Butylated hydroxyanisole specifically inhibits tumor necrosis factor-induced cytotoxicity and growth enhancement.

The effect of commonly used food antioxidants on recombinant tumor necrosis factor alpha (rTNF-alpha)-induced cytotoxicity, growth enhancement and adhesion has been evaluated. Butylated hydroxyanisole (BHA) and 4-hydroxymethyl-2,6-di-t-butylphenol (HBP) were the only two of nine antioxidants that completely inhibited rTNF-alpha-induced cytotoxicity in L929 and WEHI 164 fibrosarcoma cells. Ethoxyquin, propyl gallate and butylated hydroquinone only partially inhibited rTNF-alpha-induced cytotoxicity, while the antioxidants butylated hydroxytoluene (BHT), alpha-tocopherol, ascorbic acid and thiodipropionic acid had minimal effects.

A comparative study of IL-12 (cytotoxic lymphocyte maturation factor)-, IL-2-, and IL-7-induced effects on immunomagnetically purified CD56+ NK cells.

IL-12, or cytotoxic lymphocyte maturation factor, is a recently cloned cytokine shown to influence lymphokine-activated killer cells activity in heterogeneous lymphocyte populations, proliferative activity as a costimulus in PBMC/PBL populations and IFN-gamma production in PBL. We have investigated the effects of IL-12 on immunomagnetically highly purified CD56+ lymphocytes, and compared the effects with those of IL-7 and IL-2. Our results show that IL-12 directly generated high lymphokine-activated killer cell activity in CD56+ NK cells, without the need for accessory cells.

Effects of n-3 and n-6 fatty acids on tumor necrosis factor cytotoxicity in WEHI fibrosarcoma cells.

Modulation by fatty acids of the cytotoxic effect of recombinant tumor necrosis factor alpha (TNF) toward WEHI 164 mouse fibrosarcoma cells has been examined. Preincubating the highly TNF-sensitive WEHI clone 13 cells for 44 hr with 50 mumol/L of 20:5n-3, 22:6n-3, 18:3n-6, 20:3n-6 or 20:4n-6 reduced cell survival 22 hr after challenge with TNF (40 ng/L) by 65%, 72%, 60%, 98% and 85%, respectively. In comparison, 18:3n-3, 18:2n-6 and 18:1n-9 had only negligible effects on TNF-induced toxicity.

Current understanding of the pathogenesis of gram-negative shock.

There is increasing evidence that gram-negative bacteria via endotoxin induce the excessive production of inflammatory cytokines, which are active in the pathogenesis of septic shock, multiorgan failure, and ARDS. In animals the injection of TNF induces pathophysiologic and histopathologic changes that are characteristic of the septic shock syndrome, and in patients there is a close association between levels of TNF and the severity of the shock. IL-1 and IFN-gamma markedly potentiate the toxic TNF effects in animal experiments.

Effects of IL-7 and IL-2 on highly enriched CD56+ natural killer cells. A comparative study.

IL-7 has been shown to induce low levels of lymphokine-activated killer cell (LAK) activity in bulk PBMC populations. We report here that immunomagnetically purified CD56+ cells from peripheral blood generated high LAK activity in response to IL-7. The LAK activity induced by IL-7 was comparable to, or slightly lower than, the LAK activity induced by IL-2.

Development of immunoassays for the detection of soluble tumour necrosis factor receptors.

Immunoassays were established for the detection of the 55 kDa and 75 kDa tumour necrosis factor receptor (TNFR) fragments present in urine. The immunoassays were based on pairs of monoclonal TNFR antibodies directed against different epitopes of the 55 kDa and 75 kDa TNFRs. The immunoassays were judged to be specific for unoccupied TNFR since the signals were inhibited by adding recombinant human or murine TNF-alpha, and to a lesser extent by rTNF-beta (LT).

Induction of cytokine production from human monocytes stimulated with alginate.

Alginates are polysaccharides with gel-forming properties composed of 1,4-linked beta-D-mannuronic acid (M), alpha-L-guluronic acid (G), and alternating (MG) blocks. Alginate can be used as a matrix for implanted cells in vivo. In this study, we have examined the ability of alginates and their components to stimulate human monocytes to produce tumor necrosis factor-alpha, interleukin-6, and interleukin-1.

Involvement of the 55- and 75-kDa tumor necrosis factor receptors in the generation of lymphokine-activated killer cell activity and proliferation of natural killer cells.

In this study we investigated the expression of the 55 kDa (p55) and the 75 kDa (p75) TNF receptors in CD56+ NK cells and their role in NK and lymphokine-activated killer cells cell functions. By using mAb against the p55 and p75 TNF-R, NK cells were found to express both p55 and p75 upon activation, and both receptors were involved in the generation of lymphokine-activated killer cells activity. Proliferative activity of IL-2 stimulated NK cells was inhibited by anti-TNF-alpha mAb, indicating that endogenously produced TNF-alpha is important for optimal proliferation of NK cells.

Independent regulation of 55-kDa and 75-kDa tumor necrosis factor receptors during activation of human peripheral blood B lymphocytes.

We have studied the expression of two different tumor necrosis factor receptors (TNFR; 55 kDa and 75 kDa) on resting and activated human peripheral blood B lymphocytes using specific monoclonal antibodies (mAb). Flow cytometric analysis revealed that most resting B cells expressed small amounts of the 75-kDa TNFR, and that the 75-kDa TNFR was markedly up-regulated upon stimulation with anti-mu or Staphylococcus aureus Cowan strain I (SAC). In contrast, the expression of the 55-kDa TNFR was low on resting as well as on activated cells.

Immunomagnetic isolation of NK and LAK cells.

The present study describes the immunomagnetic isolation of human natural killer (NK) and lymphokine activated killer (LAK) cells. Antibodies against CD56 and sheep anti-mouse IgG-coated magnetic monodisperse particles (Dynabeads M-450) were used for the positive isolation of CD56+ cells from unstimulated mononuclear cells (PBMC). A highly enriched population of CD56+ cells (less than or equal to 3% contaminating cells) was obtained with this method.

A rapid and sensitive immunoassay for tumor necrosis factor using magnetic monodisperse polymer particles.

A sensitive and rapid immunoassay for the detection of tumor necrosis factor (TNF) has been developed. Magnetic monodisperse polymer particles (M-280 Dynabeads) used as solid phase material, were coated with a neutralizing mouse monoclonal antibody to TNF. The coated Dynabeads were shown to have a more rapid binding capacity for recombinant (r) TNF as compared to standard immunowells coated with antibodies to TNF.

Binding and regulation of cellular functions by monoclonal antibodies against human tumor necrosis factor receptors.

The present study was undertaken to further characterize the interaction of monoclonal antibodies (mAbs) against tumor necrosis factor (TNF) receptors with different targets, and to assess their ability to influence TNF effects on U937 and human endothelial cell (HEC) functions. Actions of recombinant TNF-alpha on U937 and HEC were effectively inhibited by Htr-5 and Utr-1, and to a greater extent by a combination of both mAbs. These observations indicate that TNF interaction with antigenically different components of membrane receptors (p55 and p75) represents a crucial step in transduction of signals for TNF toxicity against U937 and TNF activation of HEC functions.

Regulation of interleukin-2 and interleukin-6 production from T-cells: involvement of interleukin-1 beta and transforming growth factor-beta.

The effect of recombinant (r) interleukin-1 beta (rIL-1 beta) and transforming growth factor-beta (TGF-beta) on the production of interleukin-2 (IL-2) and interleukin-6 (IL-6) from an antigen-specific (LBRM-33-1A5) and an antigen-nonspecific (EL-4-NOB-1) T-cell line was investigated. rIL-1 beta induced the production of IL-2 and IL-6 from EL-4-NOB-1 cells in a dose-related manner. The LBRM-33-1A5 cells required phytohemagglutinin (PHA) in addition to rIL-1 beta in order to produce IL-2 and IL-6.

Characterization of binding and biological effects of monoclonal antibodies against a human tumor necrosis factor receptor.

Three different antibodies against a human TNF receptor (htr-1, htr-5, and htr-9) have been examined for their binding pattern to U937 cells and ability to mimic TNF-alpha activity in U937 cells, Fs4 fibroblasts, and human endothelial cells. Flow cytometric analysis revealed that htr-5 and htr-9 bound specifically to a TNF receptor on U937 cells that could be blocked by pretreatment with rTNF-alpha. Pretreatment of U937 cells with rTNF-beta blocked the binding of htr-9, but to a lesser extent htr-5 binding.

Endotoxin, tumor necrosis factor-alpha and interleukin 1 induce interleukin 6 production in vivo.

The ability of Escherichia coli-derived lipopolysaccharide (LPS), recombinant (r) interleukin 1-beta (rIL-1 beta), and r murine tumor necrosis factor-alpha (rMuTNF-alpha) to induce interleukin 6 (IL-6) production in vivo was investigated. Peak serum IL-6 concentration was attained after 2 hr of LPS injection into mice. The coinjection of antiserum against rMuTNF-alpha with LPS resulted in a reduction of the induced serum IL-6 level, indicating the involvement of endogenous TNF-alpha in LPS induction of IL-6.

Local production of tumor necrosis factor alpha, interleukin 1, and interleukin 6 in meningococcal meningitis. Relation to the inflammatory response.

We examined the cerebrospinal fluid (CF) taken on admission from 60 patients with infections caused by Neisseria meningitidis for presence of TNF-alpha, IL-1, and IL-6. TNF-alpha was detected in CF in 55 and 19% (p = 0.03), IL-1 in 50 and 15% (p = 0.

Interleukin 4 induces selective production of interleukin 6 from normal human B lymphocytes.

In this paper we have shown that extensively purified human B lymphocytes respond to IL-4 treatment with a marked production of IL-6. Addition of anti-mu potentiated the effect of IL-4 on IL-6 production. Other cytokines tested like TNF-alpha and-beta, IFN-gamma, IL-1, IL-2, and IL-5 did not induce IL-6 secretion when given to resting B cells.

A flow cytometric and immunofluorescence microscopic study of tumor necrosis factor production and localization in human monocytes.

The production and localization of tumor necrosis factor (TNF) in human monocytes were investigated by using monoclonal and polyclonal antibodies against recombinant human TNF together with flow cytometry and immunofluorescence microscopy. Lipopolysaccharide (LPS) induced a rapid and transient accumulation of TNF in perinuclear vesicles which was detected 20 min after the addition of LPS. The fluorescence intensity of the vesicles peaked at 40 min of LPS exposure, concomitantly with the release of TNF into the medium.

Cytokine regulation of interleukin 6 production by human endothelial cells.

The influence of recombinant (r) human tumor necrosis factor alpha (rTNF-alpha), r human interleukin 1 beta (rIL-1 beta), and r human interferon gamma (rIFN-gamma) on the production of interleukin 6 (IL-6) by human endothelial cells (HEC) was investigated. The addition of 1-100 U/ml of either rTNF-alpha or rIL-1 beta to cultures of HEC monolayers caused a dose-related increase in IL-6 production as detected after 24 hr of incubation. In contrast to rIL-1 beta and rTNF-alpha, the use of up to 1000 U/ml of rIFN-gamma caused only a moderate increase in IL-6 production.

Interleukin-6 in synovial fluid from patients with arthritis.

Synovial fluid and serum from patients with rheumatoid arthritis, other inflammatory arthritides, and traumatic arthritis were assayed for the presence of interleukin-6 (IL-6) by means of an IL-6-dependent mouse hybridoma cell line. The cytokine was detected in all the samples of synovial fluid (range 50-22000 U/ml). IL-6 in synovial fluid was positively correlated (r = 0.

Retinoic acid induces a specific membrane glycoprotein in human epithelial cell lines.

Retinoic acid (RA) inhibits growth, increases the cytokeratin content, and alters the cytoskeleton of the human cervical cell line NHIK 3025. Using RA-treated NHIK 3025 cells as immunogen we prepared murine monoclonal antibodies (IgG1) which recognized an RA-induced cell-surface antigen which could not be detected in untreated NHIK 3025 cells. Analysis of the Triton soluble proteins by SDS-gel electrophoresis and immunoblotting revealed that the cell-surface antigen is a 140-kDa glycoprotein (gp140).

The complex pattern of cytokines in serum from patients with meningococcal septic shock. Association between interleukin 6, interleukin 1, and fatal outcome.

Serum samples from patients with meningococcal disease were examined for the presence of IL-6, TNF-alpha, and LPS. Median serum concentration of IL-6 was 1,000 times higher in patients with septic shock (189 ng/ml) than in patients with bacteriaemia, meningitis, or combined septic shock and meningitis. 11 of 21 patients with serum levels greater than 3.

Synergistic growth-inhibitory activity of tumour necrosis factor and alpha interferon. Contribution to the monocyte-derived cytostatic activity towards human leukaemia K562 cells.

Monocyte supernatants are cytotoxic towards WEHI 164 clone 13 cells and cytostatic towards K562 cells. The cytotoxic activity towards the clone 13 cells is entirely due to tumour necrosis factor alpha (TNF alpha), since it was completely neutralized by recombinant TNF alpha (rTNF) antiserum, and identical dose-response curves were obtained with supernatants and rTNF alpha. The cytostatic activity towards the K562 cells, however, was only partly due to TNF alpha, since this activity was only partly neutralized by the rTNF alpha antiserum.