Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human lung dendritic cells (DC) are considerably more potent than alveolar macrophages (AM) in inducing allogeneic T-cell proliferation. Tumor necrosis factor (TNF) alpha and beta produced during alloreaction are likely to be major inflammatory cytokines involved. Their concentrations were therefore analyzed during the interaction of AM or DC with allogeneic T cells. TNF alpha and TNF beta levels were respectively three-fold and sevenfold higher in the presence of DC as compared with AM. Cytokines such as interleukin-4 (IL-4), interleukin-10 (IL-10), and transforming growth factor beta (TGF beta) were compared as to their ability to control DC-induced T-cell proliferation as well as TNF alpha or TNF beta production. IL-10 had the unique capacity of reducing both TNF alpha and TNF beta production by 60 +/- 5% (mean +/- SEM) and 63 +/- 12%, respectively, while inhibiting T-cell proliferation by only 32 +/- 23%. IL-4 and TGF beta increased the release of TNF beta by 275 +/- 22% and 95 +/- 32%, respectively, while that of TNF alpha was slightly decreased or unchanged. An additive effect of IL-10 to cyclosporine was found for all three parameters studied. Interaction between CD4 or CD8 with DC was affected similarly by IL-10. Part of this effect could be due to the downregulation of class I and class II major histocompatibility complex expression.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1995 Jul
PMID:Interleukin-10 decreases tumor necrosis factor alpha and beta in alloreactions induced by human lung dendritic cells and macrophages. 759 41

The mechanisms by which the sex hormones achieve their bone-sparing effects remains unresolved. Interleukin-1 beta (IL-1 beta) is an autocrine/paracrine regulator of bone that may be produced in an estrogen-sensitive manner. The regulation of IL-1 beta production by the gonadal steroids was tested in the human osteoblastic HOBIT cell model. Dose-dependent 4-8-fold increases (P < 0.05) in IL-1 beta mRNA levels followed a 6-48 h treatment with 17 beta-estradiol or testosterone. Receptor mediation of these responses was indicated by experiments using 17 alpha-estradiol or flutamide. Tumor necrosis factor-alpha (TNF) dependent increase IL-1 beta mRNA levels were additive to the effects of the steroids. Testosterone and TNF increased IL-1 beta protein release (P < 0.05) while 17 beta-estradiol had little effect on release. The bone-sparing effects of the gonadal steroids may be accomplished, in part, through their mediation of local IL-1 beta production.
Mol Cell Endocrinol 1995 Apr 28
PMID:Sex hormones mediate interleukin-1 beta production by human osteoblastic HOBIT cells. 764 54

Tumor necrosis factor (TNF)-alfa has been described as a mononuclear phagocyte-produced cytotoxin that causes the necrosis and regression of some tumors. The mechanism of the cytotoxicity and the basis for the differential cytotoxic effects of TNF against cells of various origin remains unclear. It has also been reported, that murine TNF stimulates the production of platelet-activating factor (PAF) by cultured peritoneal macrophages, and that PAF enhances TNF production by alveolar macrophages. Furthermore, it is known that the synthesis and release of PAF are inhibited by plasma proteinase inhibitors. This study was devoted to investigate the effects of two specific PAF antagonists (BN 52021 and 50730), and a proteinase inhibitor (aprotinin; GordoxR) on the TNF-induced cytotoxicity in L929 murine fibroblasts. Our present findings indicate that TNF-induced cytotoxicity is inhibited in a dose-dependent manner by the PAF antagonists studied and by the kallikrein inhibitor aprotinin. These findings provide further evidence suggesting that PAF might be involved in the process of the TNF-alfa-induced cytotoxicity of L929 mouse fibroblasts.
Mol Immunol 1993 Apr
PMID:Platelet-activating factor antagonists (BN 52021 and BN 50730) inhibit tumor necrosis factor-alfa-mediated cytotoxicity on murine L929 tumor cells. 768 48

Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional, proinflammatory cytokine that is capable of activating a diverse number of target genes within multiple cell types. Little information is known regarding the role of TNF-alpha in the regulation of human airway mucin hypersecretion and MUC-2 gene expression. To assess the effect of TNF-alpha exposure on mucin secretion, human airway organ cultures and primary cultures of human airway epithelial cells were stimulated with 20 ng/ml of recombinant human TNF-alpha and mucin secretion quantitated by an enzyme-linked immunosorbent assay using a specific monoclonal antibody directed against human airway mucin. Significant increases in mucin secretion from human airway organ cultures were initially detected at 1 h, peaked at 8 h, and persisted for 24 h. The TNF-alpha-mediated mucin hypersecretion at 8 h was concentration dependent. Significant increases in mucin secretion from primary cultures of human airway epithelial cells were initially detected at 4 h, peaked at 48 h, and persisted for 72 h after stimulation with 20 ng/ml of recombinant human TNF-alpha. The TNF-alpha-mediated mucin hypersecretion at 48 h from primary cultures of human airway epithelial cells was inhibited by coincubation with soluble 55 kD, type I TNF receptors. Using reverse transcription-polymerase chain reaction and a human pulmonary mucoepidermoid carcinoma cell line (NCI-H292), increases in MUC-2 steady-state mRNA levels were first detectable after 30 min of TNF-alpha stimulation and persisted for 24 h. Cycloheximide did not inhibit TNF-alpha-mediated MUC-2 mRNA expression at 1 h, suggesting that new protein translation was not required.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1995 Feb
PMID:Tumor necrosis factor-alpha induces mucin hypersecretion and MUC-2 gene expression by human airway epithelial cells. 786 17

Tumor necrosis factor-alpha (TNF), an inflammatory cytokine released by macrophages, may be a mediator of lung injury during septicemia. We previously reported that the cyclooxygenase inhibitor ibuprofen and histamine receptor antagonists cimetidine (H2 antagonist) and diphenhydramine (H1 antagonist) attenuate lung injury and reduce circulating TNF surges during porcine sepsis. Since pulmonary alveolar macrophages (PAM) may participate in early sepsis by producing TNF, we hypothesized that the TNF activity of PAM is reduced by ibuprofen, cimetidine, and diphenhydramine. To test this, we examined changes in PAM-derived TNF bioactivity and cell viability of freshly isolated porcine PAM during exposure to bacterial endotoxin (LPS), ibuprofen, cimetidine, and diphenhydramine. The TNF activity (% L929 cytotoxicity of PAM conditioned medium) was elevated in LPS-stimulated PAM cultures (15 to 25% increase at 1 to 6 h and 40 to 43% increase at 6 to 48 h, compared with non-LPS-stimulated cultures), and ibuprofen (150 micrograms/ml) added with LPS decreased the TNF activity for 24 h (20 to 28% reduction at 1 to 24 h). Ibuprofen added 1 h after LPS was less effective in reducing the PAM-derived TNF activity (20 to 22% reduction at 2 to 6 h). Cimetidine (112 micrograms/ml) reduced the TNF activity of LPS-stimulated PAM cultures during the first 4 h of LPS exposure (15 to 24% decrease at 1 to 4 h). Diphenhydramine (150 micrograms/ml) attenuated the PAM-derived TNF activity but also decreased viability of PAM, indicating a toxic effect of this agent on PAM.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1993 Feb
PMID:Pharmacologic reduction in tumor necrosis factor activity of pulmonary alveolar macrophages. 809 99

Tumor necrosis factor-alpha (TNF) is an important humoral mediator of sepsis and endotoxin-induced shock. However, Streptococcus pneumoniae, a gram-positive organism, is the most common causative agent of community-acquired pneumonia and sepsis. We hypothesized that the pathogenesis of pneumococcal pneumonia and sepsis involves pneumococcus-stimulated TNF synthesis, and we tested that hypothesis in vitro by comparing heat-killed type III and type V pneumococcus and 23-valent purified pneumococcal capsular polysaccharides with Escherichia coli and purified lipopolysaccharide (LPS) as stimuli for TNF production by the murine macrophage cell line RAW 264.7. We evaluated TNF production in response to various doses and times of exposure to these agents, as well as the effects of indomethacin on TNF production in response to these agents. Stimulation with both types of heat-killed pneumococcus resulted in TNF production in a dose-response fashion, as did stimulation with E. coli. Fewer type III pneumococci (10 bacteria/ml) were required to stimulate significant TNF secretion than either type V pneumococcus or E. coli, but the overall dose-response curves of the three bacteria were similar. The dose-response curves for pneumococcal capsular polysaccharides and LPS were very similar, although at the highest concentration pneumococcal capsular polysaccharides stimulated more TNF secretion than did LPS (469 versus 213 U/ml). The kinetics of pneumococcus-stimulated TNF secretion were identical to the kinetics of LPS-stimulated TNF secretion. In the presence of indomethacin, pneumococcus-stimulated TNF production decreased by 87.5%, as compared with pneumococcus alone. In contrast, LPS with indomethacin stimulated 19.5% more TNF than LPS alone.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1994 Mar
PMID:Heat-killed pneumococci and pneumococcal capsular polysaccharides stimulate tumor necrosis factor-alpha production by murine macrophages. 811 47

Tumor necrosis factor-alpha (TNF) induces clustering of theca-interstitial cells (TIC) isolated from immature, hypophysectomized rats, while inhibiting luteinizing hormone (LH)-stimulated androstenedione in vitro. Stimulators of PKC, 1-oleoyl-2-acetyl-sn-glycerol (OAG, 50 and 100 microM) and phorbol-12-myristate-13-acetate (PMA, 50 nM), caused TIC clustering by 6 days in vitro. Clustering induced by these compounds resembled that induced by TNF. The protein kinase inhibitor, staurosporine at 1 and 10 nM, impaired TNF-induced TIC clustering for 6 days, as did the protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperizine dihydrochloride (H-7); conversely, the protein kinase inhibitor, chelerythrine chloride (0.1, 1.0 or 10 microM), did not attenuate TNF-directed clustering. The protein kinase inhibitors did not reverse the suppression of LH-stimulated androstenedione by TNF. Inhibitors of the EGF receptor PTK, A23 (10, 50, or 100 microM) and A46 (0.1, 1.0, 10, or 50 microM), impaired TNF-induced TIC clustering, while TNF suppression of LH-directed androstenedione was unaffected. EGF-induced TIC clustering was also impaired by A46, while A23 was less effective. Both A23 and A46 blocked EGF attenuation of LH-directed androstenedione after 4 days. When challenged with TNF (1 ng/ml) or PMA (50 nM), PKC activity increased in TIC. A23 (50 microM) and A46 (10 microM) each alone blocked the TNF-associated increase in PKC activity; however, PKC activity attributable to PMA was unaffected by A46. Together, these results suggest that TNF-induced TIC clustering involves activation of PTK which directs subsequent increases in PKC activity; however, mechanisms by which TNF inhibits LH-stimulated steroidogenesis remains elusive.
Mol Cell Endocrinol 1993 Nov
PMID:Involvement of protein kinase C and protein tyrosine kinase pathways in tumor necrosis factor-alpha-induced clustering of ovarian theca-interstitial cells. 814 4

Tumor necrosis factor-alpha (TNF) has been implicated in the pathogenesis of a variety of human diseases including septic shock, cachexia, graft-versus-host disease and several autoimmune diseases. Monoclonal antibodies directed against TNF provide an attractive mode of therapeutic intervention in these diseases. We have generated a murine monoclonal antibody (A2) with high affinity and specificity for recombinant and natural human TNF. To increase its therapeutic usefulness, we used genetic engineering techniques to replace the murine constant regions with human counterparts while retaining the murine antigen binding regions. The resulting mouse-human chimeric antibody should have reduced immunogenicity and improved pharmacokinetics in humans. Molecular analysis of light chain genomic clones derived from the murine hybridoma suggests that two different alleles of the same variable region gene have rearranged independently and coexist in the same hybridoma cell. The chimeric A2 antibody (cA2) exhibits better binding and neutralizing characteristics than the murine A2 which was shown to contain a mixture of two kappa light chains. The properties of cA2 suggest that it will have advantages over existing murine anti-TNF antibodies for clinical use.
Mol Immunol 1993 Nov
PMID:Construction and initial characterization of a mouse-human chimeric anti-TNF antibody. 823 30

Tumor necrosis factor (TNF) down-regulates the production of bone matrix proteins by osteoblasts, thereby inhibiting bone formation. Osteocalcin, the major noncollagenous protein in bone, is inhibited by TNF at the transcriptional level. Mapping studies were undertaken to characterize the TNF-responsive element (TNFRE) in the osteocalcin promoter. Deletion analysis localized the TNFRE to the -522/-511 region, which contains a 9-bp palindromic motif (AGGCTGCCT). Promoter segments containing this sequence down-regulated a heterologous simian virus 40 promoter. Site-specific mutagenesis of the TNFRE eliminated TNF down-regulation. Mobility shift assays demonstrated that a constitutively expressed nuclear factor bound to the TNFRE; this factor was tentatively identified as the p50 homodimer of NF-kappa B. TNF stimulation induced a second TNFRE-binding protein which displaced the constitutive factor. The TNF-induced protein was not inhibitable by the NF-kappa B consensus sequence and was unreactive with anti-NF-kappa B antiserum. DNase footprinting demonstrated that both factors protected the -522/-501 portion of the promoter, consistent with the results of mapping studies and competitive mobility shift assays. It is hypothesized that the generalized catabolic activities of TNF in infectious and malignant diseases may be regulated via this novel element.
Mol Cell Biol 1993 Jun
PMID:Characterization of a tumor necrosis factor-responsive element which down-regulates the human osteocalcin gene. 838 44

Fibroblasts may play an important role in the modulation of immune and inflammatory responses through elaboration of cytokines. To test this hypothesis, human lung fibroblasts were isolated from transbronchial biopsy specimens and assayed for production of interleukin-6 (IL-6) and granulocyte/macrophage colony-stimulating factor (GM-CSF). The sources of fibroblasts included lung allografts, recipient lungs obtained at time of transplant, and normal lung tissue removed during tumor resection. During the course of these studies, several early-passage fibroblasts from transplant recipients were observed to contain mycoplasma (MP)-like organisms as detected by extranuclear fluorescent staining with Hoechst 33258. Positive staining cultures were associated with isolation of Mycoplasma fermentans. IL-6 and GM-GSF as measured by ELISA were found to be elevated over 50-fold in conditioned medium from MP-infected fibroblasts as compared with noninfected lines. Treatment of cells with mycoplasma removal agent (MRA) eliminated extranuclear Hoechst fluorescence and significantly reduced the production of these cytokines. Tumor necrosis factor-beta (TNF-beta) induction of IL-6 and GM-CSF was amplified synergistically in infected cultures. No additional production of IL-6 or GM-CSF was observed in infected cultures treated with interferon-gamma (IFN-gamma) despite the ability of IFN-gamma to modestly induce IL-6 in uninfected cultures. Thus, in vitro infection of lung fibroblasts with MP represents a potent stimulus for the production of inflammatory cytokines and, therefore, necessitates rigorous control for these organisms in cell culture studies.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1993 Apr
PMID:Enhanced secretion of immune-modulating cytokines by human lung fibroblasts during in vitro infection with Mycoplasma fermentans. 847 29


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