Overexpansion of Th17 and Th1/17 Cells in Patients with Myelodysplastic Syndrome

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2698-2698
Author(s):  
Elena E. Solomou ◽  
A. Tsanaktsi ◽  
V. Fertakis ◽  
K. Dallas ◽  
S. Karambina ◽  
...  

Abstract IL17-producing T cells have been recently described as a distinct T cell helper population (Th17 cells) characterized by expression of membrane CD4 and IL23R and intracellular expression of the orphan nuclear receptor RORgt. In Th17 cells the transcription factor RORgt induces the transcription of IL17 gene, whereas in Th1 cells the transcription factor Tbet is responsible for the transcription of IFNg gene. Th1 along with Th17 cells are thought to contribute to the pathogenesis of autoimmune diseases. In murine models Th17 cells are fully polarized. In humans a proportion of Th17 cells are also positive for interferon gamma (IFN-g); they are named Th1/17 cells and their function is yet unclear. In patients with colitis and seronegative arthritis Th17 cells are increased. The induction of Th17 and Th1/17 in patients with MDS has not been previously evaluated. To examine the expression of Th17 and Th1/17 cells in this disease, peripheral blood mononuclear cells (PBMC) from patients with MDS were cultured in vitro for 6 days in RPMI-1640, 15% FBS supplemented with PHA (0.1 μg/mL) and IL-2 (10 ng/mL). Percentages of CD4+IL23R+IL-17+ T cells (Th17) and CD4+IL23R+IL17+IFN-g+ T cells (Th1/17) in patients with MDS were determined by flow cytometry: Th17 cells were markedly increased in patients (n=30) compared to healthy controls (n=15), (17.5% ± 3.4 vs 2.5% ± 0.4, p=0.008). Th1/Th17 cells were also significantly increased in MDS patients compared to controls (15.17% ± 2.80 vs 2.56% ± 0.80, p=0.008). None of the patients had been on immunosuppressive treatment or transfused before sampling. In multi-transfused patients with no underlying hematologic disease examined (n=3) the Th17 and Th1/17 populations were comparable to those of healthy donors. In patients with MDS the majority of the Th17 cells expressed also IFNg (90.07% ± 2.87) whereas in healthy controls only 59.7% ± 5.5 of the Th17 cells were also positive for IFNg (p<0.0001). There were no differences between different subtypes of MDS (RA, RARS, and RAEB). Using confocal microscopy, purified CD4+ T cells from PBMC cultures from patients (n=5) showed increased Tbet and RORgt expression at the single-cell level compared to controls (n=3),(T-bet: 22.03 ± 1.20 vs 11.60 ± 0.35 arbitrary units respectively, p<0.0001 and RORãt: 28.90 ± 0.35 vs 21.03 ± 1.20 arbitrary units, p=0.0008. For each sample 100 cells were analyzed). We next asked whether kinases involved in the induction of Tbet are also involved in the induction of RORgt. We analyzed the effects of rottlerin, a PKC-theta inhibitor, SB203580, a p38 MAPK pathway inhibitor, and PD98059, an ERK pathway inhibitor, on Th17 and Th1/17 cell induction in patients (n=7) and controls (n=4). Rottlerin decreased the Th17 content in patients and controls by 45.0%, and the Th1/17 content by 64.8%. SB203580 showed a 17% and 18% decrease on Th17 and on Th1/17 content, respectively, in patients and controls. PD98059 showed no effect on Th17 and Th1/17 populations in patients and controls. By immunoblots, in normal CD4+T cells rottlerin decreased both T-bet and RORgt protein levels by 50% and 20%, respectively. SB203580, decreased RORgt levels by 25%, and PD98059 did not obviously decrease Tbet but decreased RORgt levels by 20%. CD4+IL23R+IL-17+ T cells and CD4+IL23R+IL17+IFN-g+ T cells are increased in most patients with MDS. T cells have recently been implicated in MDS pathogenesis. Although more studies are needed in order to define the role of Th17 and Th1/17 cells in the pathogenesis of MDS, our in vitro data with the kinase inhibitors may suggest a probable therapeutic target for patients with MDS.

2016 ◽  
Vol 76 (4) ◽  
pp. 740-747 ◽  
Author(s):  
Cristina Rozo ◽  
Yurii Chinenov ◽  
Reena Khianey Maharaj ◽  
Sanjay Gupta ◽  
Laura Leuenberger ◽  
...  

ObjectivesDeregulated production of interleukin (IL)-17 and IL-21 contributes to the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Production of IL-17 and IL-21 can be regulated by ROCK2, one of the two Rho kinases. Increased ROCK activation was previously observed in an SLE cohort. Here, we evaluated ROCK activity in a new SLE cohort, and an RA cohort, and assessed the ability of distinct inhibitors of the ROCK pathway to suppress production of IL-17 and IL-21 by SLE T cells or human Th17 cells.MethodsROCK activity in peripheral blood mononuclear cells (PBMCs) from 29 patients with SLE, 31 patients with RA and 28 healthy controls was determined by ELISA. SLE T cells or in vitro-differentiated Th17 cells were treated with Y27632 (a pan-ROCK inhibitor), KD025 (a selective ROCK2 inhibitor) or simvastatin (which inhibits RhoA, a major ROCK activator). ROCK activity and IL-17 and IL-21 production were assessed. The transcriptional profile altered by ROCK inhibitors was evaluated by NanoString technology.ResultsROCK activity levels were significantly higher in patients with SLE and RA than healthy controls. Th17 cells exhibited high ROCK activity that was inhibited by Y27632, KD025 or simvastatin; each also decreased IL-17 and IL-21 production by purified SLE T cells or Th17 cells. Immune profiling revealed both overlapping and distinct effects of the different ROCK inhibitors.ConclusionsROCK activity is elevated in PBMCs from patients with SLE and RA. Production of IL-17 and IL-21 by SLE T cells or Th17 cells can furthermore be inhibited by targeting the RhoA-ROCK pathway via both non-selective and selective approaches.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 235.1-236
Author(s):  
R. Kumar ◽  
N. Yoosuf ◽  
C. Gerstner ◽  
S. Turcinov ◽  
K. Chemin ◽  
...  

Background:Autoimmunity to citrullinated autoantigens forms a critical component of disease pathogenesis in rheumatoid arthritis (RA). Presence of anti-citrullinated protein antibodies (ACPAs) in patients has high diagnostic value. Recently, several citrullinated antigen specific CD4+T cells have been described. However, detailed studies of their T-cell receptor usage and in-vivo profile suffer from the disadvantage that these cells are present at very low frequencies. In this context, we here present a pipeline for TCR repertoire analysis of antigen-specific CD4+T cells from RA patients, including both citrulline and influenza (control) specificities using in-vitro peptide challenge induced-cell expansion.Objectives:To enable studies of the T cell repertoire of citrullinated antigen-specific CD4+T cells in rheumatoid arthritisMethods:Peripheral blood mononuclear cells (PBMCs) (n=7) and synovial fluid mononuclear cells (SFMCs) (n=5) from HLA-DR*0401-postive RA patients were cultured in the presence of citrullinated Tenascin C peptide cocktails or influenza peptides (positive control). Citrulline reactive cells were further supplemented with recombinant human IL-15 and IL-7 on day 2. All cultures were replenished with fresh medium on day 6 and rIL-2 was added every 2 days from then. Assessment of proportion of peptide-HLA-tetramer positive cells was performed using flow cytometry whereby individual antigen-specific CD4+T cells were sorted into 96-well plates containing cell lysis buffer, followed by PCR-based alpha/beta TCR sequencing. TCR sequencing data was demultiplexed and aligned for TCR gene usage using MiXCR. Some tetramer positive cells were sorted into complete medium containing human IL-2 and PHA for expansion of antigen-specific cells. Cells were supplemented with irradiated allogenic PBMCs (30 times number of antigen specific cells). Clones of antigen specific CD4+T cells were further subjected to tetramer staining to confirm expansion of cells.Results:As evidenced by increase in frequency of tetramer positive CD4+T cells, in vitro peptide stimulation resulted in expansion of both influenza specific (Fig. 1a) and citrullinated antigen specific (Fig. 1b) CD4+T cells. Polyclonal in-vitro expansion of tenascin C tetramer positive sorted cells followed by tetramer staining further confirmed antigen specificity and enrichment for antigen specific CD4+T cells after polyclonal stimulation (Fig.1c). TCR repertoire analysis in PB and SF dataset from the first patient showed clonal expansion of influenza specific cells in both sites. Synovial fluid had more diversity of expanding clones as compared to paired PB, with few expanded clones being shared among SF and PB. We observed a more diverse TCR repertoire in citrulline specific CD4+T cells. We also observed sharing of TCR alpha chains among different citrulline specific CD4+T cell clones.Fig. 1In-vitroexpansion of antigen specific CD4+T cells:Conclusion:This method provides a highly suitable approach for investigating TCR specificities of antigen specific CD4+T cells under conditions of low cell yields. Building on this dataset will allow us to assess specific features of TCR usage of autoreactive T cells in RA.PBMCs were cultured in presence of (a) influenza (HA, MP54) and (b) citrullinated tenascin peptides. The proportion of antigen specific CD4+T cells was assessed using HLA-class II tetramer staining. We observed an increase in frequency of (a) Infleunza specific cells (red dots in upper left and lower right quadrants) and (b) citrullinated tenascin C specific cells (red dots in lower right quadrant), at day 13 post culture as compared to day 3. (c) Sorting of citrullinated tenascin specific CD4+T cells, followed by PHA expansion resulted in visible increase in proportion of citrullinated tenascin specific CD4+T cells.Disclosure of Interests:Ravi kumar: None declared, Niyaz Yoosuf: None declared, Christina Gerstner: None declared, Sara Turcinov: None declared, Karine Chemin: None declared, Vivianne Malmström Grant/research support from: VM has had research grants from Janssen Pharmaceutica


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 468-468
Author(s):  
Pawel Muranski ◽  
Sid P Kerkar ◽  
Zachary A Borman ◽  
Robert Reger ◽  
Luis Sanchez-Perez ◽  
...  

Abstract Abstract 468 We have recently demonstrated that Th17-polarized TCR transgenic CD4+ T cells specific for TRP-1 melanoma antigen are superior to Th1-polarized cells in mediating effective anti-tumor responses against advanced disease after adoptive transfer. The therapeutic activity of Th17-skewed cells is critically dependent on their ability to secrete IFN-γ, suggesting that the Th17 subset might evolve in vivo. However, the developmental program of Th17-polarized cells in vivo remains substantially un- elucidated. We developed a novel TCR-transduction technique that enabled us to rapidly confer specificity for a cognate antigen upon any population of T cells, regardless of its genetic background, its previous polarization history or its state of differentiation. Using adoptive transfers into tumor-bearing hosts, we were able to study the functionality of these genetically-engineered T cells in vivo. In vitro, CD4+ T cells cultured in type 17 conditions acquired end-effector phenotype (CD62Llow, CD45RBlow), but proliferated slower than cells grown in type 1 condition. Thus, we hypothesized that Th17-polarized cells might represent a less mature, more central-memory like subset. This notion was supported by their ability to secrete high quantities of IL-2 and higher expression of IL-7 receptor. In contrast, Th1-polarized cells upon in vitro re-stimulation upregulated PRDM1 that encodes BLIMP1, a molecule associated with the end-effector senescent phenotype. Moreover, Th1-skewed cells overexpressed caspase 3 and were prone to activation-induced cell death as measured by annexin V assay, while type 17 cells were resistant to apoptosis, and robustly expanded in secondary cultures. Using the TCR gene transfer technique we tested the treatment outcomes when Th17-polarized cells deficient for IL-17A were used. In contrast to wild-type (WT)-derived Th17 cells that effectively eradicated established tumors, we observed significant impairment of treatment with IL-17A-deficent cells. Similarly, we observed reduction in treatment efficacy when CCR6-deficient Th17 cells were transferred. CCR6 is a receptor for CCL20, a chemokine highly induced Th17 cells and thought to contribute to the trafficking of those cells to the site of inflammation. In both cases however, the addition of exogenous vaccination and IL-2 significantly improved treatment efficacy. Thus, we concluded that Th17-associated factors play the role in the anti-cancer activity of type 17 cells. To address the question whether plasticity of Th17-skewed effectors is important for their function upon ACT, we treated animals with TCR-transduced Th17-skewed cells derived from IFN-γ-deficient CD4+ cells as well as from t-bet-deficient mice, which are not able to develop type 1 responses. In contrast to WT-derived Th17 effectors, IFN-γ-deficient cells did not show any anti-tumor activity, while t-bet-deficient Th17 cells were able to mediate only minimal delay in tumor growth, suggesting that indeed the capacity to acquire Th1-like properties is essential for the anti-tumor function of Th17-skewed lymphocytes. Overall, here we demonstrate that TCR gene engineered Th17-polarized cells can efficiently treat advanced tumor. The high activity of in vitro-generated anti-tumor Th17 cells relies on the contribution of type 17-associated characteristics, including both the secretion of inflammatory factors IL-17A and CCL20, as well as the superior capacity to survive and expand upon the secondary stimulation. Importantly however, type 1-defining t-bet-mediated plasticity in the lineage commitment is required for the full therapeutic effect, underscoring the dualistic nature of Th17-skewed cells. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 711-711
Author(s):  
Srimoyee Ghosh ◽  
Sergei B Koralov ◽  
Irena Stevanovic ◽  
Mark S Sundrud ◽  
Yoshiteru Sasaki ◽  
...  

Abstract Abstract 711 Naïve CD4 T cells differentiate into diverse effector and regulatory subsets to coordinate the adaptive immune response. TH1 and TH2 effector subsets produce IFN-γ and IL-4, respectively, whereas proinflammatory TH17 cells are key regulators of autoimmune inflammation, characteristically produce IL-17 and IL-22 and differentiate in the presence of inflammatory cytokines like IL-6 and IL-21 together with TGF-β. Naive T cells can also differentiate into tissue-protective induced T regulatory (iTreg) cells. NFAT proteins are highly phosphorylated and reside in the cytoplasm of resting cells. Upon dephosphorylation by the Ca2+/calmodulin-dependent serine phosphatase calcineurin, NFAT proteins translocate to the nucleus, where they orchestrate developmental and activation programs in diverse cell types. In this study, we investigated the role of the Ca/NFAT signaling pathway in regulating T cell differentiation and the development of autoimmune diseases. We generated transgenic mice conditionally expressing a hyperactivable version of NFAT1 (AV-NFAT1) from the ROSA26 locus. To restrict AV-NFAT1 expression to the T cell compartment, ROSA26-AV-NFAT1 transgenic mice were bred to CD4-Cre transgenic mice. Naïve CD4 T cells freshly isolated from AV mice produced significantly less IL-2 but increased amounts of the inhibitory cytokine IL-10. To investigate the role of NFAT1 in the generation of TH1, TH2, Tregand TH17 cells, the respective cell types were generated from CD4 T cells of AV mice by in vitro differentiation. T cells from AV-NFAT1 mice exhibited a dysregulation of cytokine expression, producing more IFN-γ and less IL-4. While the numbers of CD4+CD25+ “natural” Treg cells in peripheral lymphoid organs and their in vitro suppressive functions were slightly decreased in AV mice, iTreg generation from CD4+CD25- T cells of AV mice as compared to wild type cells was markedly enhanced. Moreover, TH17 cells generated in vitro from CD4 T cells of AV mice in the presence of IL-6, IL-21 and TGF-β exhibited dramatically increased expression of both IL-10 and IL-17 as compared to wild type controls. To investigate putative NFAT binding sites in the IL-10 and IL-17 gene loci, we performed chromatin immunoprecipitation experiments. We show that NFAT1 can bind at the IL-17 locus at 3 out of 9 CNS regions which are accessible specifically during TH17 but not during TH1 and TH2 differentiation. Furthermore, we provide evidence that NFAT1 binds one CNS region in the IL10-locus in TH17 cells. To verify our observations in vivo, we induced experimental autoimmune encephalitis (EAE) in AV mice and wild type controls with the immunodominant myelin antigen MOG33-55 emulsified in complete Freund‘s adjuvant. While wild type animals showed a normal course of disease with development of tail and hind limb paralysis after approximately 10 days, AV mice showed a markedly weaker disease phenotype with less severe degrees of paralysis and accelerated kinetics of remission. Moreover at the peak of the response, there were fewer CD4+CD25- but more CD4+CD25+ T cells in the CNS of AV animals compared to wild type controls. Surprisingly, these cells produced significantly more IL-2, IL-17 and IFN-γ upon restimulation, even though they displayed decreased disease. In summary, our data provide strong evidence that NFAT1 contributes to the regulation of IL-10 and IL-17 expression in TH17 cells and show that increasing NFAT1 activity can ameliorate autoimmune encephalitis. This could occur in part through upregulation of IL-10 expression as observed in vitro, but is also likely to reflect increased infiltration of regulatory T cells into the CNS as well as increased conversion of conventional T cells into Foxp3+ regulatory T cells within the CNS. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1730-1730
Author(s):  
Izumi Masamoto ◽  
Sawako Horai ◽  
Tomohiro Kozako ◽  
Makoto Yoshimitsu ◽  
Junko Niimoto ◽  
...  

Abstract Abstract 1730 Human T-lymphotropic virus type-1(HTLV-1) is the causative agent of adult T cell leukemia/lymphoma (ATL). HTLV-1 infected T cell growth or leukemogenesis in ATL is controlled by various host immune surveillance systems. Among them, CD70 on HTLV-1 infected T cells coupled with CD27 on virus specific cytotoxic T cells has been suggested to play an important role in ATL leukemogenesis. The CD70 molecule is the only known ligand for CD27, a member of the tumor necrosis factor (TNF) receptor superfamily 7. This negative immunoregulatory pathway downregulates cytotoxic T lymphocyte activity against CD70-expressing virus infected cells. In the present study, we examined CD70 expression on primary lymphocytes of HTLV-1 carriers and ATL patients, its relationship with HTLV-1 Tax protein expression, and the effect on CTL induction. CD70 expression was higher on peripheral blood mononuclear cells (PBMCs) of HTLV-1 infected carriers compared with healthy donors (p = 0.021, n = 21, Mann-Whitney U test), and higher in ATL patients compared to carriers (p = 0.045, n = 38, Mann-Whitney U test). CD70 expression may be observed in CD4 T cells, as well as B cells, but not in CD8 T cells or monocytes. CD70 expression in CD4 T cells is related to HTLV-1 infection, because of increased detection of HTLV-1 Tax protein during over night culture of CD70-expressing cells. Experiments using an ATL cell line, in which Tax expression is inducible by doxycycline stimulation, demonstrated enhanced CD70 expression when Tax protein was induced in HTLV-1 infected cells. Anti-CD70 antibody enhanced CD107a mobilization, a marker of recent cytotoxic degranulation, in HTLV-1 Tax specific CTLs in PBMCs from asymptomatic carriers in vitro, suggesting that the CD70/CD27 pathway plays an important role in the immune response to HTLV-1 infection in carriers, as well as ATL patients. Disclosures: No relevant conflicts of interest to declare.


2012 ◽  
Vol 142 (5) ◽  
pp. S-176
Author(s):  
Mary E. Morgan ◽  
Bin Zheng ◽  
Martijn H. den Brok ◽  
Henk van de Kant ◽  
Pim J. Koelink ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Takahiro Teshima ◽  
Yunosuke Yuchi ◽  
Ryohei Suzuki ◽  
Hirotaka Matsumoto ◽  
Hidekazu Koyama

Adipose tissue-derived mesenchymal stem cells (ADSCs) have anti-inflammatory and immunomodulatory characteristics. Many studies have suggested that the immunomodulation of ADSCs is largely mediated by secreted paracrine factors. Various factors are secreted from ADSCs, among which extracellular vesicles are considered to play a major role in the communication between ADSCs and target cells. Several studies have reported the function of canine ADSC-derived extracellular vesicles (cADSC-EVs), but few studies have reported the immunomodulatory effects of cADSC-EVs on immune cells. The purpose of this study was to investigate the effects of cADSC-EVs on in vitro-stimulated CD4+ T cells isolated from peripheral blood mononuclear cells (PBMCs). cADSC-EVs were isolated from cADSCs under naive conditions or primed conditions by tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). The expression levels of several microRNAs in cADSC-EVs were altered by priming with TNFα and IFNγ. Culturing PBMCs stimulated with concanavalin A in the presence of naive or primed cADSC-EVs inhibited the differentiation of PBMCs and CD4+ T cells and promoted apoptosis of PBMCs. CD4+, CD8+, and CD4+CD8+ T cells were decreased, while CD3+CD4-CD8- T cells were increased. T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cells were analyzed by flow cytometry. cADSC-EVs inhibited the proliferation of Th1 and Th17 cells and enhanced Th2 and Treg cell proliferation. However, CD4+ T cells that had incorporated labeled cADSC-EVs comprised only a few percent of all cells. Therefore, these responses of stimulated CD4+ T cells may be due to not only direct effects of cADSC-EVs but also to indirect effects through interactions between cADSC-EVs and other immune cells. In conclusion, cADSC-EVs exert immunosuppressive effects on stimulated CD4+ T cells in vitro. These findings may be useful for further studies of immune diseases.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5580-5580
Author(s):  
Marco Romano ◽  
Lucia Catani ◽  
Daria Sollazzo ◽  
Martina Barone ◽  
Margherita Perricone ◽  
...  

Abstract Introduction: Myelofibrosis (MF) is a clonal disorder associated mainly with JAK2V617F and MPL mutations. Recently, a new mutation in the gene encoding calreticulin (CALR) was discovered in the majority of JAK2/MPL negative patients. MF is burdened by a high rate of potentially life-threatening infections. The issue of recurrent and opportunistic infections is increased after the introduction in clinical practice of JAK inhibitors with immunosuppressive activity. However, the role of crucial immune cell subsets is still poorly characterized. Here, we investigated the phenotype/function of selected immune cells in MF. Specifically, we focused on circulating regulatory (Tregs) and IL-17-producing T cells (Th17 cells), monocytes and dendritic cells (DCs). Monocyte-derived DCs were also characterized. Methods: We characterized circulating Th17 cells, Tregs, monocytes and DCs of 17 untreated MF patients and 8 healthy controls (HC) by flow cytometry. Th17 cells were identified as CD4+ CD161+ CD196+ cells while Tregs were enumerated as CD4+ CD25high CD127low T cells. We also tested the in vitro suppressive activity of circulating CD4+ CD25+ Tregs with a mixed leukocyte reaction assay. Two subpopulations of circulating DCs, myeloid CD11c+ and plasmacytoid CD123+cells, were enumerated as well. In addition, after immunomagnetic selection, we tested both phenotype of circulating monocytes and their capacity to differentiate into CD14-derived immature and mature DCs, using a specific cytokines cocktail. JAK2V617F and MPL mutations were detected with RT-PCR while the presence of CALR mutations were tested with Exon 9 Next Generation Sequencing assay. Results: JAK2V617F (11 cases), MPL (3 cases), and CARL (3 cases) mutations were detected. We found that circulating CD4+CD25highCD127low Tregs were reduced in MF patients as compared with healthy controls (p=0.043), although their suppressive ability was maintained. We also found a lower number of circulating Th17 cells (p=0.0026) in MF patients. This finding was particularly evident in JAK2V617F+(p=0.008) and CARL+(p=0.03) patients. Despite their number was in the normal range, circulating monocytes from MF patients showed reduced expression of the CD86 co-stimulatory molecule. Moreover, as compared with the normal counterparts, immature monocytes-derived DCs from patients maintained low CD14 expression without upregulating the CD80 co-stimulatory molecule expression (p=0.0063). Interestingly, at variance with plasmacytoid DCs, a reduced number of circulating myeloid DCs was observed in MF patients as compared with that of HC (p=0.01). Conclusions: Here we demonstrated that specific crucial subsets of immune cells show quantitative and/or qualitative abnormalities in MF patients. These findings may be useful to better understand the increased susceptibility of these patients to infections, since Th17 cells play a role in bacterial and fungal infections while myeloid DCs regulate Th1 activity. Of note, DCs inhibition might result in increased propensity to infections and compromised immune response to cancer.In addition, since monocytes are DC precursors, alterations in their differentiation pathway may contribute to develop defective immune responses. Disclosures Martinelli: NOVARTIS: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; PFIZER: Consultancy; ARIAD: Consultancy.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3031-3031 ◽  
Author(s):  
Jeffrey S. Weber ◽  
Rupal Ramakrishnan ◽  
Andressa Laino ◽  
Anders E. Berglund ◽  
David Woods

3031 Background: PD-1 blocking antibodies have significant efficacy in the treatment of melanoma; however, many patients fail to respond and resistance mechanisms remain unknown. We addressed the role of Tregs, an immunosuppressive T-cell population, in patient outcome after treatment with nivolumab. Methods: Peripheral blood mononuclear cells (PBMC) were obtained from patients on trials with nivolumab as adjuvant therapy for resected disease or as treatment for metastatic melanoma. To measure suppression, Tregs were flow-sorted from PBMC and evaluated in allogeneic mixed lymphocyte reactions. Tregs and conventional CD4 T-cells were evaluated for gene expression changes by RNA-sequencing. Treg percentages and phosphorylated STAT3 (pSTAT3) expression were evaluated by flow cytometry. The effects of PD-1 blockade with nivolumab were evaluated in vitro using T-cells from baseline patient PBMC samples. Results: Tregs from responding patients or adjuvant patients without evidence of disease (NED) had reduced suppressive function post-nivolumab (p < 0.05), but no changes were observed in relapsing/non-responding patients; their Tregs were more suppressive than NED/responding Tregs (p < 0.001). NED Tregs had unique gene expression changes and associated pathways post-nivolumab compared to relapsing patient Tregs and conventional CD4 T-cells, including up-regulation of proliferation pathways (q < 8e-19) and downregulation of oxidative phosphorylation (q < 7e-5). NED Tregs had upregulation of pSTAT3 expression post-nivolumab (p < 0.05), which was not observed in relapsing patients. Evaluation of Tregs from patients with active disease also showed upregulation of pSTAT3 in responders (p < 0.05) but not non-responders. The relative increase in Treg pSTAT3 was associated with increased overall survival (R2= 0.49, p < 0.05). In vitro assays using PD-1 blocking antibodies recapitulated the increase in pSTAT3 (p < 0.05) and Treg percentages (p < 0.001), which were diminished with the addition of a STAT3 inhibitor (p < 0.01). Conclusions: These results demonstrate previously unknown roles of decreased Treg suppressive function and induction of STAT3 as biomarkers of patient’s outcome to nivolumab therapy.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3482-3482
Author(s):  
Minghui Li ◽  
Kai Sun ◽  
Mark Hubbard ◽  
Doug Redelman ◽  
Angela Panoskaltsis-Mortari ◽  
...  

Abstract IL-17-producing CD4 T cells (Th17) are a recently identified T helper subset that plays a role in mediating host defense to extracellular bacteria infections and is involved in the pathogenesis of many autoimmune diseases. In vitro induction of IL-17 in murine CD4+ T cells has been shown to be dependent on the presence of the proinflammatory cytokines TGF-β and IL-6 whereas IFNγ can suppress the development of Th17 cells. In the current study, we examined the roles of TNFα and IFNγ on IL-17 production by purified T cells in vitro and in vivo after allogeneic bone marrow transplantation (BMT). We present findings that expression of TNFα by the T cell itself is necessary for optimal development of Th17 under in vitro polarizing conditions. A novel role for T cell-derived TNFα in Th17 induction was observed when in vitro polarization of Tnf−/−CD4+ T cells resulted in marked reductions in IL-17+CD4+ T cells compared to Tnf+/+CD4+ T cells. In marked contrast, T cell-derived IFNγ markedly inhibited Th17 development as more IL-17+CD4+ T cells were found in Ifnγ−/−CD4+ T cells than in Ifnγ+/+CD4+ T cells, and of particular interest was the dramatic increase in IL-17+CD8+ cells from Ifnγ−/− mice. To determine if T cell-derived TNFα or IFNγ can regulate Th17 development in vivo we examined the differentiation of alloreactive donor T cells following allogeneic BMT. We have found that donor-derived Th17 cells can be found in lymphoid tissues and GVHD-affected organs after allogeneic BMT. However, transfer of Tnf−/− CD4+ T cells after allogeneic BMT resulted in marked reductions in Th17 cells in the spleen (18×103 vs 7×103, P<0.05). In agreement with the in vitro data and in contrast to what was observed with transfer of Tnf−/− CD4+ T cells, transfer of donor Ifnγ−/− T cells resulted in marked increases in not only IL-17+CD4+ but also IL-17+CD8+ T cells infiltrating the liver (7×103 vs 14×103, P<0.05; 4×104 vs 12.5×104, P<0.05). These results suggest that the donor T cell-derived TNFα and IFNγ opposingly regulate IL-17 induction of both CD4+ and CD8+ T cells in vitro and after allogeneic BMT which correlates with GVHD pathology.


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