scholarly journals Interferon-? Mediates Opposing Effects on Interferon-?-dependent Interleukin-12 p70 Secretion by Human Monocyte-Derived Dendritic Cells

2007 ◽  
Vol 65 (2) ◽  
pp. 107-117 ◽  
Author(s):  
T. Nagai ◽  
O. Devergne ◽  
G. A. van Seventer ◽  
J. M. van Seventer
2006 ◽  
Vol 74 (6) ◽  
pp. 3296-3304 ◽  
Author(s):  
Elena Giacomini ◽  
Ambar Sotolongo ◽  
Elisabetta Iona ◽  
Martina Severa ◽  
Maria Elena Remoli ◽  
...  

ABSTRACT The Mycobacterium tuberculosis genome encodes 13 sigma factors. We have previously shown that mutations in some of these transcriptional activators render M. tuberculosis sensitive to various environmental stresses and can attenuate the virulence phenotype. In this work, we focused on extracytoplasmic factor σE and studied the effects induced by the deletion of its structural gene (sigE) in the infection of human monocyte-derived dendritic cells (MDDC). We found that the wild-type M. tuberculosis strain (H37Rv), the sigE mutant (ST28), and the complemented strain (ST29) were able to infect dendritic cells (DC) to similar extents, although at 4 days postinfection a reduced ability to grow inside MDDC was observed for the sigE mutant ST28. After mycobacterium capture, the majority of MDDC underwent full maturation and expressed both inflammatory cytokines, such as tumor necrosis factor alpha, and the regulatory cytokines interleukin-12 (IL-12), IL-18, and beta interferon (IFN-β). Conversely, a higher level of production of IL-10 was observed in ST28-infected MDDC compared to H37Rv- or ST29-infected cell results. However, in spite of the presence of IL-10, supernatants from ST28-infected DC induced IFN-γ production by T cells similarly to those from H37Rv-infected DC culture. On the other hand, IL-10 impaired CXCL10 production in sigE mutant-infected DC and, indeed, its neutralization restored CXCL10 secretion. In line with these results, supernatants from ST28-infected cells showed a decreased capability to recruit CXCR3+ CD4+ T cells compared to those obtained from H37Rv-infected DC culture. Thus, our findings suggest that the sigE mutant-induced secretion of IL-10 inhibits CXCL10 expression and, in turn, the recruitment of activated-effector cells involved in the formation of granulomas.


Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3499-3504 ◽  
Author(s):  
Paul J. Mosca ◽  
Amy C. Hobeika ◽  
Timothy M. Clay ◽  
Smita K. Nair ◽  
Elaine K. Thomas ◽  
...  

Abstract Dendritic cells (DCs) may arise from multiple lineages and progress through a series of intermediate stages until fully mature, at which time they are capable of optimal antigen presentation and T-cell activation. High cell surface expression of CD83 is presumed to correlate with full maturation of DCs, and a number of agents have been shown to increase CD83 expression on DCs. We hypothesized that interleukin 12 (IL-12) expression would be a more accurate marker of functionally mature DCs capable of activating antigen-specific T cells. We used combinations of signaling through CD40, using CD40 ligand trimer (CD40L), and interferon gamma to demonstrate that CD83 expression is necessary but not sufficient for optimal production of IL-12 by DCs. Phenotypically mature DCs could be induced to produce high levels of IL-12 p70 only when provided 2 simultaneous stimulatory signals. By intracellular cytokine detection, we determined that only a subset of cells that express high levels of CD80 and CD83 generate large amounts of IL-12. DCs matured with both signals are superior to DCs stimulated with the individual agents in activating antigen-specific T cell in vitro. These findings have important implications regarding the identification, characterization, and clinical application of functionally mature DCs.


Blood ◽  
2005 ◽  
Vol 105 (8) ◽  
pp. 3206-3213 ◽  
Author(s):  
Jens Dannull ◽  
Smita Nair ◽  
Zhen Su ◽  
David Boczkowski ◽  
Christian DeBeck ◽  
...  

Abstract The objective of this study was to investigate whether the immunostimulatory properties of human monocyte-derived dendritic cells (DCs) could be enhanced by triggering OX40/OX40L signaling. Since monocyte-derived DCs possess only low-cell surface levels of OX40L in the absence of CD40 signaling, OX40L was expressed by transfection of DCs with the corresponding mRNA. We show that OX40L mRNA transfection effectively enhanced the immunostimulatory function of DCs at multiple levels: OX40L mRNA transfection augmented allogeneic and HLA class II epitope-specific CD4+ T-cell responses, improved the stimulation of antigen-specific cytotoxic T lymphocytes (CTLs) in vitro without interfering with the prostaglandin E2 (PGE2)–mediated migratory function of the DCs, and facilitated interleukin 12 p70 (IL-12p70)–independent T helper type 1 (Th1) polarization of naive CD4+ T-helper cells. Furthermore, vaccination of tumor-bearing mice using OX40L mRNA–cotransfected DCs resulted in significant enhancement of therapeutic antitumor immunity due to in vivo priming of Th1-type T-cell responses. Our data suggest that transfection of DCs with OX40L mRNA may represent a promising strategy that could be applied in clinical immunotherapy protocols, while circumventing the current unavailability of reagents facilitating OX40 ligation.


mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Laura Spelmink ◽  
Vicky Sender ◽  
Karina Hentrich ◽  
Thomas Kuri ◽  
Laura Plant ◽  
...  

ABSTRACTA functional immune response is crucial to prevent and limit infections withStreptococcus pneumoniae. Dendritic cells (DCs) play a central role in orchestrating the adaptive and innate immune responses by communicating with other cell types via antigen presentation and secretion of cytokines. In this study, we set out to understand how pneumococci activate human monocyte-derived DCs to produce interleukin-12 (IL-12) p70, an important cytokine during pneumococcal infections. We show that IL-12p70 production requires uptake of bacteria as well as the presence of the adaptor molecule TRIF, which is known to transfer signals of Toll-like receptor 3 (TLR3) or TLR4 from the endosome into the cell. While TLR4 is redundant for IL-12p70 production in DCs, we found that TLR3 is required to induce full IL-12p70 secretion. Influenza A virus (IAV) infection of DCs did not induce IL-12p70 but markedly upregulated TLR3 expression that during coinfection withS. pneumoniaesignificantly enhanced IL-12p70 secretion. Finally, we show that pneumococcal RNA can act as a bacterial stimulus for TLR3 and that it is a key signal to induce IL-12p70 production during challenge of DCs with pneumococci.IMPORTANCEStreptococcus pneumoniae, a common colonizer of the nose, is the causative agent of severe and deadly diseases. A well-orchestrated immune response is vital to prevent and limit these diseases. Dendritic cells (DCs) reside in the mucosal linings of the lungs and sample antigens. They are activated by pathogens to present antigens and secrete cytokines. While many studies focus on murine models, we focused our work on human monocyte-derived DCs. We found that pneumococcal RNA is an important stimulus in DCs to activate the endosomal receptor TLR3, a receptor previously not identified to sense pneumococci, and its adaptor molecule TRIF. This leads to secretion of the cytokine interleukin-12 (IL-12). Severe pneumococcal pneumonia occurs closely after influenza A virus (IAV) infection. We show that IAV infection upregulates TLR3 in DCs, which sensitizes the cells to endosomal pneumococcal RNA. This new insight contributes to unlock the interplay between pneumococci, IAV, and humans.


2002 ◽  
Vol 70 (10) ◽  
pp. 5533-5539 ◽  
Author(s):  
Kenneth C. Bagley ◽  
Sayed F. Abdelwahab ◽  
Robert G. Tuskan ◽  
Timothy R. Fouts ◽  
George K. Lewis

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.


Author(s):  
Christiane Braun ◽  
Sebastian Schlaweck ◽  
Solveig Nora Daecke ◽  
Peter Brossart ◽  
Annkristin Heine

AbstractThe PI3Kδ-inhibitor Idelalisib is approved for the treatment of Non-Hodgkin lymphoma. However, its use has been decreased within the last years due to deleterious infections such as cytomegalovirus and pneumocystis jirovecii. Here, we have investigated the effect of Idelalisib on human monocyte-derived dendritic cells (DCs) as important players in the induction of immune responses. We found that Idelalisib-treated DCs displayed impaired T cell stimulatory function. PI3Kδ inhibition during differentiation resulted in decreased Interleukin-12, Interleukin-13 and TNFα production by DCs after lipopolysaccharide stimulation. Moreover, DCs showed decreased expression of the activation marker CD83 after Idelalisib treatment. Further, in line with this was the failure of Idelalisib-treated DCs to properly induce allogeneic T cells in a dose-dependent manner. Finally, activation of the NFκB pathway was also ablated in Idelalisib-treated DCs. Our results implicate that severe infectious complications may not only result from direct PI3Kδ-inhibition in T cells, but also from impaired DC function in Idelalisib-treated patients. Here, we provide new insight into the pathogenesis of Idelalisib-associated infectious complications. Our study may further provide a rationale for the use of Idelalisib as a novel therapeutic option in inflammatory diseases.


Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3499-3504 ◽  
Author(s):  
Paul J. Mosca ◽  
Amy C. Hobeika ◽  
Timothy M. Clay ◽  
Smita K. Nair ◽  
Elaine K. Thomas ◽  
...  

Dendritic cells (DCs) may arise from multiple lineages and progress through a series of intermediate stages until fully mature, at which time they are capable of optimal antigen presentation and T-cell activation. High cell surface expression of CD83 is presumed to correlate with full maturation of DCs, and a number of agents have been shown to increase CD83 expression on DCs. We hypothesized that interleukin 12 (IL-12) expression would be a more accurate marker of functionally mature DCs capable of activating antigen-specific T cells. We used combinations of signaling through CD40, using CD40 ligand trimer (CD40L), and interferon gamma to demonstrate that CD83 expression is necessary but not sufficient for optimal production of IL-12 by DCs. Phenotypically mature DCs could be induced to produce high levels of IL-12 p70 only when provided 2 simultaneous stimulatory signals. By intracellular cytokine detection, we determined that only a subset of cells that express high levels of CD80 and CD83 generate large amounts of IL-12. DCs matured with both signals are superior to DCs stimulated with the individual agents in activating antigen-specific T cell in vitro. These findings have important implications regarding the identification, characterization, and clinical application of functionally mature DCs.


2006 ◽  
Vol 74 (3) ◽  
pp. 1890-1895 ◽  
Author(s):  
Ulrike Meltzer ◽  
David Goldblatt

ABSTRACT Dendritic cells (DCs) are critical antigen presentation cells whose influence on murine immune responses to polysaccharide antigens has only recently been elucidated. Little is known about human DC-polysaccharide interactions. We set out to study the interaction between human monocyte-derived DCs and pneumococcal capsular polysaccharides (PPS) in vitro. Immature DCs were generated from peripheral blood monocytes and incubated with fluorescein isothiocyanate-labeled PPS type 9N or 14 for assessment of uptake. DCs were exposed to PPS type 1, 6B, 9N, 14, 19F, or 23F in the absence or presence of Escherichia coli lipopolysaccharide (LPS) for assessment of phenotypic DC maturation and cytokine production. PPS were taken up by immature DCs and proceeded to HLA-DR+ and lysosome-associated membrane protein-1+ late endosomal compartments. Uptake was reduced in the presence of cytochalasin D and wortmannin, suggesting that both cytoskeletal rearrangements and phosphatidylinositol 3-kinase activation may be required for internalization. None of the PPS tested induced DC phenotype changes, maturation, or interleukin-12 (IL-12)/IL-10 production. However, PPS were capable of modulating the response of the DCs to a second signal such as LPS. Exposure of DCs to PPS in the presence of LPS resulted in an altered cytokine balance with significantly increased IL-10 production and reduced IL-12 production compared to LPS alone. This effect was not seen using the control antigen tetanus toxoid. DC-pneumococcus interaction may affect subsequent immune responses to pneumococci, as an altered cytokine balance may have a profound effect on DC-driven T-cell priming.


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