bluuebunny/crossref_metadata_2025 huggingface dataset:
Potentiation by human serum of anti-inflammatory cytokine production by human macrophages in response to apoptotic cells
Authors: Kurosaka Kahori , Watanabe Naoko , Kobayashi Yoshiro
Published: September 2022

Phagocytosis of apoptotic cells by macrophages leads to the production of anti-inflammatory cytokines, thereby preventing inflammation. In this study, we demonstrate that human serum potentiates the production of anti-inflammatory cytokines, IL-10 and TGF-β, by PMA-treated THP-1 cells and human monocyte-derived macrophages in response to apoptotic cells, which results in great suppression of the production of proinflammatory cytokine IL-8. Human IgG but not its F(ab)′2 suppressed the IL-8 production. Pretreatment of macrophages but not apoptotic cells with human serum or human IgG caused the suppression, suggesting that immune complex may not be formed with apoptotic cells. When FcγRI was specifically down-modulated by a monoclonal antibody, M22, the potentiating effects of human serum and human IgG on the anti-inflammatory cytokine production and the suppressive effects on IL-8 production were completely abolished. Thus, human IgG and FcγRI appear to be critical in leading to the production of anti-inflammatory cytokines by macrophage in response to apoptotic cells.
Phosphatidylinositol 3-kinase and extracellular signal-regulated kinase are recruited for Fc receptor-mediated phagocytosis during monocyte-to-macrophage differentiation
Authors: García-García Erick , Rosales Ricardo , Rosales Carlos
Published: September 2022

The molecular mechanism involved in Fc receptor-mediated phagocytosis in the different cell types of the immune system is still poorly defined. We investigated the role of phosphatidylinositol 3-kinase (PI 3-K) and extracellular signal-regulated kinase (ERK) in phagocytosis by monocytes and by monocyte-differentiated macrophages. Peripheral blood monocytes and monocytic cells (THP-1 cell line) were able to ingest IgG-coated erythrocytes in the absence of additional stimulus. Phagocytosis by these cells was not blocked by wortmannin and LY294002, specific inhibitors of PI 3-K, or by PD98059, a specific MEK/ERK inhibitor. However, upon differentiation of THP-1 monocytes to macrophages, through treatment with retinoic acid and interferon-γ (IFN-γ), wortmannin and PD98059 blocked Fc receptor-mediated phagocytosis efficiently. Inhibition of phagocytosis by PD98059 was observed after 24 h of IFN-γ treatment, whereas wortmannin could inhibit phagocytosis only after 48 h of IFN-γ treatment. Additionally, phagocytosis of IgG-coated erythrocytes by neutrophils, a more efficient phagocyte, was inhibited by wortmannin and PD98059. Neutrophils and monocyte-differentiated macrophages presented significantly more efficient phagocytosis than monocytes upon PMA stimulation. Taken together, these results indicate that poorly phagocytic leukocytes, such as monocytes, do not require PI 3-K and ERK for phagocytosis. Upon differentiation into macrophages, however, ERK first and PI 3-K second are recruited for regulation of phagocytosis. In addition, our data support the idea that professional phagocytes require ERK and PI 3-K for efficient phagocytosis.
Selective expansion of perforin-positive CD8+ T cells by immature dendritic cells infected with live Bacillus Calmette-Guérin mycobacteria
Authors: Tsunetsugu-Yokota Yasuko , Tamura Hideto , Tachibana Mikiko , Ogata Kiyoyuki , Honda Mitsuo , Takemori Toshitada
Published: September 2022

Live, but not dead Bacillus Calmette-Guérin (BCG) is partially protective against infection by Mycobacterium tuberculosis, which causes a disease with high mortality in immune compromised individuals. We have shown that uptake of BCG induces maturation of immature dendritic cells (DCs) regardless of the viability of the bacteria. Importantly, when T cells are cocultured with live BCG-infected DCs, the proportion of CD45RA− perforin+ CD8+ T cells is markedly expanded markedly; however, little expansion is seen when T cells are cocultured with DCs harboring heat-killed BCG. The direct contact of T cells with live BCG-infected DCs was required for the expansion of perforin+ CD8+ T cells. These CD8+ T cells demonstrated a high level of killing activity against BCG-infected macrophages. There was little contribution of cytokines, including IFN-γ, TNF-α, and IL-12, to the expansion of CD8+ T cells by live BCG-infected DCs. We found that the interaction between BCG-infected DCs and CD8+ T cells through CD40/CD40L was crucial for the expansion and maturation of CD8+ T cells, the process of which was CD4-independent. In contrast, blocking the CD58/CD2 but not the CD40/CD40L interaction reduced production of IFN-γ without affecting the maturation of CD8+ T cells. This indicates that the production of IFN-γ and perforin by CD8+ T cells is mediated by distinct signals delivered from BCG-infected DCs. Thus, BCG-specific CD8+ CTL memory cells may be maintained for a long period of time in BCG-vaccinated hosts, and these cells could mature rapidly into effectors through the potent antigen-presenting function of DCs upon mycobacterial infection.
CD137 is expressed by follicular dendritic cells and costimulates B lymphocyte activation in germinal centers
Authors: Pauly Susanne , Broll Karin , Wittmann Margarethe , Giegerich Gerhard , Schwarz Herbert
Published: September 2022

CD137, a member of the TNF receptor family, and its ligand are expressed on T lymphocytes and antigen-presenting cells (APC), respectively. During interaction with APC, T lymphocytes receive a potent, costimulatory signal through CD137. Reverse signaling has been demonstrated for the CD137 ligand, which causes activation in monocytes. Here we show that B lymphocytes also receive costimulatory signals through the CD137 ligand. Immobilized CD137 augmented proliferation of preactivated B lymphocytes up to fivefold and immunoglobulin synthesis, up to threefold. CD137 had no effect on resting cells. Further, we show that CD137 is expressed in vivo by follicular dendritic cells (FDC) in germinal centers. Germinal centers form during humoral immune responses and are essential for B lymphocyte affinity maturation. These data imply that, similar to the CD40 receptor/ligand system, which mediates T lymphocyte help to B lymphocytes after the first antigen encounter, the CD137 receptor/ligand system may mediate costimulation of B lymphocytes by FDC during affinity maturation.
Interleukin-1 in the genesis and progression of and risk for development of neuronal degeneration in Alzheimer's disease
Authors: Griffin W Sue T , Mrak Robert E
Published: September 2022

Interleukin-1 (IL-1), a key molecule in systemic immune responses in health and disease, has analogous roles in the brain where it may contribute to neuronal degeneration. Numerous findings suggest that this is the case. For example, IL-1 overexpression in the brain of Alzheimer patients relates directly to the development and progression of the cardinal neuropathological changes of Alzheimer's disease, i.e., the genesis and accumulation of β-amyloid (Aβ) plaques and the formation and accumulation of neurofibrillary tangles in neurons, both of which contribute to neuronal dysfunction and demise. Several genetic studies show that inheritance of a specific IL-1A gene polymorphism increases risk for development of Alzheimer's disease by as much as sixfold. Moreover, this increased risk is associated with earlier age of onset of the disease. Homozygosity for this polymorphism in combination with another in the IL-1B gene further increases risk.
Potent induction of activin A secretion from monocytes and bone marrow stromal fibroblasts by cognate interaction with activated T cells
Authors: Abe Masahiro , Shintani Yasumi , Eto Yuzuru , Harada Kazuyo , Kosaka Masaaki , Matsumoto Toshio
Published: September 2022

Activin A is a multifunctional cytokine essential for cell differentiation and apoptosis including erythroid cell differentiation in the bone marrow. In addition, activin A is induced by inflammation and exerts anti-inflammatory effects. However, the mechanism of activin A induction is still unclear, especially by inflammatory processes. Here we show that activin A secretion from monocytes and bone marrow stromal fibroblasts, its major sources in the bone marrow, is markedly enhanced by cognate interaction with activated T cells. This process is mediated by CD40/CD40 ligand interaction as well as concomitantly secreted T cell-derived cytokines, granulocyte macrophage-colony stimulating factor, and interferon-γ. Furthermore, stromal fibroblasts as well as monocytes provide a costimulatory signal to anti-CD3-treated T cells via CD80 and CD86 to maintain the enhanced activin A production. These findings suggest that activin A is potently induced in the bone marrow and may play a role in the suppression of inflammatory or immune processes.
Murine polymorphonuclear neutrophils produce interferon-γ in response to pulmonary infection withNocardia asteroides
Authors: Ellis Terri N , Beaman Blaine L
Published: September 2022

Nocardia asteroides causes an acute, necrotizing pneumonia characterized by extensive infiltration of polymorphonuclear neutrophils (PMNs) into the lungs. Although PMNs have historically been classified as end-point cells, recent investigations have indicated that PMNs have the ability to secrete cytokines such as interleukin (IL)-4 and IL-12. This study investigated the ability of PMNs to produce cytokines in a murine model of N. asteroides pulmonary infection. Flow cytometric analysis demonstrated the production of interferon-γ (IFN-γ), but not IL-4, by PMNs in response to this infection. IFN-γ production correlated with peak infiltration of PMNs into the lungs. Cell sorting and enzyme-linked immunosorbent assay were used to confirm cytokine production by cells with nuclear morphology characteristic of PMNs. This is the first report of IFN-γ production by neutrophils in response to an infection in vivo. These results suggest that PMNs play an important role in directing the host toward a T helper cell type 1 phenotypic response in the lungs.
Macrophages in gene therapy: cellular delivery vehicles and in vivo targets
Authors: Burke B , Sumner S , Maitland N , Lewis C E
Published: September 2022

The appearance and activation of macrophages are thought to be rapid events in the development of many pathological lesions, including malignant tumors, atherosclerotic plaques, and arthritic joints. This has prompted recent attempts to use macrophages as novel cellular vehicles for gene therapy, in which macrophages are genetically modified ex vivo and then reintroduced into the body with the hope that a proportion will then home to the diseased site. Here, we critically review the efficacy of various gene transfer methods (viral, bacterial, protozoan, and various chemical and physical methods in transfecting macrophages in vitro, and the results obtained when transfected macrophages are used as gene delivery vehicles. Finally, we discuss the use of various viral and nonviral methods to transfer genes to macrophages in vivo. As will be seen, definitive evidence for the use of macrophages as gene transfer vehicles has yet to be provided and awaits detailed trafficking studies in vivo. Moreover, although methods for transfecting macrophages have improved considerably in efficiency in recent years, targeting of gene transfer specifically to macrophages in vivo remains a problem. However, possible solutions to this include placing transgenes under the control of macrophage-specific promoters to limit expression to macrophages or stably transfecting CD34+ precursors of monocytes/macrophages and then differentiating these cells into monocytes/macrophages ex vivo. The latter approach could conceivably lead to the bone marrow precursor cells of patients with inherited genetic disorders being permanently fortified or even replaced with genetically modified cells.
Molecular mechanisms of platelet-mediated leukocyte recruitment during myocardial reperfusion
Authors: Kupatt Christian , Wichels Reinhard , Horstkotte Jan , Krombach Fritz , Habazettl Helmut , Boekstegers Peter
Published: September 2022

Leukocyte interaction with platelets and endothelial cells as cause of myocardial stunning was investigated. Mice were anesthetized and, after thoracotomy, the LAD was ligated for 20 min. Where indicated, rhodamine 6G for leukocyte labeling, fluorescence-labeled platelets, and the GPIIb/IIIa antagonist Tirofiban wer infused at the onset of reperfusion in vivo. After 15 min, hearts were quickly excised and analyzed by fluorescence microscopy or assessed for left ventricular developed pressure (LVDP). After in vivo ischemia and reperfusion, leukocyte retention in the heart was 55 ± 5/field in wild-type hearts, 38 ± 3/field in P-selectin−/− hearts, and 23 ± 4/field in P-selectin/intercellular adhesion molecule-1 (ICAM-1)−/− hearts. Postischemic LVDP (48±4 mmHg in wild-type hearts) improved in P-selectin−/− and P-selectin/ICAM-1−/− hearts (58±4 and 79±6 mmHg). Tirofiban reduced platelet adhesion (23±4/field vs. 61±2/field in wild-type hearts) and leukocyte recruitment (34±2/field), improving LVDP (63±4 mmHg). Whereas wild-type platelets displayed similar adherence to P-selectin/ICAM-1−/− hearts as platelets from the same genetic strain (63±3 vs. 61±4 platelets/field), wild-type platelet infusion restored postischemic leukocyte recruitment in P-selectin/ICAM-1−/− hearts (55±4/field vs. 23±4/field), an effect sensitive to Tirofiban inhibition (23±4 leukocytes/field, 22±3 platelets/field). We conclude that platelets contribute postischemic leukocyte adhesion in the heart via P-selectin and GPIIb/IIIa.
The role of ceramide of human macrophage gangliosides in activation of human macrophages
Authors: Berenson Charles S , Gallery Melissa A , Smigiera Jane M , Rasp Robin H
Published: September 2022

Gangliosides of macrophages have immunoregulatory and structural attributes, distinct from neural gangliosides. We previously produced a monoclonal antibody to human macrophage gangliosides (HMG; mAb25F4), which inhibited macrophage migration and recognized a surface-accessible epitope. We investigated expanded immunoregulatory properties and molecular domains for antibody recognition. mAb25F4 directly induced human macrophage production of proinflammatory cytokines, interleukin-1β, and tumor necrosis factor α. Conditions were established for selective, reversible depletion of HMG with D-threo-(R, R)-1-phenyl-2-decanoyl-amino-3-morpholine-1-propa-nol. mAb25F4 had diminished recognition for ganglioside-depleted macrophages, which was restored with regeneration of gangliosides. Although desialylation of HMG did not impair mAb25F4 recognition, enzymatic cleavage of ceramide abolished antibody binding. Antibody recognition was specific for the ceramide fraction, with preferential recognition or ceramide of HMG and murine macrophage gangliosides and limited recognition for neural tissue ceramide and gangliosides. This study underscores the importance of structurally distinct ceramide of macrophage gangliosides as a critical domain for ganglioside-mediated activation of human macrophages.
Disruption of CD40/CD40 ligand interaction with cleavage of CD40 on human gingival fibroblasts by human leukocyte elastase resulting in down-regulation of chemokine production
Authors: Nemoto Eiji , Tada Hiroyuki , Shimauchi Hidetoshi
Published: September 2022

CD40 is a crucial element in the process of fibroblast activation. We demonstrated that treatment of human gingival fibroblast (HGF) with human leukocyte elastase (HLE), a neutrophil serine protease, down-regulated the expression of CD40 and binding to the CD40 ligand (CD40L) using flow cytometry. The other neutrophil serine proteases, cathepsin G and proteinase 3, exhibited markedly less activity for CD40 reduction. The CD40 reduction by HLE was also observed in skin and lung fibroblasts, but not in monocytes, macrophages, and dendritic cells. The reduction resulted from direct proteolysis by HLE on the cell surface, because HLE reduced CD40 on fixed HGF and also on cell lysates and membranes. HLE treatment of HGF decreases interleukin (IL)-8 and macrophage chemoattractant protein-1 production by HGF when stimulated by CD40L, but not by IL-1α, suggesting that HLE inhibited a CD40-dependent cell activation. These results suggest that HLE possesses an anti-inflammatory effect for the HGF-mediated inflammatory process.
Effects of catecholamines on kinase activation in lung neutrophils after hemorrhage or endotoxemia
Authors: Arcaroli John , Yang Kuang-Yao , Yum Ho-Kee , Kupfner John , Pitts Todd M , Park Jong Sung , Strassheim Derek , Abraham Edward
Published: September 2022

Catecholamines are released in high levels after hemorrhage or endotoxemia and have been shown to modulate immune function, including cellular release of inflammatory mediators. In the present experiments, we examined the effects of endogenous and exogenous catecholamines on neutrophil accumulation and activation in the lungs using pretreatment with α- or β-antagonists or α-adrenergic agonists before hemorrhage or endotoxemia. These studies showed that α-, but not β-adrenergic stimuli, modulated the severity of acute lung injury after hemorrhage or endotoxemia, and α-adrenergic stimuli was proinflammatory after hemorrhage but anti-inflammatory after endotoxemia. The observed α-adrenergic effects on lung neutrophil activation appeared to involve primarily the extracellular signal-regulated kinase pathway at the upstream kinase Raf, but not Ras. Although p38 and protein kinase A were activated in lung neutrophils after hemorrhage or endotoxemia, these kinases were not affected by α- or β-adrenergic modulation. These results demonstrate that catecholamines have important immunomodulatory effects in vivo that affect intracellular signaling pathways in neutrophils and neutrophil-driven, inflammatory processes such as the development of acute lung injury.
Platelet factor 4 induces human natural killer cells to synthesize and release interleukin-8
Authors: Martí Francesc , Bertran Esther , Llucià Montserrat , Villén Esther , Peiró Matilde , Garcia Joan , Rueda Fèlix
Published: September 2022

We provide evidence that platelet factor 4 (PF4), but not the related chemokine neutrophil-activating polypeptide-2, induced highly purified human natural killer (NK) cells to produce interleukin (IL)-8 in a time- and dosage-dependent manner. This ability was retained even while PF4 was bound to heparin. PF4 increased the steady state level of IL-8 mRNA, likely implying a transcriptional effect of PF4. Stimulation of NK cells through the Fc receptor for immunoglobulin G-IIIA was foud to synergistically increase the effect of PF4 on IL-8 production but did not affect IL-2-related activities such as cytotoxic activity and proliferation. Pertussis toxin did not block the PF4-derived IL-8 production in NK cells, but this response was sensitive to wortmannin, implicating a role of phosphatidylinositol 3-kinase in the intracellular signaling pathway triggered by PF4. Our results characterize a new capacity for PF4 and provide further evidence for the pivotal role of NK cells in the environment of inflammation.
High circulating levels of the IL-1 type II decoy receptor in critically ill patients with sepsis: association of high decoy receptor levels with glucocorticoid administration
Authors: Müller Beat , Peri Giuseppe , Doni Andrea , Perruchoud André P , Landmann Regine , Pasqualini Fabio , Mantovani Alberto
Published: September 2022

The objective of this study was to evaluate whether the interleukin (IL)-1 decoy receptor (R), a negative pathway of regulation of IL-1, is correlated with severity of infection in critically ill patients and reflects the activation of anti-inflammatory pathways by glucocorticoid hormones. Plasma samples were obtained from 101 consecutive, critically ill patients admitted to the intensive care unit with different severities of microbial infection, as defined by standardized criteria. Here, we report that the IL-1 type II decoy R(II) is elevated in critically ill patients, especially in severe, systemic infection and culture-positive infections. In patients with a marked systemic inflammatory response syndrome 4, a pronounced, sepsis-induced further increase of circulating IL-1 decoy RII levels was evident. Thirty-six patients treated with glucocorticoid hormones had significantly higher levels of IL-1 decoy RII, but lower IL-6 and C-reactive protein, than 67 untreated subjects. The usefulness of IL-1RII, in particular as a potential marker for the activation of anti-inflammatory pathways or for responsiveness to anti-inflammatory agents such as glucocorticoid hormones, deserves further analysis.
FcγR cross-linking mediates NF-κB activation, reduced antigen presentation capacity, and decreased IL-12 production in monocytes without modulation of myeloid dendritic cell development
Authors: Drechsler Yvonne , Chavan Sangeeta , Catalano Donna , Mandrekar Pranoti , Szabo Gyongyi
Published: September 2022

Stimulation of monocytes (MO) through receptors for the Fc region of immunoglobulin G (FcγR) activates a variety of responses, including phagocytosis, antibody (Ab)-dependent cellular cytotoxicity, and production of cytokines. We previously reported that the MO subpopulation that expresses FcγR in high density produces high levels of tumor necrosis factor α (TNF-α) compared with FcγR-negative MO. Here, we show that cross-linking MO via FcγRI or FcγRII but not via FcγRIII activates nuclear regulatory factor-κB (NF-κB), a transcription factor involved in regulation of TNF-α. NF-κB activation peaked at 2.75 h after FcγRI cross-linking, involved p65 and p50 (heterodimer) and not c-rel-containing NF-κB complexes, and was mediated via IκB degradation. Cross-linking FcγRI, -II, as well as -III inhibited interleukin (IL)-12 (p70) production in MO, whether stimulated with Staphylococcal enterotoxin B (P<0.02) or lipopolysaccharide (P<0.02). Inhibition of IL-12 by FcγR cross-linking was not mediated by TNF-α, as the presence of an anti-TNF-α Ab could not restore the reduced IL-12 production. Decreased IL-12 production correlated with reduced antigen presentation capacity (P<0.01) in the FcγR-cross-linked MO. Blood MO can give rise to myeloid dendritic cells (DC). FcγR cross-linking did not modulate in vitro maturation of MO to fully functional myeloid DC. Allostimulatory capacity in mixed leukocyte reaction and DC marker expression (CDla, CD80, CD86) was not different between control and FcγRI cross-linked DC. These results suggest that signals mediated via FcγRI, -II, and -III have overlapping yet distinct effects on MO, which are likely to be involved in the fine-tuning of the immune responses to various stimuli.
Alternative activation and increase ofTrypanosoma cruzisurvival in murine macrophages stimulated by cruzipain, a parasite antigen
Authors: Stempin Cinthia , Giordanengo Laura , Gea Susana , Cerbán Fabio
Published: September 2022

We studied the macrophage (Mo) activation pathways through Mo interaction with immunogenic Trypanosoma cruzi antigens as cruzipain (Cz) and R13. J774 cells, peritoneal and spleen Mo from normal mice, were used. Although Mo classic activation was observed in the presence of lipopolysaccharide, evaluated through nitric oxide (NO) and interleukin (IL)-12 production, Cz and R13 did not activate Mo in this way. To study the alternative pathway, we examined the arginase activity in Mo cultured with Cz. An increase of arginase activity was detected in all Mo sources assayed. An increase of IL-10 and transforming growth factor-β in culture supernatants from Mo stimulated with Cz was observed. The study of expression of B7.1 and B7.2 in spleen Mo revealed that Cz induces preferential expression of B7.2. In vitro studies revealed that Cz stimulated J774 cells and then, infected with trypomastigotes of T. cruzi, developed a higher number of intracellular parasites than unstimulated infected Mo. Thus, Cz favors the perpetuation of T. cruzi infection. In addition, a down-regulation of inducible NO synthase was observed in J774 cells stimulated with Cz. These results suggest that Cz interaction with Mo could modulate the immune response generated against T. cruzi through the induction of a preferential metabolic pathway in Mo.
Salmonellavirulence factor SipB induces activation and release of IL-18 in human dendritic cells
Authors: Dreher Donatus , Kok Menno , Obregon Carolina , Kiama Stephen G , Gehr Peter , Nicod Laurent P
Published: September 2022

Interleukin-18 (IL-18) plays an important role in innate and acquired immunity, in particular against intracellular pathogens. However, little is known about the microbial factors that trigger IL-18 secretion by dendritic cells (DCs). To determine the influence of bacterial virulence factors on the activation and release of IL-18, we infected human monocyte-derived DCs with virulence mutants of the facultative intracellular pathogen Salmonella typhimurium. Our results show that infection by S. typhimurium causes caspase-1-dependent activation of IL-18 and triggers the release of IL-18 in human DCs. The secretion of IL-18 by the DCs was closely correlated with the ability of the S. typhimurium strains to induce apoptosis. We demonstrate that activation and release of IL-18 are blocked by mutations in the Salmonella sipB gene, which encodes a virulence factor that activates caspase-1 to induce apoptosis. These findings indicate that the activation and release of IL-18 induced by bacterial virulence factors may represent one component of innate immunity against the intracellular bacteria.
Nitric oxide participates in the intestinal pathology associated with murine syngeneic graft-versus-host disease
Authors: Flanagan D M , Jennings C D , Goes S W , Caywood B E , Gross R , Kaplan A M , Bryson J S
Published: September 2022

Syngeneic graft-versus-host disease (SGVHD) develops following lethal irradiation, reconstitution with syngeneic bone marrow, and treatment with a short course of cyclosporin A (CsA) therapy. The disease is characterized by the development of a T helper cell type 1-like cytokine response [interleukin (IL)-12, interferon-γ (IFN-γ), and tumor necrosis factor α], and macrophage activation is central to development of the syndrome. It has been shown that nitric oxide (NO) participates significantly in the development of allogeneic GVHD. Studies were initiated to determine if NO participates in the pathology associated with SGVHD. Significant increases in inducible NO synthase (iNOS) mRNA and circulating NO were found in the tissues of SGVHD versus control animals. Treatment of SGVHD animals with the iNOS inhibitor aminoguanidine (AG) reversed the pathology associated with this disease. Furthermore, AG treatment reduced the production of IL-12 and IFN-γ mRNA in the colons of CsA-treated mice. These studies demonstrate that NO participates in the pathological processes that are associated with the development of murine SGVHD.
CpG-DNA-induced IFN-α production involves p38 MAPK-dependent STAT1 phosphorylation in human plasmacytoid dendritic cell precursors
Authors: Takauji Rumiko , Iho Sumiko , Takatsuka Hisakazu , Yamamoto Saburo , Takahashi Takayuki , Kitagawa Harukazu , Iwasaki Hiromichi , Iida Reiko , Yokochi Takashi , Matsuki Takasumi
Published: September 2022

Human plasmacytoid or CD4+CD11c− type 2 dendritic cell precursors (PDC) were identified as natural type I interferon (IFN)-producing cells in response to viral and bacterial infection. They represent effector cells of innate immunity and link it to the distinct adaptive immunity by differentiating into mature DC. It has been reported that oligodeoxyribonucleotides containing unmethylated CpG motifs (CpG DNA) stimulate PDC to produce IFN-α, but the molecular mechanisms involved remain unknown. We found that CpG-DNA-induced IFN-α production in PDC was completely impaired by the inhibitor of the p38 mitogen-activated protein kinase (MAPK) pathway. Expression of IFN regulatory factor (IRF)-7 was enhanced by CpG-DNA treatment, which was preceded by the phosphorylation of signal transducer and activator of transcription (STAT)1 on Tyr-701, as well as its enhanced phosphorylation on Ser-727. All of these events were also suppressed by the p38 MAPK inhibitor. STAT1, STAT2, and IRF-9, components of IFN-stimulated gene factor 3 (ISGF3), were recognized in the nuclear fraction of CpG-DNA-treated cells. Neither anti-IFN-α/β antibodies (Ab) nor anti-IFNAR Ab suppressed STAT1 phosphorylation, enhancement of IRF-7 expression, or IFN-α production in the early phase of the culture. These results suggest that CpG DNA induces p38 MAPK-dependent phosphorylation of STAT1 in a manner independent of IFN-α/β, which may cause ISGF3 formation to increase the transcription of the IRF-7 gene, thereby leading to IFN-α production in human PDC.
The A2A receptor mediates an endogenous regulatory pathway of cytokine expression in THP-1 cells
Authors: Bshesh Khaled , Zhao Bin , Spight Donn , Biaggioni Italo , Feokistov Igor , Denenberg Alvin , Wong Hector R , Shanley Thomas P
Published: September 2022

Adenosine is an endogenous nucleoside that regulates numerous cellular functions including inflammation. Adenosine acts via cell-surface receptors subtyped as A1, A2A, A2B, and A3. The A2A receptor (A2AR) has been linked to anti-inflammatory effects of adenosine. Furthermore, microarray analysis revealed increased A2AR mRNA in lipopolysaccharide (LPS)-stimulated monocytes. We hypothesized that endogenous adenosine inhibited LPS-mediated tumor necrosis factor (TNF) production via A2AR stimulation. Using THP-1 cells, our results demonstrated that LPS increased expression of cellular A2AR and adenosine. A2AR agonism with 2-p-(2-carboxyethyl)phenethylamino-5′-N-ethylcarboxamido adenosine (CGS 21680) after LPS decreased TNF production in a dose- and time-dependent manner, whereas A2AR antagonism significantly increased TNF and blocked the inhibitory effect of CGS 21680. This inhibitory pathway involved A2AR stimulation of cyclic adenosine monophosphate (cAMP) to activate protein kinase A, resulting in phosphorylation of cAMP response element-binding protein (CREB). Phospho-CREB had been shown to inhibit nuclear factor-κB transcriptional activity, as was observed with CGS 21680 treatment. Thus, following immune activation with LPS, endogenous adenosine mediates a negative feedback pathway to modulate cytokine expression in THP-1 cells.
IL-5-induced integrin adhesion of human eosinophils caused by ERK1/2-mediated activation of cPLA2
Authors: Zhu Xiangdong , Jacobs Benjamin , Boetticher Evan , Myou Shigeharu , Meliton Angelo , Sano Hiroyuki , Lambertino Anissa T , Muñoz Nilda M , Leff Alan R
Published: September 2022

We examined the mechanism by which interleukin (IL)-5 causes β2-integrin adhesion of human eosinophils. IL-5 caused time-dependent activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38α in eosinophils as detected by their phosphorylation. Preincubation of eosinophils with U0126, a mitogen-activated protein kinase/ERK kinase inhibitor, suppressed IL-5-induced activation of cytosolic phospholipase A2 (cPLA2) and eosinophil adhesion, and p38 inhibition by SB203580 had neither effect. ERK1/2 phosphorylation and eosinophil adhesion were blocked by inhibition of the src-family tyrosine kinase, Janus tyrosine kinase (JAK)2, or phosphoinositide-3 kinase (PI3K). Coimmunoprecipitation assay demonstrated that Lyn, a src-family tyrosine kinase, was constitutively associated with PI3K. Inhibition of src-tyrosine kinase but not JAK2 suppressed PI3K activation. Our data suggest that IL-5 induces β2-integrin adhesion of human eosinophils by regulation of cPLA2 activation caused by ERK1/2 phosphorylation. This phosphorylation results from activation of PI3K and protein tyrosine kinases. We also find that src-family tyrosine kinase, possibly Lyn, is the upstream kinase causing PI3K activation.
Monocytes are progressively activated in the circulation of pregnant women
Authors: Luppi Patrizia , Haluszczak Catherine , Betters Dawn , Richard Craig A H , Trucco Massimo , DeLoia Julie A
Published: September 2022

Pregnancy is characterized by the presence of generalized leukocyte activation. We used flow cytometry to investigate changes in phenotype and intracellular cytokines of circulating granulocytes, monocytes, and T lymphocytes of pregnant women during gestation. We report that peripheral circulation of pregnancy is characterized by an increased percentage of granulocytes and a decrease in lymphocytes. The proportion of monocytes remains stable throughout gestation; however, a progressive up-regulation of surface markers CD11a, CD54, and CD64 was detected. Monocytes also showed higher production of interleukin (IL)-12 and IL-1β compared with the nonpregnant state, and granulocytes had greater potential to synthesize IL-8. All these changes were particularly marked in late gestation. T lymphocytes did not have any characteristics of the activated state and showed a decreased IL-6 production. These findings demonstrate that activation of maternal monocytes and granulocytes increases during pregnancy and support the idea that pregnancy results in an elevation of the innate immune system and suppression of the adaptive immune system.
Differential regulation of dendritic cell function by the immunomodulatory drug thalidomide
Authors: Mohty Mohamad , Stoppa Anne-Marie , Blaise Didier , Isnardon Daniel , Gastaut Jean-Albert , Olive Daniel , Gaugler Béatrice
Published: September 2022

Thalidomide (Thal) was shown to be a potent immunomodulating agent. Because of their central role in controlling immunity, we investigated the effects of Thal on monocyte-derived dendritic cells (Mo-DC). The addition of 10 μg/ml or 20 μg/ml Thal from the beginning of monocyte culture with granulocyte macrophage-colony stimulating factor and interleukin (IL)-4 did not block Mo-DC differentiation. Moreover, Thal alone could not induce Mo-DC maturation. However, Thal exerted a modulation of Mo-DC functional properties. At 10 μg/ml, Thal modified the allostimulatory capacity of DC little, whereas a dose of 20 μg/ml up-regulated this capacity (P=.05) and increased IL-12p70 production in a dose-dependent manner between 10 and 20 μg/ml (P=.001). Mo-DC generated with 10 μg/ml Thal were poor stimulators of T helper cell type 1 (Th1) responses (P=.01), but 20 μg/ml was able to strengthen Th1 responses (P=.03). Also, Thal induced a significant reduction of IL-10 production in response to the maturation-inducing stimulus CD40L. Similarly, tumor necrosis factor α production was significantly decreased when Mo-DC were exposed to 10 μg/ml Thal, and a dose of 20 μg/ml did not induce any significant changes. The effects of Thal in vitro on the secretion of IL-12p70 and strengthening of Th1 responses might contribute to the antitumor effects of Thal. Thus, DC appear to be potential targets for the immunomodulatory capacity of Thal, defining a new mechanism of action of this drug.
TNF-related apoptosis-inducing ligand (TRAIL) up-regulates cyclooxygenase (COX)-1 activity and PGE2 production in cells of the myeloid lineage
Authors: Secchiero Paola , Gonelli Arianna , Ciabattoni Giovanni , Melloni Elisabetta , Grill Vittorio , Rocca Bianca , Delbello Giorgio , Zauli Giorgio
Published: September 2022

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) up-regulated the expression of constitutive cyclooxygenase (COX)-1 protein in HL-60 cells without affecting COX-2. The TRAIL-mediated COX-1 up-regulation was accompanied by a significant increase of the PGE2 synthesis and release, which was suppressed by the COX-1 inhibitor valeryl salicylate but not by the COX-2 inhibitor NS-398. Experiments carried out by adding exogenous PGE2 to HL-60 cells indicated that PGE2 was not involved in TRAIL cytotoxicity and rather showed a dose-dependent protection against TRAIL-induced apoptosis. Importantly, the ability of TRAIL to increase PGE2 production was also observed in normal, human CD34-derived myeloid cells and in freshly isolated peripheral blood CD14+ monocytes. Moreover, in contrast to HL-60 cells, primary, normal cells were not susceptible to TRAIL cytotoxicity. These data indicate that the ability of TRAIL to up-regulate eicosanoid production and release is not confined to malignant leukemic cells, but it may also play a role in normal hematopoiesis.
The immune system and prion diseases: a relationship of complicity and blindness
Authors: Aucouturier Pierre , Carnaud Claude
Published: September 2022

In most documented infectious forms of transmissible spongiform encephalopathies, prions must transit through the lymphoreticular compartment before invading the central nervous system. A major goal has been to identify the cell susbsets that support replication and propagation of prions from sites of penetration to sites of neuroinvasion. The conclusions, still fragmentary and confusing, point at a few candidates: follicular dendritic cells (FDCs) and more recently, dendritic cells (DCs). It is clear, however, that lymphoinvasion does not depend on a single-cell type but needs a coordinated network of cells. Discrepancies between models suggest that the actors may vary according to prion strains. A second center of interest has emerged following reports that anti-prion protein (PrP) antibodies blocked in vitro cell conversion of normal PrP into pathological PrP and cured infected cell lines. As isoform conversion is a critical event in prion propagation and formation of lesions, the identification of immune agents capable of inhibiting the reaction is of major importance. In vivo experiments suggest that antibodies produced in transgenic mice or an ongoing immune reaction induced by peptides can prevent PrP conversion and retard disease progression. These results do not say whether clinical disease can be durably delayed and if immunological tolerance to PrP can be easily broken in infected individuals. Altogether, these results suggest that the unconventional relationship between prions and the immune system is on the eve of new and fascinating developments. Whether they will provide innovative strategies for early diagnosis and preventive treatments is still an open question.
Identification and characterization of a novel mouse gene encoding a Ras-associated guanine nucleotide exchange factor: expression in macrophages and myocarditis elicited byTrypanosoma cruziparasites
Authors: Ferreira Ludmila R P , Abrantes Eduardo F , Rodrigues Cibele V , Caetano Braulia , Cerqueira Gustavo C , Salim Anna Christina , Reis Luiz F L , Gazzinelli Ricardo T
Published: September 2022

The ability of Trypanosoma cruzi to activate macrophages is, at least in part, attributed to the glycosylphosphatidylinositol-anchored mucin-like glycoproteins (GPI-mucins) expressed in the surface of the trypomastigote stage of the parasite. The differential display reverse transcriptase-polymerase chain reaction and the reverse Northern blot were used to study modulation of gene expression in murine macrophages exposed to GPI-mucins and in cardiac tissues from mice infected with T. cruzi. Among several cDNAs that were more abundant in lanes corresponding to macrophages stimulated with GPI-mucins as compared with resting cells, we confirmed the differential expression of A1, interleukin-18, and GPIγ4. Some of these genes were also shown to have enhanced expression in the cardiac tissue (DAP-12, A1, and GPIγ4) from infected animals. The expression of GPIγ4 was also enhanced in human monocytes stimulated with GPI-mucins or bacterial lipopolysaccharides. The complete sequence of the GPIγ4 transcript and its gene including the 5′ upstream region was defined. GPIγ4 was encoded by a novel, single copy gene present in mouse as well as human genomes and showed conserved homology to different members of the guanine nucleotide exchange factor family.
Circulating Tumor DNA After Neoadjuvant Chemotherapy in Breast Cancer Is Associated With Disease Relapse
Authors: Cailleux Frédéric , Agostinetto Elisa , Lambertini Matteo , Rothé Françoise , Wu Hsin-Ta , Balcioglu Mustafa , Kalashnikova Ekaterina , Vincent Delphine , Viglietti Giulia , Gombos Andrea , Papagiannis Andreas , Veys Isabelle , Awada Ahmad , Sethi Himanshu , Aleshin Alexey , Larsimont Denis , Sotiriou Christos , Venet David , Ignatiadis Michail
Published: September 2022

PURPOSE

Detection of circulating tumor DNA (ctDNA) after neoadjuvant chemotherapy in patients with early-stage breast cancer may allow for early detection of relapse. In this study, we analyzed ctDNA using a personalized, tumor-informed multiplex polymerase chain reaction–based next-generation sequencing assay.

METHODS

Plasma samples (n = 157) from 44 patients were collected before neoadjuvant therapy (baseline), after neoadjuvant therapy and before surgery (presurgery), and serially postsurgery including a last follow-up sample. The primary end point was event-free survival (EFS) analyzed using Cox regression models.

RESULTS

Thirty-eight (86%), 41 (93%), and 38 (86%) patients had baseline, presurgical, and last follow-up samples, respectively. Twenty patients had hormone receptor–positive/human epidermal growth factor receptor 2–negative, 13 had triple-negative breast cancer, and 11 had human epidermal growth factor receptor 2–positive disease. Baseline ctDNA detection was observed in 22/38 (58%) patients and was significantly associated with Ki67 > 20% ( P = .036) and MYC copy-number gain ( P = .0025, false discovery rate = 0.036). ctDNA detection at presurgery and at last follow-up was observed in 2/41 (5%) and 2/38 (5%) patients, respectively. Eight relapses (seven distant and one local) were noted (median follow-up 3.03 years [range, 0.39-5.85 years]). After adjusting for pathologic complete response (pCR), ctDNA detection at presurgery and at last follow-up was associated with shorter EFS (hazard ratio [HR], 53; 95% CI, 4.5 to 624; P < .01, and HR, 31; 95% CI, 2.7 to 352; P < .01, respectively). Association between baseline detection and EFS was not observed (HR, 1.4; 95% CI, 0.3 to 5.9; P = .67).

CONCLUSION

The presence of ctDNA after neoadjuvant chemotherapy is associated with relapse in early-stage breast cancer, supporting interventional trials for testing the clinical utility of ctDNA monitoring in this setting.
Antidiabetogenic action of Morus rubra L. leaf extract in streptozotocin-induced diabetic rats
Authors: Sharma Suman Bala , Gupta Shipra , Ac Rini , Singh Usha Rani , Rajpoot Reenu , Shukla Santosh Kumar
Published: September 2022

Objectives

Researchers all over the world are exploring herbal supplements to control diabetes and its complications. This study evaluated the antidiabetic action of Morus rubra L. aqueous leaf extract through its effect on hyperglycaemia, dyslipidaemia and oxidative stress in streptozotocin-induced diabetic rats.

Methods

The extract was orally administered to diabetic rats (100, 200 and 400 mg/kg body weight) daily for 21 days. Fasting blood glucose was measured on days 0, 7, 14 and 21. At the end of the experiment, blood samples were drawn to measure glucose tolerance, glycosylated haemoglobin, insulin, C-peptide and lipid parameters. Antioxidant enzymes (superoxide dismutase and catalase), reduced glutathione and lipid peroxides were determined in blood and liver tissue. Histopathological examination of pancreatic tissue was also performed.

Key findings

The extract showed a dose-dependent fall in fasting blood glucose. Treatment with 400 mg/kg extract produced a significant reduction in glycosylated haemoglobin with a concomitant elevation in plasma insulin and C-peptide levels. The altered serum lipids in diabetic rats were significantly restored following treatment with the extract. In erythrocytes, as well as liver, the activity of antioxidant enzymes and content of reduced glutathione were found to be significantly enhanced, while levels of serum and hepatic lipid peroxides were suppressed in extract-fed diabetic rats. Histopathological examination of pancreatic tissue revealed an increased number of islets and β-cells in extract-treated diabetic rats.

Conclusions

M. rubra aqueous leaf extract leads to control over hyperglycaemia and dyslipidaemia. The study also demonstrates its antioxidant nature, and hence it may be protective against diabetic complications.
Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes
Authors: Lee Cheuk-Lun , Jiang Pingping , Sit Wai-Hung , Yang Xiatong , Wan Jennifer Man-Fan
Published: September 2022

Objectives

Lymphocyte homoeostasis is essential in inflammatory and autoimmune diseases. In search of natural fungal metabolites with effects on lymphocyte homoeostasis, we recently reported that polysaccharopeptide (PSP) from Coriolus versicolor exhibited ciclosporin-like activity in controlling aberrant lymphocyte activation. This object of this study was to investigate its effect on lymphocyte homoeostasis. This was done by investigating the mechanistic actions of PSP in relation to ciclosporin by performing cell cycle and cell death analysis of human lymphocytes in vitro.

Methods

We investigated the effect of PSP in the presence and absence of ciclosporin on cell proliferation, cell cycle, cell death, immunophenotype and cell cycle regulatory proteins in human lymphocytes.

Key findings

The data showed that PSP exhibited homoeostatic activity by promoting and inhibiting the proliferation of resting and phytohaemagglutinin (PHA)-stimulated lymphocytes, respectively. PHA-stimulated lymphocytes exhibited G0/G1 cell cycle arrest that was accompanied by a reduction of cyclin E expression with PSP treatment. Both PSP and ciclosporin blocked the reduction of the CD4/CD8 ratio in stimulated lymphocytes. PSP did not induce cell death in human lymphocytes, but the suppression of the Fasreceptor suggested a protective role of PSP against extrinsic cell death signals. These homoeostatic effects were more potent with combined PSP and ciclosporin treatment than with either fungal metabolite alone.

Conclusions

Collectively, the results reveal certain novel effects of PSP in lymphocyte homoeostasis and suggest potential as a specific immunomodulatory adjuvant for clinical applications in the treatment of autoimmune diseases.
Imaging of the Lymphatic Vessels for Surgical Planning: A Systematic Review
Authors: van Heumen Saskia , Riksen Jonas J. M. , Bramer Wichor M. , van Soest Gijs , Vasilic Dalibor
Published: September 2022

Background

Secondary lymphedema is a common complication after surgical or radiotherapeutic cancer treatment. (Micro) surgical intervention such as lymphovenous bypass and vascularized lymph node transfer is a possible solution in patients who are refractory to conventional treatment. Adequate imaging is needed to identify functional lymphatic vessels and nearby veins for surgical planning.

Methods

A systematic literature search of the Embase, MEDLINE ALL via Ovid, Web of Science Core Collection and Cochrane CENTRAL Register of Trials databases was conducted in February 2022. Studies reporting on lymphatic vessel detection in healthy subjects or secondary lymphedema of the limbs or head and neck were analyzed.

Results

Overall, 129 lymphatic vessel imaging studies were included, and six imaging modalities were identified. The aim of the studies was diagnosis, severity staging, and/or surgical planning.

Conclusion

Due to its utility in surgical planning, near-infrared fluorescence lymphangiography (NIRF-L) has gained prominence in recent years relative to lymphoscintigraphy, the current gold standard for diagnosis and severity staging. Magnetic resonance lymphography (MRL) gives three-dimensional detailed information on the location of both lymphatic vessels and veins and the extent of fat hypertrophy; however, MRL is less practical for routine presurgical implementation due to its limited availability and high cost. High frequency ultrasound imaging can provide high resolution imaging of lymphatic vessels but is highly operator-dependent and accurate identification of lymphatic vessels is difficult. Finally, photoacoustic imaging (PAI) is a novel technique for visualization of functional lymphatic vessels and veins. More evidence is needed to evaluate the utility of PAI in surgical planning.