Inhibition of IL-1 induced tissue factor (TF) synthesis and procoagulant activity (PCA) in purified human monocytes by IL-4, IL-10 and IL-13

Exposure of monocytes to pro-inflammatory cytokines or lipopolysaccharide (LPS) may induce synthesis and expression of tissue factor (TF). In this paper we have focused on the induction of TF-activity in human monocytes by the pro-inflammatory cytokines recombinant human interleukin 1 (rhIL-1 alpha) (rhIL-1 beta) (rhIL-6) and human tumour necrosis factor alpha (rhTNF-alpha), measured as procoagulant activity (PCA) in a microtitre plate-based clot assay. In addition we have studied the modulation of IL-1 alpha/beta induced TF-mRNA and PCA by rhIL-4, rhIL-10 and rhIL13. IL-1 alpha and IL-1 beta induced a concentration dependent increase in TF-activity. Neither IL-6 nor TNF-alpha gave rise to procoagulant activity at the concentrations tested (0.2-20 ng/ml). IL-4, IL-10 and IL-13, all effectively diminished IL-1 alpha/beta induced PCA, shown at the protein- and at the mRNA-level, while cell viability was unaffected. These results add to the previously demonstrated role of IL-4 and IL-10 as inhibitors of LPS-induced TF-activity, showing that these anti-inflammatory cytokines are not specific for LPS-activation but interfere with other stimulating substances such as IL-1, which may be involved in diseases where LPS is not present.     

The effect of novel polymorphisms in the interleukin-6 (IL-6) gene on IL-6 transcription and plasma IL-6 levels, and an association with systemic-onset juvenile chronic arthritis

During active disease, patients with systemic-onset juvenile chronic arthritis (S-JCA) demonstrate a rise and fall in serum interleukin-6 (IL-6) that parallels the classic quotidian fever. To investigate the possibility that this cytokine profile results from a difference in the control of IL-6 expression, we examined the 5' flanking region of the IL-6 gene for polymorphisms. A G/C polymorphism was detected at position -174. In a group of 383 healthy men and women from a general practice in North London, the frequency of the C allele was 0.403 (95% confidence interval 0.37-0.44). In comparison, 92 patients with S-JCA had a different overall genotype frequency, especially those with onset of disease at < 5 yr of age. This was mainly due to the statistically significant lower frequency of the CC genotype in this subgroup. When comparing constructs of the 5' flanking region (-550-+61 bp) in a luciferase reporter vector transiently transfected into HeLa cells, the -174C construct showed 0.624+/-0.15-fold lower expression than the -174G construct. After stimulation with LPS or IL-1, expression from the -174C construct did not significantly change after 24 h, whereas expression from the -174G construct increased by 2.35+/-0.10- and 3.60+/-0.26-fold, respectively, compared with the unstimulated level. Plasma levels of IL-6 were also measured in 102 of the healthy subjects, and the C allele was found to be associated with significantly lower levels of plasma IL-6. These results suggest that there is a genetically determined difference in the degree of the IL-6 response to stressful stimuli between individuals. The reduced frequency of the potentially protective CC genotype in young S-JCA patients may contribute to its pathogenesis. Similarly the individual's IL-6 genotype may be highly relevant in other conditions where IL-6 has been implicated, such as atherosclerosis.     

Serum interleukin-6 (IL-6) and interleukin-4 (IL-4) in patients with multiple myeloma (MM)

In this study we determined, in patients with multiple myeloma (MM), serum levels of IL-4 and IL-6 at diagnosis and during the course of the disease, seeking a correlation with disease activity and prognosis. We studied 54 MM patients, 41 of whom responded to chemotherapy whilst 11 were resistant. At diagnosis, IL-6 was increased in 66% of patients (median 35.5 pg/ml) whereas IL-4 was low (median 4 pg/ml) in 75% of patients. In responding patients, IL-4 increased in remission (median 25 pg/ml), whereas IL-6 decreased (median 4 pg/ml). In chemotherapy-resistant patients, IL-6 and IL-4 values remained stable during the course of the disease.     

Fas/APO-1 (CD95)-mediated apoptosis is activated by interferon-gamma and interferon- in interleukin-6 (IL-6)-dependent and IL-6-independent multiple myeloma cell lines

A poor response to Fas-induced apoptosis is evident in some multiple myeloma (MM) cell lines and primary cells. In this study, we have examined the possibility to increase the sensitivity to Fas-induced apoptosis by pretreatment of MM cells with interferon-gamma (IFN-gamma) or interferon-alpha (IFN-alpha). Both IFN-gamma and IFN-alpha markedly increased the Fas-induced apoptosis in all cell lines tested (U-266-1970, U-266-1984, and U-1958). In the U-266-1970 and U-1958 cell lines, pretreatment with either IFN-gamma or IFN-alpha also inhibited proliferation in a dose-dependent manner. In contrast, IFN-gamma activation of the Fas death pathway in the U-266-1984 cells was not accompanied by growth inhibition. Incubation with the IFNs increased the Fas antigen expression in one of three cell lines but did not alter the expression of Bcl-2 or Bax. The IFNs are important regulators of growth and survival in MM cells. Our results suggest that activation of Fas-mediated apoptosis is a novel mechanism by which the IFNs exert inhibitory effects on MM cells.     

Nitric oxide prevents IL-1beta and IFN-gamma-inducing factor (IL-18) release from macrophages by inhibiting caspase-1 (IL-1beta-converting enzyme)

Procytokine processing by caspase-1 is required for the maturation and release of IL-1beta and IFN-gamma-inducing factor (IGIF) (or IL-18) from activated macrophages (Mphi). Nitric oxide (NO) has emerged as a potent inhibitor of cysteine proteases. Here, we tested the hypothesis that NO regulates cytokine release by inhibiting IL-1beta-converting enzyme (ICE) or caspase-1 activity. Activated RAW264.7 cells released four to five times more IL-1beta, but not TNF-alpha, in the presence of the NO synthase inhibitor N(G)-monomethyl-L-arginine. Stimulated peritoneal Mphi from wild-type mice (inducible NO synthase (iNOS)+/+) also released more IL-1beta if exposed to N(G)-monomethyl-L-arginine, whereas Mphi from iNOS knockout mice (iNOS-/-) did not. Inhibition of NO synthesis in stimulated RAW264.7 cells also resulted in a threefold increase in intracellular caspase-1 activity. The NO donor S-nitroso-N-acetyl-DL-penicillamine inhibited caspase-1 activity in cells as well as the activity of purified recombinant caspase-1 and also prevented the cleavage of pro-IL-1beta and pro-IGIF by recombinant caspase-1. The inhibition of caspase-1 by NO was reversible by the addition of DTT, which is consistent with S-nitrosylation as the mechanism of caspase-1 inhibition. An in vivo role for the regulation of caspase-1 by NO was established in iNOS knockout animals, which exhibited significantly higher plasma levels of IL-1beta and IFN-gamma than their wild-type counterparts at 10 h following LPS injection. Taken together, these data indicate that NO suppresses IL-1beta and IGIF processing by inhibiting caspase-1 activity, providing evidence for a unique role for induced NO in regulating IL-1beta and IGIF release.     

Induction of interleukin-6 (IL-6) autoantibodies through vaccination with an engineered IL-6 receptor antagonist

Neutralization of cytokine activity by monoclonal antibodies or receptor antagonists is beneficial in the treatment of immune and neoplastic diseases, but the necessity for continuous parenteral delivery of these anticytokine agents poses considerable practical limitations. A viable alternative is to induce a neutralizing antibody response. Using transgenic mice with high circulating levels of human interleukin-6 (hIL-6), we show that injection of the hIL-6 receptor antagonist Sant1 (an IL-6 variant with seven amino-acid substitutions) induces a strong anti-hIL-6 antibody response. The elicited antibodies bind circulating hIL-6 with very high affinity, totally masking it, and neutralize hIL-6 bioactivity both in vitro and in vivo.     

Tricycloillicinone, a novel prenylated c6-c3 compound increasing choline acetyltransferase (ChAT) activity, isolated from Illicium tashiroi

Tricycloillicinone (1), a novel tricyclic prenylated C6-C3 compound, has been isolated as a neurotrophic substance from the woods of Illicium tashiroi and its structure has been elucidated by spectroscopic analyses. Compound 1 could increase ChAT activity in culture of P10 rat septal neurons.     

Level of interleukin-6 (IL-6), soluble interleukin-6 receptors (sIL-6R) and tumor necrosis factor alpha (TNF-alpha) in untreated and progressing multiple myeloma]

The effect of original analogues of the 6-9 C-terminal AVP fragment, D-MRP and D-MPRG, on the active avoidance behaviour of rats was studied using intranasal administration in a wide range of doses. The dose in 0.1 mcg/kg was the most efficient for D-MPR and 0.01 mcg/kg for D-MPRG, which for the tripeptide was ten times, and for the tetrapeptide hundred times lower than the corresponding dose of AVP used in the similar experiments. The tri- and tetrapeptide were shown to facilitate the active avoidance behaviour affecting both the formation of the reaction and consolidation of memory trace. The peptides mostly affect the perception processes, i.e., the detection of a specific stimulus from the environment, the estimation and memorizing of its biological significance.     

Bladder sensory power factor (BSPF): a novel diagnostic tool

45 patients who had received total laryngectomy for laryngeal neoplasia were reviewed with CT, using a study protocol for systematic evaluation as well as the identification of the principal sites of probable recurrence. The advantages of this technique, and some of the considerations which have to be taken into account to avoid error in diagnosis, are commented upon.     

Interleukin-6 (IL-6) inhibits thyroid function in the presence of soluble IL-6 receptor in cultured human thyroid follicles

Interleukin-6 (IL-6), a pleiotropic cytokine, is postulated to be involved in the pathogenesis of sick euthyroid syndrome, although the direct in vitro effects of IL-6 on human thyroid function are controversial. Because IL-6 signal can be transduced when the complex of IL-6 and soluble IL-6 receptor (sIL-6R) binds to gp 130, an IL-6 signal transducer, we studied the effects of IL-6 and sIL-6R on thyroid function, using human thyroid follicles obtained from patients with Graves' disease. IL-6 alone had no inhibitory effect on TSH-induced thyroid function (125I incorporation and organic 125I release), even at supraphysiological concentrations. However, in the presence of physiological concentrations of sIL-6R (100 ng/ml), IL-6 inhibited thyroid function dose dependently and completely, accompanied with the decreased ratio of 125I-T3/125I-T4 not only in the thyroid follicles but also in the culture medium. Thyroid follicles did not secrete sIL-6R but produced IL-6 constitutively. Consistent with these findings, sIL-6R inhibited thyroid function slightly at high concentrations. Furthermore, RT-PCR analyses revealed that human thyroid follicles expressed the messenger RNAs for IL-6 and gp130 but scarcely messenger RNA for IL-6R. These in vitro findings suggest that IL-6 alone hardly affects thyroid function in thyroid follicles in which IL-6R gene is scarcely expressed. However, because sIL-6R is present abundantly in serum, IL-6 in vivo would be capable of inhibiting the synthesis and release of T4 and, to a greater extent, T3 from the thyroid gland. These in vitro findings are at least partly related to the development of sick euthyroid syndrome.     

Molecular cloning of a novel ADP-ribosylation factor (ARF) expressed in planarians

In part I of this study, a method for the objective evaluation of profile nasal esthetics was detailed, and normative values for males and females were presented. In part II, identical methodology was applied to the preoperative lateral cephalograms of 13 female patients with vertical maxillary excess to determine how the nasal profile esthetics of these patients varies from the norm. This data was compared to the normative data established for females in part I. Results determined that patients with vertical maxillary excess have increased nasal length caused by a more superiorly positioned soft tissue nasion, decreased thickness of soft tissue at rhinion, increased nasal form angle, and increased absolute nasal tip angle related to an increased inclination of the cranial base, increased forward projection of the anterior nasal spine (tip support), and decreased incidence of supratip break. These findings suggest a characteristic appearance similar to the type II nasal characteristic (aquiline form) established in part I.     

Definition of the mitogenic factor (MF) as a novel streptococcal superantigen that is different from streptococcal pyrogenic exotoxins A, B, and C

Human T cell activation by recombinant mitogenic factor (rMF) was investigated in comparison with that by recombinant streptococcal pyrogenic exotoxins (rSPE) A, B, and C. Recombinant MF, rSPEA, and rSPEC were mitogenic for peripheral blood mononuclear cells (PBMC), whereas rSPEB was not. Recombinant MF required only HLA-DR for the stimulation of PBMC, as determined using monoclonal antibodies (mAb) to HLA class II molecules and the mouse L cells transfected with HLA class II molecules. Recombinant SPEA and rSPEC required HLA-DR or HLA-DQ molecule. Recombinant MF selectively stimulated V beta 2, V beta 7, V beta 8, V beta 18 and V beta 21-bearing T cells, whereas rSPEA and rSPEC activated V beta 2 and V beta 6-bearing T cells as evaluated by the quantitative T cell receptor (TCR) analytical method. No clonality was observed in the nucleotide sequences of complementarity determining region 3 of TCR V beta in T cells responding to rMF. The profiles of cytokine production by PBMC in response to rMF, rSPEA, and rSPEC were quite similar. In summary, these results demonstrate that both HLA class II molecules and the TCR V beta required for rMF-mediated T cell activation are distinct from those required for rSPEA or rSPEC-mediated activation. Therefore, the MF is a novel streptococcal super-antigen which is different from SPEA, SPEB, and SPEC.