reconstitution of W/Wv mice with bone marrow-derived mast cells from their control +/+ counterparts. Cromolyn pretreatment of Balb/c mice reduced exclusively the early plasma exudation and histamine influx. Blocking of histamine receptors inhibited not only the early plasma exudation but also temporarily diminished primary leukocyte influx and levels of MCP-1 and IL-1β. In conclusion, mast cells play an important role in the initiation of zymosan-induced peritonitis and modulate its further course.
Neutrophil secretory vesicles are the intracellular reservoir for GPI-80, a protein with adhesion-regulating potential
Authors: Dahlgren Claes , Karlsson Anna , Sendo Fujiro
Published: September 2022

The subcellular localization of GPI-80, a novel, adhesion-regulating protein, was investigated in human neutrophils. Surface expression of GPI-80 was determined by FACS analysis as well as by the ability for phospholipase C to cleave the protein from the cell surface. Increasing amounts of GPI-80 were exposed on the cell surface after weak stimulation with the chemoattractant fMLF, suggesting that the protein can be translocated to the plasma membrane from intracellular stores. By subcellular fractionation of the neutrophils, GPI-80 was defined as a component of a light membrane fraction, containing secretory vesicles and plasma membranes, and it was absent from the neutrophil granule fractions. Separation of the plasma membranes from the secretory vesicles by flotation gradient fractionation confirmed that the GPI-80 was localized in the mobilizable secretory vesicles by approximately 50%, and the rest was plasma membrane-bound. Thus, we identify secretory vesicles as the reservoir of GPI-80 from which it may translocate to the plasma membrane after weak stimulation of the cells.
Chronic granulomatous disease: more than the lack of superoxide?
Authors: Geiszt Miklós , Kapus András , Ligeti Erzsébet
Published: September 2022

Chronic granulomatous disease (CGD) is an inherited disease characterized by severe and recurrent bacterial and fungal infections manifested in most cases in early childhood. Phagocytic cells of CGD patients are unable to produce superoxide anions, and their efficiency in bacterial killing is significantly impaired. Recent work has shown alterations in the electrophysiological properties of CGD granulocytes, which might contribute to the pathogenesis of the disease. The new aspects that we discuss in this review concern the proton channel function of gp91phox (the electron-transporting subunit of the NADPH oxidase) and the electrogenic activity of the active enzyme complex, which can affect the transmembrane trafficking of several ions. Based on the reviewed data, we also propose a hypothesis that the absence of a functional NADPH oxidase in CGD neutrophils could result in altered ion compositions within intracellular and intraphagosomal spaces during the process of phagocytosis.
Activation-induced expression of CD1d antigen on mature T cells
Authors: del C. Salamone María , Rabinovich Gabriel A , Mendiguren Ana K , Salamone Gabriela V , Fainboim Leonardo
Published: September 2022

In the present study, we investigated the expression of human CD1d antigen on activated mature T cells. Expression of this glycoprotein was found to be highly regulated and dependent on PHA stimulation. Flow cytometry studies using the NOR3.2 antibody, which recognized CD1d under denaturing conditions, showed a clear increase in its expression after PHA stimulation. Expression of this molecule after PHA activation was confirmed by analysis of its corresponding transcript by RT-PCR. A single band representing mRNA for CD1d membrane isoform was observed in activated PBMC as well as in ER3 CD1D-transfected and MOLT-4, pre-T cell lines, which were used as controls. Western blot analysis revealed an activation-dependent increase in CD1d protein expression when PBMC and enriched T cells were activated for different time periods. Activation-dependent expression of CD1d antigen was also confirmed in allogenic-activated T cells, suggesting that this event could have biological significance. Finally, immunocytochemical studies showed the presence of this protein at the plasma membrane accompanied by a cytoplasmic and perinuclear distribution. Results presented herein provide the first experimental evidence showing that CD1d antigen is present on circulating, activated T lymphocytes, suggesting that its expression is dependent on the activation state of the cells. Elucidation of the molecular mechanisms implicated in the activation-dependent expression of this nonclassical antigen will provide new insights into the understanding of antigen presentation and immune regulation.
Differential effects of anti-FcγRIIIb autoantibodies on polymorphonuclear neutrophil apoptosis and function
Authors: Durand Véronique , Pers Jacques-Olivier , Renaudineau Yves , Saraux Alain , Youinou Pierre , Jamin Christophe
Published: September 2022

Anti-Fcγ receptor IIIb (FcγRIIIb) human autoantibodies (Ab) have been classified previously into three groups, based on the results of an indirect immunofluorescence (IIF) test and an enzyme-linked immunosorbent assay (ELISA): IIF+/ELISA+ (group A), IIF+/ELISA− (group B), and IIF−/ELISA+ (group C) sera. In this study, differential effects between IIF+ autoAb, recognizing cell-bound FcγR, and those ELISA+, recognizing only cell-free FcγR, were studied on polymorphonuclear neutrophils (PMN). Neither group A nor B autoAb was cytotoxic, although both prolonged the survival of PMN by delaying spontaneous apoptosis. By the same extent, the PMN-binding antisera stimulated the appearance of a CD11bdim population, following a 12-h incubation. This event was associated with a lowered expression of β2 integrin molecules, resulting in altered PMN function. Treatment with groups A and B autoAb reduced adhesiveness and respiratory burst. This impairment of the responses was more pronounced when the cells originated from donors NA1+NA1+ rather than donors NA2+NA2+. From our observations, the influences of anti-FcγRIIIb autoAb on PMN survival, as well as function and subsequent dysregulation of the inflammatory response, have proven somewhat dependent on their target antigens, as determined by IIF coupled with ELISA and FcγRIIIb polymorphism.
CpG-containing oligodeoxynucleotides induce TNF-α and IL-6 production but not degranulation from murine bone marrow-derived mast cells
Authors: Zhu Fu-Gang , Marshall Jean S
Published: September 2022

Mast cells are sentinel cells critical to the initiation of innate immune and inflammatory responses, particularly at mucosal surfaces. To fulfill this function they can be activated by several pathogen-associated stimuli to produce cytokines with or without concurrent degranulation. We examined the ability of immunostimulatory DNA sequences including CpG motifs, which are found in increased quantities in bacterial DNA, to activate mouse bone marrow-derived mast cells (mBMMC). Mast cells were treated with a range of doses of CpG-containing oligodeoxynucleotides or control oligodeoxynucleotides without CpG within their sequence. There was a dose-dependent increase in the production of both interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) by mast cells treated with the CpG-containing oligodeoxynucleotides. The cytokine levels induced were directly related to the number of CpG within a given length of sequence. Treatment with oligonucleotides containing 3CpG induced an eightfold increase in TNF production over control incubated mast cells. Other cytokines, including granulocyte-macrophage colony-stimulating factor, IL-4, interferon-γ, and IL-12 were not induced by oligonucleotide treatment. Neither CpG containing oligodeoxynucleotides nor control oligodeoxynucleotides induced degranulation of mast cells. Bacterial DNA from Escherichia coli also induced IL-6 from mBMMC but neither calf thymus DNA nor methylase-treated E. coli DNA had such an effect. Examination of the uptake of Texas red-labeled CpG and non-CpG-containing oligodeoxynucleotides revealed that they were both similarly taken up by the mBMMC. These results have important implications for the mechanism by which mast cells respond to bacteria and for the potential role of mast cells in DNA vaccination.
Regulation of hematopoiesis through adhesion receptors
Authors: Prosper Felipe , Verfaillie Catherine M
Published: September 2022

Normal steady-state hematopoiesis takes place in the bone marrow microenvironment. Soluble factors as well as contact interactions between the hematopoietic cells and the marrow microenvironment dictate the fate of hematopoietic stem cells and progenitors. Over the last decade it has become clear that cell-cell and cell-extracellular matrix interactions through adhesion receptors play a major role in the hematopoietic process. They are required for the residence of stem cells and progenitors in the marrow, as well as for homing of stem and progenitor cells to the marrow in the setting of stem cell transplantation. Furthermore, adhesion receptors play an important role in regulation of cell behavior, either through direct activation of signal pathways important for cell survival, cell growth, and cell fate decision-making processes, or by modulating responses to growth factors. Insights in the abnormalities seen in these interactions in diseases of the hematopoietic system will help to develop better therapeutic strategies based on the pathogenesis of these diseases.
Lymphoid neogenesis:de novoformation of lymphoid tissue in chronic inflammation through expression of homing chemokines
Authors: Hjelmström Peter
Published: September 2022

Chronic inflammation is a complex pathophysiological process with accumulation of mononuclear cells seen in response to invading pathogens, neoplastic transformation, or autoimmune recognition of self-antigens. The inflammatory process has evolved to facilitate effective elimination of pathogens and tumors and it is normally transient and turned off when the causative stimulus has been eliminated. Occasionally, however, the process is sustained for a long time and can lead to severe tissue damage. This is seen in organ-specific autoimmune diseases such as rheumatoid arthritis, Sjögren's syndrome, and Hashimoto's thyroiditis, but also in infectious diseases such as Helicobacter pylori-induced gastritis. Disturbingly, many of these chronic inflammatory diseases are associated with an increased risk for neoplastic transformation and development of lymphomas. This review summarizes experimental evidence suggesting that chronic inflammation involves ectopic de novo formation of organized lymphoid tissue and that this lymphoid neogenesis is regulated by expression of homing chemokines.
DNA damage and apoptosis in mononuclear cells from glucose-6-phosphate dehydrogenase-deficient patients (G6PD Aachen variant) after UV irradiation
Authors: Efferth Thomas , Fabry Ursula , Osieka Rainhardt
Published: September 2022

Patients affected with X chromosome-linked, hereditary glucose-6-phosphate dehydrogenase (G6PD) deficiency suffer from life-threatening hemolytic crises after intake of certain drugs or foods. G6PD deficiency is associated with low levels of reduced glutathione. We analyzed mononuclear white blood cells (MNC) of three males suffering from the German G6PD Aachen variant, four heterozygote females of this family, one G6PD-deficient male from another family coming from Iran, and six healthy male volunteers with respect to their DNA damage in two different genes (G6PD and T-cell receptor-δ) and their propensity to enter apoptosis after UV illumination (0.08–5.28 J/cm2). As determined by PCR stop assays, there was more UV-induced DNA damage in MNC of G6PD-deficient male patients than in those of healthy subjects. MNC of G6PD-deficient patients showed a higher rate of apoptosis after UV irradiation than MNC of healthy donors. MNC of heterozygote females showed intermediate rates of DNA damage and apoptosis. It is concluded that increased DNA damage may be a result of deficient detoxification of reactive oxygen species by glutathione and may ultimately account for the higher rate of apoptosis in G6PD-deficient MNC.
Importance of CD44v7 isoforms for homing and seeding of hematopoietic progenitor cells
Authors: Christ Oliver , Günthert Ursula , Haas Rainer , Zöller Margot
Published: September 2022

The adhesion molecule CD44 consists of many isoforms of which particularly CD44v7 is of major importance in hematopoietic progenitor cell homing. An increase of progenitor cells in the periphery was observed after treating mice with a CD44v7-specific antibody, concomitant with a substantially augmented marrow-repopulating ability (MRA). Because CD44v7 is expressed on a fraction of bone marrow cells (BMC) as well as on long-term bone marrow culture-derived stromal cells, we aimed to differentiate between the functional relevance of CD44v7 on either cell type by transferring CD44v7+/+ BMC into CD44v7-/- mice and vice versa. CD44v7+/+ BMC homed poorly in the bone marrow of CD44v7-/- mice and their MRA was severely impaired. CD44v7-/- BMC, instead, exhibited an improved MRA when transferred into the CD44v7+/+ host, although their MRA remained below that of CD44v7+/+ BMC. Thus, it is predominantly, but not exclusively, expression of CD44v7 on stromal cells which supports progenitor cell homing.
MHCII,Tlr4andNramp1genes control host pulmonary resistance against the opportunistic bacteriumPasteurella pneumotropica
Authors: Chapes Stephen K , Mosier Derek A , Wright Albion D , Hart Marcia L
Published: September 2022

MHCII, Tlr4, and Nramp1 genes are each independently important in pulmonary immunity. To determine the effect of these genes on host resistance, mice carrying various combinations of functional alleles for these three genes were experimentally challenged with the opportunistic bacterium, Pasteurella pneumotropica. MHCII-/-,Tlr4d/d, and Nramp1s/s mice were significantly more susceptible to experimental infections byP. pneumotropica after intranasal challenge compared to mice carrying functional alleles at only one of those genes. P. pneumotropica were cultured from the lungs of challenged mice, and the severity of the pneumonia strongly correlated with the number of isolated bacteria. Mice with the genotype MHCII-/-Tlr4n/n genotype were less susceptible to pneumonia than MHCII+/+, Tlr4d/d mice. It is interesting that the Nramp1 gene contribution to host resistance was apparent only in the absence of functional MHCII or Tlr4 genes. These data suggest that MHCII,Tlr4, and Nramp1 genes are important to pulmonary bacterial resistance.
A p74 common gamma receptor chain isoform facilitates IL-2 and IL-15 responses by the myelomonocytic cell line Tf-1β2
Authors: Monson Nancy L , Fenske Timothy J , Wei Shyng , Okragly Angela J , de Jong Jill L O , Haak-Frendscho Mary , O'Shea John , Djeu Julie , Sondel Paul M
Published: September 2022

Functional forms of the IL-2, IL-4, IL-7, IL-9, and IL-15 receptors require the γc receptor component. We have described previously a myeloid cell line called Tf-1β, which binds IL-2 with intermediate-affinity and proliferates in response to IL-2. In this study, we characterize γc expression on Tf-1β2 cells, a derivative of Tf-1β cells stimulated exclusively with IL-2. Although Tf-1β2 cells bind IL-2 with intermediate-affinity and proliferate in response to IL-2, this cell line does not express the p64 γc chain at the protein level. This result was surprising because prior studies suggest these cells should not be expected to proliferate in response to IL-2 or IL-15 in the absence of the p64 γc chain. A p74 protein was detected by western blot following immunoprecipitation with an anti-γc polyclonal antibody, and a p74 protein was identified consistently in complex with IL-2 and IL-15 on these cells. However, the γc gene in these Tf-1β2 cells shows no evidence of mutation by sequence analysis. Furthermore, inhibition of glycosylation of these Tf-1β2 cells by tunicamycin treatment yields a standard 39-kDa molecule recognized on western blot with anti-γc antibody, as seen for the standard 64-kDa isoform of γc. These results demonstrate that a 74-kDa γc receptor isoform was involved in the response of the Tf-1β2 cells to cytokines which normally interact with the 64-kDa γc chain.
SJL and NOD macrophages are uniquely characterized by genetically programmed, elevated expression of the IL-12(p40) gene, suggesting a conserved pathway for the induction of organ-specific autoimmunity
Authors: Alleva David G , Johnson Eric B , Wilson Jerry , Beller David I , Conlon Paul J
Published: September 2022

Genetic susceptibility of the SJL mouse to experimental autoimmune encephalomyelitis (EAE) appears, in part, to be a result of genes that promote abnormal development of the pathogenic Type 1 (Th1) phenotype of neuroantigen-specific T-cells. Because antigen-presenting/accessory cells (APCs) produce cytokines that can modulate the development of Th1 and Th2 phenotypes, we addressed whether APCs from SJL mice were genetically programmed for elevated expression of the Th1-promoting cytokine, IL-12. Activated peritoneal macrophages (Mφ; i.e., APC) from naïve SJL mice produced levels of TNF-α, IL-1, IL-6, IL-10, and TGF-β within the range of six normal strains. In contrast, SJL IL-12p40 (in addition to IL-12p70) production was consistently five- to 20-fold greater than that of any normal strain tested, which arose from elevated expression of the IL-12p40 but not the IL-12p35 gene, because p40 mRNA levels were eight- to 15-fold greater than those of normal strains. This aberrancy in IL-12p40 expression appears identical to that observed in the NOD mouse, another strain prone to organ-specific autoimmunity. A genetically programmed bias toward elevated expression of IL-12 in Mφ from the SJL and NOD strains of autoimmunity provides a conserved mechanism for the dominant Th1 development of naïve, autoantigen-specific T-cells in these strains. This study is the first demonstration of a genetically programmed aberrant phenotype that is intrinsically expressed within a cell type in the SJL mouse and provides insight into its predisposition for EAE.
Differential expression of Toll-like receptor 2 in human cells
Authors: Flo Trude H , Halaas Øyvind , Torp Sverre , Ryan Liv , Lien Egil , Dybdahl Brit , Sundan Anders , Espevik Terje
Published: September 2022

Human Toll-like receptor 2 (TLR2) is a receptor for a variety of microbial products and mediates activation signals in cells of the innate immune system. We have investigated expression and regulation of the TLR2 protein in human blood cells and tissues by using two anti-TLR2 mAbs. Only myelomonocytic cell lines expressed surface TLR2. In tonsils, lymph nodes, and appendices, activated B-cells in germinal centers expressed TLR2. In human blood, CD14+ monocytes expressed the highest level of TLR2 followed by CD15+ granulocytes, and CD19+ B-cells, CD3+ T-cells, and CD56+ NK cells did not express TLR2. The level of TLR2 on monocytes was after 20 h up-regulated by LPS, GM-CSF, IL-1, and IL-10 and down-regulated by IL-4, IFN-γ, and TNF. On purified granulocytes, LPS, GM-CSF, and TNF down-regulated, and IL-10 modestly increased TLR2 expression after 2 h. These data suggest that TLR2 protein expression in innate immune cells is differentially regulated by inflammatory mediators.
Inhibition of FasL sustains phagocytic cells and delays myogenesis in regenerating muscle fibers
Authors: Sandri Marco , Sandri Claudia , Brun Barbara , Giurisato Emanuele , Cantini Marcello , Rossini Katia , Destro Chiara , Arslan Paola , Carraro Ugo
Published: September 2022

Macrophage-muscle cell interactions are complex, and the majority is unknown. The persistence of inflammatory cells in skeletal muscle could be critical for myofiber viability. In the present paper, we show that FasL plays a role in the resolution of muscle inflammation. We analyzed inflamed muscles of normal mice treated from day 3 to day 8 with a FasL inhibitor (Fas-Ig) or with control Ig. Treated muscles were collected at 3, 5, and 10 days. The treatment with recombinant Fas-Ig protein induced a severe persistence of inflammatory cells at 5 days (115,000±27,838 vs. 41,661±6848, p<0.01) and 10 days from injury (145,500±40,850 vs. 5000±1000, p<0.001). Myofiber regeneration was highly impaired (37±14 vs. 252±28, p<0.01). Apoptosis of phagocytic cells was absent during Fas-Ig treatment (0.9±0.6 vs. 1300±150,p<0.0001), but apoptotic, mononucleated cells appeared at day 10, 2 days after the suspension of Fas-Ig administration. The time course of FasL expression during muscle inflammation, at mRNA and protein level, reveals a peak during myoblast proliferation. The peak of FasL expression coincides with the peak of apoptosis of phagocytic cells. In situ hybridization shows the co-expression of FasL and MyoD mRNA in mononucleated cells, i.e., myoblasts. Experiments on the myoblast cell culture confirmed the expression of FasL in myoblasts. The findings shown here indicate one of the pathways to control myoblast-macrophage interaction and might be relevant for the control of inflammatory cells in muscle tissue. Perhaps altering FasL expression with recombinant proteins could ameliorate inflammation in degenerative myopathies and up-regulate muscle regeneration.
Chemokines in cutaneous wound healing
Authors: Gillitzer Reinhard , Goebeler Matthias
Published: September 2022

Healing of wounds is one of the most complex biological events afterbirth as a result of the interplay of different tissue structures and alarge number of resident and infiltrating cell types. The latter aremainly constituted by leukocyte subsets (neutrophils, macrophages, mastcells, and lymphocytes), which sequentially infiltrate the wound siteand serve as immunological effector cells but also as sources ofinflammatory and growth-promoting cytokines. Recent data demonstratethat recruitment of leukocyte subtypes is tightly regulated bychemokines. Moreover, the presence of chemokine receptors on residentcells (e.g., keratinocytes, endothelial cells) indicates thatchemokines also contribute to the regulation of epithelialization,tissue remodeling, and angiogenesis. Thus, chemokines are in anexclusive position to integrate inflammatory events and reparativeprocesses and are important modulators of human-skin wound healing.This review will focus preferentially on the role of chemokines duringskin wound healing and intends to provide an update on the multiplefunctions of individual chemokines during the phases of woundrepair.
NK cell-mediated anti-tumor immune response to human prostate cancer cell, PC-3: immunogene therapy using a highly secretable form of interleukin-15 gene transfer
Authors: Suzuki Kazuhiro , Nakazato Haruki , Matsui Hiroshi , Hasumi Masaru , Shibata Yasuhiro , Ito Kazuto , Fukabori Yoshitatsu , Kurokawa Kohei , Yamanaka Hidetoshi
Published: September 2022

Interleukin (IL)-15 is a pleiotropic cytokine that is important forinnate and adaptive immune cell homeostasis. The expression of IL-15protein is controlled by posttranscriptional mechanisms. Here, weconstructed a human IL-15 expression vector consisting of the humanIL-2 signal peptide, the human IL-15 mature peptide-coding sequences,and an out-of-frame human growth hormone gene. Human prostate cancercells, PC-3, transfected with this highly secretable form of the IL-15gene, successfully secreted abundant bioactive IL-15 protein. In nudemice, the growth of PC-3 cells producing IL-15 was remarkably retarded.NK cell-depletion using anti-asialo GM1 antibody restoredtumorigenicity. Histologically, tumors derived from IL-15-producingPC-3 cells contained necrotic areas with high apoptotic index.Splenocytes incubated with supernatant of transfectants killed targetPC-3 cells and expressed a significantly high level of mIFN-γ mRNA.These observations suggest that NK cell-mediated, anti-tumor effects ofIL-15 could provide a potential rationale for gene therapy of prostatecancer.
Ovalbumin aerosols induce airway hyperreactivity in naïve DO11.10 T cell receptor transgenic mice without pulmonary eosinophilia or OVA-specific antibody
Authors: Wilder Julie A , Collie David S , Bice David E , Tesfaigzi Yohannes , Lyons C Richard , Lipscomb Mary F
Published: September 2022

The pathobiology of allergic asthma is being studied using murine models, most of which use systemic priming followed by pulmonary challenges with the immunizing antigen. In general, mice develop eosinophilic pulmonary inflammation, increased antigen-specific immunoglobulins, and airway hyperreactivity (AHR), all of which are dependent on antigen-specific T cell activation. To establish a model of allergic asthma, which did not require systemic priming, we exposed DO11.10 T cell receptor transgenic mice, which have an expanded repertoire of ovalbumin (OVA), peptide-specific T cells, to limited aerosols of OVA protein. DO11.10 +/− mice developed AHR in the absence of increases in total serum IgE, OVA-specific IgG, or eosinophilia. The AHR was accompanied by pulmonary recruitment of antigen-specific T cells with decreased expression of CD62L and CD45RB and increased expression of CD69, a phenotype indicative of T cell activation. Our results support recent hypotheses that T cells mediate AHR directly.
UVB-irradiated dendritic cells are impaired in their APC function and tolerize primed Th1 cells but not naive CD4+ T cells
Authors: Denfeld Ralf W , Hara Hisamichi , Tesmann Jens P , Martin Stefan , Simon Jan C
Published: September 2022

We have shown that low-dose UVB radiation converts Langerhans cells(LC) from immunogenic to tolerogenic APC. Therefore, we questionedwhether low-dose UVB irradiation of bone marrow-derived dendritic cells(DC) alters their APC function, thereby inducing tolerance in T cells.To address this issue, cocultures of DC; and naïve, allogeneicT cells; naïve, OVA-specific TCR-transgenic T cells fromDO11.10 mice; or primed, antigen-specific T cells using the Th1 cloneAE7 were analyzed. First, we found low-dose UVB-irradiated DC(UVB-DC) to dose-dependently (50–200 J/m2) inhibit T-cellproliferation of naive and primed T cells. In addition, supernatantsharvested from cocultures of UVB-DC and naive T cells showed markedlyreduced levels of IL-2 and IFN-γ and to a lesser degree of IL-4 andIL-10, suggesting a preferential down-regulation of Th1 responses byUVB-DC. FACS analysis of UVB-DC revealed no changes in surfaceexpression of MHC, costimulatory, and adhesion molecules. To testtolerance induction, allo- or antigen-specific T cells isolated fromcocultures with unirradiated DC and UVB-DC were restimulated withunirradiated DC or IL-2. It is interesting that UVB-DC inducedantigen-specific tolerance in the Th1 clone AE7. In contrast, UVB-DCinduced a partial inhibition of allogeneic T-cell proliferation but notolerance with similar unresponsiveness to restimulation with IL-2 andunirradiated DC irrespective of their haplotype. Similar observationswere made when naïve, TCR-transgenic T cells from DO11.10 micewere used. In conclusion, UVB-DC are impaired in their APC function andtolerize the primed antigen-specific Th1 clone AE7 but not naive allo-or OVA-specific T cells.
Expression and function of galectin-3, a β-galactoside-binding protein in activated T lymphocytes
Authors: Joo Hong-Gu , Goedegebuure Peter S , Sadanaga Noriaki , Nagoshi Makoto , von Bernstorff Wolfram , Eberlein Timothy J
Published: September 2022

A soluble beta-galactoside-binding lectin, galectin-3 has been shown tobe involved in cell adhesion and activation of immune cells. Althoughgalectin-3 is known to be expressed in various types of cells, it hasnot been shown whether galectin-3 is expressed in T lymphocytes. Wepresent evidence here that galectin-3 is expressed in activated murineT lymphocytes including CD4+ and CD8+ T cellsbut not in resting T cells. Galectin-3 expression was induced byanti-CD3 mAb or mitogen and enhanced by common γ-chain signalingcytokines, IL-2, IL-4, and IL-7, in activated T lymphocytes, whereasthe inflammatory cytokines including TNF-α and IFN-γ did not.Galectin-3 expression and proliferation were down-regulated bywithdrawal of IL-2 and gamma irradiation. Anti-sense but not sensephosphorothioated oligonucleotides for galectin-3 inhibited galectin-3expression and blocked proliferation of T cells significantly. Thisstudy suggests that up-regulation of galectin-3 plays an important rolein proliferation of activated T lymphocytes.