The effect of tumour necrosis factor-alpha (TNF-alpha) muteins on human neutrophils in vitro

Analysis of the effect of rutin on GSK-3β and TNF-α expression in lung cancer

The aim of the present study was to investigate the effect of rutin treatment on the expression of glycogen synthase kinase (GSK)-3β and tumor necrosis factor (TNF)-α in A549 human lung carcinoma cells. The A549 cells were divided into control, cisplatin and rutin (low, middle and high) groups. ELISA and western blot analysis of TNF-α expression, 4′,6-diamino-2-phenylindole (DAPI) staining and GSK-3β immunofluorescence staining were used to investigate the effect of rutin in the human lung carcinoma cells, using cisplatin as a positive control. TNF-α expression was significantly higher in the rutin and cisplatin groups compared with the control group. Additionally, DAPI staining revealed that the number of apoptotic cells was higher in the rutin and cisplatin groups compared with the control group, and immunofluorescence showed that the expression of GSK-3β in the cisplatin and rutin groups was significantly higher compared with that in the control group. The results of the present study suggest that rutin promotes the TNF-α-induced apoptosis of A549 human lung carcinoma cells. Furthermore, rutin may be able to regulate the expression of GSK-3β protein in these cells.

Local immunotherapy with rhTNF-alpha mutein induces strong antitumor activity without overt toxicity--a review

Tumor necrosis factor (TNF-alpha) is a cytokine possessing antitumor and immunomodulatory properties. The studies reviewed in the present paper evaluate the effect of intratumor or intraperitoneal (i.t./i.p.) injections of human recombinant TNF-alpha (rhTNF-alpha) and its derivatives (muteins V and VI) on the course of experimental tumors. The aim of local cytokine administration was to avoid or reduce the induction of undesired systemic symptoms. Although total remissions were not observed in the studies, morphological analysis of lung tissue, accepted as the toxicity index of the cytokines, showed that rhTNF-alpha produced the least side effects. Mutein V selectively binds to p55R receptor and at the same time exhibits high antitumor activity. These results confirm the usefulness of studies on the structurally altered rhTNF-alpha derivatives, produced by means of genetic engineering techniques, which bind selectively to different cellular receptors of TNF-alpha and show similar or stronger antitumor activity compared with a native molecule, without inducing undesired symptoms.

Polymorphic analysis of the high-affinity tumor necrosis factor receptor 2

The tumor necrosis factor receptor 2 (TNF-RII, CD120b, TNF-R p75/80) gene has recently been characterised. It is located on chromosome 1p362 and consists of 10 exons and 9 introns A number of biallelic polymorphisms have been found in exons 4, 6, 9 and 10 based on differences between published sequences. In this study we have used polymerase chain reaction methodology in association with sequence-specific primers (PCR-SSP) incorporating mismatches at the 3' end to identify these polymorphisms. We were able to confirm the presence of a single biallelic polymorphism in exon 6 corresponding to a (T/G) at nucleotide 676 of TNF-RII mRNA (gb:M32315) which results in an amino acid change and three biallelic polymorphisms in exon 10 (in the3'UTR) corresponding to (A/G) at nucleotide 1663, (T/G) at nucleotide 1668 and a (C/T) at nucleotide 1690 of gb:M32315, whereas no polymorphisms were observed in exons 4 and 9. Here we report that in 192 unrelated UK Caucasian individuals the allele frequencies determined by direct counting were: 676-T (0.77), 1663-G (0.51), 1668-T (0.95), and 1690-T (0.64) and the calculated gene frequencies were; 676-T (0.52), 676-G (0.12); 1663-G (0.30), 1663-A (0.28); 1668-T (0.77), 1668-G (0.025); and 1690-T (0.40), 1690-C (0.20). Furthermore, the presence of an A allele at nucleotide position 1663 was found to be strongly associated with the presence of a C allele at nucleotide position 1690 and a G allele at nucleotide position 1668 whereas the presence of a G allele at position 1663 was associated with the absence of a C allele at nucleotide position 1690.

The influence of recombinant human tumor necrosis factor alpha and its muteins used alone or in combination with 2-chlorodeoxyadenosine on normal and leukemic hematopoiesis in vitro

We investigated the influence of TNF alpha and its muteins III, V and VI on the colony growth of normal and CML CFU-GM cells as well as on CFU-L clonogenic blasts from AML patients in cultures in vitro. The muteins were constructed using a synthetic cDNA fragment substituting nucleotides coding for the N-terminal amino acids in the chain of native TNF alpha. We observed that TNF alpha and mutein VI inhibited the growth of colonies formed by both types of CFU-GM and CFU-L cells in a greater degree than muteins III and V. In addition, the percentage of colony growth inhibition after the use of mutein VI was the greatest. These observations were the basis for the evaluation of interaction between 2-CdA and TNF alpha and between 2-CdA and mutein VI. We have confirmed that 2-CdA used together with mutein VI acts synergistically on CFU-GM and CFU-L cells, whereas 2-CdA and TNF alpha show the additive effect.

The role of receptors for tumour necrosis factor-alpha in the induction of human polymorphonuclear neutrophil chemiluminescence

Tumour necrosis factor-alpha (TNF-alpha) is a potent mediator of inflammation, which exerts profound effects on polymorphonuclear neutrophils (PMN). TNF-alpha binds to distinct cell surface receptors termed p55 and p75, expressed in approximately equal amounts on the PMN surface. We have studied the effects of TNF-alpha on the priming of F-Met-Leu-Phe (FMLP)-stimulated oxidative metabolism of PMN, using a luminol-enhanced chemiluminescence assay, and have examined the relative roles of PMN receptors for TNF-alpha in priming this oxidative metabolism, using antibodies with p55 and p75 receptor-specific agonistic and antagonistic activities. We have obtained the following results: (1) Antibody Htr-9 with agonistic activity at the p55 receptor mimicked the effect of TNF-alpha; however, a combination of Htr-9 and TNF-alpha did not results in any further increase in chemiluminescence relative to the response observed with TNF-alpha alone. The p75 agonistic antibody MR2-1 actually decreased basal and FMLP-enhanced chemiluminescence. Additionally, MR2-1 substantially inhibited the effects of both TNF-alpha itself and of the p55 agonist Htr-9. (2) Addition of antibodies with antagonistic activities at the p55 (antibody TBP-2) and p75 (antibody Utr-1) receptors resulted in a marked inhibition of the PMN response to TNF-alpha. A combination of both Utr-1 and TBP-2 was most effective at inhibiting the action of TNF. We have confirmed previously published observations that TNF-alpha alone effectively stimulates the oxidative metabolism of PMN in vitro, and that pre-incubation of PMN with TNF-alpha enhances subsequent generation of oxidative metabolites in response to FMLP. We conclude that both p55 and p75 receptors play a critical role in mediating the activation of PMN by TNF-alpha.