IL-6 and leukemia-inhibitory factor are involved in the generation of tumor-associated macrophage: regulation by IFN-γ

Tumor-associated macrophages (TAMs), the most abundant immunosuppressive myeloid cells in the tumor microenvironment, exhibit an IL-10highIL-12low profile called M2, opposite to the immunostimulatory M1. We reported that ovarian cancer ascites switched monocyte differentiation into TAM-like cells that exhibit most phenotypic and functional characteristics of TAMs, suggesting that soluble mediators are involved in the differentiation of monocytes into TAM-like cells. We observed that leukemia-inhibitory factor and IL-6, present at high concentrations in ovarian cancer ascites, skew monocyte differentiation into TAM-like cells by increasing macrophage colony-stimulating factor consumption. Moreover, we observed that IFN-γ switches established TAMs into immunostimulatory M1 cells and skews monocyte differentiation from TAM-like cells to M1s. In addition to revealing a new tumor-escape mechanism associated with TAM generation via leukemia-inhibitory factor and IL-6, these findings offer novel therapeutic perspectives to subvert TAM-induced immunosuppression and to improve antitumor immunotherapy efficacy

Estrogen Receptor α Participates to the Beneficial Effect of Red Wine Polyphenols in a Mouse Model of Obesity-Related Disorders

Red wine polyphenol extracts (polyphenols) ameliorate cardiovascular and metabolic disorders associated with obesity. Previously, we demonstrated that the alpha isoform of estrogen receptor (ERα) triggers the vascular protection of polyphenols. Here, we investigated the contribution of ERα on the effects of polyphenols on cardiovascular and metabolic alterations associated with obesity. We used ovariectomized wild type or ERα-deficient mice receiving standard (SD) or western (WD) diets, or SD and WD containing polyphenols (SD+polyphenols and WD+polyphenols, respectively) over a 12-week period. Body weight was measured during treatment. Echocardiography examination was performed before sacrifice. Blood and tissues were sampled for biochemical and functional analysis with respect to nitric oxide (NO(•)) and oxidative stress. Vascular reactivity and liver mitochondrial complexes were analyzed. In WD-fed mice, polyphenols reduced adiposity, plasma triglycerides and oxidative stress in aorta, heart, adipose and liver tissues and enhanced NO(•) production in aorta and liver. ERα deletion prevented or reduced the beneficial effects of polyphenols, especially visceral adiposity, aortic and liver oxidative stresses and NO(•) bioavailability. ERα deletion, however, had no effect on polyphenol\u27s ability to decrease the fat accumulation and oxidative stress of subcutaneous adipose tissue. Also, ERα deletion did not modify the decrease of ROS levels induced by polyphenols treatment in the visceral adipose tissue and heart from WD-fed mice. Dietary supplementation of polyphenols remarkably attenuates features of metabolic syndrome; these effects are partially mediated by ERα-dependent mechanisms. This study demonstrates the therapeutic potential of this extract in metabolic and cardiovascular alterations linked to excessive energy intake

A New NO-Releasing Nanoformulation for the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronicand progressive disease which continues to carry an unacceptablyhigh mortality and morbidity. The nitric oxide (NO) pathwayhas been implicated in the pathophysiology and progressionof the disease. Its extremely short half-life and systemiceffects have hampered the clinical use of NO in PAH. In anattempt to circumvent these major limitations, we have developeda new NO-nanomedicine formulation. The formulationwas based on hydrogel-like polymeric composite NO-releasingnanoparticles (NO-RP). The kinetics of NO release fromthe NO-RP showed a peak at about 120 min followed by asustained release for over 8 h. The NO-RP did not affect theviability or inflammation responses of endothelial cells. TheNO-RP produced concentration-dependent relaxations of pulmonaryarteries in mice with PAH induced by hypoxia. Inconclusion, NO-RP drugs could considerably enhance thetherapeutic potential of NO therapy for PAH

Tipifarnib prevents development of hypoxia-induced pulmonary hypertension

Aims. RhoB plays a key role in the pathogenesis of hypoxia - induced pulmonary hypertension. Farne sylated RhoB promotes growth responses in cancer cells and we investigated whether inhibition of protein farnesylation will have a protective effect. Methods and Results. The analysis of l ung tissues from rodent models and pulmonary hypertensive patients showed increased levels of protein farnesylation. Oral farnesyltransferase inhibitor tipifarnib prevented development of hypoxia - induced pulmonary hypertension in mice. Tipifarnib reduced hypoxia - induced vascular cell proliferation, increased endothelium - dependent vasodilatation and reduced vasoconstriction of intrapulmonary arteries without affecting cell viability. Protective effects of tipifarnib were associated with inhibition of Ras and RhoB, actin depolymerisation and increased eNOS expression in vi tro and in vivo . Farnesylated - only RhoB (F - RhoB) increased proliferative responses in cultured pulmonary vascular cells, mimicking the effects of hypoxia, while both geranylgeranylated - only RhoB (GG - RhoB) and tipifarnib had an inhibitory effect. Label - fre e proteomics linked F - RhoB with cell survival, activation of cell cycle and mitochondrial biogenesis. Hypoxia increased and tipifarnib reduced the levels of F - RhoB - regulated proteins in the lung, reinforcing the importance of RhoB as a signalling mediator. Unlike simvastatin, tipifarnib did not increase the expression levels of Rho proteins. Conclusions. Our study demonstrates the importance of protein farnesylation in pulmonary vascular remodeling and provides a rationale for selective targeting of this pa thway in pulmonary hypertension

A New NO-Releasing Nanoformulation for the Treatment of Pulmonary Arterial Hypertension

Copyright The Author(s) 2016. This article is published with open access at Springerlink.com. Open Access - This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were madePulmonary arterial hypertension (PAH) is a chronic and progressive disease which continues to carry an unacceptably high mortality and morbidity. The nitric oxide (NO) pathway has been implicated in the pathophysiology and progression of the disease. Its extremely short half-life and systemic effects have hampered the clinical use of NO in PAH. In an attempt to circumvent these major limitations, we have developed a new NO-nanomedicine formulation. The formulation was based on hydrogel-like polymeric composite NO-releasing nanoparticles (NO-RP). The kinetics of NO release from the NO-RP showed a peak at about 120 min followed by a sustained release for over 8 h. The NO-RP did not affect the viability or inflammation responses of endothelial cells. The NO-RP produced concentration-dependent relaxations of pulmonary arteries in mice with PAH induced by hypoxia. In conclusion, NO-RP drugs could considerably enhance the therapeutic potential of NO therapy for PAH.Peer reviewedFinal Published versio

Tumour stromal cells derived from paediatric malignancies display MSC-like properties and impair NK cell cytotoxicity

<p>Abstract</p> <p>Background</p> <p>Tumour growth and metastatic infiltration are favoured by several components of the tumour microenvironment. Bone marrow-derived multipotent mesenchymal stromal cells (MSC) are known to contribute to the tumour stroma. When isolated from healthy bone marrow, MSC exert potent antiproliferative effects on immune effector cells. Due to phenotypic and morphological similarities of MSC and tumour stromal cells (TStrC), we speculated that immunotherapeutic approaches may be hampered if TStrC may still exhibit immunomodulatory properties of MSC.</p> <p>Methods</p> <p>In order to compare immunomodulatory properties of MSC and tumour stromal cells (TStrC), we established and analyzed TStrC cultures from eleven paediatric tumours and MSC preparations from bone marrow aspirates. Immunophenotyping, proliferation assays and NK cell cytotoxicity assays were employed to address the issue.</p> <p>Results</p> <p>While TStrC differed from MSC in terms of plasticity, they shared surface expression of CD105, CD73 and other markers used for MSC characterization. Furthermore, TStrC displayed a strong antiproliferative effect on peripheral blood mononuclear cells (PBMC) in coculture experiments similar to MSC. NK cell cytotoxicity was significantly impaired after co-culture with TStrC and expression of the activating NK cell receptors NKp44 and NKp46 was reduced.</p> <p>Conclusions</p> <p>Our data show that TStrC and MSC share important phenotypic and functional characteristics. The inhibitory effect of TStrC on PBMC and especially on NK cells may facilitate the immune evasion of paediatric tumours.</p

Lipodystrophy and obesity are associated with decreased number of T cells with regulatory function and pro-inflammatory macrophage phenotype

Background/Objectives:In lipodystrophy (LD) adipose tissue function to store lipids is impaired, leading to metabolic syndrome, similar to that found in obesity. Emerging evidence links dysmetabolism with disorders of the immune system. Our aim is to investigate whether T-cell populations with regulatory function and monocyte-derived macrophages (MDMs) are affected by LD and obesity.Subjects/Methods:Blood was collected from 16 LD, 16 obese (OB, BMI&gt;30 kg m -2) and 16 healthy normal-weight women (CNT). Physical parameters, plasma lipid profile, glucose, HbA1c, leptin levels were determined. Flow cytometry was employed to assess the number of circulating CD4 + /CD25 hi regulatory T cells (Tregs) and invariant natural killer T (iNKT) cells. Characterization of MDMs included: 1. morphological/oil-Red-O staining analyses to define two morphotypes: lipid laden (LL) and spindle-like (sp) MDM; 2. gene expression studies; 3. use of conditioned medium from MDMs (MDMs CM) on human SGBS cells.Results:As compared to CNT, LD and, to a lesser extent, obesity were associated with reduced Tregs and iNKTs (P&lt;0.001 and P&lt;0.01 for LD and OB, respectively), higher number of LL-MDMs (P&lt;0.001 and P&lt;0.01 for LD and OB, respectively), lower number of sp-MDMs (P&lt;0.001 for both LD and OB), which correlated with increased paracrine stimulation of lipid accumulation in cells (P&lt;0.001 and P&lt;0.01 for LD and OB, respectively). LD MDMs showed decreased and increased expression for anti-inflammatory (IL10 and CD163) and pro-inflammatory (CD68 and CCL20) marker genes, respectively. Analysis of correlation indicated that Tregs are directly related with HDL (P&lt;0.01) and inversely related with LL-MDM (P&lt;0.001) and that LL-MDM are directly related with triglycerides (P&lt;0.01) and oxidized LDL (P&lt;0.01).Conclusions:LD and obesity are associated with changes in the immune system: a significant reduction in the number of T cells with regulatory function and a shift of MDM towards lipid accumulation. Lipid profile of the patients correlates with these changes

IL-26 is overexpressed in chronically HCV-infected patients and enhances TRAIL-mediated cytotoxicity and interferon production by human NK cells

Objective Interleukin-26 (IL-26) is a member of the IL-10 cytokine family, first discovered based on its peculiar expression by virus-transformed T cells. IL-26 is overexpressed in chronic inflammation (rheumatoid arthritis and Crohn’s disease) and induces proinflammatory cytokines by myeloid cells and some epithelial cells. We thus investigated the expression and potential role of IL-26 in chronic HCV infection, a pathology associated with chronic inflammation.Design IL-26 was quantified in a cohort of chronically HCV-infected patients, naive of treatment and its expression in the liver biopsies investigated by immunohistochemistry. We also analysed the ability of IL-26 to modulate the activity of natural killer (NK) cells, which control HCV infection. Results The serum levels of IL-26 are enhanced in chronically HCV-infected patients, mainly in those with severe liver inflammation. Immunohistochemistry reveals an intense IL-26 staining in liver lesions, mainly in infiltrating CD3+ cells. We also show that NK cells from healthy subjects and from HCV-infected patients are sensitive to IL-26. IL-26 upregulates membrane tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) expression on CD16− CD56bright NK cells, enabling them to kill HCV-infected hepatoma cells, with the same efficacy as interferon (IFN)-α-treated NK cells. IL-26 also induces the expression of the antiviral cytokines IFN-β and IFN-γ, and of the proinflammatory cytokines IL-1β and TNF-α by NK cells. Conclusions This study highlights IL-26 as a new player in the inflammatory and antiviral immune responses associated with chronic HCV infection

Implication of 4E-BP1 protein dephosphorylation and accumulation in pancreatic cancer cell death induced by combined gemcitabine and TRAIL

Pancreatic cancer cells show varying sensitivity to the anticancer effects of gemcitabine. However, as a chemotherapeutic agent, gemcitabine can cause intolerably high levels of toxicity and patients often develop resistance to the beneficial effects of this drug. Combination studies show that use of gemcitabine with the pro-apoptotic cytokine TRAIL can enhance the inhibition of survival and induction of apoptosis of pancreatic cancer cells. Additionally, following combination treatment there is a dramatic increase in the level of the hypophosphorylated form of the tumour suppressor protein 4E-BP1. This is associated with inhibition of mTOR activity, resulting from caspase-mediated cleavage of the Raptor and Rictor components of mTOR. Use of the pan-caspase inhibitor Z-VAD-FMK indicates that the increase in level of 4E-BP1 is also caspase-mediated. ShRNA-silencing of 4E-BP1 expression renders cells more resistant to cell death induced by the combination treatment. Since the levels of 4E-BP1 are relatively low in untreated pancreatic cancer cells these results suggest that combined therapy with gemcitabine and TRAIL could improve the responsiveness of tumours to treatment by elevating the expression of 4E-BP1

Identification and manipulation of tumor associated macrophages in human cancers

Evading immune destruction and tumor promoting inflammation are important hallmarks in the development of cancer. Macrophages are present in most human tumors and are often associated with bad prognosis. Tumor associated macrophages come in many functional flavors ranging from what is known as classically activated macrophages (M1) associated with acute inflammation and T-cell immunity to immune suppressive macrophages (M2) associated with the promotion of tumor growth. The role of these functionally different myeloid cells is extensively studied in mice tumor models but dissimilarities in markers and receptors make the direct translation to human cancer difficult. This review focuses on recent reports discriminating the type of infiltrating macrophages in human tumors and the environmental cues present that steer their differentiation. Finally, immunotherapeutic approaches to interfere in this process are discussed