Serum Tumor Necrosis Factor Activity Research Articles

Experimental Hemorrhage and Blunt Trauma Do Not Increase Circulating Tumor Necrosis Factor

Tumor necrosis factor (TNF) is a potent cytokine mediator of the shock states associated with sepsis and burn injury. This experimental study was done to determine whether circulating TNF plays a major role in the vasomotor collapse seen following experimental hemorrhage and blunt injury. Twenty anesthetized pigs were divided into two groups. Ten animals were bled 60% of their calculated blood volume in 15 minutes. Animals in Group IA (n = 5) had no treatment, and Group IB animals (n = 5) were given twice the shed volume as crystalloid 30 minutes after hemorrhage. The other animals, groups IIa and IIb (n = 5 each), were first subjected to a blunt injury to the thigh sufficient to cause a midshaft femur fracture, then bled and similarly treated. In both groups, mean arterial pressure (MAP), cardiac output (CO), and serum TNF activity by L929 bioassay were measured at 15-minute intervals for 120 minutes after hemorrhage or hemorrhage and blunt injury. An additional three animals were infused with 4 x 10(8)/kg heat-killed E. coli to validate the TNF assay. All bled animals sustained a fall in MAP and CO to a mean of 33% of baseline values, with or without fracture. Group IB and IIB animals responded to fluid resuscitation by restoration of MAP and CO to 85%-97% of the baseline values. Tumor necrosis factor was not detectable before injury and remained undetectable in all these animals during the 120 minutes of the experiment despite hemorrhage alone or combined hemorrhage and blunt trauma, with or without fluid resuscitation. The test animals receiving the E. coli responded with markedly elevated TNF levels, which peaked at 90 minutes after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal anti-tumor necrosis factor-α antibody treatment of rat cardiac allografts: Synergism with low-dose cyclosporine and immunohistological studies

Tumor necrosis factor (TNF) levels have been reported to be elevated during episodes of human renal, hepatic, and cardiac transplant rejection. In addition, we have shown polyclonal anti-TNF antibodies to have immunosuppressive effects. The present study was performed to evaluate the efficacy of a monoclonal anti-TNF-α antibody in rat cardiac transplantation as the sole immunosuppressant and in conjunction with low-dose cyclosporine (CsA). We also performed immuno-histological studies to localize intragraft TNF and evaluate graft infiltrating cells (GICs), and we measured serum TNF levels by an ELISA. Untreated Buffalo to Lewis heterotopic rat cardiac transplants reject in 10.5 ± 0.4 days. A 10-day induction course of CsA (2 mg/kg/day, po) prolonged survival to 16.7 ± 2.7 days ( P < 0.05 vs control), and 10 days of anti-TNF (2000 U/day, ip) prolonged survival to 22.6 ± 0.8 days ( P < 0.05 vs control). Combination of anti-TNF plus CsA synergistically prolonged graft survival to 40.7 ± 1.8 days. Three-day courses of anti-TNF were moderately effective (13.7 ± 0.5 days, P < 0.05 vs control) and were also synergistic with CsA (27.8 ± 2.2). Intragraft TNF localization using immunoperoxidase showed extensive perivascular and mononuclear cell staining in control hearts vs minimal staining in anti-TNF-treated groups. Likewise, serum TNF levels were significantly lowered for treated groups vs control (83.1 ± 14.0 pg/ml for control; 39.5 ± 13.8 for anti-TNF; and 13.4 ± 5.4 for anti-TNF + CsA; P < 0.05 vs control for all groups). Evaluation of GICs by peroxidase staining showed a significantly lower fraction of cytotoxic T-lymphocytes in anti-TNF-treated grafts (71% OX-8+ leukocytes for control vs 33% in anti-TNF grafts, P < 0.05). In conclusion, monoclonal anti-TNF-α antibody is effective in induction therapy of rat cardiac allografts in highly histoincompatible strains, and this effect is synergistic with low-dose CsA. Therapy with anti-TNF lowers serum TNF activity, as well as intragraft TNF production, and decreases infiltration by cytotoxic T-cells. This confirms that TNF is an important mediator of allograft rejection in our model and suggests mechanisms of action of anti-TNF immunotherapy.

Correlation of clinical and laboratory data with serum tumor necrosis factor activity in horses with experimentally induced endotoxemia

SUMMARY Serum tumor necrosis factor (tnf) activity was quantitated in 8 horses given an iv infusion of endotoxin (0.03 μg of lipopolysaccharide/kg of body weight, from Escherichia coli 055:B5) in 0.9% NaCl solution over 1 hour. Serum tnf activity was likewise measured in 6 horses given only 0.9% sterile NaCl solution at the same rate. The duration of serum tnf activity was determined, and serum tnf activity was correlated with clinical and laboratory changes during the induced endotoxemia. Horses had no serum tnf activity prior to endotoxin administration, but geometric mean serum tnf activity was significantly higher from 1 to 4 hours after the start of the infusion. In response to endotoxin, horses seemed depressed, had signs of mild to moderate abdominal pain, developed tachycardia and fever, and had leukopenia followed by leukocytosis. Association between serum tnf activity and temperature, heart rate, attitude abnormality score, and wbc count of horses given endotoxin was significant. Serum tnf activity had a significant positive linear correlation with attitude abnormality and heart rate and a negative linear correlation with the wbc count during endotoxemia. Geometric mean serum tnf activity peaked approximately 1.5 hours prior to mean peak fever, and these data were significantly correlated. Results of this study suggest that tnf is an important mediator of endotoxemia in horses.

Altered macrophage activity and tumor necrosis factor: Tumor necrosis and host cachexia

Tumor necrosis factor (TNF) may be a mediator of cancer cachexia. This study evaluates the activity of macrophages from non-tumor-bearing (NTB) and tumor-bearing (TB) rats by measuring TNF production in response to endotoxin (LPS), both in vitro and in vivo, and correlates macrophage activity with tumor burden and parameters of host cachexia. Isolated macrophages from rats with small tumors, normal food intake, and weight gain secreted more TNF in response to 10 μg/ml LPS than macrophages from control NTB rats and behaved similar to activated macrophages from rats previously treated with thioglycollate. Heightened macrophage activity (increased production of TNF in response to LPS) in TB rats increased further as tumor burden increased ( r = 0.889, P < 0.001). Tumor resection reversed the heightened macrophage activity as LPS-induced levels of TNF secreted by macrophages from resected TB rats were not different from those of sham-operated NTB control rats. TB rats had serum levels of TNF activity following an iv bolus of 10 mg/kg LPS greater than those of NTB rats ( P < 0.05). In addition, peak serum TNF activity levels following iv LPS increased directly as tumor burden increased ( r = 0.91, P < 0.001). Supernatants from tissue cultures of the tumor (MCA sarcoma) failed to have any detectable TNF activity. However, large tumors in vivo had increased amounts of necrosis (78 ± 8%), increased numbers of infiltrating macrophages, and increased levels of TNF (480 ± 68 U/ml) compared to small tumors. Rats with large tumors also had detectable TNF activity in serum (28 ± 13 U/ml), as well as reduced food intake and body weight loss, while STB animals did not. The results suggest that host macrophages are activated in response to a malignant tumor prior to clinical signs of cachexia. As tumor progresses macrophage activity further increases and elevated levels of TNF production are associated with both tumor necrosis and host cachexia.

Immunological mechanisms of antitumor activity of some kinds of crude drugs on tumor necrosis factor production

Previously, we described the antitumor activity of four crude drugs, A. capillaris, S. doederleinii, A. macrocephala and S. subprostrata. Tumor necrosis factor (TNF) can be produced in animals by injecting Bacillus Calmette-Guerin (BCG) or Corynebacterium parvum (CP) as priming agents and endotoxin (LPS) as an eliciting agent. However, because of their severe toxic action, it is inappropriate to use these agents to induce intrinsic TNF in cancer patients. In the present paper, we began with the investigation of a fluorometric method using ethidium bromide (EB) to assay TNF activity in serum in vitro, and then examined whether the four crude drugs displayed the priming and eliciting activities for TNF production. The TNF activity in a serum sample could be titrated using the fluorometric method in addition to a method using 3H-thymidine. The fluorometric method was superior to the radio-method as regards simplicity, safety and reproducibility. A. capillaris, S. doederleinii and S. subprostrata showed priming activity for TNF production in mice without the liver and spleen hyperplasia seen in the case of CP, S. subprostrata showed an eliciting activity in CP-primed mice. These results suggest that the crude drugs might be useful as inducers of intrinsic TNF in cancer patients.

TNF Activity in the Sera of Patients with Head and Neck Carcinoma

Although some authors have suggested the possibility of spontaneous production of tumor necrosis factor (TNF) in human, there are only a few reports about serum TNF activity in cancer patients. In the present study, TNF activity in the sera of 15 patients suffering from head and neck carcinomas was measured by L assay using L-M cell derived from the murine tumorigenic fibroblast line.Untreated sera possessed L-M cell cytotoxicity equivalent to 5-80 units/ml of human recombinant TNF (hrTNF), however, major part of the cytotoxicity was lost by heat-inactivation at 56°C for 30min. Meanwhile, hrTNF was not inactivated at 56°C. Moreover, the residual activity of the heat-inactivated sera was not inhibited by anti-TNF rabbit serum.In conclusion, the sera of the patients of head and neck cancer contained considerable level of L-M cell cytotoxic factor, but did not any detectable level of TNF.

Participation of tumor necrosis factor in the mediation of gram negative bacterial lipopolysaccharide-induced injury in rabbits.

Macrophages are induced by LPS to release a number of products that determine the host response during gram negative sepsis. To examine the role of one such substance, tumor necrosis factor (TNF), in mediating LPS-induced injury, we employed a rabbit model of endotoxic shock to (a) determine the kinetics and extent of release of TNF into plasma after injection of LPS, and (b) to evaluate the protective effect of in vivo neutralization of LPS-induced TNF by prior infusion of anti-TNF antibody. TNF was maximally induced 45-100 min after injection of 10 micrograms i.v. parent Salmonella minnesota Re595 LPS or 250 micrograms Re595 LPS-HDL complexes. Maximal induction of TNF by LPS was associated with development of hypotension, focal hepatic necrosis, intravascular fibrin deposition and lethality. Based on (a) the peak levels of TNF observed in serum, 2.5 X 10(3) U/ml, (b) the specific activity of purified rabbit macrophage-derived TNF, 1 X 10(8) U/mg, and (c) the biphasic disappearance of intravenously injected purified TNF (t1/2 = 0.5 min, 11 min) we constructed a kinetic model showing that at least 130 micrograms of TNF (1.3 X 10(7) U) was released into plasma 30-200 min postinjection of LPS. Prior infusion of anti-TNF antibody (30-45 min before LPS injection) resulted in neutralization of the LPS-induced serum TNF activity and provided significant protection from the development of hypotension, fibrin deposition, and lethality. Thus, these results provide further evidence that TNF plays a central role mediating the pathophysiologic changes that occur during gram negative endotoxic shock.

Endogenous Tumor Necrosis Factor Induction with Bordetella pertussis Vaccine as a Triggering Agent and Its Therapeutic Effect on MM46 Carcinoma‐bearing Mice

Induction of endogenous tumor necrosis factor (TNF) by administration of Bordetella pertussis vaccine (BPV) as a triggering agent and its therapeutic effect against MM46 carcinoma were investigated in C3H/He mice. Test triggering agents were injected intravenously into mice after intravenous injection of 4‐fold dilution of macrophage activating factor (MAF) or 104 units of murine interferon‐γ (Mu‐IFN‐γ). Then sera were obtained from the mice, and their TNF activities were assayed on L‐929 cells by the method of Ruff and Gifford. The triggering activity of BPV was the highest among those of conventional triggers, such as lipopolysaccharide (LPS) of Escherichia coli, and OK‐432. The levels of serum TNF activity triggered by BPV (4 × 109 cells), LPS of E. coli (3 μg) and OK‐432 (3 KE) were 5350, 85 and 102 units/ml, respectively. Growth of MM46, a spontaneous mammary carcinoma cell line of C3H/He was observed for 35 days after tumor inoculation and was suppressed significantly by intravenous injection of MAF and BPV (4 × 109 cells). On local injection of BPV (2 × 109 cells) into murine tumors, complete regression was observed in 67% of the mice tested with or without MAF priming on day 25 after tumor inoculation, and intratumoral TNF activity was observed even in the case of the single injection of BPV.

Involvement of tumor necrosis factor in endotoxin-triggered neutrophil adherence to sinusoidal endothelial cells of mouse liver and its modulation in acute phase

Tumor necrosis factor (TNF) has been shown to mediate lipopolysaccharide-induced neutrophil adhesion to liver sinusoidal endothelium in vivo. Female NMRI mice received either 5 micrograms lipopolysaccharide (R595) per animal alone (model A) or together with 116 mumol D-galactosamine (model B). One hour after injection, TNF activity in the serum was detectable to an equal extent in both models. Neutrophils in the liver, which had been identified by chloroacetate esterase staining of liver sections and quantitated by light microscopy, started to increase at 1 h and were elevated 10-fold above baseline at 6 h after application in (A) and (B). If 0.5 micrograms TNF instead of lipopolysaccharide was injected alone (model C) or together with D-galactosamine (model D), neutrophil influx into the liver was comparable to that observed in (A) or (B). Alanine aminotransferase activity in the serum was nearly normal in (A) and (C) 6 h after injection, while it reached levels up to 50-fold above baseline in models (B) and (D). This reflects the well-known D-galactosamine sensitization against lipopolysaccharide or TNF. Furthermore, degranulation of a large number of intrasinusoidal neutrophils could be observed 9 h after lipopolysaccharide-galactosamine injection. The administration of 116 mumol D-galactosamine per animal alone led neither to a measurable TNF activity in the serum nor to an increase in alanine aminotransferase activity or number of liver neutrophils. If the animals had received 50 microliter turpentine subcutaneously 24 h prior to lipopolysaccharide, TNF or D-galactosamine injection, the induced acute-phase reaction suppressed the increase of liver neutrophils in all models. Acute-phase reaction also prevented neutrophil degranulation and the rise of alanine aminotransferase in (B) to a great extent, while serum TNF activity was only minimally affected. It is concluded that TNF mediates neutrophil adhesion to the sinusoidal endothelium in vivo and that acute-phase reactants prevent lipopolysaccharide- or TNF-induced neutrophil influx into the liver.