Release of soluble ICAM-1 from human lung fibroblasts, aortic smooth muscle cells, dermal microvascular endothelial cells, bronchial epithelial cells, and keratinocytes.

We determined effects of IL-1alpha, TNFalpha and IFNgamma on sICAM-1 release in culture media from human aortic smooth muscle cells (AOSMC), dermal microvascular endothelial cells (DMEC), keratinocytes (KC), bronchial epithelial cells (BEC) and lung fibroblasts (LF) as determined by ELISA. Under basal conditions of cultures for 20 h, low concentrations of sICAM-1 were only detected in the culture media of two (DMEC and BEC) of these cell types. IL-1alpha, TNFalpha and IFNgamma stimulated sICAM-1 from these cells. IFNgamma stimulated more shedding from AOSMC, BEC and KC than IL-1alpha or TNFalpha. TNFalpha enhanced more sICAM-1 release from DEMC than from AOSMC, BEC and LF. IL-1alpha and IFNgamma or TNFalpha and IFNgamma acted synergistically to enhance shedding of sICAM-1 from these cells. The levels sICAM-1 in pathophysiological conditions may influence leukocyte-vascular cell interactions to block leukocyte transmigration to tissue injury sites as a negative feedback mechanism.     

The histone deacetylase inhibitor ITF2357 reduces production of pro-inflammatory cytokines in vitro and systemic inflammation in vivo

We studied inhibition of histone deacetylases (HDACs), which results in the unraveling of chromatin, facilitating increased gene expression. ITF2357, an orally active, synthetic inhibitor of HDACs, was evaluated as an anti-inflammatory agent. In lipopolysaccharide (LPS)-stimulated cultured human peripheral blood mononuclear cells (PBMCs), ITF2357 reduced by 50% the release of tumor necrosis factor-alpha (TNFalpha) at 10 to 22 nM, the release of intracellular interleukin (IL)-1alpha at 12 nM, the secretion of IL-1beta at 12.5 to 25 nM, and the production of interferon-gamma (IFNgamma) at 25 nM. There was no reduction in IL-8 in these same cultures. Using the combination of IL-12 plus IL-18, IFNgamma and IL-6 production was reduced by 50% at 12.5 to 25 nM, independent of decreased IL-1 or TNFalpha. There was no evidence of cell death in LPS-stimulated PBMCs at 100 nM ITF2357, using assays for DNA degradation, annexin V, and caspase-3/7. By Northern blotting of PBMCs, there was a 50% to 90% reduction in LPS-induced steady-state levels of TNFalpha and IFNgamma mRNA but no effect on IL-1beta or IL-8 levels. Real-time PCR confirmed the reduction in TNFalpha RNA by ITF2357. Oral administration of 1.0 to 10 mg/kg ITF2357 to mice reduced LPS-induced serum TNFalpha and IFNgamma by more than 50%. Anti-CD3-induced cytokines were not suppressed by ITF2357 in PBMCs either in vitro or in the circulation in mice. In concanavalin-A-induced hepatitis, 1 or 5 mg/kg of oral ITF2357 significantly reduced liver damage. Thus, low, nonapoptotic concentrations of the HDAC inhibitor ITF2357 reduce pro-inflammatory cytokine production in primary cells in vitro and exhibit anti-inflammatory effects in vivo.     

In humans, corticotropin releasing hormone antagonizes some of the negative immunoregulatory effects of serotonin

Both corticotropin releasing hormone (CRH) and serotonin (5-HT) participate in the stress response and are known to modulate cytokine release by human immune cells. Extracellular 5-HT concentrations at or above the serum values have negative immunoregulatory effects by inhibiting the production of interferon-gamma (IFNgamma), a pro-inflammatory cytokine produced by Th-1-like lymphocytes, whereas 5-HT has no significant effects on the production of interleukin-10 (IL-10), an anti-inflammatory cytokine. In one study, CRH significantly decreases IFNgamma production by cultured human peripheral blood immunocytes, whereas in other studies CRH increases the production of cytokines, such as IL-1, IL-2 and IL-6. The aims of the present study were to examine i) the effects of CRH, 10-9 M, 10(-8) M and 10(-7) M, on the stimulated production of IFNgamma, IL-10 and tumor necrosis factor-alpha (TNFalpha) by human whole blood; and ii) whether CRH, 10(-9) M, 10(-8) M and 10(-7) M, may antagonize some of the negative immunoregulatory effects of 5-HT, 1.5 microg/mL or 15 microg/mL. We found that CRH, 10(-9) M, 10(-8) M and 10(-7) M, had no significant effects either on the stimulated production of IFNgamma, IL-10 or TNFalpha or on the IFNg/IL-10 production ratio, which reflects the pro-inflammatory capacity of the culture. 5-HT, 1,5 microg/dL and 15 microg/dL, significantly suppressed the production of IFNgamma and TNFalpha and the IFNg/IL-10 production ratio. CRH, 10(-7) M, significantly reversed the 5-HT (1.5 microg/mL and 15 microg/mL)-induced suppression of IFNg production. CRH at all concentrations significantly blocked the 5-HT (1.5 microg/mL and 15 microg/mL)-induced suppression of TNFalpha production. The results suggest that CRH has no significant direct effects on the production of IFNgamma, IL-10 and TNFalpha, but antagonizes the negative immunoregulatory effects of 5-HT on the production of IFNgamma and TNFalpha and on the IFNgamma/IL-10 production ratio.     

Serum Th1 and Th2 profile cytokine level changes in patients with Graves' ophthalmopathy treated with corticosteroids.

The aim of this study was to estimate the influence of corticosteroids on Th1 and Th2 serum cytokine balance in patients with GO: IFNgamma, TNFalpha, IL-4 and IL-10. Further, we tested the hypothesis of an up-regulation of Th2 immune response during successful treatment with corticosteroids to explain their beneficial effect in Graves' ophthalmopathy. Serum cytokines were detected in three groups of subjects: 20 patients with Graves' disease without ophthalmopathy (Gd), 16 patients with clinical symptoms of ophthalmopathy (GO) (CAS over 3 points, last consultation record for GO less than a year old) and 16 healthy volunteers. Corticosteroid therapy consisted of intravenous infusions of methylprednisolone (MP) (2 series, 3 g each time) and subsequent treatment with oral prednisone (60 mg per day) in a tapering schedule. The serum samples were collected 24 hours before MP, 24 hours after MP, 14 days of treatment with prednisone and at the end of corticosteroid therapy. The levels of IFNgamma, TNFalpha, IL-4 and IL-10 in the serum were determined using ELISA. Statistical significance was estimated by the Mann-Whitney U-test. Our findings show a deviation to systemic Th2 profile cytokines in Graves' disease. In patients with GO, we found a significantly increased serum IL-10 concentration. In corticosteroid-responsive patients, the balance of serum cytokines IL-4/IFNgamma, IL-4/TNFalpha, IL-10/IFNgamma and IL-10/TNFalpha increased and remained upregulated until the end of the study. In non-responders, the balance of serum cytokines studied increased after methylprednisolone but declined markedly during continuation of the therapy with prednisone. In summary, our results show that efficient corticosteroid therapy may be related to its influence on Th2/Th1 profile cytokine balance. The upregulation of serum IL-4 and IL-10 during successful treatment with corticosteroids indicate the possibility of using these cytokines as predictors of the beneficial effect of corticosteroids in Graves' ophthalmopathy.     

Comparative methods for multiplex analysis of cytokine protein expression in plasma of lipopolysaccharide-treated mice

Changes in circulating cytokines might serve as predictors of compound-evoked inflammatory responses. CD-1 mice were treated with lipopolysaccharide (LPS; 0.2 ml of 0.25 mg/ml, intraperitoneal) for subsequent expression measurement of plasma cytokine protein expression at 24-h post-treatment using multiple antibody Western blot, and at both 2-h and 24-h post-treatment using antibody array and suspension bead array. Antibody array provided a semi-qualitative assessment and suggested significantly increased expression of GCSF at 2-h post-treatment and GCSF, IL-6, IL-12, MCP-1, MCP-5, RANTES and sTNFR1 at 24-h post-treatment. Densitometric analysis of multiple antibody Western blots provided a semi-quantitative assessment and indicated significantly increased expression of IL-6, IL-12, IL-17, GCSF, eotaxin, and MCP-2 at 24-h post-treatment. The suspension bead array yielded statistically significant cytokine protein expression increases for IL-6, IL-10, IFNgamma and TNFalpha at both 2-h and 24-h post-treatments, while significant expression at 24-h post-treatment only was noted for IL-1beta, IL-5, IL-12 and GM-CSF. Suspension bead array provided the greatest range of detection, revealing subtle increased expression of GM-CSF, IL-1beta, IL-5, IL-10, TNFalpha and IFNgamma at 24-h post-treatment, not detected by antibody array or multiple antibody Western blot. Suspension bead array proved to be the best method for detection of LPS-evoked changes in plasma cytokine levels.     

Differential regulation of cytokine and chemokine production in lipopolysaccharide-induced tolerance and priming

LPS pretreatment of human pro-monocytic THP-1 cells induces tolerance to secondary LPS stimulation with reduced TNFalpha production. However, secondary stimulation with heat-killed Staphylococcus aureus (HKSa) induces priming as evidenced by augmented TNFalpha production. The pro-inflammatory cytokine, IFNgamma, also abolishes suppression of TNFalpha in LPS tolerance. The effect of LPS tolerance on HKSa and IFNgamma-induced inflammatory mediator production is not well defined. We hypothesized that LPS, HKSa and IFNgamma differentially regulate pro-inflammatory mediators and chemokine production in LPS-induced tolerance. THP-1 cells were pretreated for 24 h with LPS (100 ng/ml) or LPS (100 ng/ml) + IFNgamma (1 microg/ml). Cells were subsequently stimulated with LPS or HKSa (10 microg/ml) for 24 h. The production of the cytokines TNFalpha, IL-6, IL-1beta, and GMCSF and the chemokine IL-8 were measured in supernatants. LPS and HKSa stimulated TNFalpha (3070 +/- 711 pg/ml and 217 +/- 9 pg/ml, respectively) and IL-6 (237 +/- 8.9 pg/ml and 56.2 +/- 2.9 pg/ml, p < 0.05, n = 3, respectively) in control cells compared to basal levels (< 25 pg/ml). LPS induced tolerance to secondary LPS stimulation as evidenced by a 90% (p < 0.05, n = 3) reduction in TNFalpha. However, LPS pretreatment induced priming to HKSa as demonstrated by increased TNFalpha (2.7 fold, from 217 to 580 pg/ml, p < 0.05, n = 3 ). In contrast to suppressed TNFalpha, IL-6 production was augmented to secondary LPS stimulation (9 fold, from 237 to 2076 pg/ml, p < 0.01, n = 3) and also primed to HKSa stimulation (62 fold, from 56 to 3470 pg/ml, p < 0.01, n = 3). LPS induced IL-8 production and to a lesser extent IL-1beta and GMCSF. LPS pretreatment did not affect secondary LPS stimulated IL-8 or IL-1beta, although HKSa stimulation augmented both mediators. In addition, IFNgamma pretreatment reversed LPS tolerance as evidenced by increased TNFalpha levels while IL-6, IL-1beta, and GMCSF levels were further augmented. However, IL-8 production was not affected by IFNgamma. These data support our hypothesis of differential regulation of cytokines and chemokines in gram-negative- and gram-positive-induced inflammatory events. Such changes may have implications in the pathogenesis of polymicrobial sepsis.     

Cytokine and eicosanoid regulation by Schistosoma mansoniduring LSE penetration

Cercarial penetration, in low to moderate numbers, does not cause a normal skin inflammatory response; therefore, the authors sought to determine whether cercariae can down-regulate keratinocyte activation and thus the secretion of pro-inflammatory cytokines and eicosanoids. Human living skin equivalent (LSE, Organogenesis) consisting of dermal, epidermal and stratum corneum-like layers was used as the skin substrate. The surface of the LSE membrane was exposed to 100 ng IFNgamma or ~850 cercariae for 18 h. Incubation media and tissue was then assayed for IL-1alpha, IL-6, IL-8, TNFalpha, 5-HETE, 12-HETE, PGF(2), LTB(4), and LTC(4) via RIA and Western Blots. TNFalpha was not detected. Secreted IL-1alpha levels were (mean +/- S.E.M. (n)): Control, 1.03 ng +/- 0.15 (11); IFNgamma 1.90 ng +/- 0.48 (5); cercariae, 1.79 ng +/- 0.22 (22). In spite of this increase, cercariae down-regulated IL-8 (cercariae 11.13 +/- 1.70 ng vs. IFNgamma = 16.47 +/- 0.29 ng, p = 0.04) and LTB(4) (cercariae = 98.86 +/- 19.65 pg/0.1 ml vs. IFNgamma = 193.42 +/- 44.21 pg/0.1 ml p = 0.02). No changes were seen in IL-6, 12-HETE, 5-HETE, and PGE(2) levels. It is concluded that cercarial penetration causes a release of IL-1alpha consistent with skin trauma; however, schistosomulae may regulate the production of chemotactic (neutrophils, macrophages, T-cells, etc.) and activation factors such as IL-8 and LTB(4).     

A synergistic role for IL-1beta and TNFalpha in monocyte-derived IFNgamma inducing activity

Although much is known about classic IFNgamma inducers, little is known about the IFNgamma inducing capability of inflammasome-activated monocytes. In this study, supernatants from LPS/ATP-stimulated human monocytes were analyzed for their ability to induce IFNgamma production by KG-1 cells. Unexpectedly, monocyte-derived IFN inducing activity was detected, but it was completely inhibited by IL-1beta, not IL-18 blockade. Moreover, size-fractionation of the monocyte conditioned media dramatically reduced the IFNgamma inducing activity of IL-1beta, suggesting that IL-1beta requires a cofactor to induce IFNgamma production in KG-1 cells. Because TNFalpha is known to synergize with IL-1beta for various gene products, it was studied as the putative IL-1beta synergizing factor. Although recombinant TNFalpha (rTNFalpha) alone had no IFNgamma inducing activity, neutralization of TNFalpha in the monocyte conditioned media inhibited the IFNgamma inducing activity. Furthermore, rTNFalpha restored the IFNgamma inducing activity of the size-fractionated IL-1beta. Finally, rTNFalpha synergized with rIL-1beta, as well as with rIL-1alpha and rIL-18, for KG-1 IFNgamma release. These studies demonstrate a synergistic role between TNFalpha and IL-1 family members in the induction of IFNgamma production and give caution to interpretations of KG-1 functional assays designed to detect functional IL-18.     

Treatment of Brucella-susceptible mice with IL-12 increases primary and secondary immunity

Celiac disease is a gluten-induced T-cell mediated autoimmune process that results in the destruction of the intestinal mucosa and is associated with an expansion of CD8(+) CD103(+) TCRalphabeta intraepithelial lymphocytes (IELs) in the damaged epithelium. The role of this IEL population in the pathology is unknown. The aim of this work was to compare the cytokine profile and the cytotoxicity pattern from CD8(+) IEL clones isolated from celiac (CD) and non-celiac (NCD) biopsies. We report that the number of IL-10 producing CD clones was significantly lower (26%) than that obtained from the NCD sample (62%). Instead, IL-2 was produced by more CD (44%) than NCD clones (26%). Cytotoxicity patterns against intestinal epithelial cell lines suggest different functional subsets of CD8(+) IELs. CD clones capable of high cytotoxicity produced IL-2 whereas most cytotoxic NCD IELs produced IL-10. This clonal analysis indicates that an impaired immune regulation in celiac mucosa may be partially attributed to the low generation of regulatory CD8(+) IELs that produce IL-10.     

Functional and structural regression of the rabbit corpus luteum is associated with altered luteal immune cell phenotypes and cytokine expression patterns

Following attenuation of progesterone production corpora lutea are selectively cleared, a process associated with recruitment of macrophages. In the rabbit little is known about luteal immune cell phenotypes and expression of cytokines, which influence immune cells and resident luteal cells, during luteolysis. Consequently, we studied luteal immune cells by immunohistochemistry as well as luteal IL-10, TNFalpha, MCP-1, IFN-gamma, and IL-1beta mRNA expression by semiquantitative RT-PCR from day 8 to day 20 in pseudopregnant rabbits (d8-d20 p.hCG). Luteal function was assayed by serum progesterone levels. Functional luteolysis commenced by d14 p.hCG as indicated by attenuation of serum progesterone levels. X4(+) tissue macrophage levels increased transiently on d12 and d14 p.hCG, whereas CD5(+) T-cell levels transiently declined on these two days. CD68(+) macrophages increased progressively after d16 p.hCG. The luteal mRNA level of the anti-inflammatory cytokine IL-10 as well as the mRNA levels of the pro-inflammatory cytokines TNFalpha and MCP-1 increased after d16 p.hCG and remained elevated up to d20 p.hCG. IFN-gamma and IL-1beta mRNA expression did not vary systematically. In summary, luteolysis was associated with an initial transient increase of X4(+) macrophages and decrease of CD5(+) T-cells, and later recruitment of CD68(+) macrophages. During structural regression pro- and anti-inflammatory cytokines are upregulated possibly to control immune cell function.     

Syndecan-1 is an in vivo suppressor of Gram-positive toxic shock

Heparan sulfate proteoglycans bind to and regulate many inflammatory mediators in vitro, suggesting that they serve an important role in influencing inflammatory responses in vivo. Here we evaluated the role of syndecan-1, a major heparan sulfate proteoglycan, in modulating inflammatory responses in Gram-positive toxic shock, a systemic disease that is a significant cause of morbidity and mortality. Syndecan-1-null and wild-type mice were injected intraperitoneally with staphylococcal enterotoxin B, a pyrogenic superantigen, and their inflammatory responses were assessed. Syndecan-1-null mice showed significantly increased liver injury, vascular permeability, and death in response to staphylococcal enterotoxin B challenge compared with wild-type mice. Although serum levels of systemic IL-2 and IFNgamma were similar between the two backgrounds, those of TNFalpha and IL-6 were significantly increased in syndecan-1-null mice undergoing Gram-positive toxic shock. Furthermore, syndecan-1-null mice challenged with staphylococcal enterotoxin B showed enhanced T cell accumulation in tissues, whereas immunodepletion of T cells protected syndecan-1-null mice from the magnified systemic cytokine storm, inflammatory tissue injury, and death. Importantly, syndecan-1 shedding was induced in wild-type mice injected with staphylococcal enterotoxin B, and the administration of heparan sulfate, but not syndecan-1 core protein, rescued syndecan-1-null mice from lethal toxic shock by suppressing the production of TNFalpha and IL-6, and attenuating inflammatory tissue injury. Altogether, these data suggest that syndecan-1 shedding is a key endogenous mechanism that protects the host from Gram-positive toxic shock by inhibiting the dysregulation and amplification of the inflammatory response.     

Effects of tumor necrosis factor alpha on taurine uptake in cultured rat astrocytes

Taurine is known to play a major role in volume regulation in astrocytic swelling associated with stroke and brain trauma. Apart from brain edema, the severity of brain injury is related to the levels of inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha). TNFalpha had been shown to be closely associated with brain edema formation since the neutralization of TNFalpha reduced brain edema. Considering taurine has osmoregulatory functions in astrocytes, experiments were performed to study the effects of TNFalpha on taurine uptake in cultured astrocytes. Astrocytes exposed to 20 ng/ml of TNFalpha for 48 h showed a 91% increase in taurine uptake and significant increase was observed after 24 h exposure. This cytokine caused neither significant changes in cell volume nor taurine release. The increased in taurine uptake induced by TNFalpha was unlikely resulted from the modification of Na(+) movement because TNFalpha decreased tyrosine uptake, Na(+)-dependent transport system. In contrast to TNFalpha, interferon-gamma (IFNgamma) did not significantly affect taurine uptake. Taken together, our results did not support a suggestion that TNFalpha affects cell volume regulation via modulating taurine uptake in astrocytes. Increasing lines of evidence have demonstrated that taurine has anti-inflammatory and anti-oxidative effects, these findings therefore suggested that the increase in taurine uptake might be an adaptive response or a tool for astrocytes against oxidative stress.     

The negative immunoregulatory effects of serotonin (5-HT) moduline,an endogenous 5-HT1B receptor antagonist with anti-anxiety properties

BACKGROUND: Serotonin (5-HT) has negative immunoregulatory effects by reducing the interferon-gamma (IFNgamma)/interleukin-10 (IL-10) production ratio by stimulated immune cells. Leukocytes have functional 5-HT1B receptors. 5-HT moduline, an endogenous 5-HT1B receptor antagonist, may antagonize the 5-HT1B agonist-induced proliferation of immune cells. AIMS: To examine the effects of 5-HT moduline on the stimulated production of IFNgamma, tumor necrosis factor alpha (TNFalpha) and IL-10. RESULTS: 5-HT moduline, 10(-6) M and 10(-5)M, significantly reduced the production of IFNgamma and the IFNgamma/IL-10 ratio. 5-HT moduline 10(-5)M significantly reduced the production of TNFalpha. The combination of 5-HT, 15 microg/mL, with 5-HT moduline, 10(-6)M and 10(-5)M, further decreases the IFNgamma/IL-10 production ratio. INTERPRETATION: 5-HT moduline has negative immunoregulatory effects.