scholarly journals Cholera Toxin Impairs the Differentiation of Monocytes into Dendritic Cells, Inducing Professional Antigen-Presenting Myeloid Cells

2010 ◽  
Vol 79 (3) ◽  
pp. 1300-1310 ◽  
Author(s):  
Filippo Veglia ◽  
Ester Sciaraffia ◽  
Antonella Riccomi ◽  
Dora Pinto ◽  
Donatella R. M. Negri ◽  
...  

ABSTRACTCholera toxin (CT) is a potent adjuvant for mucosal vaccination; however, its mechanism of action has not been clarified completely. It is well established that peripheral monocytes differentiate into dendritic cells (DCs) bothin vitroandin vivoand that monocytes are thein vivoprecursors of mucosal CD103−proinflammatory DCs. In this study, we asked whether CT had any effects on the differentiation of monocytes into DCs. We found that CT-treated monocytes, in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 4 (IL-4), failed to differentiate into classical DCs (CD14lowCD1ahigh) and acquired a macrophage-like phenotype (CD14highCD1alow). Cells differentiated in the presence of CT expressed high levels of major histocompatibility complex class I (MHC-I) and MHC-II and CD80 and CD86 costimulatory molecules and produced larger amounts of IL-1β, IL-6, and IL-10 but smaller amounts of tumor necrosis factor alpha (TNF-α) and IL-12 than did monocytes differentiated into DCs in the absence of CT. The enzymatic activity of CT was found to be important for the skewing of monocytes toward a macrophage-like phenotype (Ma-DCs) with enhanced antigen-presenting functions. Indeed, treatment of monocytes with scalar doses of forskolin (FSK), an activator of adenylate cyclase, induced them to differentiate in a dose-dependent manner into a population with phenotype and functions similar to those found after CT treatment. Monocytes differentiated in the presence of CT induced the differentiation of naïve T lymphocytes toward a Th2 phenotype. Interestingly, we found that CT interferes with the differentiation of monocytes into DCsin vivoand promotes the induction of activated antigen-presenting cells (APCs) following systemic immunization.

2005 ◽  
Vol 73 (1) ◽  
pp. 413-421 ◽  
Author(s):  
Kenneth C. Bagley ◽  
Sayed F. Abdelwahab ◽  
Robert G. Tuskan ◽  
George K. Lewis

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.


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.


2019 ◽  
Author(s):  
Shira Tabachnick-Cherny ◽  
Dikla Berko ◽  
Sivan Pinto ◽  
Caterina Curato ◽  
Yochai Wolf ◽  
...  

AbstractProtective MHC-I dependent immune responses require an overlap between repertoires of proteins directly presented on target cells and cross-presented by professional antigen presenting cells (APC), specifically dendritic cells (DCs). How stable proteins that rely on DRiPs for direct presentation are captured for cell-to-cell transfer remains enigmatic. Here we address this issue using a combination of in vitro and in vivo approaches involving stable and unstable versions of ovalbumin model antigens displaying DRiP-dependent and -independent antigen presentation, respectively. Apoptosis, but not necrosis of donor cells was found associated with robust p62-dependent global protein aggregate formation and captured stable proteins permissive for DC cross-presentation. Potency of aggregates to serve as antigen source was directly demonstrated using polyglutamine-equipped model substrates. Collectively, our data implicate global protein aggregation in apoptotic cells as a mechanism that ensures the overlap between MHC-I epitopes presented directly or cross-presented by APC and demonstrate the unusual ability of DC to process stable protein aggregates.SummaryProtective T cell immunity relies on the overlap of the antigen repertoire expressed by cells and the repertoire presented by dendritic cells that are required to trigger naïve T cells. We suggest a mechanism that contributes to ensure this antigenic overlap. Our findings demonstrate that upon apoptosis stable proteins are aggregated in p62-dependent pathway and that dendritic cells are capable to efficiently process these aggregates to retrieve antigens for T cell stimulation.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jie Yang ◽  
Yiming Yang ◽  
Huahua Fan ◽  
Hejian Zou

TGF-β-induced regulatory T cells (iTregs) retain Foxp3 expression and immune-suppressive activity in collagen-induced arthritis (CIA). However, the mechanisms whereby transferred iTregs suppress immune responses, particularly the interplay between iTregs and dendritic cells (DCs)in vivo, remain incompletely understood. In this study, we found that after treatment with iTregs, splenic CD11c+DCs, termed “DCiTreg,” expressed tolerogenic phenotypes, secreted high levels of IL-10, TGF-β, and IDO, and showed potent immunosuppressive activityin vitro. After reinfusion with DCiTreg, marked antiarthritic activity improved clinical scores and histological end-points were observed. The serological levels of inflammatory cytokines and anti-CII antibodies were low and TGF-βproduction was high in the DCiTreg-treated group. DCiTregalso induced new iTregsin vivo. Moreover, the inhibitory activity of DCiTregon CIA was lost following pretreatment with the inhibitor of indoleamine 2,3-dioxygenase (IDO). Collectively, these findings suggest that transferred iTregs could induce tolerogenic characteristics in splenic DCs and these cells could effectively dampen CIA in an IDO-dependent manner. Thus, the potential therapeutic effects of iTregs in CIA are likely maintained through the generation of tolerogenic DCsin vivo.


2021 ◽  
Author(s):  
Tyler Jacks ◽  
Alex Jaeger ◽  
Lauren Stopfer ◽  
Emma Sanders ◽  
Demi Sandel ◽  
...  

Abstract Effective immunosurveillance of cancer requires the presentation of peptide antigens on major histocompatibility complex Class I (MHC-I). Recent developments in proteomics have improved the identification of peptides that are naturally presented by MHC-I, collectively known as the “immunopeptidome”. Current approaches to profile tumor immunopeptidomes have been limited to in vitro investigation, which fails to capture the in vivo repertoire of MHC-I peptides, or bulk tumor lysates, which are obscured by the lack of tumor-specific MHC-I isolation. To overcome these limitations, we report here the engineering of a Cre recombinase-inducible affinity tag into the endogenous mouse MHC-I gene and targeting of this allele to the KrasLSL-G12D/+; p53fl/fl (KP) mouse model (KP; KbStrep). This novel approach has allowed us to isolate tumor-specific MHC-I peptides from autochthonous pancreatic ductal adenocarcinoma (PDAC) and lung adenocarcinoma (LUAD) in vivo. With this powerful analytical tool, we were able to profile the evolution of the LUAD immunopeptidome through tumor progression and show that in vivo MHC-I presentation is shaped by post-translational mechanisms. We also uncovered novel, putative LUAD tumor associated antigens (TAAs). Many peptides that were recurrently presented in vivo exhibited very low expression of the cognate mRNA, provoking reconsideration of antigen prediction pipelines that triage peptides according to transcript abundance. Beyond cancer, the KbStrep allele is compatible with a broad range of Cre-driver lines to explore antigen presentation in vivo in the pursuit of understanding basic immunology, infectious disease, and autoimmunity.


2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.


Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 624-630 ◽  
Author(s):  
Y Sonoda ◽  
Y Kuzuyama ◽  
S Tanaka ◽  
S Yokota ◽  
T Maekawa ◽  
...  

Abstract We studied the effects of recombinant human interleukin-4 (rhIL-4) on megakaryocyte colony formation from enriched hematopoietic progenitors. IL-4 strongly inhibited pure and mixed megakaryocyte colony formation in a dose-dependent manner. Formation of erythroid bursts, eosinophil colonies, and erythrocyte-containing mixed colonies was not affected by the addition of IL-4 as reported previously (Sonoda Y, et al; Blood 75:1615, 1990). Delayed addition experiments suggested that IL-4 acts on an early stage of proliferation of megakaryocyte progenitors. Neutralizing antibodies (antisera) prepared against transforming growth factor beta, tumor necrosis factor alpha, interferon alpha (IFN alpha), and IFN gamma did not affect the inhibitory effects of IL-4 on pure and mixed megakaryocyte colony formation. In addition, the inhibitory effects of IL-4 was also seen in serum-free cultures and in cultures containing highly enriched CD34+, HLA-DR+ cells as a target population. These results indicate that IL-4 may function as one of the negative regulators in human megakaryocytopoiesis in vitro.


2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Kirsi Tamminen ◽  
Suvi Heinimäki ◽  
Timo Vesikari ◽  
Vesna Blazevic

We have previously shown that rotavirus (RV) inner capsid protein VP6 has an adjuvant effect on norovirus (NoV) virus-like particle- (VLP-) induced immune responses and studied the adjuvant mechanism in immortalized cell lines used as antigen-presenting cells (APCs). Here, we investigated the uptake and presentation of RV VP6 and NoV GII.4 VLPs by primary bone marrow-derived dendritic cells (BMDCs). The adjuvant effect of VP6 on GII.4 VLP presentation and NoV-specific immune response induction by BMDC in vivo was also studied. Intracellular staining demonstrated that BMDCs internalized both antigens, but VP6 more efficiently than NoV VLPs. Both antigens were processed and presented to antigen-primed T cells, which responded by robust interferon γ secretion. When GII.4 VLPs and VP6 were mixed in the same pulsing reaction, a subpopulation of the cells had uptaken both antigens. Furthermore, VP6 copulsing increased GII.4 VLP uptake by 37% and activated BMDCs to secrete 2-5-fold increased levels of interleukin 6 and tumor necrosis factor α compared to VLP pulsing alone. When in vitro-pulsed BMDCs were transferred to syngeneic BALB/c mice, VP6 improved NoV-specific antibody responses. The results of this study support the earlier findings of VP6 adjuvant effect in vitro and in vivo.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3808-3808
Author(s):  
Zhen Cai ◽  
Wenye Huang ◽  
Wenji Sun

Abstract Mycophenolate mofetil (MMF) is a newly developed immunosuppressor, currently widely used in allogeneic bone marrow transplantation. Its active metabolite, mycophenolic acid (MPA) is a noncompetitive, reversible inhibitor of the enzyme inosine 59-monophosphate dehydrogenase, which plays a major role in the de novo synthesis of guanosine nucleotides. Unlike other cells that also use the salvage pathway for purine biosynthesis, proliferating B and T cells are dependent on the de novo pathway generate guanosine. Thus, MMF exerts its immunosuppressive effects of lymphocyte proliferation. Recently, some studies found that MPA could inhibit the immun immune function of antigen presenting cells. Dendritic cells (DCs), the most potent antigen presenting cells with the unique ability to prime naive T cells, play a central role in antigen processing and presentation to induce T cell response in vitro and in vivo. This study is to evaluate the effects of MPA, the in vivo active metabolite of MMF, on the maturation and immune function of murine bone marrow-derived dendritic cells, and to explore the underlying mechanisms of MMF in graft versus host disease. Bone marrow-derived dendritic cells (DC) were cultured with GM-CSF and IL-4 in the presence of MPA at doses of 0.01 and 0.1μmol/L. The ability of the allostimulatory activities of the DCs on allogeneic T cells was assessed by MLR. IL-12 production in culture supernatant and the Th1/Th2 cytokines such as IL-2, IFN-g, IL-4 and IL-10 levels in mixed lymphocyte reaction (MLR) supernatant were examined by ELISA assays. The activity of NF-κB in DCs was measured with Western blot assays. Our results showed that DCs cultured in the presence of MPA expressed lower levels of CD40, CD80 and CD86, exhibited weaker activity of stimulating the allogeneic T cell proliferation and weaker in antigen presenting function with a concurrent reduction of IL-12 production. MPA-treated DCs stimulated allogeneic T cells to secrete higher levels of Th2 cytokines IL-4 and IL-10 but lower levels of Th1 cytokines IL-2 and IFN-g than did DCs not treated with MPA. The activity of NF-κB was decreased in DCs treated with MPA in a dose-dependent manner. We conclude that MPA, and hence MMF, exerts a negative effect on the maturation and immune function of in vitro cultured DCs, and drives a shift of Th1 cytokines to Th2 cytokines in MLR. This negative effect is associated with a decrease in NF-κB activity. Say something about the significance of this finding regarding GVHD.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4803-4803
Author(s):  
Weihua Song ◽  
Teru Hideshima ◽  
Yu-Tzu Tai ◽  
Kenneth C. Anderson ◽  
Nikhil C. Munshi

Abstract Perifosine is a synthetic novel alkylphospholipid, a new class of antitumor agent which targets cell membranes and inhibits Akt activation. Perifosine inhibits multiple myeloma (MM) cell growth in vitro and in vivo mouse model. Currently perifosine is under the evaluation of phase II clinical trail in MM. Although perifosine has shown significant direct antitumor effects, its effect on immune system has not yet been clarified. The objective of this study is to evaluate the effects of perifosine on the activity of antigen presenting cells (APCs). Monocyte-derived dendritic cells (DCs) from normal human donors were used as the APCs, and mature DCs were obtained by the treatment of TNF-α and IL-1β. Perifosine was used at the concentrations of 2.5 uM, 5 uM and 10 uM for the treatment with DCs. We first evaluated the effect of perifosine on the survival of DCs. We observed that the perifosine treatment up to 48 hours had no effect on viability (>90%) of DCs, assessed by annexin V and PI staining. Alteration of phenotype by perifosine on DCs was further examined by flow cytometry. Our results demonstrated that with dose-dependent manner, perifosine led to a significant down-regulation of surface antigens on immature DCs at 24 and 48 hours, which associated to costimulation (CD40, CD80 and CD86), antigen presentation (HLA-ABC, HLA-DPQR) and maturation (CD83). However, we did not observed significant effect of perifosine on above surface markers on mature DCs. Since DCs play a crucial role on the regulation of Th1/Th2 immune responses by the production of IL-12, we next evaluated IL-12 secretion by DCs with and without perifosine treatment. Importantly, treatment with perifosine significantly decreased LPS-induced-IL-12 production, compared to untreated DCs (untrt vs. trt = 192.29 vs. 166.23 pg/ml (2.5uM), 111.19 pg/ml (5uM) and 44.886 pg/ml (10uM)) at 24 hours. To assess the effect of perifosine on DCs function on the regulation of T cell responses, we stimulated allogenic T cells with mature DCs with or without the pre-treatment of perifosine. The proliferation assay by 3H-TdR incorporation and IFN-γ production by ELISA indicated perifosine-treated DCs had no significant effect on the regulation of T cells function. Taken together, these results showed that DCs function are influenced by the treatment of perifosine. Our pre-clinical data therefore indicates the need to monitor immune functions in patients under the Akt inhibitor treatment.


Sign in / Sign up

Export Citation Format

Share Document