TNF-α In Cell Culture Supernatants Research Articles

High expression of circulating exosomal PD-L1 contributes to immune escape of hepatocellular carcinoma and immune clearance of chronic hepatitis B.

To investigate the expression of programmed death ligand-1 (PD-L1) in circulating exosomes, and to define the role of exosomal PD-L1 in promoting immune escape mechanism during chronic hepatitis B infection (CHB) and related liver diseases. The levels of PD-L1 expressed in exosomes were detected by ELISA. CD8+T cells were sorted and cytotoxicity test was assessed by flow cytometry. PD-L1 protein expression in hepatocellular carcinoma (HCC) and normal adjacent tissues were detected by immunohistochemistry. Circulating exosomal PD-L1 levels were significantly higher in patients with CHB and HCC than in healthy controls (F =7.46, P=0.001). Levels of CD107a on CD8+T cells in patients with CHB receiving PD-L1 blocking antibody were significantly lower than in patients receiving isotype blocking antibody (t = 4.96, P < 0.01). Levels of TNF-α in cell culture supernatants of the PD-L1 blocking antibody group were significantly higher than in the isotype blocking antibody group (t =5.92, P < 0.01). Compared with patients receiving isotype blocking antibody, levels of CD107a on CD8+T cells significantly increased in patients with HCC receiving anti-PD-L1 antibody (t = 3.51, P<0.05). Compared with adjacent tissues, the levels of PD-L1 protein expression in HCC tissues were slightly higher; however, no significant difference between the two groups was observed. PD-L1 blockade in exosomes might promote the cytotoxic function of CD8+T cells and inhibit immune evasion during progression of HCC. Blocking PD-L1 in exosomes reduced the cytotoxic function of CD8+T cells in patients with CHB while enhancing the production of proinflammatory cytokines.

LncRNA FLG-AS1 Mitigates Diabetic Retinopathy by Regulating Retinal Epithelial Cell Inflammation, Oxidative Stress, and Apoptosis via miR-380-3p/SOCS6 Axis.

The objective of this study is to investigate lncRNA FLG-AS1-mediated miR-380-3p/SOCS6 axis in inflammation, oxidative stress, and apoptosis of retinal epithelial cells in diabetic retinopathy (DR). Fasting blood was collected from 60 DR patients and 60 healthy controls. The Pearson correlation was used to analyze the correlation between the expression levels of FLG-AS1 and miR-380-3p in DR patients. qRT-PCR and/or Western blotting were used to detect the expression of FLG-AS1, miR-380-3p, and SOCS6. After gain of function of FLG-AS1 or SOCS6 or loss of function of miR-380-3p, high glucose (HG)-treated human retinal pigment epithelial ARPE-19 cells were subjected to TUNEL assessment of apoptosis. ELISA was performed to detect the expression levels of IL-1β, IL-6, and TNF-α in cell culturesupernatant. DCFH-DA was used to detect the level of ROS in the cells. MDA and SOD assay kits were used to measure the activity of MDA and SOD in the cells. Dual-luciferase reporter assay was performed to verify the binding between miR-380-3p and FLG-AS1 or between miR-380-3p and SOCS6. Streptozotocin injections were used to induce diabetes in rats which were injected with FLG-AS1 overexpression lentiviral vectors in the eye. Twenty weeks later, retinal tissue was isolated and stained with hematoxylin-eosin or TUNEL. Compared to that in healthy controls, FLG-AS1 expression decreased 2.5-fold and miR-380-3p expression increased 2.6-fold in the serum of DR patients. The expression levels of FLG-AS1 and miR-380-3p were negatively correlated in DR patients (r = -0.3772, P = 0.003). Overexpression of FLG-AS1 reduced inflammation, oxidative stress, and apoptosis of HG-treated ARPE-19 cells and alleviated retinal injury in diabetic rats. FLG-AS1 promoted the expression of SOCS6 by targeting miR-380-3p. Inhibition of miR-380-3p or overexpression of SOCS6 reduced inflammation, oxidative stress, and apoptosis of HG-treated ARPE-19 cells. FLG-AS1 mitigates DR by regulating retinal epithelial cell inflammation, oxidative stress, and apoptosis via the miR-380-3p/SOCS6 axis.

Development of monoclonal antibodies for quantification of bovine tumor necrosis factor-α

The expression of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) is associated with production losses in dairy cows and is a hallmark of early inflammatory processes. Reliable tools for the detection and quantification of soluble as well as cytoplasmatic bovine TNF-α are needed to deepen our understanding of inflammatory dynamics in dairy cows. The objective of this study was to generate a monoclonal antibody (mAb) pair that could be used to quantify bovine TNF-α in cell culture supernatants and plasma and to detect cytoplasmatic TNF-α in bovine leukocyte populations. One mouse was immunized with a recombinant fusion protein of bovine TNF-α and equine IL-4 generated in Chinese hamster ovary cells. Murine monoclonal antibodies specific to bovine TNF-α were produced in hybridoma cell lines and selected based on their specificity to the recombinant IL-4/TNF-α protein. Clones 197-1 and 65-2, both murine IgG1 isotypes, detected the bovine TNF-α fusion protein as well as the native protein produced by peripheral blood mononuclear cells (PBMC) stimulated with a combination of phorbol myristate acetate and ionomycin. Both mAbs were tested for and lacked cross-reactivity to equine IL-4 and 3 other recombinant bovine cytokines (IFN-γ, IL-10, and CCL5) and were used to develop a fluorescent bead-based assay. The range of bovine TNF-α detection in the assay was 0.2 to 620 ng/mL, and the test was used to quantify native bovine TNF-α in cell culture supernatants of stimulated PBMC and in plasma from ex vivo whole-blood stimulations. Sample matrices were spiked with TNF-α, with subsequent recovery rates (mean ± SD) of 89% ± 9 (n = 3) in culture medium and 94% ± 12 (n = 3) in heat-inactivated fetal bovine serum. Serial dilutions of plasma and cell culture supernatants from stimulated whole blood or PBMC indicated excellent accuracy for quantification of native TNF-α in bovine samples. Both bovine TNF-α mAbs also detected intracellular TNF-α in bovine CD14+ monocytes and CD4+/CD8+ lymphocytes. In conclusion, we demonstrated that the mAbs generated provide valuable new tools to quantify native bovine TNF-α in a wide concentration range and to characterize intracellular TNF-α expression in bovine leukocytes.

Morus alba L. (Sangzhi) alkaloids (SZ-A) exert anti-inflammatory effects via regulation of MAPK signaling in macrophages

Ethnopharmacological relevanceMorus alba L. (Sangzhi) alkaloids (SZ-A) tablets have been approved by the China National Medical Products Administration for T2DM treatment. Our previous study (Liu et al., 2021) revealed that SZ-A protected against diabetes and inflammation in KKAy mice. However, the mechanism and components in SZ-A exerting anti-inflammatory effects are unclear. Aim of the studyInvestigate the effects and molecular mechanisms of SZ-A on inflammation, and identify anti-inflammatory active components in SZ-A. Materials and methodsThe major ingredients in SZ-A were analyzed by HPLC and sulfuric acid - anthrone spectrophotometry. The inhibitory activities of SZ-A on lipopolysaccharide (LPS)-stimulated inflammation were determined in bone marrow-derived macrophage (BMDM) and RAW264.7 cells. The cytokine levels of IL-6 and TNF-α in cell culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression levels of IL-6 and TNF-α were detected by qRT-PCR. The levels of protein phosphorylation of p38 MAPK, ERK, and JNK were analyzed by Western blot. ResultsThe main components in SZ-A were found to be 1-deoxynojirimycin (DNJ), 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), fagomine (FAG), polysaccharide (APS), and arginine (ARG). SZ-A reduced the levels of IL-6 and TNF-α secreted by LPS-induced RAW264.7 and BMDM cells. Simultaneously, the mRNA expression levels of IL-6 and TNF-α were all significantly suppressed by SZ-A in a concentration-dependent manner. Furthermore, SZ-A inhibited the phosphorylation of p38 MAPK, ERK, and JNK in BMDM and the activation of ERK and JNK signaling in RAW264.7 cells. We also observed that DNJ, DAB, FAG, and ARG markedly downregulated IL-6 and TNF-α cytokine levels, while APS did not have an obvious effect. ConclusionsSZ-A attenuates inflammation at least partly by blocking the activation of p38 MAPK, ERK, and JNK signaling pathways. DNJ, FAG, DAB, and ARG are the main constituents in SZ-A that exert anti-inflammatory effects.

Pravastatin sodium attenuated TREM-1-mediated inflammation in human peripheral blood mononuclear cells

Pravastatin sodium on triggering receptor expressed on myeloid cell-1 (TREM-1)-mediated inflammation in human peripheral blood mononuclear cells (PBMCs) has been poorly investigated. In this study, we isolated PBMCs from the peripheral blood samples of patients with chronic obstructive pulmonary disease, treated the cells with pravastatin sodium, and determined a concentration at which more than 90% cells could survive. Then we treated cells with 10 ng/ml of lipopolysaccharide, added with 10, 50, 100 μM of pravastatin sodium combined with or without LR-12, a known TREM-1 inhibitor. The expression of TREM-1 was determined by quantitative RT-PCR. The levels of TREM-1, IL-6, and TNF-α in cell culture supernatant were measured with ELISA. Simultaneously, NF-κB signaling pathway-related protein p-p65 and p-IκBα were detected by Western blot assay. Results demonstrated that pravastatin sodium significantly mitigated lipopolysaccharide-stimulated TREM-1 over-expression at mRNA and protein levels dose-dependently. Elevated IL-6 and TNF-α levels changed synchronously. LR-12 inhibited the TREM-1 over-expression and inflammatory factor production but did not show extra synergistic effect to pravastatin. Lipopolysaccharide induced phospho-p65 and -IκBα over-expression was weakened significantly when cells were treated with pravastatin sodium. In conclusion, pravastatin could inhibit TREM-1-medieted inflammation and NF-κB signaling pathway was involved.

Posaconazole in Vitro Action on Peripheral Blood Mononuclear Cells From Sarcoidosis Patients

SESSION TITLE: Diffuse Lung Disease 1 SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: Treatment with anti-fungal medication is as efficient as corticosteroids in sarcoidosis in many, albeit not all, patients.Insoluble β-glucan, a component in the fungal cell wall, induced the production of several cytokines from peripheral blood mononuclear cells (PBMC) “in vitro”. Against this background two hypotheses can be formulated: anti-fungal medication influences immune cell activity and decreases the secretion of cytokines after stimulation with insoluble β-glucan and anti-fungal medication acts on insoluble β-glucan and decreases its capacity to induce cytokine production from PBMC. METHODS: Human PBMCs from sarcoidosis (n=6) and healthy subjects (n=5) were stimulated for 4h with particulate (1→3)-β-D-glucan (BGP) after 24h preincubation with posaconazole, with methylprednisolone or with medium alone. We preincubated the BGP with or without the Posaconazole for 1h before adding the PBMCs from healthy subjects for additional 4h. The viability of the cells was determined, the concentrations of TNF-α in cell culture supernatants were measured and expression of NF-kB mRNA. RESULTS: When adding the PBMCs from healthy subjects for additional 4 h to BGP preincubated either with or without Posaconazole, there was no difference in TNF-α production (884 ± 23.9 pg/ml; 981 ± 70.2 pg/ml). Meanwhile, the secretion of TNF-α was significantly higher in sarcoidosis when PBMCs were stimulated with BGP (2162 ± 432.6 pg/ml; 1338 ± 116.7 pg/ml; p=0,032) than in healthy subjects. However, in sarcoidosis patients, preincubation of PBMCs with Posaconazole significantly reduced the secretion of TNF-α after stimulation with BGP (p=0,046), while having no effect on the healthy. On the other hand, Posaconazole significantly reduced the expression of NF-Kb in both groups and there was no significant difference in cell viability in cultures. Thus, the results demonstrate that the inhibitory effect of Posaconazole on PBMCs from sarcoidosis patients is neither a cytotoxic effect of Posaconazole on PBMCs nor a result of the interaction of Posaconazole with BGP. CONCLUSIONS: We have demonstrated that posaconazole “in vitro”significantly reduces the secretion of TNF-α from sarcoidosis patients. The results are consistent with our previous clinical research.There, we have already demonstrated that antifungal treatment is as efficient as corticosteroid treatment of granulomatous inflammation in many, albeit not all,sarcoidosis patients. CLINICAL IMPLICATIONS: Additional studies are required to define the phenotype where the antifungal treatment is not efficient. DISCLOSURE: The following authors have nothing to disclose: Marjeta Tercelj-Zorman, Sanja Stopinsek, Barbara Salobir, Alojzij Ihan, Sasa Simcic No Product/Research Disclosure Information

Development of a bead‐based multiplexed assay for simultaneous quantification of five bovine cytokines by flow cytometry

Quantifying cytokines is extremely important in studies of host-pathogen interactions. Multiplex assays are commercially available but only for human and mouse cytokines. Here a method for the simultaneous quantification of five important bovine cytokines IFNγ, IL-4, IL-10, IL-12, and TNFα in cell culture supernatants, using flow cytometry was reported. Functional beads from BD Biosciences expressing specific APC intensity were used. Commercially available antibodies against bovine cytokines were covalently coupled to beads as capture antibodies. Fixed recombinant cytokines were revealed with a second monoclonal antibody coupled with biotin, then revealed with streptavidin-PE. This complex was analyzed using a standard flow cytometer. Experiments were performed to check no cross reactions had occurred. The limits of detection ranged between 0.08 and 0.4 ng/ml depending on the cytokine, and the linearity between the lower and higher limits was remarkable (R2 > 99.8%). Finally, native cytokines from cell culture supernatants were tested. Results were compared using the standard ELISA test and showed that concentrations of native cytokine in cell culture supernatants were comparable with the two methods, with a wider dynamic range using beads and flow cytometry than with ELISA assays. Bovine IFNγ, IL-4, IL-10, IL-12, and TNFα in culture supernatants can be now simultaneously detected in a single assay, using a standard flow cytometer for both basic and high-throughput analyses. © 2017 International Society for Advancement of Cytometry.

Dihydroquercetin (DHQ) ameliorated concanavalin A-induced mouse experimental fulminant hepatitis and enhanced HO-1 expression through MAPK/Nrf2 antioxidant pathway in RAW cells

Autoimmune hepatitis represents a ubiquitous human health problem and has a poor prognosis. Dihydroquercetin (DHQ), a well-known antioxidant, significantly inhibits fulminant hepatitis through anti-oxidant and anti-inflammation mechanisms. In this study, we show that administration of DHQ ameliorated concanavalin A (ConA)-induced mouse liver injury by increasing the survival rate, reducing the serum ALT and AST level, preventing histopathological injuries and decreasing pro-inflammatory cytokine mRNA expression in hepatic tissue. As macrophages/Kupffer cells in oxidative stress and pro-inflammatory mediators play an important role in the pathogenesis of immune-mediated hepatitis, we further exposed mouse RAW264 macrophage cell lines to ConA in vitro and found that DHQ significantly inhibited mRNA expression and secretion of IFN-γ and TNF-α in cell culture supernatant. In addition, DHQ significantly enhanced heme oxygenase-1 (HO-1) expression in a dose- and time-dependent manner via increased Nrf2 expression in cytoplasm and nuclear translocation. Furthermore, DHQ enhanced phosphorylation of three members of the mitogen-activated protein kinase (MAPK) family, and cell treatment with MEK/ERK (PD98059), p38 (SB203580) and JNK (SP600125) inhibitors reduced DHQ-induced HO-1 expression. These results indicate that DHQ possesses hepatoprotective properties against ConA-induced liver injury, which are attributed to its ability to scavenge oxidative stress and to inhibit the release of inflammatory mediators via upregulation of HO-1 activity through the MAPK/Nrf2 signaling pathway in macrophages/Kupffer cells.

PGE2 induces MUC2 and MUC5AC expression in human intrahepatic biliary epithelial cells via EP4/p38MAPK activation

Background. MUC2 and MUC5AC overproduction is considered to be associated with hepatolithiasis and related to inflammation. However, mechanisms underlying MUC upregulation under inflammatory stimulation in human intrahepatic biliary epithelial cells (HIBECs) are not completely understood.Material and Methods. Expression of MUC2 and MUC5AC mRNA in HIBECs was detected by real-time PCR. Expression of COX-2, EP4, and phosphorylated ERK, JNK and p38MAPK protein was detected by Western blot. Concentrations of PGE2, IL-1ß and TNF-α in cell culture supernatants were measured using the Quantikine Elisa kit.Results. COX-2 expression as well as PGE2 production in HIBECs was upregulated significantly by LPS, which was completely blocked by either TLR4 antagonist or NFkB inhibitor. Selective COX-2 inhibitor suppressed LPS-induced MUC2 and MUC5AC mRNA expression remarkably. Exogenous PGE2 increased MUC2 and MUC5AC mRNA expression in a dosage-dependent manner independent of IL-1ß and TNF-α. PGE2 receptor EP4 agonist elevated MUC2 and MUC5AC expression, whereas EP4 antagonist had the opposite effect. Expression of phosphorylated p38MAPK was upregulated by exogenous PGE2, and p38MAPK inhibitor reduced MUC2 and MUC5AC expression in HIBECs. In addition, it was found that levels of PGE2, MUC2 and MUC5AC in bile samples from the hepatic ducts affected by intrahepatic stones were significantly higher than those from the unaffected hepatic ducts of patients with hepatolithiasis.Conclusions. Our findings indicate that PGE2 induces MUC2 and MUC5AC expression in HIBECs via EP4-p38MAPK signaling.

Effects of high mobility group box-1 protein on cytokine expreesion in splenic dendritic cells in rats

Objective To investigate the effect of high mobility group box-1 protein (HMGB1) on cytokine expression in splenic dendritic cell (DCs). Method DCs isolated from the spleens of male Wistar rats were seed-ed on 96-well (1×10s cells/well) cell culture plates, and the cells were stimulated with HMGB1 for various length of time or in different concentrations. (1) The time-dependent response between HMGB1 and tumor necrosis factor-α(TNF-α) as well as interleukin-12 (IL-12) gene/protein expressions: 24 wells of DCs were dividedly into six groups including 24 h-normal controls (n=4), 48 h-normal controls (n=4), 72 h-normal controls (n=4), and 24 h-HMGB1 treated group (n=4), 48 h-HMGB1 treated group (n=4) as well as 72 h-HMGB1 treated group (n=4), respectively. Among three HMGB1-treated groups, DCs were stiraulated by 1 μg/mL HMGB1. DCs were denatured in cell culture plates to determine gene expression of IL-12 as well as TNF-α, and supernatants were harvested to determine Il-12 as well as TNF-α protein levels. (2) The dose-dependent response between HMGB1 and TNF-α as well as IL-12 gene/protein expressions: 16 wells of DCs were dividedly into four groups in-cludingnormal controls (n=4), 0.1 μg/mL HMGB1 treated group (n=4), 1 μg/mL HMGB1 treated group (n =4), and 10 μg/mL HMGB1 treated group (n=4), respectively. After stimulated for 48 h, DCs were dena-tured in cell culture plates to determine gene expression of IL-12 as well as TNF-α, and supernatants were harvest-ed to determine IL-12 as well as TNF-α protein levels. Total RNA was extracted from cells using the single-step technique of acid guanidinium thiocyanate-chloroform extraction according to the manufacturer' s instruction (Promega, Madison, WI). mRNA for TNF-α and IL-12 were quantified by SYBR Green two-step, real-time re-verse transeription-polymerase chain reaction taking glyceraldehyde-3-phesphate dehydrogenase (GAPDH) as an internal standard. Levels of IL-12 and TNF-α in cell culture supernatants were determined with ELISA, strictly fol-lowing the protocols provided by the manufacturer. Data were analyzed with a one-way ANOVA. A P-values <0.05 were considered statistically significant. Results After stimulation with 1 μg/mL HMGB1, IL-12 and TNF-α protein and gene expressions in rat splenic DCs were markedly up-regulated at 24 h to 72 h (P<0.05 or P<0.01), and the expression levels of IL-12 and TNF-α peaked at 48 h (P<0.01). When DCs were cultured in the presence of 0.1 μg/mL, 1 μg/mL, and 10 μg/ml HMGBI for 48 h, expressions of IL-12 and TNF-α were also significantly up-regulated (P<0.01), and values of these cytokines were highest in 1 μg/mL HMGB1-treated group (P<0.01). Conclusions These data suggest that HMGB1 appears to be a potential immunostimulatory signal that induced DC maturation, and HMGB1 stimulation can result in marked up-regulation of IL-12 as well as TNF-α synthesis and release in splenic DCs. Key words: High mobility group box-1 protein; Dendritic cells; Interleukin-12; Tumor necrosis factor-α; Immune regulation

Regulation of Chemokine Expression by NaCl Occurs Independently of Cystic Fibrosis Transmembrane Conductance Regulator in Macrophages

Chronic pulmonary inflammation and infection are the leading causes of morbidity and mortality in cystic fibrosis (CF). While the effect of mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) on airways remains controversial, some groups have demonstrated increases in Na(+) and Cl(-) in CF airway surface liquid compared to normal airways. We investigated the consequences of NaCl on pro-inflammatory chemokine and cytokine production by macrophages. Stimulation of mouse macrophages with increasing amounts of NaCl induced macrophage inflammatory protein-2 (MIP-2) and tumor necrosis factor-alpha (TNF-alpha) production. Further, co-incubation of macrophages with NaCl in the presence of either lipopolysaccharide (LPS) or TNF-alpha synergistically increased MIP-2 production. Both the NaCl and NaCl plus LPS responses were partially dependent on endogenous production and autocrine signaling by TNF-alpha. To investigate the role of CFTR in MIP-2 production, we compared the responses of wild-type and DeltaF508 CF mouse macrophages to NaCl and LPS. The responses of macrophages from both strains were indistinguishable. In addition, CFTR mRNA was not expressed in macrophages. Taken together, these findings suggest that NaCl stimulates MIP-2 production by macrophages through a mechanism that is partially dependent on TNF-alpha but independent of macrophage CFTR expression.