scholarly journals Differentiation and function of human monocyte-derived dendritic cells under the influence of leflunomide

2011 ◽  
Vol 63 (2) ◽  
pp. 353-364
Author(s):  
Z. Stojic-Vukanic ◽  
M. Colic ◽  
A. Backovic ◽  
J. Antic-Stankovic ◽  
B. Bufan ◽  
...  

Leflunomide is an immunosuppressive drug effective in experimental models of transplantation and autoimmune diseases and in the treatment of active rheumatoid arthritis (RA). Having in mind that it has been shown that some other immunosuppressive drugs (glucocorticoids, mycophenolate mofetil, sirolimus etc.) impair dendritic cell (DC) phenotype and function, we investigated the effect of A77 1726, an active metabolite of leflunomide, on the differentiation and function of human monocyte-derived dendritic cells (MDDC) in vitro. Immature MDDC were generated by cultivating monocytes in medium supplemented with GM-CSF and IL-4. To induce maturation, immature MDDC were cultured for 2 additional days with LPS. A77 1726 (100 ?M) was added at the beginning of cultivation. Flow cytometric analysis showed that MDDC differentiated in the presence of A77 1726 exhibited an altered phenotype, with a down-regulated surface expression of CD80, CD86, CD54 and CD40 molecules. Furthermore, the continuous presence of A77 1726 during differentiation and maturation prevented successful maturation, judging by the decreased expression of maturation marker CD83, costimulatory and adhesive molecules on A77 1726-treated mature MDDC. In addition, A77 1726-pretreated MDDC exhibited a poor stimulatory capacity of the allogeneic T cells and a low production of IL-10 and IL-18. These data suggest that leflunomide impairs the differentiation, maturation and function of human MDDC in vitro, which is an additional mechanism of its immunosuppressive effect.

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3312
Author(s):  
Matjaž Weiss ◽  
Marko Anderluh ◽  
Martina Gobec

The O-GlcNAcylation is a posttranslational modification of proteins regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase. These enzymes regulate the development, proliferation and function of cells, including the immune cells. Herein, we focused on the role of O-GlcNAcylation in human monocyte derived dendritic cells (moDCs). Our study suggests that inhibition of OGT modulates AKT and MEK/ERK pathways in moDCs. Changes were also observed in the expression levels of relevant surface markers, where reduced expression of CD80 and DC-SIGN, and increased expression of CD14, CD86 and HLA-DR occurred. We also noticed decreased IL-10 and increased IL-6 production, along with diminished endocytotic capacity of the cells, indicating that inhibition of O-GlcNAcylation hampers the transition of monocytes into immature DCs. Furthermore, the inhibition of OGT altered the maturation process of immature moDCs, since a CD14medDC-SIGNlowHLA-DRmedCD80lowCD86high profile was noticed when OGT inhibitor, OSMI-1, was present. To evaluate DCs ability to influence T cell differentiation and polarization, we co-cultured these cells. Surprisingly, the observed phenotypic changes of mature moDCs generated in the presence of OSMI-1 led to an increased proliferation of allogeneic T cells, while their polarization was not affected. Taken together, we confirm that shifting the O-GlcNAcylation status due to OGT inhibition alters the differentiation and function of moDCs in in vitro conditions.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3596-3596
Author(s):  
Lilach Lifshitz ◽  
Galit Tabak ◽  
Max Gassman ◽  
Moshe Mittelman ◽  
Drorit Neumann

Abstract Abstract 3596 Poster Board III-533 The immunomodulatory effects of erythropoietin (EPO) on the cellular and humoral compartments of the immune system were originally described by our group in multiple myeloma patients and have been further elucidated in murine experimental models (Mittelman, 2001; Katz 2005; 2007; Prutchi-Sagiv, 2006). However, the mechanisms of action by which EPO affects lymphocyte number and function are still unknown, particularly since lymphocytes do not carry EPO receptors (EPO-R). We thus set to unravel mechanisms underlying the anti-neoplastic immunomodulatory action of EPO. These studies led us to the novel discovery that dendritic cells (DCs) express EPO-R, and that EPO enhances their survival and function (Prutchi-Sagiv, 2008; Lifshitz, 2009). Here we focus on macrophages as an additional EPO target, since in analogy to DCs, macrophages are also antigen presenting cells, and serve as key effectors of the innate immune response. Using murine models, we first explored the in-vivo effects of EPO using recombinant human EPO (rHuEPO, EPREXR, JC)-injected mice, as well as transgenic mice over-expressing human EPO (termed tg6). EPO treatment was associated with an increased splenic macrophage population, detected by F4/80 expression, and an increased number of macrophages expressing CD11b, CD80 and MHC class II. We further explored the effect of in-vivo EPO administration in an inflammatory model exploiting thioglygollate injection to induce recruitment of peritoneal inflammatory macrophages. The inflammatory macrophages obtained from both EPO injected and from tg6 mice displayed increased expression of F4/80, CD11b, CD80 and MHC class II and augmented phagocytic activity, as compared to the control counterparts. These results are supported by in-vitro studies in bone marrow derived macrophages (BMDMs). We show that BMDMs express EPO-R mRNA, as detected by RT-PCR. In-vitro stimulation of the BMDMs with rHuEPO activated multiple signaling pathways including STAT1, STAT5, MAPK, AKT and NFkB indicating macrophage activation via surface EPO-R. EPO treatment of the BMDMs up-regulated their surface expression of CD11b, F4/80 and CD80, as well as enhanced their phagocytic activity. EPO treatment of LPS-stimulated BMDMs augmented IL-12 secretion, and decreased IL-10 secretion. In conclusion our results show that macrophages are direct targets of EPO and that EPO treatment enhances their pro-inflammatory activity and function. These findings point to the multifunctional role of EPO and may advance its clinical applications as an anti-neoplastic immunomodulator. Disclosures: Mittelman: BioGAL- Start up (inactive): Equity Ownership, Patents & Royalties. Off Label Use: Non erythroid effects: immune, anti-cancer (all under investigation).


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4298-4298
Author(s):  
Sara Trabanelli ◽  
Antonio Curti ◽  
Darina Očadlíková ◽  
Cecilia Evangelisti ◽  
Valentina Salvestrini ◽  
...  

Abstract Abstract 4298 Indoleamine 2,3-dioxygenase (IDO1) and indoleamine 2,3-dioxygenase-like (IDO2) are enzymes involved in the tryptophan catabolism along the kynurenine pathway. While it is established that IDO1-expressing dendritic cells (DCs) contribute to tolerance in a number of biological settings, little is known about the expression and function of IDO2 in DCs. Human DCs can be generated in vitro to obtain immunogenic antigen-presenting cells (APC), used as cellular vaccines. In the clinical setting, DCs are commonly matured with a cytokine cocktail (CC) which includes TNF-a, IL-1b, IL-6 and PGE2. In particular, PGE2 enhances APC function of DCs by increasing IL-12 production and facilitating DC migration to lymph nodes. However, PGE2 is also a strong IDO1 inducer, which by this route can also limit the anti-tumor activity of DC-based immunotherapies. Thus, understanding the roles of IDO1 and IDO2 in DCs may impact the development of vaccines or DC-based immunotherapies. In the present study, we fully characterized IDO1 and IDO2 expression and function in human monocyte-derived dendritic cells (Mo-DCs). Mo-DCs were generated from purified CD14+ monocytes after culture with GM-CSF and IL-4 and then matured with CD40L, LPS alone, LPS plus IFN-g and the CC. We observed that immature Mo-DCs had little if any expression of both IDO1 and IDO2, whereas mature Mo-DCs exhibited upregulation of both enzymes. Among the different maturation stimuli, CC was the most effective in upregulating IDO1 and IDO2, both at the message and protein levels. This effect was associated also with the highest kynurenine production. By means of IDO1 and IDO2 expression, mature Mo-DCs were inhibited in stimulating allogeneic T cell proliferation and generated a population of CD4+CD25+FOXP3+ Tregs which highly suppressed allogeneic and autologous T-cell proliferation. On the basis of evidence that IDO1 is preferentially inhibited by the L-isoform of 1 methyl-tryptophan (1-MT) and IDO2 by the D-isoform, we performed functional enzyme tests in presence of both isoforms. Notably, both isoforms exhibited inhibitory effects, although we observed a stronger effect of L-1-MT than with D-1-MT suggesting a greater contribution of IDO1 than IDO2. These results offer direct evidence that Mo-DCs express functional IDO1 and IDO2 proteins. During the maturation phase, Mo-DCs enhance their tolerogenic qualities, and in particular the capacity to induce Tregs, through the upregulation of both IDO1 and IDO2. Beside the critical role of IDO1 in enhancing the immunosuppressive capacity of DCs, we show, for the first time, that IDO2 is involved also. Our findings imply that, from a clinical standpoint, to improve the efficacy of DC-based vaccines mature DCs should be combined with molecules that can inhibit the activity of both IDO1 and IDO2. Disclosures: Metz: NewLink Genetics: Employment. Prendergast:New Link Genetics Corp: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.


2009 ◽  
Vol 9 (7-8) ◽  
pp. 910-917 ◽  
Author(s):  
Biljana Bufan ◽  
Slavko Mojsilović ◽  
Dragana Vučićević ◽  
Dragana Vučević ◽  
Saša Vasilijić ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Der-Yuan Chen ◽  
Pei-Shan Song ◽  
Jau-Shyong Hong ◽  
Ching-Liang Chu ◽  
I-Horng Pan ◽  
...  

Dendritic cells (DCs) play an important role in connecting innate and adaptive immunity. Thus, DCs have been regarded as a major target for the development of immunomodulators. In this study, we examined the effect of dextromethorphan (DXM), a common cough suppressant with a high safety profile, on the activation and function of DCs. In the presence of DXM, the LPS-induced expression of the costimulatory molecules in murine bone marrow-derived dendritic cells (BMDCs) was significantly suppressed. In addition, DXM treatment reduced the production of reactive oxygen species (ROS), proinflammatory cytokines, and chemokines in maturing BMDCs that were activated by LPS. Therefore, DXM abrogated the ability of LPS-stimulated DCs to induce Ag-specific T-cell activation, as determined by their decreased proliferation and IFN-γsecretion in mixed leukocyte cultures. Moreover, the inhibition of LPS-induced MAPK activation and NF-κB translocation may contribute to the suppressive effect of DXM on BMDCs. Remarkably, DXM decreased the LPS-induced surface expression of CD80, CD83, and HLA-DR and the secretion of IL-6 and IL-12 in human monocyte-derived dendritic cells (MDDCs). These findings provide a new insight into the impact of DXM treatment on DCs and suggest that DXM has the potential to be used in treating DC-related acute and chronic diseases.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2229-2229
Author(s):  
Karin von Schwarzenberg ◽  
Alessio Nencioni ◽  
Anita Bringmann ◽  
Lothar Kanz ◽  
Franco Patrone ◽  
...  

Abstract Proteasome inhibitors (PI) show antitumor activity against a broad spectrum of human malignancies both in vitro and in vivo. Yet, the consequences of exposure to these compounds on the immune system still have to be clearly determined. In the present study, we have investigated the effect of the proteasome inhibitors on human monocyte-derived dendritic cells (DCs). Exposure to PI results in a reduced activation induced DC maturation and cytokine production, inhibition of their migratory capacity and impaired ability to stimulate T-cell responses. These functional and phenotypic alterations were paralleled by a decreased phosphorylation of the MAP kinase member ERK1/2 while not affecting p38. Furthermore, incubation of DC with bortezomib inhibited the expression of nuclear localized transcription factors that were shown to be important for DC differentiation and function like IRF3, Rel-b and c-rel. Addition of PI to culture medium induced apoptosis of differentiated DCs and strongly reduced the yield of viable DCs when given to monocytes before differentiation to DCs was induced. DC apoptosis was accompanied by caspase activation as detected by caspase-3 and PARP cleavage. Cytochrome c cytosolic relocalization was detectable following exposure to bortezomib and was not prevented by caspase inhibition. This points to the mitochondrial damage as to an upstream event in DC apoptosis via proteasome inhibition. While not affecting Bcl-2 levels, bortezomib was found to promote Bax upregulation in DCs, thus providing a possible explanation for mitochondria dysfunction in response to this compound. In conclusion, this study shows that besides the inhibition of Nf-kB bortezomib is affecting several other pivotal signal transduction pathways in human cells and suggests that inhibition of DC function and induction of apoptosis in DCs may represent a mechanism by which bortezomib can affect the immune responses in patients treated with this compound.


2010 ◽  
Vol 78 (11) ◽  
pp. 4763-4772 ◽  
Author(s):  
Raquel M. Gonçalves ◽  
Karina C. Salmazi ◽  
Bianca A. N. Santos ◽  
Melissa S. Bastos ◽  
Sandra C. Rocha ◽  
...  

ABSTRACT Clearing blood-stage malaria parasites without inducing major host pathology requires a finely tuned balance between pro- and anti-inflammatory responses. The interplay between regulatory T (Treg) cells and dendritic cells (DCs) is one of the key determinants of this balance. Although experimental models have revealed various patterns of Treg cell expansion, DC maturation, and cytokine production according to the infecting malaria parasite species, no studies have compared all of these parameters in human infections with Plasmodium falciparum and P. vivax in the same setting of endemicity. Here we show that during uncomplicated acute malaria, both species induced a significant expansion of CD4+ CD25+ Foxp3+ Treg cells expressing the key immunomodulatory molecule CTLA-4 and a significant increase in the proportion of DCs that were plasmacytoid (CD123+), with a decrease in the myeloid/plasmacytoid DC ratio. These changes were proportional to parasite loads but correlated neither with the intensity of clinical symptoms nor with circulating cytokine levels. One-third of P. vivax-infected patients, but no P. falciparum-infected subjects, showed impaired maturation of circulating DCs, with low surface expression of CD86. Although vivax malaria patients overall had a less inflammatory cytokine response, with a higher interleukin-10 (IL-10)/tumor necrosis factor alpha (TNF-α) ratio, this finding did not translate to milder clinical manifestations than those of falciparum malaria patients. We discuss the potential implications of these findings for species-specific pathogenesis and long-lasting protective immunity to malaria.


Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 617 ◽  
Author(s):  
Helen Freyberger ◽  
Yunxiu He ◽  
Amanda Roth ◽  
Mikeljon Nikolich ◽  
Andrey Filippov

A potential concern with bacteriophage (phage) therapeutics is a host-versus-phage response in which the immune system may neutralize or destroy phage particles and thus impair therapeutic efficacy, or a strong inflammatory response to repeated phage exposure might endanger the patient. Current literature is discrepant with regard to the nature and magnitude of innate and adaptive immune response to phages. The purpose of this work was to study the potential effects of Staphylococcus aureus phage K on the activation of human monocyte-derived dendritic cells. Since phage K acquired from ATCC was isolated around 90 years ago, we first tested its activity against a panel of 36 diverse S. aureus clinical isolates from military patients and found that it was lytic against 30/36 (83%) of strains. Human monocyte-derived dendritic cells were used to test for an in vitro phage-specific inflammatory response. Repeated experiments demonstrated that phage K had little impact on the expression of pro- and anti-inflammatory cytokines, or on MHC-I/II and CD80/CD86 protein expression. Given that dendritic cells are potent antigen-presenting cells and messengers between the innate and the adaptive immune systems, our results suggest that phage K does not independently affect cellular immunity or has a very limited impact on it.


2021 ◽  
Vol 12 ◽  
Author(s):  
Molly Javier Uyeda ◽  
Robert A. Freeborn ◽  
Brandon Cieniewicz ◽  
Rosa Romano ◽  
Ping (Pauline) Chen ◽  
...  

Type 1 regulatory T (Tr1) cells are subset of peripherally induced antigen-specific regulatory T cells. IL-10 signaling has been shown to be indispensable for polarization and function of Tr1 cells. However, the transcriptional machinery underlying human Tr1 cell differentiation and function is not yet elucidated. To this end, we performed RNA sequencing on ex vivo human CD49b+LAG3+ Tr1 cells. We identified the transcription factor, BHLHE40, to be highly expressed in Tr1 cells. Even though Tr1 cells characteristically produce high levels of IL-10, we found that BHLHE40 represses IL-10 and increases IFN-γ secretion in naïve CD4+ T cells. Through CRISPR/Cas9-mediated knockout, we determined that IL10 significantly increased in the sgBHLHE40-edited cells and BHLHE40 is dispensable for naïve CD4+ T cells to differentiate into Tr1 cells in vitro. Interestingly, BHLHE40 overexpression induces the surface expression of CD49b and LAG3, co-expressed surface molecules attributed to Tr1 cells, but promotes IFN-γ production. Our findings uncover a novel mechanism whereby BHLHE40 acts as a regulator of IL-10 and IFN-γ in human CD4+ T cells.


Author(s):  
KANCHAN K. MISHRA ◽  
SUMIT BHARADVA ◽  
MEGHNAD G. JOSHI ◽  
ARVIND GULBAKE

Dendritic cells (DCs) play a critical role in the regulation of adaptive immune responses, furthermore they act as a bridge between the innate and the adaptive immune systems they have been ideal candidates for cell-based immunotherapy of cancers and infections in humans. The first reported trial using DCs in 1995, since they have been used in trials all over the world for several of indications, including cancer and human immunodeficiency virus infection. Generally, for in vitro experiments or for DCs vaccination monocyte-derived dendritic cells (moDCs) were generated from purified monocytes that isolated from peripheral blood by density gradient centrifugation. A variety of methods can be used for enrichment of monocytes for generation of clinical-grade DCs. Herein we summarized up to date understanding of systems and inputs used in procedures to differentiate DCs from blood monocytes in vitro.


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