Genetic screen in myeloid cells identifies TNF-α autocrine secretion as a factor increasing MDSC suppressive activity via Nos2 up-regulation

Objective.To determine whether levels of plasma-soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) are elevated in patients with rheumatoid arthritis (RA) and whether levels are correlated with disease activity and other variables.Methods.Our study included 71 patients with RA and 50 age- and sex-matched healthy controls. Clinical characteristics and laboratory measures, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and 28-joint Disease Activity Score (DAS28) were assessed. Plasma levels of sTREM-1 and tumor necrosis factor-α (TNF-α) were measured by ELISA.Results.Patients with RA had significantly higher plasma sTREM-1 levels than healthy controls (170.10 ± 84.71 pg/ml vs 97.41 ± 40.64 pg/ml; p < 0.001). In patients with RA, plasma sTREM-1 levels were found to be correlated with DAS28, ESR, CRP, white blood cell counts, neutrophil counts, and plasma TNF-α levels (r = 0.329, p = 0.005; r = 0.241, p = 0.043; r = 0.314, p < 0.001; r = 0.261, p = 0.028; r = 0.278, p = 0.019; and r = 0.313, p = 0.009, respectively). Plasma sTREM-1 levels in patients with active disease status (DAS28 > 3.2) were significantly higher than in those with low disease status (DAS28 ≤ 3.2; 208.89 ± 100.14 pg/ml vs 150.29 ± 68.70 pg/ml; p = 0.005).Conclusion.Patients with RA had higher plasma sTREM-1 levels than healthy controls, and plasma sTREM-1 levels were correlated with disease activity measures, suggesting that plasma sTREM-1 could play a role in the inflammatory process associated with TNF-α, and that it may be a useful disease activity marker in RA.

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TNF-α-Mediated Tumor Promotion Is Characterized by Enhanced Vasculogenesis and Generation of Myeloid/Endothelial Vascular Leukoctyes.

Blood ◽

10.1182/blood.v110.11.3905.3905 ◽

2007 ◽

Vol 110 (11) ◽

pp. 3905-3905

Author(s):

Bin Li ◽

Matthew Pagni ◽

Justin Cates ◽

D. Brent Polk ◽

Pampee P. Young

Keyword(s):

Myeloid Cells ◽

Fold Increase ◽

Vascular Density ◽

Tnf Receptors ◽

Blocking Antibody ◽

Modest Contribution ◽

Tnf Α ◽

In Cells

Abstract Whereas in many contexts myeloid cells are cytotoxic, it is well-established that as yet unknown microenvironment cues instruct the infiltrating tumor associated myeloid cells (TAMs) to drive malignant progression and dissemination. Recently, we and others have characterized a significant subpopulation of tumor associated myeloid cells that co-express endothelial and myeloid markers designated “vascular leukocytes”. Studies suggest that vascular leukocytes play an important role in tumor progression and also demonstrate modest contribution to functional vessels, i.e. vasculogenesis, suggesting that they represent a critical tumor-promoting TAM subpopulation. We have identified TNFα as a key regulator of the vascular transdifferentiation of myeloid progenitors in vitro and within the tumor milieu. TNFα at 40ng/ml significantly increased the numbers of flk-1/VE-cadherin dual positive, early outgrowth EPCs from human CD14+ cells by day 7 (about five fold of the control), starting with increased spindle-shaped population appeared as early as day 3. Consistent with this, we observed increased flk-1 expression by ∼9-fold (p<0.05) in cells treated with 40ng/ml TNFα by real time RT-PCR. Transcripts for VE-cadherin and tie2, both endothelial-enriched, were detected by day 3 in cells exposed to 40ng/ml TNFa but not in its absence (control). TNFα-directed upregulation of endothelial markers in mouse monocytes in vitro was dependent on TNFα receptors as monocytes isolated from mice lacking both TNF receptors displayed significantly delayed endothelial marker upregulation. These data suggested that TNF was a component of the molecular pathway that accelerated, but was not required for, endothelial transdifferentiation of murine and human myeloid cells. Enhanced TNFα expression in both B16 murine melanoma and PyV-mT tumor showed local TNFα significantly promoted tumor growth versus control (>5-fold increase for B16 tumor, p=0.04; >8-fold increase for PyV-mT tumor, p<0.01). Both tumor models indicated that overexpressing TNFα caused higher vascular density over control, while tumor necrosis was significantly reduced. Additionally, we observed increased bone marrow-derived vessels (vasculogenesis) in mouse TNFα-overexpressing tumors, which can be specifically inhibited by an anti-TNFα blocking antibody. A significant increase in association of vascular leukoctyes was detected in tumors overexpressing TNFα by FACs, which was abrogated in the mice lacking TNF receptors. Interestingly, TNF-overexpressing tumors did not recruit greater overall numbers of tumor-associated (myeloid or lymphoid) leukocytes, suggesting a specific role in myeloid to endothelial transdifferentiation in vivo. Our studies suggest that TNFα constitutes part of the microenvironment repertoire that biases recruited myeloid cells towards a proangiogenic/provasculogenic phenotype.

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Lineage-Plasticity and Inflammatory Change of Human FoxP3+ Regulatory T Cells in Acute Viral Infection: Implication in Immune-Mediated Tissue Injury

Blood ◽

10.1182/blood.v124.21.4132.4132 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4132-4132

Author(s):

Yoon Seok Choi ◽

Jeewon Lee ◽

Ik-Chan Song ◽

Deog-Yeon Jo ◽

Eui-Cheol Shin

Keyword(s):

T Cells ◽

Viral Infection ◽

Treg Cell ◽

Liver Damage ◽

Cd4 T Cells ◽

Treg Cells ◽

Suppressive Activity ◽

Suppressive Function ◽

Acute Viral Infection ◽

Tnf Α

Abstract FoxP3+ CD4+CD25hi regulatory T (Treg) cells play a major role in maintaining the immune homeostasis by preventing the activation of self-reactive T cells as well as in controlling a series of immune responses in viral infections. Recent studies suggest that lineage-commitment of CD4+T cells, including Treg cells, is not a fixed fate, rather a status with a wide range of plasticity. Functional changes and lineage-plasticity of Treg cells during acute viral infection, especially of human, have not been reported so far. Herein, we investigated whether Treg cells show the functional plasticity and whether such changes can affect the regulation of immunopathology in a human acute viral infection. As a model of human acute viral infection, we used a cohort of patients with acute hepatitis A (AHA), since tissue (liver) injury in AHA is mediated exclusively by activated T cells, not by direct cytopathic effect of virus. To assess the plasticity of Treg cell lineage, first, we examined the production of a variety of inflammatory cytokines from Treg cells following T cell receptor (TCR) stimulation of peripheral blood lymphocytes with anti-CD3/CD28 antibody, using intracellular cytokine staining and multicolor flow cytometry. We found that a significant proportion of FoxP3+ CD4+CD25hi Treg cells produced TNF-α following TCR stimulation in patients with AHA, but not in heathy subjects. Analyses at multiple time points during the course of infection showed that TNF-α production from Treg cells decreased in convalescent phase. Likewise, we observed that liver-infiltrating Treg cells also produced TNF-α after TCR stimulation. Moreover, highly-purified CD4+CD25hiCD127lo/-Treg cells could also produce TNF-α following TCR stimulation, indicating that Treg cells of AHA patients can produce TNF-α in direct response to TCR stimulation. Next, to exclude the possibility that TNF-α might be secreted from transiently FoxP3-expressing activated non-Treg CD4+ T cells, we examined the expression level of CD127 on TNF-α-secreting FoxP3+ CD4+ T cells. TNF-α+ Treg cells expressed CD127 in the level similar to conventional TNF-α- counterpart, and CD127 expression levels of both Treg populations were much lower than FoxP3- CD4+ T cells. Furthermore, DNA methylation analysis of Treg cell-specific demethylated region (TSDR) after sorting TNF-α+ Treg cells revealed completely demethylated pattern in highly conserved CpG island of FOXP3 gene. These findings support that TNF-α is produced from bona fide Treg cells, not from FoxP3-expressing activated non-Treg CD4+T cells. In analysis of immunophenotypes, TNF-α+ Treg cells were enriched in CD45RA-FoxP3lo population, implying their reduced in vivo suppressive activity. Along with the lower level of FoxP3, TNF-α+ Treg cells showed lower level of CD39 expression, a surrogate marker of Treg cell suppressive activity, compared to TNF-α- Treg cells. Furthermore, TNF-α+Treg cells showed a robust evidence of lineage-plasticity toward Th17 lineage, expressing a key transcription factor RORγt. Consistently, they expressed CCR6 and co-produced IL-17A following TCR stimulation, which are the hallmark of Th17 effector function. To analyze the clinical implication of attenuate suppressive function and plasticity shown by TNF-α+ Treg cells, we examined correlation between production of proinflammatory cytokines from Treg cells and severity of liver damage in AHA. As a result, proportion of TNF-α-producing Treg cells closely and linearly correlated with severity of liver damage, suggesting the critical role of TNF-α+ Treg cells in the immunopathogenesis of AHA. However, Treg cell suppression assay in the absence or presence of anti-TNF-α antibody showed that Treg cell suppressive function was not affected by TNF-α blockade. This indicates that attenuated function of TNF-α+Treg cells is not attributed simply to production of a kind of inflammatory cytokine, rather to more complicated reprogramming mechanism. Taken together, these data provide a clear evidence of attenuated suppressive activity and Th17-toward lineage plasticity of FoxP3+ Treg cells, represented by TNF-α production, in a human acute viral infection. Also, we suggest one possible mechanism that lineage plasticity and inflammatory changes of Treg cells could be implicated in the immunopathogenesis of human diseases. Disclosures No relevant conflicts of interest to declare.

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Early myeloid cells are high producers of nitric oxide upon CD40 plus IFN-γ stimulation through a mechanism dependent on endogenous TNF-α and IL-1α

European Journal of Immunology ◽

10.1002/(sici)1521-4141(200005)30:5<1263::aid-immu1263>3.0.co;2-5 ◽

2000 ◽

Vol 30 (5) ◽

pp. 1263-1271 ◽

Cited By ~ 34

Author(s):

Iñigo Angulo ◽

Joaquín Rullas ◽

José Antonio Campillo ◽

Eva Obregón ◽

Andrew Heath ◽

...

Keyword(s):

Nitric Oxide ◽

Myeloid Cells ◽

Tnf Α ◽

Ifn Γ

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Suppressive effect of TNF-α and IL-1 on alveolar fibroblast proliferation in sarcoidosis

Mediators of Inflammation ◽

10.1155/s0962935192000474 ◽

1992 ◽

Vol 1 (5) ◽

pp. 319-322

Author(s):

E. Fireman ◽

D. Aderka ◽

S. Ben Efraim ◽

J. Greif ◽

D. Wallach ◽

...

Keyword(s):

Alveolar Macrophages ◽

Interleukin 1 ◽

Suppressive Effect ◽

Lung Fibroblasts ◽

Fibroblast Proliferation ◽

Suppressive Activity ◽

Normal Ranges ◽

Tnf Α ◽

Factor Α

The nature of soluble factors that regulate fibroblast proliferation have not been finally characterized. Our aim was to study the role of tumour necrosis factor α (TNF-α) and interleukin-1 (IL-1) in the suppressive activity of alveolar macrophages on autologous lung fibroblasts proliferation in sarcoidosis. We found that supernatants recovered from alveolar macrophages suppressed the proliferation of alveolar fibroblast in sarcoidosis by 35.5 ± 1.13% compared to 3 ± 16% in controls (p < 0.001 between the two groups). This suppression correlated with high content of TNF-α and IL-1 in sarcoidosis patients stage II-III (7.7 ± 2.9 ng/ml TNF-α and 157 ± 53 U/ml IL-1 compared to 3.4 ± 2.4 ng/ml TNF-α and 43 U/ml IL-1 in controls; p < 0.01 and p < 0.001, respectively). Both cytokines in sarcoidosis stage I were within the normal ranges. Exogenous TNF-α (1000-0.5 ng/ml) and IL-1 (500-0.24 ng/ml) had an additive suppressive activity on fibroblast proliferation which was partially reversed by indomethacin.

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