• Tuberculosis and Respiratory Diseases
• /
• v.42 no.3
• /
• pp.302-313
• /
• 1995

Background: Tumor necrosis factor(TNF) showed antitumor cytolytic effects on sensitive tumor cells in numerous in vivo and in vitro studies. But it could not be administered systemically to human because of severe systemic adverse effects at effective concentrations against tumor cells. Many studies showed that a high concentrations of TNF in the local milieu may evoke in vivo TNF-responsive mechanisms sufficient to suppress tumor growth. Recently developed technique of TNF gene transfer to tumor cells using retrovirus vector could be a good candidate for local TNF administration. TNF is also known to synergistically enhance in vitro cytotoxicity of chemotherapeutic drugs targeted to DNA topoisomerase II against TNF-sensitive tumor cell lines. In this study the in vitro chemosensitivity against DNA topoisomerase II targeted chemotherapeutic drugs was evaluated using some respiratory cancer cell lines to which TNF gene had been transferred. Method: NCI-H2058, a human mesothelioma cell line, A549, a human lung adenocarcinoma cell line and WEHI 164 cell line, a murine fibrosarcoma cell line were treated with etoposide and doxorubicin, which are typical topoisomerase II - targeted chemotherapeutic agents, at different concentration. The resultant cytotoxicity was measured by MIT assay. Then the cytotoxicity of the same chemotherapeutic agents was measured after TNF-$\alpha$ gene-transfer and the two results were compared. Results: The cytotoxicity was not increased significantly in WEHI164 cell line and A549 cell line but statistically significant increase was observed in H2058 cell line when TNF-$\alpha$ gene was transferred(p<0.05). Conclusion: These findings show that TNF-$\alpha$ gene transfer to respiratory cancer cell lines results in variable effects on chemosensitivity against topoisomerase II inhibitor among different cell lines in vitro and can be additively cytotoxic in certain selective tumor cell lines.

• Biomedical Science Letters
• /
• v.10 no.2
• /
• pp.65-73
• /
• 2004

I report that single-stranded antisense as a part of large circular (LC-) genomic DNA of recombinant M13 phage exhibits enhanced stability, sequence specific antisense activity, and no need for target site search. A cDNA fragment (708 bp) of rat TNF-$\alpha$ was inserted into a phagemid vector, and TNF-$\alpha$ antisense molecules (TNF$\alpha$-LCAS) were produced as single-stranded circular DNA. When introduced into a rat monocyte/macrophage cell line, WRT7/P2, TNF$\alpha$-LCAS was able to ablate LPS-induced TNF-$\alpha$ mRNA to completion. The antisense effect of TNF$\alpha$-LCAS was shown to be sequence-specific because expressions of three control genes ($\beta$-actin, GAPDH and IL-1$\beta$) were not significantly altered by the antisense treatment. Further, TNF$\alpha$-LCAS was found to be highly efficacious as only 0.1 $\mu$g (0.24 nM) of TNF$\alpha$-LCAS was sufficient to block TNF-$\alpha$ expression in 1$\times10^5$ WRT7/P2 cells. I have also observed specific antisense activity in reduction of NF-$\kappa$B gene expression. The results suggest that an antisense sequence as a part of single-stranded circular genomic DNA has a specific antisense activity.

• IMMUNE NETWORK
• /
• v.24 no.1
• /
• pp.4.1-4.19
• /
• 2024

TNF, a pleiotropic proinflammatory cytokine, is important for protective immunity and immunopathology during Mycobacterium tuberculosis (Mtb) infection, which causes tuberculosis (TB) in humans. TNF is produced primarily by phagocytes in the lungs during the early stages of Mtb infection and performs diverse physiological and pathological functions by binding to its receptors in a context-dependent manner. TNF is essential for granuloma formation, chronic infection prevention, and macrophage recruitment to and activation at the site of infection. In animal models, TNF, in cooperation with chemokines, contributes to the initiation, maintenance, and clearance of mycobacteria in granulomas. Although anti-TNF therapy is effective against immune diseases such as rheumatoid arthritis, it carries the risk of reactivating TB. Furthermore, TNF-associated inflammation contributes to cachexia in patients with TB. This review focuses on the multifaceted role of TNF in the pathogenesis and prevention of TB and underscores the importance of investigating the functions of TNF and its receptors in the establishment of protective immunity against and in the pathology of TB. Such investigations will facilitate the development of therapeutic strategies that target TNF signaling, which makes beneficial and detrimental contributions to the pathogenesis of TB.

• Journal of Dairy Science and Biotechnology
• /
• v.25 no.2
• /
• pp.1-4
• /
• 2007

The present study was performed to elucidate the ability of anti-$TNF-{\alpha}$ antibodies produced in sheep colostrums to neutralise $TNF-{\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. Colostrums from sheep immunized against $TNF-{\alpha}$ significantly inhibited $TNF-{\alpha}$ bioactivity in the cell based assay. The higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent $TNF-{\alpha}$ induced intestinal damage in the intact animal.

• Restorative Dentistry and Endodontics
• /
• v.24 no.1
• /
• pp.187-199
• /
• 1999

Bone remodeling is characterized by the continuing processes of osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Bone metabolism is tightly regulated at the local level by networks of hormones, cytokines, and other factors. In pathological conditions of bone remodeling, including osteoporosis and periodontal diseases, inflammatory cytokines and local mediators are responsible for enhancement of osteoclast resorption and inhibition of repair at the sites of bone resorption. TNF-${\alpha}$ is a pleiotropic hormone with actions on the differentiation, growth, and functional activities of normal and malignant cells from numerous tissues. TNF-${\alpha}$ has been proposed as a local mediator of the control of bone turnover in situations of chronic inflammation, and it has been assumed that the local source of TNF-${\alpha}$ is the monocyte in the adjacent bone marrow or the local circulation. TNF-${\alpha}$ is a potent inducer of bone resorption. TNF-${\alpha}$ is known to induce the activation of apoptotic signaling pathway, which leads to the apoptosis of bone cells. We demonstrated that treatment of murine osteoblastic MC3T3E1 cells with TNF-${\alpha}$ decreases proliferation as well as alkaline phosphatase (ALP) activity in a dose depenent manner. In addition, TNF-${\alpha}$ increases osteoclast-like cell formation in $1{\alpha}$, 25(OH)2D3 or PGE2-treated bone marrow cell culture. When cells were cultured in TNF-${\alpha}$ free ${\alpha}$-MEM, this inhibitory effect of ALP activity was reversible up to 10 ng/ml TNF-${\alpha}$, in contrast, at the 20 ng/ml TNF-${\alpha}$, irreversible. In this concentration, TNF-${\alpha}$ may induce apoptosis in MC3T3E1 cells. In this study, TNF-${\alpha}$ induces apoptosis resulting in chromosomal DNA fragmentation, preceded by JNK/SAPKs and caspase-3 activation. Our present results show that JNK/SAPKs and caspase-3 are activated by TNF-${\alpha}$, suggesting that the JNK/SAPKs and caspase-3 participate in the bone resorption, associated with apoptosis.

• Toxicological Research
• /
• v.13 no.3
• /
• pp.203-208
• /
• 1997

The antigenic potential of M3S tumor necrosis factor-$\alpha$(M3S TNF), which is a mutated form of TNF(TNF mutein) designed to reduce adverse effects of wild type human TNF, was investigated in the present study. The antigenicity of M3S TNF was examined by conducting active systemic anaphylaxis (ASA) test in guinea pigs, heterologous(mouse-rat) passive cutaneous anaphylaxis(PCA) test and passive hemagglutination(PHA) test. The experimental animals were divided into low, medium, high and the highest dose groups and the groups with or without immunoadjuvant, sensitized according to the appropriate schedule and challenged. In ASA test, when challenged with 120 $\mu\textrm{g}$ /animal, moderate to severe positive anaphylactic responses were observed in groups sensitized with 12 $\mu\textrm{g}$ /animal, 120 $\mu\textrm{g}$ /animal and 120 $\mu\textrm{g}$ /animal+Freund's complete adjuvant. In PCA test, positive responses were observed in the group sensitized with the highest dose emulsified with an alum(12 $\mu\textrm{g}$ /animal+alum). In PHA test, positive responses were observed in the group sensitized with 3 $\mu\textrm{g}$ /animal emulsified with an alum. All the other groups in each experiment showed negative responses. Based on these results, M3S TNF is considered to have some antigenic potential.

• Journal of Life Science
• /
• v.16 no.7 s.80
• /
• pp.1207-1213
• /
• 2006

Tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ has been implicated in skeletal diseases by promoting bone loss in inflammatory bone diseases. In the present study, we examined the effects of $TNF-{\alpha}$ on osteoblastic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). $TNF-{\alpha}$ dose-dependently promoted matrix mineralization of hBMSCs with a maximal stimulation at 2ng/ml. $TNF-{\alpha}$ increased expression of alkaline phosphatase, which plays a crucial role for the matrix deposition. The $TNF-{\alpha}-stimulated$ osteoblastic differentiation was not affected by $NF_kB$ inhibitors, BAY and SN50. However, a JNK-specific inhibitor, SP600125 completely abolished the $TNF-{\alpha}-stimulated$ matrix mineralization and expression of alkaline phosphatase. These results suggest that $TNF-{\alpha}$ enhances osteoblastic differentiation of hBMSCs through JNK-dependent pathway.

• Biomolecules & Therapeutics
• /
• v.6 no.1
• /
• pp.31-36
• /
• 1998

Capsular polysaccharides (CPs) from Streeptococcus pneumoniae were examined for the ability to induce secretory responses in a pure population of peritoneal macrophages. The highly purified CPs were able to affect the macrophage, ie, secretion of tumor necrosis factor-alpha (TNF-$\alpha$) and nitrite. As after stimulation with CPs, secretion of TNF-u induced by these CPs reached its maximum within the first few hours of the interaction, while secretion of nitrite was increased with time. In addition, production of TNF-$\alpha$ and nitrite was increased in a dose-dependent manner. In the presence of indomethacin, CP-stimulated TNF-$\alpha$ production was not altered. In contrast, LPS with indomethacin stimulated 24.5% more TNF-$\alpha$ than LPS alone, suggesting that the intracellular signaling processes for TNF production are differentially stimulated by CP and LPS. The results demonstrate that CPs are potent inducer of macrophage secretory activities.

• Journal of Oral Medicine and Pain
• /
• v.24 no.4
• /
• pp.361-374
• /
• 1999

F. nucleatum is a gram-negative obligate anaerobe which is the principal and most frequent cause of gingival inflammation and is the predominant pathogen isolated in subsequent periodontal breakdown. It is also one of the most numerous bacteria found in subgingival plaque samples from healthy sites; its numbers are about 10-fold greater in plaque from periodontally diseased sites. The purpose of this study is to examine the effects of outer membrane(OM), outer membrane vesicle(OMV), and lipopolysaccharide(LPS) from F. nucleatum ATCC 25586 strain on the growth of human gingival fibroblasts and HOS 941 cells, and on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes. For the examination of cytotoxic effects, $TNF-{\alpha}$ production and $TNF-{\alpha}$ mRNA expression, the MTT assay, the ELISA and the RT-PCR were performed, respectively. All extracts of F. nucleatum tested were cytotoxic to both of human gingival fibroblasts and HOS 941 cells, and the significant difference of cytotoxic activity among the extracts was not observed. In the effects of these extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes, all extracts of F. nucleatum tested also stimulated the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression, but the effects of the OM extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression were higher than those of the OMV and the LPS extracts. The pattern of the $TNF-{\alpha}$ mRNA expression was similar to that of the $TNF-{\alpha}$ production. These results indicate that F. nucleatum seems to contribute to the pathogenesis of periodontal diseases at least by its cytotoxicity, directly and its $TNF-{\alpha}$ production, indirectly.

• Journal of Life Science
• /
• v.29 no.11
• /
• pp.1251-1257
• /
• 2019

Peptidoglycan (PG) is found in atheromatous lesions of arteries, where monocytes/macrophages express inflammatory cytokines, including tumor necrosis factor-alpha ($TNF-{\alpha}$). This study investigated the effects of PG on $TNF-{\alpha}$ expression and examined possible cellular factors involved in $TNF-{\alpha}$ upregulation. The overall aim was to identify the molecular mechanisms underlying inflammatory responses to bacterial pathogen-associated molecular patterns in the artery. Exposure of human THP-1 monocytic cells to PG enhanced the secretion of $TNF-{\alpha}$ and induced its gene transcription. Inhibition of TLR-2/4 with OxPAPC significantly inhibited $TNF-{\alpha}$ gene expression, whereas inhibition of LPS by polymyxin B did not. The PG-induced expression of $TNF-{\alpha}$ was also significantly suppressed by pharmacological inhibitors that modulate activities of cellular signaling molecules; for example, U0126 (an ERK inhibitor), SB202190 (a p38 MAPK inhibitor), and SP6001250 (a JNK inhibitor) significantly attenuated PG-induced transcription of $TNF-{\alpha}$ and secretion of its gene product. $TNF-{\alpha}$ expression was also inhibited by rapamycin (an mTOR inhibitor), LY294002 (a PI3K inhibitor), and Akt inhibitor IV (an Akt inhibitor). ROS-regulating compounds, like NAC and DPI, also significantly attenuated $TNF{\alpha}$ expression induced by PG. These results suggest that PG induces $TNF-{\alpha}$ expression in monocytes/macrophages by multiple molecules, including TLR-2, PI3K, Akt, mTOR, MAPKs, and ROS.