scholarly journals Differential Regulation of Inflammatory Cytokine Secretion by Human Dendritic Cells upon Chlamydia trachomatis Infection

2004 ◽  
Vol 72 (12) ◽  
pp. 7231-7239 ◽  
Author(s):  
Ana Gervassi ◽  
Mark R. Alderson ◽  
Robert Suchland ◽  
Jean François Maisonneuve ◽  
Kenneth H. Grabstein ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Chlamydia Trachomatis ◽  
Wide Spectrum ◽  
Cytokine Secretion ◽  
Host Cells ◽  
Microbial Pathogens ◽  
Potential Contribution ◽  
Necrosis Factor Alpha ◽  
Chlamydia Trachomatis Infection ◽  
Tnf Α

ABSTRACT Chlamydia trachomatis is an obligate intracellular gram-negative bacterium responsible for a wide spectrum of diseases in humans. Both genital and ocular C. trachomatis infections are associated with tissue inflammation and pathology. Dendritic cells (DC) play an important role in both innate and adaptive immune responses to microbial pathogens and are a source of inflammatory cytokines. To determine the potential contribution of DC to the inflammatory process, human DC were infected with C. trachomatis serovar E or L2. Both C. trachomatis serovars were found to infect and replicate in DC. Upon infection, DC up-regulated the expression of costimulatory (B7-1) and cell adhesion (ICAM-1) molecules. Furthermore, chlamydial infection induced the secretion of interleukin-1β (IL-1β), IL-6, IL-8, IL-12p70, IL-18, and tumor necrosis factor alpha (TNF-α). The mechanisms involved in Chlamydia-induced IL-1β and IL-18 secretion differed from those of the other cytokines. Chlamydia-induced IL-1β and IL-18 secretion required infection with viable bacteria and was associated with the Chlamydia-induced activation of caspase-1 in infected host cells. In contrast, TNF-α and IL-6 secretion did not require that the Chlamydia be viable, suggesting that there are at least two mechanisms involved in the Chlamydia-induced cytokine secretion in DC. Interestingly, an antibody to Toll-like receptor 4 inhibited Chlamydia-induced IL-1β, IL-6, and TNF-α secretion. The data herein demonstrate that DC can be infected by human C. trachomatis serovars and that chlamydial components regulate the secretion of various cytokines in DC. Collectively, these data suggest that DC play a role in the inflammatory processes caused by chlamydial infections.

Morin Promotes the Production of Th2 Cytokine by Modulating Bone Marrow-Derived Dendritic Cells

2006 ◽  
Vol 34 (04) ◽  
pp. 667-684 ◽  
Author(s):  
Chia-Yang Li ◽  
Jau-Ling Suen ◽  
Bor-Luen Chiang ◽  
Pei-Dawn Lee Chao ◽  
Shih-Hua Fang
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Dendritic Cells ◽  
Interleukin 12 ◽  
Th2 Response ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Th Differentiation ◽  
Th1 And Th2 Responses

Our previous studies had reported that morin decreased the interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS)-activated macrophages, suggesting that morin may promote helper T type 2 (Th2) response in vivo. Dendritic cells (DCs) are the most potent antigen presenting cells and known to play a major role in the differentiation of helper T type 1 (Th1) and Th2 responses. This study aimed to reveal whether morin is able to control the Th differentiation through modulating the maturation and functions of DCs. Bone marrow-derived dendritic cells (BM-DCs) were incubated with various concentrations of morin and their characteristics were studied. The results indicated that morin significantly affects the phenotype and cytokine expression of BM-DCs. Morin reduced the production of IL-12 and TNF-α in BM-DCs, in response to LPS stimulation. In addition, the proliferative response of stimulated alloreactive T cells was significantly decreased by morin in BM-DCs. Furthermore, allogeneic T cells secreted higher IL-4 and lower IFN-γ in response to morin in BM-DCs. In conclusion, these results suggested that morin favors Th2 cell differentiation through modulating the maturation and function of BM-DCs.

scholarly journals Chlamydia trachomatis Cellular Exit Alters Interactions with Host Dendritic Cells

2017 ◽  
Vol 85 (5) ◽  
Author(s):  
Ashley M. Sherrid ◽  
Kevin Hybiske
Keyword(s):  
Dendritic Cells ◽  
Dendritic Cell ◽  
Chlamydia Trachomatis ◽  
Innate Immune ◽  
Host Cells ◽  
Bacterial Survival ◽  
Content Type ◽  
Innate Immune Signaling ◽  
Host Membrane ◽  
Membrane Bound

ABSTRACT The strategies utilized by pathogens to exit host cells are an area of pathogenesis which has received surprisingly little attention, considering the necessity of this step for infections to propagate. Even less is known about how exit through these pathways affects downstream host-pathogen interactions and the generation of an immune response. Chlamydia trachomatis exits host epithelial cells through two equally active mechanisms: lysis and extrusion. Studies have characterized the outcome of interactions between host innate immune cells, such as dendritic cells and macrophages, and free, extracellular Chlamydia bacteria, such as those resulting from lysis. Exit via extrusion generates a distinct, host-membrane-bound compartment of Chlamydia separate from the original infected cell. In this study, we assessed the effect of containment within extrusions upon the interaction between Chlamydia and host dendritic cells. Extrusion dramatically affected the outcome of Chlamydia-dendritic cell interactions for both the bacterium and the host cell. Dendritic cells rapidly underwent apoptosis in response to engulfment of an extrusion, while uptake of an equivalent dose of free Chlamydia had no such effect. Containment within an extrusion also prolonged bacterial survival within dendritic cells and altered the initial innate immune signaling by the dendritic cell.

The TNF-α-308G/A Polymorphism is Not Associated with Ocular Chlamydia trachomatis Infection in Han Chinese Children

2016 ◽  
Vol 37 (2) ◽  
pp. 245-247
Author(s):  
Wenwen Xue ◽  
Qingzhong Wang ◽  
Zhiqiang Li ◽  
Lina Lu ◽  
Jianfeng Zhu ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Han Chinese ◽  
Chinese Children ◽  
Chlamydia Trachomatis Infection ◽  
Tnf Α

scholarly journals Febrile Core Temperature Is Essential for Optimal Host Defense in Bacterial Peritonitis

2000 ◽  
Vol 68 (3) ◽  
pp. 1265-1270 ◽  
Author(s):  
Qinqqi Jiang ◽  
Alan S. Cross ◽  
Ishwar S. Singh ◽  
T. Timothy Chen ◽  
Rose M. Viscardi ◽  
...  
Keyword(s):  
Core Temperature ◽  
Host Defense ◽  
Bacterial Infections ◽  
Bacterial Load ◽  
Cytokine Expression ◽  
Microbial Pathogens ◽  
Necrosis Factor Alpha ◽  
Bacterial Peritonitis ◽  
Tnf Α ◽  
Factor Alpha

ABSTRACT Fever, a nonspecific acute-phase response, has been associated with improved survival and shortened disease duration in infections, but the mechanisms of these beneficial responses are poorly understood. We previously reported that increasing core temperature of bacterial endotoxin (LPS)-challenged mice to the normal febrile range modified expression of tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), and IL-6, three cytokines critical to mounting an initial defense against microbial pathogens, but survival was not improved in the warmer animals. We speculated that our inability to show a survival benefit of optimized cytokine expression in the warmer animals reflected our use of LPS, a nonreplicating agonist, rather than an infection with viable pathogens. The objective of this study was to determine if increasing murine core temperature altered cytokine expression and improved survival in an experimental bacterial peritonitis model. We showed that housing mice at 35.5°C rather than 23°C increased core temperature from 36.5 to 37.5°C to 39.2 to 39.7°C, suppressed plasma TNF-α expression for the initial 48 h, delayed gamma interferon expression, improved survival, and reduced the bacterial load in mice infected with Klebsiella pneumoniae peritonitis. We showed that the reduced bacterial load was not caused by a direct effect on bacterial proliferation and probably reflected enhanced host defense. These data suggest that the increase in core temperature that occurs during bacterial infections is essential for optimal antimicrobial host defense.

scholarly journals Mycobacterium tuberculosis Diverts Alpha Interferon-Induced Monocyte Differentiation from Dendritic Cells into Immunoprivileged Macrophage-Like Host Cells

2004 ◽  
Vol 72 (8) ◽  
pp. 4385-4392 ◽  
Author(s):  
Sabrina Mariotti ◽  
Raffaela Teloni ◽  
Elisabetta Iona ◽  
Lanfranco Fattorini ◽  
Giulia Romagnoli ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Mycobacterium Tuberculosis ◽  
Immune Surveillance ◽  
Interleukin 10 ◽  
T Cell Response ◽  
Host Cells ◽  
Alpha Interferon ◽  
Chronic Infections ◽  
Necrosis Factor Alpha ◽  
Monocyte Differentiation

ABSTRACT Dendritic cells (DCs) are critical for initiating a pathogen-specific T-cell response. During chronic infections the pool of tissue DCs must be renewed by recruitment of both circulating DC progenitors and in loco differentiating monocytes. However, the interaction of monocytes with pathogens could affect their differentiation. Mycobacterium tuberculosis has been shown to variably interfere with the generation and function of antigen-presenting cells (APCs). In this study we found that when alpha interferon (IFN-α) is used as an inductor of monocyte differentiation, M. tuberculosis inhibits the generation of DCs, forcing the generation of immunoprivileged macrophage-like cells instead. Cells derived from M. tuberculosis-infected monocyte-derived macrophages (M. tuberculosis-infected MoMφ) retained CD14 without acquiring CD1 molecules and partially expressed B7.2 but did not up-regulate B7.1 and major histocompatibility complex (MHC) class I and II molecules. They synthesized tumor necrosis factor alpha and interleukin-10 (IL-10) but not IL-12. They also showed a reduced ability to induce proliferation and functional polarization of allogeneic T lymphocytes. Thus, in the presence of IFN-α, M. tuberculosis may hamper the renewal of potent APCs, such as DCs, generating a safe habitat for intracellular growth. M. tuberculosis-infected MoMφ, in fact, showed reduced expression of both signal 1 (CD1, MHC classes I and II) and signal 2 (B7.1 and B7.2), which are essential for mycobacterium-specific T-lymphocyte priming and/or activation. These data further suggest that M. tuberculosis has the ability to specifically interfere with monocyte differentiation. This ability may represent an effective M. tuberculosis strategy for eluding immune surveillance and persisting in the host.

scholarly journals Maturation of Human Dendritic Cells by Cell Wall Skeleton of Mycobacterium bovis Bacillus Calmette-Guérin: Involvement of Toll-Like Receptors

2000 ◽  
Vol 68 (12) ◽  
pp. 6883-6890 ◽  
Author(s):  
Shoutaro Tsuji ◽  
Misako Matsumoto ◽  
Osamu Takeuchi ◽  
Shizuo Akira ◽  
Ichiro Azuma ◽  
...  
Keyword(s):  
Cell Wall ◽  
Dendritic Cells ◽  
Mycobacterium Bovis ◽  
Surface Expression ◽  
Necrosis Factor Alpha ◽  
Mycolic Acids ◽  
Tnf Α ◽  
Toll Like Receptor 2 ◽  
Factor Alpha ◽  
Human Dendritic Cells

ABSTRACT The constituents of mycobacteria are an effective immune adjuvant, as observed with complete Freund's adjuvant. In this study, we demonstrated that the cell wall skeleton of Mycobacterium bovis bacillus Calmette-Guérin (BCG-CWS), a purified noninfectious material consisting of peptidoglycan, arabinogalactan, and mycolic acids, induces maturation of human dendritic cells (DC). Surface expression of CD40, CD80, CD83, and CD86 was increased by BCG-CWS on human immature DC, and the effect was similar to those of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), heat-killed BCG, and viable BCG. BCG-CWS induced the secretion of TNF-α, IL-6, and IL-12 p40. CD83 expression was increased by a soluble factor secreted from BCG-CWS-treated DC and was completely inhibited by monoclonal antibodies against TNF-α. BCG-CWS-treated DC stimulated extensive allogeneic mixed lymphocyte reactions. The level of TNF-α secreted through BCG-CWS was partially suppressed in murine macrophages with no Toll-like receptor 2 (TLR 2) or TLR4 and was completely lost in TLR2 and TLR4 double-deficient macrophages. These results suggest that the BCG-CWS induces TNF-α secretion from DC via TLR2 and TLR4 and that the secreted TNF-α induces the maturation of DC per se.

scholarly journals Transient Neutralization of Tumor Necrosis Factor Alpha Can Produce a Chronic Fungal Infection in an Immunocompetent Host: Potential Role of Immature Dendritic Cells

2005 ◽  
Vol 73 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Amy C. Herring ◽  
Nicole R. Falkowski ◽  
Gwo-Hsiao Chen ◽  
Rod A. McDonald ◽  
Galen B. Toews ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Fungal Infection ◽  
Immune Deviation ◽  
Immunocompetent Host ◽  
Necrosis Factor Alpha ◽  
Immature Dendritic Cells ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT The mechanisms underlying induction of immune dysregulation and chronic fungal infection by a transient tumor necrosis factor alpha (TNF-α) deficiency remain to be defined. The objective of our studies was to determine the potential contribution of neutropenia and immature dendritic cells to the immune deviation. Administration of an anti-TNF-α monoclonal antibody at day 0 neutralized TNF-α only during the first week of a pulmonary Cryptococcus neoformans infection. Transient neutralization of TNF-α resulted in transient depression of interleukin-12 (IL-12), monocyte chemotactic protein 1 (MCP-1), and gamma interferon (IFN-γ) production but permanently impaired long-term clearance of the infection from the lungs even after the levels of these cytokines increased and a vigorous inflammatory response developed. Early neutrophil recruitment was defective in the absence of TNF-α. However, as demonstrated by neutrophil depletion studies, this did not account for the decrease in IL-12 and IFN-γ levels and did not play a role in establishing chronic pulmonary cryptococcal infection. Transient TNF-α neutralization also produced a deficiency in CD11c+ MHC II+ cells and IL-12 in the lymph nodes, potentially implicating a defect in mature dendritic cell trafficking. Transfer of cryptococcal antigen-pulsed immature dendritic cells into naïve mice prior to intratracheal challenge resulted in the development of a nonprotective immune response to C. neoformans that was similar to that observed in anti-TNF-α-treated mice (increased IL-4, IL-5, and IL-10 levels, pulmonary eosinophilia, and decreased clearance). Thus, stimulation of an antifungal response by immature dendritic cells can result in an immune deviation similar to that produced by transient TNF-α deficiency, identifying a new mechanism by which a chronic fungal infection can occur in an immunocompetent host.

scholarly journals Interaction of Neisseria meningitidis with Human Dendritic Cells

2001 ◽  
Vol 69 (11) ◽  
pp. 6912-6922 ◽  
Author(s):  
Annette Kolb-Mäurer ◽  
Alexandra Unkmeir ◽  
Ulrike Kämmerer ◽  
Claudia Hübner ◽  
Thomas Leimbach ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Neisseria Meningitidis ◽  
Proinflammatory Cytokines ◽  
Interleukin 1 ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Factor Alpha ◽  
Human Dendritic Cells ◽  
Necrosis Factor

ABSTRACT Infection with Neisseria meningitidis serogroup B is responsible for fatal septicemia and meningococcal meningitis. The severity of disease directly correlates with the production of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-6, and IL-8. However, the source of these cytokines has not been clearly defined yet. Since bacterial infection involves the activation of dendritic cells (DCs), we analyzed the interaction of N. meningitidis with monocyte-derived DCs. Using N. meningitidis serogroup B wild-type and unencapsulated bacteria, we found that capsule expression significantly impaired neisserial adherence to DCs. In addition, phagocytic killing of the bacteria in the phagosome is reduced by at least 10- to 100-fold. However, all strains induced strong secretion of proinflammatory cytokines TNF-α, IL-6, and IL-8 by DCs (at least 1,000-fold at 20 h postinfection [p.i.]), with significantly increased cytokine levels being measurable by as early as 6 h p.i. Levels of IL-1β, in contrast, were increased only 200- to 400-fold at 20 h p.i. with barely measurable induction at 6 h p.i. Moreover, comparable amounts of cytokines were induced by bacterium-free supernatants of Neisseria cultures containing neisserial lipooligosaccharide as the main factor. Our data suggest that activated DCs may be a significant source of high levels of proinflammatory cytokines in neisserial infection and thereby may contribute to the pathology of meningococcal disease.

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