scholarly journals Cholera Toxin Indirectly Activates Human Monocyte-Derived Dendritic Cells In Vitro through the Production of Soluble Factors, Including Prostaglandin E2 and Nitric Oxide

2006 ◽  
Vol 13 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Kenneth C. Bagley ◽  
Sayed F. Abdelwahab ◽  
Robert G. Tuskan ◽  
George K. Lewis
Keyword(s):  
Nitric Oxide ◽  
Dendritic Cells ◽  
Cholera Toxin ◽  
Human Monocyte ◽  
Prostaglandin E ◽  
Adjuvant Effects ◽  
Camp Levels ◽  
Dc Maturation

ABSTRACT Cholera toxin (CT) is a potent adjuvant that activates dendritic cells (DC) by increasing intracellular cyclic AMP (cAMP) levels. In vivo and in vitro, very small amounts of CT induce potent adjuvant effects and activate DC. We hypothesized that DC intoxicated by CT may release factors that enhance their own maturation and induce the maturation of toxin-free bystander DC. Through the use of mixed cultures and transwell cultures, we found that human monocyte-derived DC (MDDC) pulsed with CT or other cAMP-elevating agonists induce the maturation of bystander DC. Many DC agonists including CT increase the production of prostaglandin E2 (PGE2) and nitric oxide (NO). For this reason, we determined whether the actions of PGE2 or NO are involved in the maturation of MDDC induced by CT or dibutyryl-cAMP (d-cAMP). We found that blocking the production of PGE2 or blocking prostaglandin receptors inhibited MDDC maturation induced by CT and d-cAMP. Likewise, sequestering NO or blocking the downstream actions of NO resulted in the inhibition of MDDC maturation induced by CT and d-cAMP. These results indicate that endogenously produced factors including PGE2 and NO contribute to the maturation of DC induced by CT and that these factors participate in bystander DC maturation. The results of this study may help explain why bacterial toxins that elevate cAMP are such potent adjuvants.

scholarly journals Pasteurella multocida Toxin Activates Human Monocyte-Derived and Murine Bone Marrow-Derived Dendritic Cells In Vitro but Suppresses Antibody Production In Vivo

2005 ◽  
Vol 73 (1) ◽  
pp. 413-421 ◽  
Author(s):  
Kenneth C. Bagley ◽  
Sayed F. Abdelwahab ◽  
Robert G. Tuskan ◽  
George K. Lewis
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Phospholipase C ◽  
Cholera Toxin ◽  
Pasteurella Multocida ◽  
Human Monocyte ◽  
Mouse Bone Marrow ◽  
Dependent Manner

ABSTRACT Pasteurella multocida toxin (PMT) is a potent mitogen for fibroblasts and osteoblastic cells. PMT activates phospholipase C-β through Gqα, and the activation of this pathway is responsible for its mitogenic activity. Here, we investigated the effects of PMT on human monocyte-derived dendritic cells (MDDC) in vitro and show a novel activity for PMT. In this regard, PMT activates MDDC to mature in a dose-dependent manner through the activation of phospholipase C and subsequent mobilization of calcium. This activation was accompanied by enhanced stimulation of naïve alloreactive T cells and dominant inhibition of interleukin-12 production in the presence of saturating concentrations of lipopolysaccharide. Surprisingly, although PMT mimics the activating effects of cholera toxin on human MDDC and mouse bone marrow-derived dendritic cells, we found that PMT is not a mucosal adjuvant and that it suppresses the adjuvant effects of cholera toxin in mice. Together, these results indicate discordant effects for PMT in vitro compared to those in vivo.

scholarly journals Cholera Toxin and Heat-Labile Enterotoxin Activate Human Monocyte-Derived Dendritic Cells and Dominantly Inhibit Cytokine Production through a Cyclic AMP-Dependent Pathway

2002 ◽  
Vol 70 (10) ◽  
pp. 5533-5539 ◽  
Author(s):  
Kenneth C. Bagley ◽  
Sayed F. Abdelwahab ◽  
Robert G. Tuskan ◽  
Timothy R. Fouts ◽  
George K. Lewis
Keyword(s):  
Dendritic Cells ◽  
Cyclic Amp ◽  
Cholera Toxin ◽  
Human Monocyte ◽  
Cell Types ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Heat Labile

ABSTRACT Cholera toxin (CT) and heat-labile enterotoxin (LT) are powerful mucosal adjuvants whose cellular targets and mechanism of action are unknown. There is emerging evidence that dendritic cells (DC) are one of the principal cell types that mediate the adjuvant effects of these toxins in vivo. Here we investigate the effects of CT and LT on the maturation of human monocyte-derived DC (MDDC) in vitro. We found that an enzymatically active A domain is necessary for both CT and LT to induce the maturation of MDDC and that this activation is strictly cyclic AMP (cAMP) dependent. ADP-ribosylation-defective derivatives of these toxins failed to induce maturation of MDDC, whereas dibutyryl-cyclic-3′,5′-AMP and Forskolin mimic the maturation of MDDC induced by CT and LT. In addition, an inhibitor of cAMP-dependent kinases, Rp-8-Br-cAMPs, blocked the ability of CT, LT, and Forskolin to activate MDDC. CT, LT, dibutyryl-cyclic-3′,5′-AMP, and Forskolin also dominantly inhibit interleukin 12 and tumor necrosis factor alpha production by MDDC in the presence of saturating concentrations of lipopolysaccharide. Taken together, these results show that the effects of CT and LT on MDDC are mediated by cAMP.

scholarly journals Effects of Filovirus Interferon Antagonists on Responses of Human Monocyte-Derived Dendritic Cells to RNA Virus Infection

2016 ◽  
Vol 90 (10) ◽  
pp. 5108-5118 ◽  
Author(s):  
Benjamin C. Yen ◽  
Christopher F. Basler
Keyword(s):  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ebola Virus ◽  
Human Monocyte ◽  
Marburg Virus ◽  
Innate Immune ◽  
Dc Maturation

ABSTRACTDendritic cells (DCs) are major targets of filovirus infectionin vivo. Previous studies have shown that the filoviruses Ebola virus (EBOV) and Marburg virus (MARV) suppress DC maturationin vitro. Both viruses also encode innate immune evasion functions. The EBOV VP35 (eVP35) and the MARV VP35 (mVP35) proteins each can block RIG-I-like receptor signaling and alpha/beta interferon (IFN-α/β) production. The EBOV VP24 (eVP24) and MARV VP40 (mVP40) proteins each inhibit the production of IFN-stimulated genes (ISGs) by blocking Jak-STAT signaling; however, this occurs by different mechanisms, with eVP24 blocking nuclear import of tyrosine-phosphorylated STAT1 and mVP40 blocking Jak1 function. MARV VP24 (mVP24) has been demonstrated to modulate host cell antioxidant responses. Previous studies demonstrated that eVP35 is sufficient to strongly impair primary human monocyte-derived DC (MDDC) responses upon stimulation induced through the RIG-I-like receptor pathways. We demonstrate that mVP35, like eVP35, suppresses not only IFN-α/β production but also proinflammatory responses after stimulation of MDDCs with RIG-I activators. In contrast, eVP24 and mVP40, despite suppressing ISG production upon RIG-I activation, failed to block upregulation of maturation markers or T cell activation. mVP24, although able to stimulate expression of antioxidant response genes, had no measurable impact of DC function. These data are consistent with a model where filoviral VP35 proteins are the major suppressors of DC maturation during filovirus infection, whereas the filoviral VP24 proteins and mVP40 are insufficient to prevent DC maturation.IMPORTANCEThe ability to suppress the function of dendritic cells (DCs) likely contributes to the pathogenesis of disease caused by the filoviruses Ebola virus and Marburg virus. To clarify the basis for this DC suppression, we assessed the effect of filovirus proteins known to antagonize innate immune signaling pathways, including Ebola virus VP35 and VP24 and Marburg virus VP35, VP40, and VP24, on DC maturation and function. The data demonstrate that the VP35s from Ebola virus and Marburg virus are the major suppressors of DC maturation and that the effects on DCs of the remaining innate immune inhibitors are minor.

scholarly journals Leukotriene C4 induces migration of human monocyte–derived dendritic cells without loss of immunostimulatory function

Blood ◽  
2012 ◽  
Vol 119 (13) ◽  
pp. 3113-3122 ◽  
Author(s):  
Jens Dannull ◽  
Tristan Schneider ◽  
Walter T. Lee ◽  
Nicole de Rosa ◽  
Douglas S. Tyler ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Human Monocyte ◽  
Prostaglandin E ◽  
Promising Candidate ◽  
Cancer Vaccination ◽  
Cell Responses ◽  
Intracellular Calcium Mobilization ◽  
Dc Maturation

Abstract Generation of human monocyte–derived dendritic cells (DCs) for cancer vaccination involves ex vivo maturation in the presence of proinflammatory cytokines and prostaglandin E(2) (PGE2). Although the inclusion of PGE2 during maturation is imperative for the induction of DC migration, PGE2 has unfavorable effects on the immunostimulatory capacity of these cells. Like PGE2, leukotrienes (LTs) are potent mediators of DC migration. We therefore sought to characterize the migratory and immunologic properties of DCs that matured in the presence of LTB4, LTC4, LTD4, and PGE2. Here, we demonstrate that DCs matured in the presence of LTC4, but not LTB4 or LTD4, are superior to PGE2-matured DCs in stimulating CD4+ T-cell responses and in inducing antigen-specific cytotoxic T lymphocytes (CTLs) in vitro without concomitant induction or recruitment of regulatory T cells (Tregs). LTC4-matured DCs migrate efficiently through layers of extracellular matrix and secrete higher levels of immunostimulatory IL-12p70 while producing reduced levels of immune-inhibitory IL-10, IL12p40, indoleamine-2,3-dioxidase, and TIMP-1 (tissue inhibitor of matrix metalloproteinases). Intracellular calcium mobilization and receptor antagonist studies reveal that, in contrast to LTD4, LTC4 did not signal through CysLTR1 in DCs. Collectively, our data suggest that LTC4 represents a promising candidate to replace PGE2 in DC maturation protocols for cancer vaccination.

Chloroquine stimulates absorption and inhibits secretion of ileal water and electrolytes

1982 ◽  
Vol 243 (2) ◽  
pp. G117-G126
Author(s):  
R. Fogel ◽  
G. W. Sharp ◽  
M. Donowitz
Keyword(s):  
Cholera Toxin ◽  
Calcium Content ◽  
Intracellular Camp ◽  
Rabbit Ileum ◽  
Camp Content ◽  
Serosal Surface ◽  
Ileal Absorption ◽  
Camp Levels

The effects of chloroquine diphosphate, a drug with "'membrane-stabilizing" properties, were studied on basal ileal absorption and on ileal secretion induced by increased intracellular cAMP levels and calcium (serotonin). The studies were performed on rat (in vivo) and rabbit ileum (in vitro). Intraluminal chloroquine (10(-4) M) reversed cholera toxin- and theophylline-induced secretion in rat ileum but did not alter the cholera toxin- and theophylline-induced increases in cAMP content. Addition of chloroquine (10(-4) M) to the mucosal surface of rabbit ileum did not alter basal active electrolyte transport or the serotonin-induced decreased Na and Cl absorption but inhibited the theophylline-induced C1 secretion. Addition of chloroquine (10(-4)) M) to the serosal surface stimulated net Na and Cl absorption. This effect may involve intracellular calcium. Chloroquine increased the rabbit ileal calcium content and decreased 45Ca2+ influx from the serosal surface. Both the mucosal and serosal effects of chloroquine described led to a net increase in absorptive function of the intestine and should prove useful in developing treatment of diarrheal diseases.

scholarly journals In vitro and in vivo anti-inflammatory activities of a sterol-enriched fraction from freshwater green alga, Spirogyra sp.

2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Lei Wang ◽  
You-Jin Jeon ◽  
Jae-Il Kim
Keyword(s):  
Nitric Oxide ◽  
Green Alga ◽  
Raw 264.7 Cells ◽  
Ros Generation ◽  
Prostaglandin E ◽  
No Production ◽  
Raw 264.7 ◽  
Anti Inflammatory

Abstract Background Inflammation plays a crucial role in the pathogenesis of many diseases such as arthritis and atherosclerosis. In the present study, we evaluated anti-inflammatory activity of sterol-rich fraction prepared from Spirogyra sp., a freshwater green alga, in an effort to find bioactive extracts derived from natural sources. Methods The sterol content of ethanol extract of Spirogyra sp. (SPE) was enriched by fractionation with hexane (SPEH), resulting 6.7 times higher than SPE. Using this fraction, the in vitro and in vivo anti-inflammatory activities were evaluated in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells and zebrafish. Results SPEH effectively and dose-dependently decreased the production of nitric oxide (NO) and prostaglandin E2 (PGE2). SPEH suppressed the production of pro-inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β through downregulating nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells without cytotoxicity. The in vivo test results indicated that SPEH significantly and dose-dependently reduced reactive oxygen species (ROS) generation, cell death, and NO production in LPS-stimulated zebrafish. Conclusions These results demonstrate that SPEH possesses strong in vitro and in vivo anti-inflammatory activities and has the potential to be used as healthcare or pharmaceutical material for the treatment of inflammatory diseases.

scholarly journals Inhibitory Effects of Traditional Herbal Formula Pyungwi-San on Inflammatory ResponseIn VitroandIn Vivo

2013 ◽  
Vol 2013 ◽  
pp. 1-19 ◽  
Author(s):  
Ji Young Cha ◽  
Ji Yun Jung ◽  
Jae Yup Jung ◽  
Jong Rok Lee ◽  
Il Je Cho ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Mediators ◽  
Raw 264.7 Cells ◽  
Prostaglandin E ◽  
Herbal Formula ◽  
Paw Edema ◽  
Cox 2 ◽  
Anti Inflammatory

Pyungwi-san (PWS) is a traditional basic herbal formula. We investigated the effects of PWS on induction of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), pro-inflammatory cytokines (interleukin-6 (IL-6) and tumor necrosis factor-α(TNF-α)) and nuclear factor-kappa B (NF-κB) as well as mitogen-activated protein kinases (MAPKs) in lipopolysaccharide-(LPS-) induced Raw 264.7 cells and on paw edema in rats. Treatment with PWS (0.5, 0.75, and 1 mg/mL) resulted in inhibited levels of expression of LPS-induced COX-2, iNOS, NF-κB, and MAPKs as well as production of prostaglandin E2(PGE2), nitric oxide (NO), IL-6, and TNF-αinduced by LPS. Our results demonstrate that PWS possesses anti-inflammatory activities via decreasing production of pro-inflammatory mediators through suppression of the signaling pathways of NF-κB and MAPKs in LPS-induced macrophage cells. More importantly, results of the carrageenan-(CA-) induced paw edema demonstrate an anti-edema effect of PWS. In addition, it is considered that PWS also inhibits the acute edematous inflammations through suppression of mast cell degranulations and inflammatory mediators, including COX-2, iNOS and TNF-α. Thus, our findings may provide scientific evidence to explain the anti-inflammatory properties of PWSin vitroandin vivo.

Leukemic blasts fail to differentiate into mature antigen presenting cells, and may hinder dendritic cell maturation in vitro and in vivo

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 10556-10556
Author(s):  
J. Rosenblatt ◽  
R. Stone ◽  
C. Lenahan ◽  
Z. Wu ◽  
B. Vasir ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Vaccine ◽  
Leukemia Cells ◽  
Phenotypic Characteristics ◽  
Gm Csf ◽  
Maturation In Vitro ◽  
Dc Maturation

10556 Background: Dendritic cells (DC) play a key role in the development of tumor specific immune responses. Dendritic cells differentiated from leukemic blasts (LDC) are being explored as a tumor vaccine in AML. We examined the phenotypic and functional characteristics of LDC, the phenotypic characteristics of native DC in AML patients, and the effect of leukemic blasts on the phenotype of DC generated from normal donors. Methods: Leukemia blasts were isolated from peripheral blood of 24 patients with AML. LDC were generated by culturing blasts in the presence of GM-CSF, IL-4 and TNFa for 7 days. The phenotype of circulating DC1 (CD11C+/lin-) and DC2 (CD123+/ lin-) in AML patients was assessed by multichannel FACS analysis. To assess the effect of blasts on DC maturation, adherent mononuclear cells were isolated from normal donors, combined with leukemia cells in a 10:1 ratio, and cultured with GM-CSF, IL-4, and TNFa. Results: LDC demonstrate only modest expression of the costimulatory molecules CD80 and CD86 (mean expression 10% and 32%) and poorly express the maturation marker CD83 (mean expression 4%). Interferon gamma production by autologous T cells was not higher after stimulation with LDC than with blasts. LDC stimlation resulted in a 2 fold increase in both CD4+/CD25+/CD69+ (activated) and CD4+/CD25+/FOXP3+ (regulatory) T cells. Given the inability of leukemia progenitors to differentiate into phenotypically mature DC, we assessed whether leukemia cells directly inhibit differentiation of DC from normal progenitors. Expression of costimulatory molecules was decreased in DC differentiated in the presence of blasts. Mean expression of CD80, CD83, and CD86 was 16%, 2%, 83% and 49%, 10%, 99% for DCs generated in the presence or absence blasts respectively. Phenotypic characteristics of native DC in patients with AML were examined. In 3 experiments, a predominance of DC2 was seen (ratio DC2/DC1 5), and both DC1 and DC2 poorly expressed CD83 (mean expression 9% DC1, 0.9% DC2). Conclusions: LDC have phenotypic and functional deficiencies, limiting their efficacy as a tumor vaccine. Contact with leukemic blasts may inhibit DC maturation in vitro and in vivo, which may contribute to the lack of effective antitumor immunity in AML patients. No significant financial relationships to disclose.

scholarly journals Dendritic cells require NIK for CD40-dependent cross-priming of CD8+ T cells

2015 ◽  
Vol 112 (47) ◽  
pp. 14664-14669 ◽  
Author(s):  
Anand K. Katakam ◽  
Hans Brightbill ◽  
Christian Franci ◽  
Chung Kung ◽  
Victor Nunez ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd8 T Cells ◽  
Lymphoid Organs ◽  
Serine Threonine Kinase ◽  
Cross Presentation ◽  
Inflammatory Stimuli ◽  
Dc Maturation

Dendritic cells (DCs) link innate and adaptive immunity and use a host of innate immune and inflammatory receptors to respond to pathogens and inflammatory stimuli. Although DC maturation via canonical NF-κB signaling is critical for many of these functions, the role of noncanonical NF-κB signaling via the serine/threonine kinase NIK (NF-κB–inducing kinase) remains unclear. Because NIK-deficient mice lack secondary lymphoid organs, we generated transgenic mice with targeted NIK deletion in CD11c+ cells. Although these mice exhibited normal lymphoid organs, they were defective in cross-priming naive CD8+ T cells following vaccination, even in the presence of anti-CD40 or polyinosinic:polycytidylic acid to induce DC maturation. This impairment reflected two intrinsic defects observed in splenic CD8+ DCs in vitro, namely antigen cross-presentation to CD8+ T cells and secretion of IL-12p40, a cytokine known to promote cross-priming in vivo. In contrast, antigen presentation to CD4+ T cells was not affected. These findings reveal that NIK, and thus probably the noncanonical NF-κB pathway, is critical to allow DCs to acquire the capacity to cross-present antigen and prime CD8 T cells after exposure to licensing stimuli, such as an agonistic anti-CD40 antibody or Toll-like receptor 3 ligand.

scholarly journals Dendritic Cell Responses to Early Murine Cytomegalovirus Infection

2003 ◽  
Vol 197 (7) ◽  
pp. 885-898 ◽  
Author(s):  
Marc Dalod ◽  
Tanya Hamilton ◽  
Rachelle Salomon ◽  
Thais P. Salazar-Mather ◽  
Stanley C. Henry ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocyte Activation ◽  
Murine Cytomegalovirus ◽  
Cell Responses ◽  
Dc Maturation

Differentiation of dendritic cells (DCs) into particular subsets may act to shape innate and adaptive immune responses, but little is known about how this occurs during infections. Plasmacytoid dendritic cells (PDCs) are major producers of interferon (IFN)-α/β in response to many viruses. Here, the functions of these and other splenic DC subsets are further analyzed after in vivo infection with murine cytomegalovirus (MCMV). Viral challenge induced PDC maturation, their production of high levels of innate cytokines, and their ability to activate natural killer (NK) cells. The conditions also licensed PDCs to efficiently activate CD8 T cells in vitro. Non-plasmacytoid DCs induced T lymphocyte activation in vitro. As MCMV preferentially infected CD8α+ DCs, however, restricted access to antigens may limit plasmacytoid and CD11b+ DC contribution to CD8 T cell activation. IFN-α/β regulated multiple DC responses, limiting viral replication in all DC and IL-12 production especially in the CD11b+ subset but promoting PDC accumulation and CD8α+ DC maturation. Thus, during defense against a viral infection, PDCs appear specialized for initiation of innate, and as a result of their production of IFN-α/β, regulate other DCs for induction of adaptive immunity. Therefore, they may orchestrate the DC subsets to shape endogenous immune responses to viruses.

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