JOURNAL

OF SURGICAL

RESEARCH

5 1,434-445

(1991)

CURRENT RESEARCH REVIEW Tumor Necrosis Factor-a CRAIG S. ROCK, M.D., AND STEPHEN

F. LOWRY,

M.D.’

Laboratory of Surgical Metabolism, Department of Surgery, New York Hospital-Cornell Medical College, 525 East 68th Street, New York, New York 10021 Submitted

for publication

University

August 31, 1990

hormone undergoes proteolytic cleavage of a 76 residue signal peptide, resulting in the circulating cytokine, a 157 amino acid protein with a molecular weight of 17 kDa [7]. This secreted form contains one intrachain disulfide bond [8] and exists as a dimer or trimer in solution [8-131. Each subunit of the trimeric form is composed of an antiparallel B-sandwich, and the /3 sheets are packed edge-to-face to form the trimer. The tertiary structure of the protein resembles the classic “jelly-roll” structure of viral coat proteins 1141. TNF is the first nonviral protein found to have this structure, and although this protein exhibits some overlap of biologic activity with other cytokines, such as the cytotoxic bioactivity shared with interleukin-2 and interleukin-l@, the tertiary structure of each protein is distinct [15, 161. High molecular weight cell-associated forms of TNF have also been identified [17, 181 and found to exhibit bioactivity.

Since the first report in 1975 [l] of tumor necrosis factor-a (TNF) as a protein which could cause the in uiuo regress of a murine tumor, TNF has generated immense interest. Subsequent reports linked a similar molecular weight protein, termed cachectin, to the development of tissue wasting in cachectic states. In 1985, it was determined that these proteins were, in fact, the same [2]. TNF is one of a class of proteins called cytokines; protein mediators produced by a host in response to stress-infection, inflammation, or injury. As the mechanisms underlying cytokine activity have been elucidated, their potential role in the pathogenesis of human disease has also expanded. The goal of this review is to provide an overview of research which has served to link this protein with both the normal and pathologic regulation of diverse cellular functions. STRUCTURE

Synthesis/Degradation

The gene for tumor necrosis factor-u is found on the short arm of human chromosome number 6 [3, 41, in close proximity to the gene for lymphotoxin (TNF-/3). The gene is 3 kb long and contains three introns [3]. The 3’ untranslated region of the TNF mRNA is a repeating octameric unit of adenosine and uridine residues (UUAUUUAU)” [5], a unit shared with the mRNA of many inflammatory mediators, including interleukin-1, lymphotoxin, interferons, and granulocyte macrophage colony stimulating factor (GM-CSF). When the above sequence is inserted into the mRNA for globin, the halflife of this normally stable mRNA is reduced [6], hence this sequence may provide part of the post-transcriptional control of TNF production. The precise post-transcriptional regulation of TNF, however, remains to be defined. A 233 amino acid pro-

TNF is secreted by activated macrophages/monocytes, as well as by lymphocytes, Kupffer cells [ 191, peritoneal macrophages [20], and vascular smooth muscle [21]. Activated human Langerhans cells [22], as well as murine peritoneal mast cells [ 231 and rat mesangial cells [24], have also been shown to produce TNF. Production is increased by a variety of stimuli, including the lipopolysaccharide component of the gram negative bacterial cell wall (LPS) [25-271, lipid A [26], interleukin-2 [28], interferon-T [29, 301, protozoans 1311, viral particles [32], and during host starvation [33]. LPS-mediated transcriptional activation of the TNF gene has been shown to involve kB-type enhancers [34] and is inhibited by lipid IV, [ 351. In oitro, LPS stimulates murine bone-marrow derived macrophages to produce one TNF mRNA species, with both cell-associated and secreted TNF ultimately being detected by immunoprecipitation and Western blot Recombinant murine TNF analyses, respectively. (rMuTNF), however, causes a rapid and transient ex-

’ To whom correspondence and reprint requests should be addressed at Department of Surgery, New York Hospital-Cornell University Medical College, 525 East 68th St., F-2016, New York, NY 10021. 0022-4&w/91

Copyright All

right8

$1.50 Q 1991 by Academic Press, of reproduction in any form

434 Inc. reserved.

ROCK

AND

LOWRY:

TUMOR

pression of the c-fos gene with the production of two distinct TNF mRNA species, neither of which are translated [36]. LPS-mediated transcriptional activation in peripheral blood mononuclear cells can be suppressed, in vitro, by the presence of interleukin-6 [37,38], glucocorticoids [39], and pentoxifylline (a phosphodiesterase inhibitor) [40]. While the production may be decreased in the presence of interleukin-6, TNF ultimately stimulates the production of other cytokines, for example interleukin-1 [41], 11-6 [42], and MSCSF (CSF-1) [43]. Other mediators can also influence the synthesis of TNF. Recombinant murine IL-4, for example, can block the ability of IL-2 or LPS to prime macrophages for TNF production in viuo [28]. Complement, specifically CXa, has been shown to increase transcription of TNF mRNA, but translation required the addition of another factor, in this case LPS [44]. TNF, therefore, becomes a central element in a complex network of cytokines and other mediators. Once released, TNF has a short circulating half-life, approximately 7 min in mice [45] and 14-18 min in humans [46]. Many organs, including liver, skin, gastrointestinal tract, kidney, lung, and spleen [45], appear to be not only sites for TNF binding, but also for degradation of the protein. Receptors Receptors for TNF have been detected on a wide variety of cell types [47-501. However, no correlation has been found between the presence of or number of receptors on a cell and subsequent biologic responses by that cell to TNF. Cells sensitive to cytotoxicity by TNF, such as the murine fibrosarcoma L929 cell line, have approximately 2,200 receptors per cell, with a Kd of 6.1 X 10-l”M [50], while TNF-resistant fibroblasts (FS-4) have approximately 7,500 receptors per cell, with a Kd of 3.2 X lo-“M. Macrophage-like RAW 264.7 cells, which secrete TNF as well as several other inflammatory cytokines, have approximately 1,100 receptors per cell with a Kd of 1.3 x lo-’ M [51]. Occupancy of as few as 5% of such receptors appears to elicit a maximal response [52]. Cellular binding of TNF may also vary due to differences in receptor structure. Myeloid cells and epithelial cells have recently been shown to possess different high-affinity receptors for TNF [53]. The myeloid receptor has a molecular weight of 80 kDa (fully glycosylated), while the epithelial receptor has a molecular weight of 55-60 kDa (fully glycosylated). The TNF/receptor complexes formed appear to result from the binding of one TNF molecule (of the trimer) with the receptor. Whether or not these different receptors subserve the same functional responses remains to be determined. Both down-regulation of receptor number as well as internalization of receptors have been demonstrated. Exposure of murine and human macrophages and human umbilical vein endothelial (HUVE) cells to micro-

NECROSIS

435

FACTOR-a

tubule depolymerizing agents results in a rapid decrease in surface TNF receptors [54], suggesting that microtubules are required either for receptor synthesis or transport to the plasma membrane. Exposure of RAW 264.7 cells, as well as both human and murine macrophages, to LPS results in a rapid and nearly complete internalization of TNF receptors in vitro [51]. Such internalization occurs to a lesser extent in human endothelial cells and is absent in human granulocytes and melanoma cells and mouse L929 cells after exposure to LPS [51]. In granulocytes, the shedding of TNF receptors appears to be a major regulatory step [55]. TNF activity, therefore, may be regulated by both receptor affinity as well as the down-regulation of receptor number, internalization and shedding of receptors. TNF has also been shown to possess direct intracellular effects. Smith et al. [56] demonstrated that normal murine macrophages, as well as the 5774 macrophage-like cell line, both which are resistant to extracellular TNF, were rapidly killed by intracellular administration of TNF. METABOLIC

EFFECTS

Tumor necrosis factor also appears capable of inducing a wide variety of metabolic effects, many of which are reminiscent of those observed in critically ill patients. Although these effects are clearly orchestrated in a complex, interdependent manner in uiuo, they are presented below by organ system. Hematologic It was noted by Tracey et al. [57] that rats treated with sublethal doses of TNF exhibited a 40% reduction in total red cell mass. This anemia was later found to be the result of both a decrease in red cell synthesis, as well as a decrease in the life span of circulating RBCs [58]. Activated macrophages are not only the major source of TNF production, but are also, in turn, further influenced by TNF [59,60]. TNF has also been shown to promote the differentiation of myelogenous cell lines along a monocyte/macrophage pathway [61]. The most diverse hematologic effects of TNF are exerted upon the neutrophil population. TNF causes a release of neutrophils from bone marrow, resulting in neutrophilia [62], and then regulates neutrophil chemotaxis [63], degranulation, superoxide production, and lysozyme release [64681. Natural cytotoxic (NC) activity has been proposed to be due to either a cell-associated form of TNF or one which is secreted and active locally (paracrine) [69]. Eosinophils exposed to recombinant human TNF (rhTNF) exhibit increased superoxide production, a low grade, long-term activation of their respiratory burst, and increased toxicity toward endothelial cells in uitro [70]. Endothelium/Vasculur

Smooth Muscle

Upon exposure to TNF, vascular endothelial cell monolayers are modified, with cell elongation, overlap-

436

JOURNAL

OF SURGICAL

RESEARCH:

ping, changes in the cytoskeleton, and formation of intercellular gaps [71, 721. Incubation of endothelial cells with TNF also increases procoagulant activity on the endothelial surface [73], as well as vascular permeability in vitro [72, 74, 751 and in uiuo [76]. The change in cell shape, cytoskeleton and vascular permeability have been shown to be regulated by a pertussis toxin-sensitive G protein, while the change in coagulant activity is not [72]. Cultured human umbilical vein endothelial cells are activated by TNF, as shown by increased adhesiveness for lymphocytes, increased RNA and protein synthesis, and increased cellular volume [ 771. Intracutaneous injection of recombinant human TNF in baboons (Pupio anubis) results in endothelial cell hypertrophy, increased vascular permeability, and accumulation of polymorphonuclear and mononuclear leukocytes at the site of injection [78]. Recombinant human TNF also affects vascular smooth muscle cells, where TNF induces the production, intracellular accumulation, and release of interleukin-l. In addition, smooth muscle cells are activated to release PGE, and the gene for 2’-5’-oligo-adenylate synthetase is induced [21]. This enzyme is thought to mediate the anti-viral and anti-proliferative actions of interferon. Skeletal Muscle Administration of a single dose of rhTNF to rats is reported to result in increased skeletal muscle proteolysis [79], while rats given rhTNF on a chronic basis lose total body protein at rates higher than pair-fed controls [57]. Branched-chain cu-keto acid dehydrogenase, the rate-limiting enzyme in skeletal muscle branched-chain amino acid (BCAA) oxidation, is activated following infusion of rhTNF into rats, but only the concentration of muscle phenylalanine increases, and plasma phenylalanine and BCAA concentrations remain unchanged [80]. Warren et al. [81] observed that rhTNF administration caused increased amino acid release from peripheral tissues of cancer patients, while Pomposelli et al. [82] suggested that skeletal protein degradation was increased when TNF was administered at smaller doses than those required to produce hemodynamic changes. However, these latter observations have not been confirmed by in vitro studies [83,84]. As a consequence, evidence to suggest that TNF per se is a direct proteolytic agent remains elusive. Other muscle physiologic functions, such as skeletal muscle membrane function, are also acutely influenced by exposure to TNF. The transmembrane potential difference (E,) of rat skeletal muscle fibers decreases when incubated with rhTNF. The extent of this decline is dose-dependent and is inhibited by anti-TNF monoclonal antibodies (mAb). A decline in skeletal muscle E, during TNF infusion is also seen in uiuo in rats [85], as well as in dogs [86], and occurs simultaneously with the

VOL.

51, NO. 5, NOVEMBER

1991

appearance of circulating TNF in endotoxemic humans [87]. Muscle incubated with plasma of critically ill patients shows a similar response 1881, and this effect is abrogated by mAb against TNF. Skeletal muscle carbohydrate metabolism is also affected. TNF causes glycogen breakdown, with an associated increase in both lactate and fructose 2,6 bisphosphate release in L-6 myotubules. This is followed by an increase in glucose uptake, an effect most likely mediated by an increase in glucose transporters both in the plasma and microsomal fractions [89].

Adipose Much of the early research with TNF (cachectin) focused upon lipid metabolism and the capacity of TNF to reduce serum lipoprotein lipase (LPL) activity, with a resultant hypertriglyceridemia. Kawakami and Cerami [90] noted a suppression of LPL activity and hypertriglyceridemia after LPS administration to endotoxinsensitive mice. The serum factor responsible was subsequently isolated and named “cachectin” [91], for its potential role as a mediator of cachexia. In vitro studies have shown that adipocytes exposed to TNF do not produce mRNAs specific to adipocytes (mRNAs for lipogenic enzymes) [92], and the lack of these enzymes subsequently prevents normal adipocyte metabolism. For example, LPL activity has been noted to be almost completely suppressed by TNF [93]. Recombinant human TNF has also been shown to block fatty acid synthesis in 3T3-Ll adipocytes by preventing the upregulation of genes required for the incorporation of acetate into fatty acids [94]. While lipoprotein lipase activity has been suppressed in cultures of 3T3-Ll adipocytes, Kern [95] showed that rhTNF had no effect on lipoprotein lipase activity in cultured human adipocytes. This observation underscores the requirement for careful definition of both species and tissue-specific responses elicited by this cytokine. In uiuo, rats and dogs administered sublethal doses of TNF have elevated serum levels of triglycerides and free fatty acids [57,86]. While traditionally the hypertriglyceridemia has been attributed to decreased lipoprotein lipase activity, with the exception of epididymal fat LPL, such enzyme activity in most adipose tissues in the rat is not affected by rhTNF, despite persistent de nouo hepatic lipogenesis [96]. Diabetic rats, which normally exhibit depressed levels of serum lipoprotein lipase, do not exhibit a further decline in enzyme levels after administration of TNF [97]. These animals also become hyperglycemic, with no increase in insulin levels, suggesting that an insulin-independent induction of hepatic lipid synthesis may be an important contributory factor in the development of TNF-induced hypertriglyceridemia.

ROCK

AND

LOWRY:

TUMOR

Pulmonary TNF has been proposed to have a major role in pulmonary pathology, particularly as a mediator in the pathogenesis of adult respiratory distress syndrome (ARDS). Intravenous infusion of rhTNF into rats results in increased lung tissue levels of thromboxane B, and 6-ketoprostaglandin F,, , as well as increased lung permeability [98]. None of these changes are affected by pretreatment with a platelet-activating factor (PAF) antagonist. Goldblum et al. [99] bolused rhTNF several times into rabbits, which were sacrificed 5 hr after the first bolus. Electron microscopy demonstrated endothelial injury, perivascular edema, and extravasation of an ultrastructural permeability tracer. Ferrari-Baliviera et al. demonstrated that a 24 hour infusion of TNF induced an adult respiratory distress syndrome in rats [ 1001. The lungs of treated animals demonstrated reduced compliance, as well as increased water content and cellularity. Patients with disseminated malignant melanoma or renal cell carcinoma who were treated with recombinant TNF therapy also developed pulmonary dysfunction [loll. By 2 weeks after the start of therapy, a significant decrease in Dsb (single breath diffusing capacity of carbon monoxide) was demonstrated, although none of the patients were symptomatic. The association between TNF and ARDS was demonstrated by Millar et al. [102], who found high TNF concentrations (mean 13.1 rig/ml) in bronchoalveolar lavage fluid of intubated ICU patients with ARDS, while control patients had no detectable TNF. Roberts et al. [103] noted similar findings. Since these levels of TNF are significantly higher than the plasma TNF levels which have been reported in septic patients (~1 rig/ml), local (paracrine) production is suggested [ 1031. Cardiac Numerous hemodynamic effects attributable to endotoxin, including increased cardiac output, increased heart rate, hypotension, decreased systemic vascular resistance, and decreased left-ventricular performance [ 1041, may be partially related to TNF activity. This protein has been shown to have direct effects on rat cardiac myocytes in vitro, wherein the fi-adrenergic agonist mediated increases in myocyte contractility and intracellular CAMP accumulation are both blocked by TNF [ 1051. The decrease in CAMP accumulation is the result of uncoupling of receptors to CAMP production. In vivo, Neilson et al. [106] administered 1 mg/kg of rhTNF to Sprague-Dawley rats and found no effect on blood pressure or mortality; however, the addition of a sublethal dose of LPS resulted in a metabolic acidosis, hypotension, and 100% mortality. A single dose of TNF given to dogs resulted in decreased mean arterial blood pressure and decreased left ventricular ejection fraction by the second day after infusion. After fluid resuscitation, animals had left ventricular dilatation and an in-

NECROSIS

FACTOR-a

437

creased or normal cardiac index, with decreased or normal systemic vascular resistance. These changes reverted to normal in 7 to 10 days [107]. The cardiac effects of TNF are not necessarily limited in duration. Repeated doses of TNF have been reported to cause progressive cardiac enlargement, as well as significantly decreased myocardial contractility in a patient with renal cell carcinoma who was given TNF postoperatively [lOBI. The patient presented in congestive heart failure 3 months after completion of TNF therapy. Hepatic While TNF may participate in the acceleration of peripheral tissue protein losses, hepatic protein content acutely increases after exposure to TNF (secondary to decreased proteolysis) [79] and is preserved in rats chronically exposed to the protein [ 1091. Hepatomegaly has been noted as early as 17 hr after TNF infusion in rats [ 1 lo]. An increase in glucagon-mediated hepatic uptake of amino acids may partly explain the increase in hepatic mass [ill]. Production of TNF within the liver may be affected by diet. Rats alimented using total parenteral nutrition demonstrate higher levels of cell-associated TNF within the liver than do animals alimented using chow [112]. In noncachectic, human cancer patients, administration of rhTNF results in a significant increase in C-reactive protein, an acute-phase reactant synthesized by the liver [Bl]. Chronic TNF administration has also been shown to cause significant histologic changes within the liver, as evidenced by bile duct proliferation, monocyte infiltration, and periportal inflammatory changes [57]. Such changes are similar to those observed in critically ill patients who have suffered severe inflammatory processes and prolonged periods of hyperalimentation [113]. Renal Intravenous infusion of rhTNF into rats results in acute renal tubular necrosis [114], while infusion into dogs results in a marked diuresis [115], an effect which is blocked by pretreatment with ibuprofen, or by splenectomy [116]. A possible paracrine role for TNF in the kidney has also been recently demonstrated. Recombinant human TNF in vitro causes significant secretion of renin by renal cortical slices and additionally blocks the inhibitory effects of angiotensin-II on renin release. The increase in renin secretion induced by TNF can be blocked by meclofenamate, a cyclooxygenase blocker [ 1171. These findings suggest that prostaglandins play a role in the renal cortical effects of TNF. OTHER

TISSUE

EFFECTS

In vitro, rhTNF has been shown to produce a dose-dependent inhibition of angiotensin-II-induced aldoste-

438

JOURNAL

OF SURGICAL

RESEARCH:

rone synthesis by rat adrenal glomerulosa cells [118]. Recombinant murine TNF is cytotoxic to murine pancreatic islets of Langerhans [ 1191, a phenomenon which appears to be mediated by arachidonate metabolites [120], while the functional inhibition that can also be seen after exposure to TNF operates via an unknown mechanism. Bowel necrosis is another pathologic effect of TNF infusion and appears to be mediated, at least in part, by platelet-activating factor [121]. TNF, therefore, has been shown to have a wide variety of tissue effects, both direct as well as indirect, via other mediators. SYSTEMIC DISEASE PROCESSES Role in CachexialCancer The role of TNF in cachexia has been widely discussed. The chronic administration of TNF reproduces this syndrome in animals, with a decrease in food intake in rats [57] and mice [122], as well as decreased nitrogen balance [79, 1231 and weight loss being demonstrated. As noted above, infusion of TNF also results in preservation of hepatic protein content, while skeletal muscle protein content decreases [79]. Oliff et al. [124] transfected Chinese hamster ovary (CHO) tumor cells with the gene for human TNF, then inoculated two sets of mice; one set with “normal” CHO tumor cells, and a second set with the transfected TNF-producing tumor cells (TNF mice). Animals with TNF-secreting tumors were found to develop progressive wasting and die earlier than controls. Using the same model, Brenner et al. [125] found that albumin mRNA levels decreased approximately 90% before the onset of cachexia in TNF mice. This response was associated with decreased albumin synthesis, whereas the mRNA levels of fl-actin, complement C3, and a-tubulin remained unchanged. In a rat sarcoma model, a direct correlation between serum TNF levels and tumor burden, as well as an inverse correlation between serum TNF levels and food intake and weight loss have been observed [126]. The level of TNF production by macrophages from these animals, in response to LPS, also correlated directly with tumor burden [ 1271. After resection of the tumor, circulating TNF levels became undetectable, and food intake and body weight both increased. In this model, serum triglyceride levels increased in the cachectic tumorbearing animals and decreased after tumor resection. Recently, Laskov et al. [ 1281 documented the presence of increased TNF mRNA and TNF activity from murine pre-B and B lymphoma cell cultures, while myeloma cell lines were negative for this species. TNF has also been isolated from humans with malignancy. The production of TNF in human colorectal adenocarcinoma has been localized to less than 1% of the tumor-infiltrating macrophages [ 1291. Saarinen et al. [130] found detectable levels of serum TNF in 30 of 32 children with either leukemias or solid tumors at the

VOL.

51, NO. 5, NOVEMBER

1991

time of diagnosis. While the mechanism of tumor cell lysis remains unclear, Hasegawa and Bonavida [131] found the pathology to be calcium-independent.

Role in Endotoxic

Shock

The infusion of recombinant human TNF into rats, in doses similar to those produced endogenously in response to lethal endotoxin, results in hypotension, metabolic acidosis, hemoconcentration, hyperglycemia, hyperkalemia, and death [ 1141. Diffise pulmonary inflammation and hemorrhage, ischemic and hemorrhagic lesions of the gastrointestinal tract, and acute renal tubular necrosis were all apparent at necropsy. The suggestion has been made that the mortality seen after TNF infusion in early animal studies may have been the result of endotoxin contamination of the TNF [132, 1331. Myers et al. [132] found TNF to be lethal only when given with a low dose of endotoxin, and the shock which resulted from the combination was not dependent on the synthesis of either eicosanoids or PAF. Plasma TNF levels are detected with greater frequency in septic patients, and the level of TNF has been correlated in some series with the severity of illness [134-1361. In burn patients, TNF is detectable with greater frequency (69% vs 33%) and at higher concentrations in patients with sepsis, as well as in those who ultimately die (71% vs 31%) [136]. It was also found that TNF appears transiently and repetitively, and increased serum cortisol levels correlate inversely with the presence of TNF [136]. While Debets et al. only detected circulating TNF in 25% of critically ill septic patients, the presence of detectable TNF was associated with twice the mortality rate (73% vs 34%) [137]. The difficulty in detection of TNF is probably related, in part, to its short circulating half-life, as well as the detection limit of current ELISA assays. However, a lack of circulating TNF does not preclude TNF effects, as locally secreted as well as cell-associated forms may also be operative via paracrine mechanisms under such circumstances. The infusion of endotoxin in man results in an elevation of TNF levels, with a peak level occurring 90 min after endotoxin administration [134, 1381. Fong et al. [138] demonstrated that TNF levels were significantly higher in the hepatic vein than in the arterial circulation after endotoxin infusion, revealing that the splanchnic organs are a significant source of TNF production under such circumstances. No change in circulating glucagon or insulin levels, and only transient changes in epinephrine and cortisol levels, were noted. Hence, it would not appear that the classical hormonal changes induced by endotoxin could account for the increase in splanchnic oxygen consumption and substrate changes. These influences are also further evidence suggestive of a paracrine action of TNF within splanchnic tissue.

ROCK

PREVENTING

Endotoxin/TNF

TNF

AND

LOWRY:

TUMOR

EFFECTS

Tolerance

Endotoxin tolerance following continuous infusion or repetitive doses of LPS is a well-established phenomenon in experimental animals. While the mechanism remains unclear, recent studies have demonstrated an association between endotoxin tolerance and reduced production of TNF. Repeated sublethal doses of endotoxin result not only in tolerance, but also in a decreased secretion of TNF in response to endotoxin in rats [ 1391. Zuckerman et al. [140] have shown that the refractory period to endotoxin in murine peritoneal macrophages results from a post-translational regulatory mechanism. Refractory macrophages exposed to a second dose of endotoxin actually contain increased message for TNF, as well as an accumulation of the 26-kDa TNF precursor. Endotoxin-induced tolerance has also been shown to be protective against lethal doses of TNF in rats, while TNF-induced tolerance (produced by repetitive doses of TNF) is also protective against lethal doses of endotoxin [ 1411. Tolerance appears to develop after a single exposure to TNF. Sheppard et al. [142] pretreated Fischer rats with a low dose of rhTNF, prior to endotoxin administration, rhTNF administration (lethal dose) or cecal ligation and puncture, and found significantly decreased mortality over controls. Treatment with either endotoxin or TNF, therefore, can protect against subsequent exposure to TNF. Neutrophil

Depletion

Mallick et al. [143] demonstrated that neutropenic guinea pigs treated with TNF did not exhibit histopathologic organ damage, nor any abnormal accumulation of tissue albumin. Control animals, with normal polymorphonuclear leukocyte counts, exhibited marked damage to the adrenals, kidneys and liver, with hemorrhage, congestion, and polymorphonuclear leukocyte infiltration. There was also an increase in tissue albumin accumulation in adrenals, kidneys, spleen, heart, and liver. Neutrophilic infiltration and activation, therefore, would appear to play an important role in the pathologic tissue changes associated with TNF. Antibodies

to TNF

Anti-murine TNF antibodies have been shown to provide protection from the lethal effect of Escherichia coli lipopolysaccharide in BALB/c mice [144]. While treatment of C57B1/6 mice with Lewis lung carcinomas with an anti-murine TNF antibody did not influence the development of anemia, hypoalbuminemia or increase in serum amyloid P concentration seen with increasing tumor burden, anti-murine TNF antibodies did attenuate the carcass lipid depletion and prevent the hypertriglyceridemia normally seen [ 1451.

NECROSIS

FACTOR-a

439

Administration of anti-TNF monoclonal antibodies 2 hr prior to infusion of an LD,, dose of E. coli provided essentially complete protection against counter-regulatory stress hormone release, organ dysfunction, shock, and death in baboons [146]. Treatment with anti-TNF antibodies has also been shown to increase cardiac allograft survival in rats [147]. The interrelationship between endotoxin and TNF was again evident when the use of polyvalent IgG antibodies to lipopolysaccharide in humans with endotoxic shock resulted in decreased circulating levels of endotoxin and TNF anddecreased mortality from an expected level of over 80 to 55% [148]. Studies are currently underway to determine the efficacy of anti-TNF antibodies in the treatment of patients with sepsis or cachexia.

Drug/Hormonal

Therapy

In uitro, neutrophils stimulated by lipopolysaccharide and subsequently exposed to TNF demonstrate increased adherence to nylon fiber, are primed for increased superoxide production and lysozyme release, and have decreased directed migration in response to FMLP. These effects, which may result in tissue damage in clinical conditions such as septic shock, were all counteracted by pentoxifylline [ 1491. In uiuo, Lilly et al. [ 1501 prevented TNF-induced lung injury in guinea pigs by treatment with pentoxifylline. The TNF-induced changes of increased lung water, albumin content, bronchoalveolar lavage leukocytes, and polymorphonuclear leukocytes were all prevented by such therapy. The hemodynamic changes resulting from TNF infusion can also be prevented or treated. Evans et al. [115] pretreated dogs with ibuprofen, a cyclooxygenase inhibitor, prior to a 6-hr infusion of a sublethal dose of TNF. This abolished some of the hemodynamic responses to the cytokine (as well as blunted classical hormone responses). The hypotension normally resulting from the infusion of rhTNF into dogs has also been treated by the administration of NG-methyl-L-arginine. This competitive antagonist of normal arginine metabolism restores blood pressure to normal within 2 min [151], suggesting that TNF-induced hypotension is mediated, in part, by excessive nitric oxide production. Hormonal therapy has also been effective at reversing the effects of TNF. Fraker et al. [ 1521 demonstrated that concurrent administration of insulin along with TNF in rats prevented nearly all of the nutritional and histopathologic changes associated with repeated sublethal doses of TNF. Barber et al. [ 1531 has abrogated both the systemic appearance of TNF as well as the systemic manifestations of endotoxin by pretreatment of humans with cortisol. This response is consistent with the known inhibitory effects of corticosteroids upon TNF production in vitro [154].

440

JOURNAL

OF SURGICAL

RESEARCH

VOL.

TABLE Characteristics Structure/synthesis/degradation Size Synthesized

by

1 of TNF

Activated macrophages/monocytes, lymphocytes, smooth muscle, activated Langerhans cells

enhanced by

Lipopolysaccharide, host starvation

Synthesis

decreased by

Interleukin-4, Liver,

Metabolic effects Hematologic

lipid A, interleukin-2,

interleukin-6,

skin, gastrointestinal

Neutrophilia, Differentiation activation

tract, kidney,

Kupffer

interferon-T,

glucocorticoids,

Cell elongation, procoagulant

Vascular

smooth muscle

Production and release of interleukin-1 synthetase

Skeletal

muscle

? increased proteolysis Increased glycogen breakdown,

protozoans,

macrophages,

viral particles,

vascular

complement

C5a,

pentoxifylline lung, spleen

overlapping, activity

in 3T3-Ll

cytoskeletal

changes, formation

adipocytes,

Pulmonary

Increased lung permeability, perivascular edema Mediator in development of ARDS Increased levels of thromboxane B, and 6-ketoprostaglandin

no LPL suppression

Cardiac

Increased: cardiac output, heart rate Decreased: SVR, BP, left-ventricular performance

Hepatic

Increased uptake of amino acids, increased C-reactive infiltration, periportal inflammatory changes

Renal

Acute tubular

Others

Inhibition of angiotensin-II induced aldosterone Langerhans, bowel necrosis

necrosis, diuresis, blocks inhibition

Despite the current balance of data implicating TNF as a principal mediator of significant injury-related events, there is also evidence to suggest that this cytokine exerts homeostatic and host protective effects. Cross et al. [l&5] demonstrated that C3H/HeJ mice, which are unable to produce TNF in response to endotoxin, were more susceptible to infection with a virulent Kl-encapsulated E. coli than their TNF-producing counterparts, C3H/HeN mice. Pretreatment of C3H/ HeJ mice with a combination of TNF and interleukinla conferred protection against this virulent strain of E. coli, suggesting a protective role for TNF and IL-la against organisms which need to replicate within the host. Hershman et al. [156] demonstrated that TNF can be effective both for prophylaxis as well as treatment of a bacterial challenge. A dose of TNF less than that known to cause hemodynamic changes was administered to mice either before or after im inoculation with

gaps, increased

of gene for 2’-5’-oligo-adenylate

decreased E,,,

LPL suppression

OF TNF

of intercellular

and PGEZ; induction

Adipose

EFFECTS

cells, peritoneal

neutrophil: chemotaxis, degranulation, superoxide production, lysozyme release of myelogenous cells to monocytes and macrophages, NC activity, eosinophil

Endothelium

PROTECTIVE

1997

Circulating: 15’7 AA, MW 17 kD Cell-associated: MW 26-29 kD

Synthesis

Degraded by

51, NO. 5, NOVEMBER

in cultured

human adipocytes

F,,

protein,

bile duct proliferation,

monocyte

of renin release by angiotensin-II synthesis,

cytotoxicity

to pancreatic

islets of

encapsuled Klebsiella pneumoniae, or placement of a thigh suture contaminated with K. pneumoniae. In all cases, survival was significantly improved with TNF therapy. Have11 [157] showed the importance of TNF in antibacterial resistance. Pretreatment of mice with rMuTNF provided protection against a subsequent normally lethal challenge of Listeria. Also, T cell-intact and T cell-deficient (athymic) mice treated with a monospecific murine anti-TNF IgG given within the first 3 days of a sublethal Listeriu infection (the time when hepatic and splenic bacterial counts are highest) showed exacerbation of the infection. TNF, therefore, appears to be playing a protective role in these situations. The addition of TNF to antibiotic therapy has also been investigated. Livingston et al. [ 1581 added TNF to Cefazolin therapy for the treatment of a subcutaneous S. aureus infection in a model of hemorrhagic shock in the rat. Abscess number, diameter, and weight all decreased when compared with animals treated only with Cefazo-

ROCK

AND

LOWRY:

TUMOR

lin. TNF therapy alone increased abscess diameter and weight, effects attributed to an increased inflammatory reaction. RhTNF coupled to agarose beads has been shown to cause granuloma formation in vitro [X9], as well as in uiuo [160]. TNF, therefore, probably plays a protective role by enhancing granuloma formation in diseases such as tuberculosis.

NECROSIS 9.

Beutler, B., and Cerami, A. Cachectin and tumor necrosis factor as two sides of the same biologic coin. Nature 320: 584, 1986.

10.

Davis, J. M., Narachi, M. A., Alton, N. K., and Arakawa, T. Structure of human tumor necrosis factor-a derived from recombinant DNA. Biochemistry 26: 1322,1987. Shirai, T., Yamaguchi, H., Ito, H., Todd, C. W., and Wallace, R. B. Cloning and expression in Escherichia coli of the gene for human tumour necrosis factor. Nature 313: 803, 1985.

11.

12.

Arakawa, T., and Yphantis, D. A. Molecular weight of recombinant human tumor necrosis factor-a. J. Bill. Chem. 262: 7484, 1987.

13.

Winglield, P., Pain, R. H., and Craig, S. Tumour necrosis factor is a compact trimer. FEBS Lett. 211: 179, 1987.

14.

Jones, E. Y., Stuart, D. I., and Walker, N. P. C. Structure tumour necrosis factor. Nature 338: 225, 1989.

15.

Brandhuber, B. J., Boone, T., Kenney, W. C., and McKay, D. B. Three-dimensional structure of interleukin-2. Science 238:

16.

Priestle, J. P., Schar, H.-P., and Grutter, M. G. Crystal structure of the cytokine interleukin-la. EMBO J. 7: 339, 1988.

17.

Kriegler, M., Perez, C., DeFay, K., Albert, I., and Lu, S. D. A novel form of TNF/cachectin is a cell surface cytotoxic transmembrane protein: ramifications for the complex physiology of TNF. Cell 53: 45,1988.

18.

Keogh, C., Fong, Y., Marano, M. A., Seniuk, S., He, W., Barber, A., Minei, J., Felsen, D. J., Lowry, S. F., and Moldawer, L. L. Identification of a novel tumor necrosis factor/cachectin from the livers of burned and infected rats. Arch. Surg. 125: 79, 1990.

CONCLUSIONS

As research on TNF has continued, diverse sources of production, sites of action, and regulatory effects of this cytokine have been identified (Table 1). While the prevention of TNF effects has been the focus of substantial research (eg., through the use of cyclooxygenase inhibitors, or anti-TNF antibodies), it is increasingly clear that many TNF influences are beneficial, if not essential, for normal function. This is likely true during the early course of injury or invasive infection, where the cytokine serves to direct local inflammatory responses and the appropriate flow of substrates. Further elucidation of the mechanisms by which TNF exerts such influences at the cellular and organ levels, will provide insights into the manner in which these diverse influences should be appropriately controlled or enhanced. REFERENCES 1.

2.

3.

4.

5.

6.

7. 8.

Carswell, E. A., Old, L. J., Kassel, R. L., Green, S., Fiore, N., and Williamson, B. An endotoxin-induced serum factor that causes necrosis of tumors. Proc. Natl. Acad. Sci. USA 72: 3666, 1975. Beutler, B., Greenwald, D., Hulmes, J. D., Chang, M., Pan, Y.-C. E., Mathison, J., Ulevitch, R., and Cerami, A. Identity of tumour necrosis factor and the macrophage-secreted factor cachectin. Nature 316: 552, 1985. Aggarwal, B. B., Aiyer, R. A., Pennica, D., Gray, P. W., and Goeddel, D. V. Human tumour necrosis factors: structure and receptor interactions. Ciba Found. Symp. 131: 39,1987. Nedospasov, S. A., Shakhov, A. N., Turetskaya, R. L., Mett, V. A., Azizov, M. M., Georgiev, G. P., Korobko, V. G., Dobrynin, V. N., Filippov, S. A., Bystrov, N. S., Boldyreva, E. F., Chuvpilo, S. A., Chumakov, A. M., Shingarova, L. N., and Ovchinnikov, Y. A. Tandem arrangement of genes coding for tumor necrosis factor (TNF-a) and lymphotoxin (TNF-/3) in the human genome. Cold Spring Harbor Symp. Quant. Biol. 51: 611, 1986. Caput, D., Beutler, B., Hartog, K., Thayer, R., Brown-Shimer, S., and Cerami, A. Identification of a common nucleotide sequence in the 3’-untranslated region of mRNA molecules specifying inflammatory mediators. Proc. Natl. Acad. Sci. USA 83: 1670, 1986. Shaw, G., and Kamen, R. A conserved AU sequence from the 3’ untranslated region of GM-CSF mRNA mediates selective mRNA degradation. Cell 46: 659, 1986. Beutler, B., and Cerami, A. Cachectin: More than a tumor necrosis factor. N. Engl. J. Med. 316: 379, 1987. Aggarwal, B. B., Kohr, W. J., Hass, P. E., Moffat, B., Spencer, S. A., Henzel, W. J., Bringman, T. S., Nedwin, G. E., Goeddel, D. V., and Harkins, R. N. Human tumor necrosis factor. Production, purification and characterization. J. Biol. Chem. 260:

2345,1985.

441

FACTOR-a

of

1707,1987.

Hesse, D. G., Davatelis, G., Felsen, D., Seniuk, S., Fong, Y., Tracey, K., Moldawer, L., Cerami, A., and Lowry, S. Cachectin/ tumor necrosis factor gene expression in Kupffer cells. J. Leuk. Biol. 42: 422, 1987. 20. Halme, J. Release of tumor necrosis factor-a by human peritoneal macrophages in vivo and in vitro. Am. J. Obstet. Gynecol. 161: 1718, 1989.

19.

21. Warner, S. J. C., and Libby, P. Human vascular smooth muscle cells: Target for and source of tumor munol. 142: 100, 1989.

necrosis

factor.

J. Im-

22. Larrick,

J. W., Morhenn, V., Chiang, Y. L., and Shi, T. Activated Langerhans cells release tumor necrosis factor. J. Leuk. Biol. 45: 429, 1989.

23. Gordon, J. R., and Galli, S. J. Mast cells as a source of both preformed and immunologically Nature 346: 274, 1990.

inducible

TNF-a/cachectin.

24. Baud, L., Oudinet,

J.-P., Bens, M., Noe, L., Peraldi, M.-N., Rondeau, E., Etienne, J., and Ardaillou, R. Production of tumor necrosis factor by rat mesa&al ceils in response to bacterial lipopolysaccharide. Kidney Znt. 35: 1111, 1989. 25. Beutler, B., Krochin, N., Milsark, I. W., Leudke, C., and Cerami, A. Control of cachectin (tumor necrosis factor) synthesis: mechanisms of endotoxin resistance. Science 232: 977, 1986. 26. Feist, W., Ulmer, A. J., Musehold, J., Brade, H., Kusumoto, S., and Flad, H.-D. Induction of tumor necrosis factor-a release by lipopolysaccharide and defined lipopolysaccharide partial structures. Zmmunobiology 179: 293, 1989.

27. Jongeneel, C. V., Shakhov, A. N., Nedospasov, S. A., and Cerottini, J.-C. Molecular control of tissue-specific expression at the mouse TNF locus. Eur. J. Zmmunol. 19: 549,1989. 28. McBride, W. H., Economou, J. S., Nayersina, R., Comora, S., and Essner, R. Influences of interleukins 2 and 4 on tumor necrosis factor production by murine mononuclear phagocytes. Cancer Res. 50: 2949, 1990. 29. Collart, M. A., Belin, D., Vassalli, J.-D., and Vassalli, P. Modula-

JOURNAL

OF SURGICAL

RESEARCH:

tions of functional activity in differentiated macrophages are accompanied by early and transient increase or decrease in c-fos gene transcription. J. Immunol. 139: 949,1987. 30.

31.

32.

Collar%, M. A., Belin, D., Vassalli, J.-D., DeKossodo, S., and Vassalli, P. y-Interferon enhances macrophage transcription of the tumor necrosis factor/cachectin, interleukin-1, and urokinase genes, which are controlled by short-lived repressors. J. Exp. Med. 164: 2113, 1986. Hotez, P. J., LeTrang, N., Fairlamb, A. H., and Cerami, A. Lipoprotein lipase suppression in 3T3-Ll cells by a haematoprotozoan induced mediator from peritoneal exudate cells. Parasite Immunol. 6: 203,1984. Wong, G. H. W., and Goeddal, D. V. Tumour necrosis factors a and p inhibit virus replication and synergize with interferons. Nature 323: 819, 1986.

VOL.

46.

47.

48.

49.

33.

Vaisman, N., Schattner, A., and Hahn, T. Tumour necrosis factor production during starvation. Am. J. Med. 87: 115, 1989.

34.

Shakov, A. N., Collart, M. A., Vassalli, P., Nedospasov, A., and Jongeneel, C. V. kB-type enhancers are involved in lipopolysaccharide-mediated transcriptional activation of the tumor necrosis factor (Ygene in primary macrophages. J. Exp. Med. 1'71: 35, 1990.

51.

Kovach, N. L., Yee, E., Munford, R. S., Raetz, C. R. H., and Harlan, J. M. Lipid IV, inhibits synthesis and release of tumor necrosis factor induced by lipopolysaccharide in human whole blood ex vivo. J. Exp. Med. 172: 77,199O.

52.

36.

38.

Descoteaux, crosis factor macrophages J. ZmmunoZ.

53.

Schindler, R., Mantilla, J., Endres, S., Ghorbani, R., Clark, S. C., and Dinarello, C. A. Correlations and interactions in the production of interleukin-6 (IL-6), IL-l, and tumor necrosis factor (TNF) in human blood mononuclear cells: 11-6 suppresses IL-l and TNF. Blood 75: 40, 1990.

54.

Aderka, D., Le, J., and Vilcek, J. 11-6 inhibits lipopolysaccharide-induced tumor necrosis factor production in cultured human monocytes, U937 cells, and in mice. J. Immunol. 143: 3517,1989.

41.

42.

43.

44.

45.

Han, J., Thompson, P., and Beutler, B. Dexamethasone and pentoxifylline inhibit endotoxin-induced cachectin/tumor necrosis factor synthesis at separate points in the signaling pathway. J. Ezp. Med. 172: 391,199O. Dinarello, C. A., Cannon, J. G., Wolff, S. M., Bernheim, H. A., Beutler, B., Cerami, A., Figari, I. S., Palladino Jr., M. A., and O’Connor, J. V. Tumor necrosis factor (cachectin) is an endogenous pyrogen and induces interleukin-1. J. Exp. Med. 163: 1433,1986. Fong, Y., Tracey, K. J., Moldawer, L. L., Hesse, D. G., Manogue, K. B., Kenney, J. S., Lee, A. T., Kuo, G. C., Allison, A. C., Lowry, S. F., and Cerami, A. Antibodies to cachectin/tumor necrosis factor reduce interleukin 18 and interleukin 6 appearance during lethal bacteremia. J. Exp. Med. 170: 1627,1989. Sherman, M. L., Weber, B. L., Datta, R., and Kufe, D. W. Transcriptional and posttranscriptional regulation of macrophagespecific colony stimulating factor gene expression by tumor necrosis factor. J. Clin. Znoest. 85: 442, 1990. Schindler, R., Lonnemann, G., Shaldon, S., Koch, K.-M., and Dinarello, C. A. Transcription, not synthesis, of interleukin-1 and tumor necrosis factor by complement. Kidney Int. 37: 85, 1990. Beutler, B. A., Milsark, I. W., and Cerami, A. Cachectin/tumor

1991

necrosis factor: production, distribution and metabolic fate in uiuo. J. Immunol. 136: 3972, 1985. Blick, M., Sherwin, S. A., Rosenblum, M., and Gutterman, J. Phase I study of recombinant tumor necrosis factor in cancer patients. Cancer Res. 47: 2986, 1987. Aggarwal, B. B., Eessalu, T. E., and Hass, P. E. Characterization of receptors for human tumor necrosis factor and their regulation by gamma interferon. Nature 318: 665,1985. Baglioni, C., McCandless, S., Travernier, J., andFiers, W. Binding of human tumor necrosis factor to high affinity receptors on HeLa and lymphoblastoid cells sensitive to growth inhibition. J. Biol. Chem. 260: 13395, 1985. Kull, F. C., Jacobs, S., and Cuatrecasas, P. Cellular receptor for ‘261-labeled tumor necrosis factor: Specific binding, affinity labeling, and relationship to sensitivity. Proc. Natl. Acad. Sci. USA 82: 5756,1985. Tsujimoto, M., Yip, Y. K., and Vilcek, J. Tumor necrosis factor: Specific binding and internalization in sensitive and resistant cells. Proc. Natl. Acad. Sci. USA 82: 7626, 1985. Ding, A. H., Sanchez, E., Srimal, S., and Nathan, C. F. Macrophages rapidly internalize their tumor necrosis factor receptors in response to bacterial lipopolysaccharide. J. Biol. Chem. 264: 3924,1989. Tsujimoto, M., and Vilcek, J. Tumor necrosis factor receptor in HeLa cells and their regulation by interferon y. J. Biol. Chem.

261:5384,1986.

A., and Matlashewski, G. Regulation of tumor negene expression and protein synthesis in murine treated with recombinant tumor necrosis factor. 145: 846, 1990.

Beutler, B., Milsark, I. W., Krochin, N., and Cerami, A. Cachectin (tumor necrosis factor, TNF): The monokine responsible for the lethal effect of endotoxin. Blood 66: 83a, 1985. 40.

50.

51, NO. 5, NOVEMBER

55.

Hohmann, H.-P., Remy, R., Brockhaus, M., and Van Loon, A. P. G. M. Two different cell types have different major receptors for human tumor necrosis factor (TNFtu). J. Biol. Chem. 264: 14927, 1989. Ding, A. H., Porteu, F., Sanchez, E., and Nathan, C. F. Downregulation of tumor necrosis factor receptors on macrophages and endothelial cells by microtubule depolymerizing agents. J. Exp. Med. 171: 715, 1990. Porteu, F., and Nathan, C. Shedding of tumor necrosis factor receptors by activated human neutrophils. J. Exp. Med. 172:

599,199o. 56.

Smith, M. R., Munger, W. E., Kung, H.-F., Takacs, L., and Durum, S. K. Direct evidence for an intracellular role for tumor necrosis factor-o. J. Immurwl. 144: 162, 1990.

57.

Tracey, K. J., Wei, H., Manogue, K. R., Fong, Y., Hesse, D. G., Nguyen, H. T., Kuo, G. C., Beutler, B., Cotran, R. S., Cerami, A., and Lowry, S. F. Cachectin/TNF induces cachexia, anorexia and inflammation. J. Exp. Med. 167: 1211,1988.

58.

Moldawer, L. L., Marano, M. A., Wei, H., Fong, Y., Silen, M. L., Kuo, G., Manogue, K. R., Vlassara, H., Cohen, H., Cerami, A., and Lowry, S. F. Cachectin/tumor necrosis factor-o alters red blood cell kinetics and induces anemia in vivo. FASEB J. 3: 1637,1989. Philip, R., and Epstein, L. B. Tumour necrosis factor as immunomodulator and mediator of monocyte cytotoxicity induced by itself, y interferon and interleukin 1. Nature 323: 86, 1986. Urban, J. L., Shepard, H. M., Rothstein, J. L., Sugarman, B. J., and Schreiber, H. Tumour necrosis factor: a potent effector molecule of tumour cell killing by activated macrophages. Proc. Natl. Acad. Sci. USA 83: 5233, 1986. Munker, R., Gassoon, J., Ogawa, M., and Koeffler, H. P. Recombinant human TNF induces production of granulocyte-macrophage colony stimulating factor. Nature 323: 729,1986. Ulich, T. R., de1 Castillo, J., Keys, M., Granger, G. A., and Ni, R. X. Kinetics and mechanism of recombinant human interleukin 1 a and tumour necrosis factor a induced changes in circulating numbers of neutrophils and lymphocytes. J. Zmmunol.

59.

60.

61.

62.

139:3406,1987.

ROCK

AND

LOWRY:

TUMOR

63. Ming, W. J., Bersani,

L., and Mantovani, A. Tumor necrosis factor is chemotactic for monocytes and polymorphonuclear leukocytes. J. Immunol. 138: 1469,1987.

NECROSIS 81.

64. Figari, I. S., Mori, N. A., and Palladino,

M. A. Regulation of neutrophil chemotaxis and superoxide production by recombinant tumour necrosis factor (Yand 0: effects of interferon y and interleukin 1. Blood ‘70: 979, 1987. 65. Georgielis, K., Schaefer, C., Dinarello, C. A., and Klempner, M. S. Human recombinant interleukin 1 p has no effect on intracellular calcium or on functional responses of human neutrophils. J. Immunol. 138: 3403, 1987. 66. Klebanoff, S. J., Vadas, M. A., Harlan, J. M., Sparks, L. H., Gamble, J. R., Agosti, J. M., and Waltersdorph, A. M. Stimulation of neutrophils by tumor necrosis factor. J. Zmmunol. 136:

4220,1986. 67. Larrick, J. W., Graham, D. J., Toy, K., Lin, L. S., Senyk, G., and

68.

69.

70.

71.

72.

73.

Fendly, B. M. Recombinant tumour necrosis factor causes activation of human granulocytes. Blood 69: 640, 1986. Shalaby, M. R., Aggarwal, B. B., Rinderknecht, E., Svedersky, L. P., Finkle, B. S., and Palladino Jr., M. A. Activation of human polymorphonuclear neutrophil functions by interferon-y and tumor necrosis factors. J. Immunol. 135: 2069, 1985. Patek, P. Q., and Lin, Y. Natural cytotoxic activity is not necessarily mediated by the release of tumour necrosis factor. Zmmunology 67: 509,1989. Slungaard, A., Vercellotti, G. M., Walker, G., Nelson, R. D., and Jacob, H. S. Tumor necrosis factor a/cachectin stimulates eosinophil oxidant production and toxicity towards human endothelium. J. Exp. Med. 171: 2025, 1990. Stolpen, A. H., Guinan, E. C., and Fiers, W. Recombinant tumor necrosis factor and immune interferon act singly and in combination to reorganize human vascular endothelial cell monolayers. Am. J. Pathol. 123: 16, 1986. Brett, J., Gerlach, H., Nawroth, P., Steinberg, S., Godman, G., and Stern, D. Tumor necrosis factor/cachectin increases permeability of endothelial cell monolayers by a mechanism involving regulatory G proteins. J. Exp. Med. 169: 1977, 1989. Stern, D. M., and Nawroth, P. P. Modulation of endothelial hemostatic properties by tumor necrosis factor. J. Exp. Med.

163:740,1986.

75.

76.

77.

78.

79.

80.

443

Warren, R. S., Starnes Jr., H. F., Gabrilove, J. L., Oettgen, H. F., and Brennan, M. F. The acute metabolic effects of tumour necrosis factor administration in human. Arch. Surg. 122: 1396,1987.

82. Pomposelli,

J. J., Flores, E. A., and Bistrian, B. R. The role of biochemical mediators in clinical nutrition and surgical metabolism. J. Pare&era1 Enteral Nutr. 12: 212, 1988.

83. Goldberg, A. L., Kettelhut,

I. C., Furuno, K., Fagan, M., and Baracos, V. Activation of protein breakdown and prostaglandin E2 production in rat skeletal muscle in fever is signaled by a macrophage product distinct from interleukin 1 or other known monokines. J. Clin. Invest. 81: 1378, 1988.

84. Moldawer,

85.

86.

87.

88.

L. L., Svaninger, G., Gelin, J., and Lundholm, K. G. Interleukin 1 and tumor necrosis factor do not regulate protein balance in skeletal muscle. Am. J. Physiol. 253: C766, 1987. Tracey, K. J., Lowry, S. F., Beutler, B., Cerami, A., Albert, J. D., and Shires, G. T. Cachectin/tumor necrosis factor mediates changes of skeletal muscle plasma membrane potential. J. Exp. Med. 164:1368,1986. Tracey, K. J., Lowry, S. F., Fahey III, T. J., Albert, J. D., Fong, Y., Hesse, D., Beutler, B., Manogue, K. R., Calvano, S., Wei, H., Cerami, A., and Shires, G. T. Cachectin/tumour necrosis factor induces lethal septic shock and stress hormone responses in the dog. Surg. Gynecol. Obstet. 164: 415, 1987. Minei, J. P., Fantini, G. A., Hesse, D. G., Shiono, S., Tracey, K. J., Fong, Y., Lowry, S. F., and Shires, G. T. Endotoxin infusion in human volunteers: Assessment of the early cellular membrane response. Surg. Forum 38: 102, 1987. Tracey, K. J., Lowry, S. F., Beutler, B., Cerami, A., Albert, J. D., and Shires, G. T. Cachectin/tumor necrosis factor participates in reduction of skeletal muscle membrane potential: Evidence for bioactivity in plasma during critical illness. Surg. Forum

37:13,1986. 89. Lee, M. D., Zentella,

90.

A., Pekala, P., and Cerami, A. Effect of endotoxin-induced monokines on glucose metabolism in the muscle cell line L6. Proc. Natl. Acad. Sci. USA 84: 2590, 1987. Kawakami, M., and Cerami, A. Studies of endotoxin-induced decrease in lipoprotein lipase activity. J. Exp. Med. 154: 631,

1981. 91.

74. Henning,

B., Goldblum, S., and McClain, C. Interleukin 1 and tumor necrosis factor/cachectin increase endothelial permeability in vitro. J. Leuk. Biol. 42: 551, 1987. Royall, J. A., Berkow, R. L., Beckman, J. S., Cunningham, M. K., Matalon, S., and Freeman, B. A. Tumor necrosis factor and interleukin la increase vascular endothelial permeability. Am. J. Physiol. 257: L399, 1989. Remick, D. G., Kunkel, R. G., Larrick, J. W., and Kunkel, S. L. Acute in vivo effects of human recombinant tumor necrosis factor. Lab. Invest. 56: 583, 1987. Cavender, D. E., Edelbaum, D., and Ziff, M. Endothelial cell activation inducted by tumor necrosis factor and lymphotoxin. Am. J. Pathol. 134: 551,1989. Munro, J. M., Pober, J. S., and Cotran, R. S. Tumor necrosis factor and interferon-y induce distinct patterns of endothelial activation and associated leukocyte accumulation in skin of Papio Anubis. Am. J. Pathol. 135: 121,1989. Flores, E. A., Bistrian, B. R., Pomposelli, J. J., Dinarello, C. A., Blackburn, G. L., and Istfan, N. W. Infusion of tumor necrosis factor/cachectin promotes muscle catabolism. A synergistic effect with interleukin 1. J. Clin. Invest. 83: 1614, 1989. Nawabi, M. D., Block, K. P., Chakrabarti, M. C., and Buse, M. G. Administration of endotoxin, tumor necrosis factor, or interleukin 1 to rats activates skeletal muscle branched-chain a-keto acid dehydrogenase. J. Clin. Invest. 85: 256, 1990.

FACTOR-a

92.

93.

Beutler, B., Mahoney, J., Le Trang, N., Pekala, P., and Cerami, A. Purification of cachectin, a lipoprotein lipase-suppressing hormone secreted by endotoxin-induced RAW 264.7 cells. J. Exp. Med. 161: 984, 1985. Torti, F. M., Dieckmann, B., Beutler, B., Cerami, A., and Ringold, G. M. A macrophage factor inhibits adipocyte gene expression: an in vitro model of cachexia. Science 229: 867, 1985. Beutler, B., and Cerami, A. Recombinant interleukin 1 suppresses lipoprotein lipase activity in 3T3-Ll cells. J. Zmmunol.

135: 3969,1985. 94.

95.

Patton, J. S., Shepard, H. M., Wilking, H., Lewis, G., Aggarwal, B. B., Eessalu, T. E., Gavin, L. A., and Grunfeld, C. Interferons and tumour necrosis factors have similar catabolic affects on 3T3 Ll cells. Proc. Natl. Acad. Sci. USA 83: 8313, 1986. Kern, P. A. Recombinant human tumor necrosis factor does not inhibit lipoprotein lipase in primary cultures of isolated human adipocytes. J. Lipid Res. 29: 909, 1988.

96.

Grunfeld, C., Gulli, R., Moser, A. H., Gavin, L. A., and Feingold, K. R. Effect of tumor necrosis factor administration in vivo on lipoprotein lipase activity in various tissues of the rat. J. Lipid Res. 30: 579, 1989.

97.

Feingold, K. R., Soued, M., Staprans, I., Gavin, L. A., Donahue, M. E., Huang, B.-J., Moser, A. H., Gulli, R., and Grunfeld, C. Effect of tumor necrosis factor (TNF) on lipid metabolism in the diabetic rat. J. Clin. Invest. 83: 1116, 1989. Chang, S.-W., Ohara, N., Kuo, G., and Voelkel, N. F. Tumor

98.

444

JOURNAL

OF SURGICAL

RESEARCH:

necrosis factor-induced lung injury is not mediated by plateletactivating factor. Am. J. Physiol. 267: L232, 1989. 99. Goldblum, S. E., Hennig, B., Jay, M., Yoneda, K., and McClain, C. J. Tumor necrosis factor cu-induced pulmonary vascular endothelial injury. Infect. Zmmun. 67: 1218, 1989. 100. Ferrari-Baliviera, E., Mealy, K., Smith, R. J., and Wilmore, D. W. Tumor necrosis factor induces adult respiratory distress syndrome in rats. Arch. Surg. 124: 1400, 1989. 101. Kuei, J. H., Tashkin, D. P., and Figlin, R. A. Pulmonary toxicity of recombinant human tumor necrosis factor. Chest 96: 334, 1989. 102. Millar, A. B., Foley, N. M., Singer, M., Johnson, N. MCI., Meager, A., and Rook G. A. W. Tumour necrosis factor in bronchopulmonary secretions of patients with adult respiratory distress syndrome. Lancet 2(8665): 712, 1989. 103. Roberts, D. J., Davies, J. M., Evans, C. C., Bell, M., Mostafa, S. M., and Lamche, H. Tumour necrosis factor and adult respiratory distress syndrome. Lancet 2(8670): 1043, 1989. 104. Suffredini, A. F., Fromm, R. E., Parker, M. M., Brenner, M., Kovacs, J. A., Wesley, R. A., and Parrillo, J. E. The cardiovascular response of normal humans to the administration of endotoxin. N. Engl. J. Med. 321: 280, 1989. 105. Gulick, T., Chung, M. K., Pieper, S. J., Lange, L. G., and Schreiner, G. F. Interleukin 1 and tumor necrosis factor inhibit cardiac myocyte fl-adrenergic responsiveness. Proc. N&l. Acad. Sci. USA 86: 6753,1989. 106. Neilson, I. R., Neilson, K. A., Yunis, E. J., and Rowe, M. I. Failure of tumor necrosis factor to produce hypotensive shock in the absence of endotoxin. Surgery 106: 439,1989.

107. Natanson,

109.

110.

111.

112.

113. 114.

115.

116.

C., Eichenholz, P. W., Danner, R. L., Eichacker, P. Q., Hoffman, W. D., Kuo, G. C., Banks, S. M., MacVittie, T. J., and Parrillo, J. E. Endotoxin and tumor necrosis factor challenges in dogs simulate the cardiovascular profile of human septic shock. J. Exp. Med. 169: 823, 1989. Hegewisch, S., Weh, H.-J., Hossfeld, D. K. TNF-inducedcardiomyopathy. Lancet 336: 294,199O. Fong, Y., Moldawer, L. L., Marano, M., Wei, H., Barber, A., Manogue, K., Tracey, K. J., Kuo, G., Fischman, D. A., Cerami, A., and Lowry, S. F. Cachectin/TNF or Il-la induces cachexia with redistribution of body proteins. Am. J. Physiol. 256: R659,1989. Feingold, K. R., and Grunfeld, C. Tumor necrosis factor-a stimulates hepatic lipogenesis in the rat in vivo. J. Clin. Invest. 80: 184,1987. Warren, R. S., Donner, D. B., Starnes, Jr., H. F., and Brennan, M. F. Modulation of endogenous hormone action by recombinant human tumor necrosis factor. Proc. Natl. Acad. Sci. USA 84: 8619,1987. Rock, C. S., Barber, A. E., Ng, E.-H., Jones, W. G., Roth, M. S., Moldawer, L. L., and Lowry, S. F. TPN vs. oral feeding: Bacterial translocation, cytokine response and mortality following E. coli LPS administration. Surg. Forum, 41: 14, 1990. Sheldon, G. F., Peterson, S. R., and Sanders, R. Hepatic dysfunction during hyperalimentation. Arch. Surg. 113: 504,1978. Tracey, K. J., Beutler, B., Lowry, S. F., Merryweather, J., Wolpe, S., Milsark, I. W., Hariri, R. J., Fahey III, T. J., Zentella, A., Albert, J. D., Shires, G. T., and Cerami, A. Shock and tissue injury induced by recombinant human cachectin. Science 234:

VOL. 117.

118.

119.

120.

121.

122.

123. 124.

125.

126.

51, NO. 5, NOVEMBER

1991

Antonipillai, I., Wang, Y., and Horton, R. Tumor necrosis factor and interleukin-1 may regulate renin secretion. Endocrinology 126: 273,199O. Natarajan, R., Ploszaj, S., Horton, R., and Nadler, J. Tumor necrosis factor and interleukin-1 are potent inhibitors of angiotensin-II-induced aldosterone synthesis. Endocrinology 125: 3084, 1989. Campbell, I. L., Iscaro, A., Harrison, L. C. IFN-y and tumor necrosis factor-o. Cytotoxicity to murine islets of Langerhans. J Immunol. 141:2325,1988. Rabinovitch, A., Baquerizo, H., and Sumoski, W. Cytotoxic effects of cytokines on islet o-cells: Evidence for involvement of eicosanoids. Endocrinology 126: 67, 1990. Hsueh, W., and Sun, X. Tumor necrosis factor-induced bowel necrosis: The role of platelet-activating factor. Ado Prostagkzndin Thromborane Leukotriene Res. 19: 363, 1989. Moldawer, L. L., Andersson, C., Gelin, J., and Lundholm, K. G. Regulation of food intake and hepatic protein synthesis by recombinant-derived monokines. Am. J. Physiol. 264: G450, 1988. Michie, H. R., Spriggs, D. R., Rounds, J., and Wilmore, D. W. Does cache&in cause cachexia? Surg. Forum 38: 38,1987. Oliff, A., Defeo-Jones, D., Boyer, M., Martinez, D., Kiefer, D., Vuocolo, G., Wolfe, A., and Socher, S. H. Tumors secreting human TNF/cachectin induce cachexia in mice. Cell 50: 555, 1987. Brenner, D. A., Buck, M., Feitelberg, S. P., and Chojkier, M. Tumor necrosis factor-a inhibits albumin gene expression in a murine model of cachexia. J. Clin. Znuest. 85: 248, 1990. Stovroff, M. C., Fraker, D. L., and Norton, J. A. Cachectin activity in the serum of cachectic, tumor-bearing rats. Arch. Surg.

124:94,1989. 127.

128.

129.

Stovroff, M. C., Fraker, D. L., Travis, W. D., and Norton, J. A. Altered macrophage activity and tumor necrosis factor: Tumor necrosis and host cachexia. J. Surg. Res. 46: 462, 1989. Laskov, R., Lancz, G., Ruddle, N. H., McGrath, K. M., Specter, S., Klein, T., Djeu, J. Y., and Friedman, H. Production of tumor necrosis factor (TNF-a) and lymphotoxin (TNF-P) by murine pre-B and B cell lymphomas. J. Zmmunol. 144: 3424,199O. Beissert, S., Bergholz, M., Waase, I., Lepsien, G., Schauer, A., Pfizenmaier, K., and Kronke, M. Regulation of tumor necrosis factor gene expression in colorectal adenocarcinoma: In uiuo analysis by in situ hybridization. Proc. Natl. Acad Sci. USA 86:

5064,1989. 130.

131.

132.

133.

470,1986.

134.

Evans, D. A., Jacobs, D. O., Revhaug, A., and Wilmore, D. W. The effects of tumor necrosis factor and their selective inhibition by ibuprofen. Ann. Surg. 209: 312, 1989. van Lanschot, J. B., Mealy, K., Evans, D. A., Jacobs, D. O., and Wilmore, D. W. Splenectomy abolishes the diuresis associated with tumor necrosis factor. Surg. Forum 40: 62, 1989.

135.

Saarinen, U. M., Koskelo, E.-K., Teppo, A.-M., and Siimes, M. A. Tumor necrosis factor in children with malignancies. Cancer Res. 50: 592, 1990. Hasegawa, Y., and Bonavida, B. Calcium-independent pathway of tumor necrosis factor-mediated lysis of target cells. J. Zmmunol. 142: 2670, 1989. Myers, A. K., Robey, J. W., and Price, R. M. Relationships between tumour necrosis factor, eicosanoids and platelet-activating factor as mediators of endotoxin-induced shock in mice. Br. J. Pharmacol. 99: 499, 1990. Rothstein, J. L., and Schreiber, H. Synergy between tumor necrosis factor and bacterial products causes hemorrhagic necrosis and lethal shock in normal mice. Proc. Natl. Acad. Sci. USA 85: 607,1988. Cannon, J. G., Tompkins, R. G., Gelfand, J. A., Michie, H. R., Stanford, G. G., Van Der Meer, J. W. M., Endres, S., Lonnemann, G., Corsetti, J., Chernow, B., Wilmore, D. W., Wolff, S. M., Burke, J. F., and Dinarello, C. A. Circulating interleukin1 and tumor necrosis factor in septic shock and experimental endotoxin fever. J. Infect. Dis. 161: 79, 1990. Damas, P., Reuter, A., Gysen, P., Demonty, J., Lamy, M., and

ROCK

AND

LOWRY:

TUMOR

Franchimont, P. Tumor necrosis factor and interleukin-1 serum levels during severe sepsis in humans. Crit. Cure Med. 17: 975,1989. 136.

Marano, M. A., Fong, Y., Moldawer, L. L., Wei, H., Calvano, S. E., Tracey, K. J., Barie, P. S., Manogue, K., Cerami, A., Shires, G. T., and Lowry, S. F. Serum cachectin/tumor necrosis factor in critically ill patients with burns correlates with infection and mortality. Surg. Gynecol. Obstet. 170: 32, 1990.

137.

Debets, J. M. H., Kampmeijer, R., Van Der Linden, M. P. M. H., Buurman, W. A., and Van Der Linden, C. J. Plasma tumor necrosis factor and mortality in critically ill septic patients. Crit. Cure Med. 17: 489, 1989.

138.

Fong, Y., Marano, M. A., Moldawer, L. L., Wei, H., Calvano, S. E., Kenney, J. S., Allison, A. C., Cerami, A., Shires, G. T., and Lowry, S. F. The acute splanchnic and peripheral tissue metabolic response to endotoxin in humans. J. Clin. Invest. 85: 1896, 1990.

139.

Sanchez-Cantu, L., Rode, H. N., and Christou, N. V. Endotoxin tolerance is associated with reduced secretion of tumor necrosis factor. Arch. Surg. 124: 1432, 1989.

140.

Zuckerman, S. H., Evans, G. F., Snyder, Y. M., and Roeder, W. D. Endotoxin-macrophage interaction: Post-translational regulation of tumor necrosis factor expression. J. Immunol. 143: 1223, 1989.

141.

Fraker, D. L., Stovroff, M. C., Merino, M. J., and Norton, J. A. Tolerance to tumor necrosis factor in rats and the relationship to endotoxin tolerance and toxicity. J. Exp. Med. 168: 95,1988.

142.

Sheppard, B. C., Fraker, D. L., and Norton, J. A. Prevention and treatment of endotoxin and sepsis lethality with recombinant human tumor necrosis factor. Surgery 106: 156, 1989.

143.

Mallick, A. A., Ishizaka, A., Stephens, K. E., Hatherill, J. R., Tazelaar, H. D., and Raffin, T. A. Multiple organ damage caused by tumor necrosis factor and prevented by prior neutrophi1 depletion. Chest 96: 1114, 1989.

144.

Beutler, B., Milsark, I. W., and Cerami, A. C. Passive immunization against cachectin/tumor necrosis factor protects mice from lethal effect of endotoxin. Science 229: 869, 1985.

145.

Sherry, B. A., Gelin, J., Fong, Y., Marano, M., Wei, H., Cerami, A., Lowry, S. F., Lundholm, K. G., and Moldawer, L. L. Anticachectin/tumor necrosis factor-a antibodies attenuate development of cachexia in tumor models. FASEB J. 3: 1956, 1989.

146.

Tracey, K. J., Fong, Y., Hesse, D. G., Manogue, K. R., Lee, A. T., Kuo, G. C., Lowry, S. F., and Cerami, A. Anti-cachectin/ TNF monoclonal antibodies prevent septic shock during lethal bacteremia. Nature 330(6149): 662, 1987.

147.

Imagawa, D. K., Millis, J. M., Olthoff, K. M., Seu, P., Dempsey, R. A., Hart, J., Terasaki, P. I., and Busuttil, R. W. Anti-tumor necrosis factor antibody enhances allograft survival in rats. J. Surg. Res. 48: 345, 1990.

148.

Fomsgaard, A., Baek, L., Fomsgaard, S., and Engquist, A. Preliminary study on treatment of septic shock patients with anti-

NECROSIS

FACTOR-e

lipopolysaccharide

445

IgG from blood donors. Scand. J. Infect. Dis.

21:697,1989. 149.

Sullivan, G. W., Carper, H. T., Novick, W. J., and Mandell, G. L. Inhibition of the inflammatory action of interleukin-1 and tumor necrosis factor ((u) on neutrophil function by pentoxifylline. Infect. Immun. 56: 1722, 1988. 150. Lilly, C. M., Sandhu, J. S., Ishizaka, A., Harada, H., Yonemaru, M., Larrick, J. W., Shi, T.-X., O’Hanley, P. T., and Raffin, T. A. Pentoxifylline prevents tumor necrosis factor-induced lung injury. Am. Rev. Respir. Dis. 139: 1361, 1989. 151. Kilbourn, R. G., Gross, S. S., Jubran, A., Adams, J., Griffith, 0. W., Levi, R., and Lodato, R. F. NG-methyl-L-arginine inhibits tumor necrosis factor-induced hypotension: Implications for the involvement of nitric oxide. Proc. Natl. Acad. Sci. USA 87: 3629, 1990. 152. Fraker, D. L., Merino, M. J., and Norton, J. A. Reversal of the toxic effects of cachectin by concurrent insulin administration. Am. J. Physiol. 256: E725, 1989. 153. Barber, A. E., Coyle, S. M., Fong, Y., Fischer, E., Marano, M. A., Calvano, S. E., Moldawer, L. L., Shires, G. T., and Lowry, S. F. Impact of hypercortisolemia on the metabolic and hormonal responses to endotoxin in man. Surg. Forum, 41: 74, 1990. and 154. Han, J., Thompson, P., and Beutler, B. Dexamethasone pentoxifylline inhibit endotoxin-induced cachectin/tumor necrosis factor synthesis at separate points in the signaling pathway. J. Exp. Med. 172: 391,199O. 155. Cross, A. S., Sadoff, J. C., Bernton, K. E., and Gemski, P. Pretreatment with recombinant murine tumor necrosis factor 01/ cachectin and murine interleukin 101 protects mice from lethal bacterial infection. J. Exp. Med. 169: 2021, 1989. L., Mooney, 156. Hershman, M. J., Pietsch, J. D., Trachtenberg, T. H. R., Shields, R. E., and Sonnenfeld, G. Protective effects of recombinant human tumour necrosis factor (Y and interferon y against surgically simulated wound infection in mice. Br. J. Surg. 76: 1282, 1989. 157. Havell, E. A. Evidence that tumor necrosis factor has an important role in antibacterial resistance. J. Immunol. 143: 2894, 1989. D. H., Malangoni, M. A., and Sonnenfeld, G. Im158. Livingston, mune enhancement by tumor necrosis factor-or improves antibiotic efficacy after hemorrhagic shock. J. Trauma 29: 967,1989. 159. Shikama, Y., Kobayashi, K., Kasahara, K., Kaga, S., Hashimoto, M., Yoneya, I., Hosoda, S., Soejima, K., Ide, H., and Takahashi, T. Granuloma formation by artificial microparticles in vitro. Macrophages and monokines play a critical role in granuloma formation. Am. J. Puthol. 134: 1189, 1989. 160. Kasahara, K., Kobayashi, K., Shikama, Y., Yoneya, I., Kaga, S., Hashimoto, M., Odagiri, T., Soejima, K., Ide, H., Takahashi, T., and Yoshida, T. The role of monokines in granuloma formation in mice: The ability of interleukin 1 and tumor necrosis factor-a to induce lung granulomas. Clin. Immun. Immunopathol. 51: 419, 1989.