Quantitative intracellular cytokine measurement: age-related changes in proinflammatory cytokine production

The proinflammatory cytokines play a central role in mediating cellular and physiological responses, and levels may reflect immune system effectiveness. In this study, the effect of ageing on the inflammatory response was examined using a novel method to detect production of the proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-α), IL-6 and IL-1β. Peripheral blood mononuclear cells (PBMC) obtained from healthy donors of different ages were incubated for 0, 24, 48 and 72 h with or without phorbol 12-myristate 13-acetate (PMA) stimulation. At each time point these cells were permeabilized and incubated with secondary conjugated FITC MoAbs specific for each cytokine. A flow cytometric system was developed to quantify specific intracellular fluorescence in T cells (CD3⁺) and monocytes (CD14⁺). TNF-α, IL-6 and IL-1β production in cell culture supernatants was also measured using ELISAs. In older subjects, flow cytometry detected significant increases in intracellular T cell TNF-α and IL-6 (P < 0.05). IL-1β was not detected in any of the T cell samples. Likewise, the monocytes of older subjects demonstrated increased intracellular levels of all three cytokines, but these increases were not significant (P > 0.05). These changes in intracellular proinflammatory cytokine levels may explain some of the exaggerated inflammatory responses seen in elderly patients.     

Perioperative cytokine release during coronary artery bypass grafting in patients of different ages

Surgical interventions and cardiopulmonary bypass (CPB) induce a systemic inflammatory response with cytokine release. Ageing is perceived as a process of impaired immune functions: IL-1β, IL-6 and tumour necrosis factor-alpha (TNF-α) secretion are increased while IL-2 release is reduced in advanced age. At present, little information is available about perioperative immune reactions at different stages of ageing. The aim of the present study was to compare IL-6, IL-1β, TNF-α, IL-10 and soluble IL-2 receptor (sIL-2R) in younger and older patients undergoing cardiac surgery. Male patients (n = 14) undergoing elective coronary artery bypass grafting (CABG) surgery employing CPB with moderate hypothermia were divided into two groups according to their age: group 1 included seven patients < 50 years old, group 2 included seven patients > 65 years old. All patients received general anaesthesia using a balanced technique with sufentanil, isoflurane and midazolam. Blood samples were collected pre-operatively (T1); intra-operatively during CPB (T2); post-operatively on the day of surgery (T3); on the first post-operative day (T4). Blood concentrations of IL-6, IL-1β, IL-10, TNF-α and sIL-2R were measured using commercially available ELISA kits and corrected for plasma cell volume. Statistical analysis was performed by non-parametric analysis of variance and Mann–Whitney U-test. Significance level was set to P < 0.05. There were no statistically significant differences in the perioperative release of TNF-α, IL-6, IL-1β, IL-10 and sIL-2R among the two groups. We conclude that the perioperative course of cytokine release in patients undergoing CABG surgery with CPB and comparable perioperative management does not significantly differ in the two age groups.     

Leiomyosarcoma and malignant fibrous histiocytoma share similar allelic imbalance pattern at 9p

Formalin-fixed, paraffin-embedded tissue from 45 soft tissue sarcomas was analysed for allelic imbalance/loss of heterozygosity (AI/LOH) of chromosome 9. The specimens consisted of 17 cases of soft tissue leiomyosarcoma (LMS), 4 cases of cutaneous LMS, 22 cases of conventional malignant fibrous histiocytoma (MFH) and 2 cases of angiomatoid fibrous histiocytoma. All cases were categorised morphologically and immunohistochemically. DNA was microdissected from normal and neoplastic tissues. AI/LOH was performed using six microsatellite markers on the 9p region. The frequency of allelic imbalance at different loci on chromosome 9p was analysed in LMS and MFH and then compared with values previously examined in synovial sarcoma and malignant peripheral nerve sheath tumour. Although AI/LOH and microsatellite instability (MSI) were more frequent in MFH, LMS and MFH groups showed similar patterns of allelic imbalance at the 9p region. Alterations of chromosome 9p have been reported in many cell lines and tumours including LMS and MFH. 9p21 region encodes p16^INK4A and p15^INK4B. Allelic imbalance observed at 9p 21 in this study suggests that alterations of the negative cell cycle regulators may be an important step in the pathogenesis of MFH and LMS. However, the most frequent allelic imbalance was observed at 9p24 at D9S230. Alterations of this locus were very rare in synovial sarcoma and malignant peripheral nerve sheath tumours and were absent in cutaneous LMS and angiomatoid fibrous histiocytoma. This locus may point to the existence of a genetically altered tumour suppressor gene involved in the pathogenesis of LMS and MFH. Our results support the hypothesis that MFHs may represent a morphological pathway in tumour progression of LMSs.     

Methotrexate specifically modulates cytokine production by T cells and macrophages in murine collagen-induced arthritis (CIA): a mechanism for methotrexate-mediated immunosuppression

Immunosuppressive therapy with methotrexate (MTX) has been established as effective treatment for patients with rheumatoid arthritis. To analyse the therapeutic potential and mechanisms of action of MTX, we determined serum cytokine levels and cytokine production by splenic T cells and macrophages in untreated and MTX-treated mice. Furthermore, we assessed the role of MTX in a murine model of experimental arthritis induced by collagen type II (CIA). MTX reduced spontaneous and IL-15-induced tumour necrosis factor (TNF) production by splenic T cells but not by macrophages from healthy mice in vitro in a dose-dependent manner. In contrast, interferon-gamma (IFN-γ) production was less strikingly reduced and IL-4 production was virtually unaffected. In addition, treatment of healthy mice with MTX in vivo led to reduced TNF serum levels and diminished TNF production by splenic T cells and macrophages. Intraperitoneal administration of MTX prior to the onset of arthritis completely prevented clinical and pathological signs of CIA. This was associated with a striking reduction of TNF production by spleen cells from MTX-treated mice. The role of TNF in MTX-mediated effects on cytokine production was further underlined by the finding that MTX effects on IFN-γ production were augmented in TNF-transgenic mice but abrogated in mice in which the TNF-α gene had been inactivated by homologous recombination. Thus, MTX specifically modulates spontaneous and IL-15-induced TNF-α production in mice and prevents experimental murine CIA. These data suggest that TNF production by T cells is an important target of MTX and may serve as a basis to understand and further analyse MTX-mediated mechanisms of immunosuppression in patients with RA.     

Aneurysmal benign fibrous histiocytoma: clinicopathological analysis of 40 cases of a tumour frequently misdiagnosed as a vascular neoplasm

Forty cases of the distinctive but poorly recognized aneurysmal variant of cutaneous fibrous histiocytoma are described. These tumours presented most commonly in middle-age adults, with a slight predilection for females. Anatomical distribution was wide with most cases occurring in the lower limb/limb girdle (50%), upper limb/limb girdle (20%) and trunk (17%). Lesional size ranged from 0.5 cm to 4 cm. Haemorrhage accounted for the rapid clinical growth of some lesions and the frequent clinical confusion with a cyst, a melanocytic lesion or a haemangioma. Five (19%) of the twenty-six cases with follow-up (mean duration 2.5 years) recurred locally, twice in two cases. One of these cases had involvement of a regional lymph node in the second recurrence, most likely as a result of direct local extension. Distinctive histological features were prominent blood-filled spaces, varying from artefact-like clefts to cystic areas mimicking cavernous vascular channels but devoid of an endothelial lining, prominent haemosiderin deposition, numerous siderophages and giant cells, and a moderate mitotic rate. Despite the presence of prominent secondary changes due to haemorrhage, all cases showed cellular polymorphism, hyalinized collagen bundles surrounded by tumour cells in the periphery of the lesion and 88% showed some degree of epidermal hyperplasia, as seen in common fibrous histiocytoma. Immunohistochemistry (ABC method) revealed only vimentin and, rarely, focal smooth muscle actin positivity. CD68 was positive in some reactive macrophages only. Stains for CD31, CD34, desmin and factor XIIIa were negative in all cases tested. Emphasis is placed on differential diagnosis since these lesions are commonly confused with benign and malignant vascular tumours including angiosarcoma, Kaposi's sarcoma and spindle cell haemangioendothelioma, and with angiomatoid malignant fibrous histiocytoma.     

Ewing family tumours: a paediatric perspective

Sarcomas are malignant tumours of the connective tissues and are proportionately much more common in children than in adults. The Ewing family of tumours (EFT) is a group of sarcomas sharing rearrangement of the EWSR1 gene on 22q12, and include Ewing sarcoma/primitive neuroectodermal tumour, desmoplastic small round cell tumour, angiomatoid fibrous histiocytoma and clear cell sarcoma. Other tumours harbouring EWSR1 rearrangements include myoepithelial tumours, myxoid liposarcoma and extraskeletal chondrosarcoma. In addition, a group of Ewing-like primitive round cell sarcomas have been recently described in a paediatric population, further expanding the list of EFT. This review will focus on the histopathological, immunohistochemical and molecular genetic features of EFT, with an emphasis on those predominantly occurring in the paediatric population.     

IL-1 receptor antagonist (IL-1Ra) does not inhibit the production of C-reactive protein or serum amyloid A protein by human primary hepatocytes. Differential regulation in normal and tumour cells

The synthesis of some class 1 acute-phase proteins (APP), including C-reactive protein (CRP) and serum amyloid A (SAA) protein is completely blocked by the IL-1 receptor antagonist (IL-1Ra), whereas the production of fibrinogen, a class 2 APP, is increased by IL-1Ra in hepatoma cells, but this has never been tested in human hepatocytes in primary culture. Since previous studies on the contributions of cylokine inhibitors in connective tissues diseases suggested that IL-1 and tumour necrosis factor-alpha (TNF-α) might play an important role in the regulation of CRP, we decided to examine in more detail the respective roles of IL-1β, IL-6, and TNF-α and their inhibitors in the production of APP by human primary hepatocytes versus the hepatoma cell line PLC/PRF/5. In the hepatoma cell line, IL-1β and/or TNF-α had synergistic effects with IL-6 on the production of CRP and SAA. In contrast, these cytokines were devoid of effect in normal hepatocytes. The production of fibrinogen was increased by IL-6 and decreased by IL-1 (and TNF-α) in both cell types. The secretion of CRP and SAA by primary hepatocytes incubated with a cytokine-rich mononuclear cell-conditioned medium was totally unaffected by IL-1Ra or anti-TNF-α antibodies. In contrast, the addition of IL-1Ra increased the production of fibrinogen by both hepatoma cells and primary hepatocytes incubated with the mononuclear cell-conditioned medium. We therefore conclude that IL-1β and TNF-α do not exert any significant effect on the synthesis of CRP and SAA by human primary hepatocytes.     

Reticular angiomatoid "malignant" fibrous histiocytoma--a case report with cytogenetics and molecular genetic analyses

Angiomatoid "malignant" fibrous histiocytoma is a rare sarcoma of low malignant potential that occurs most commonly in the extremities of children and young adults. Herein, we present a case of angiomatoid malignant fibrous histiocytoma with unusual histologic features arising in the mediastinum of an 80-year-old man. The tumor exhibited a reticular growth pattern and myxoid stroma. The tumor cells expressed epithelial membrane antigen and desmin. Cytogenetic analysis revealed the translocation t(2;22)(q33;q12). Molecular genetic analysis confirmed the rearrangement of the EWSR1 locus and the presence of the EWSR1/CREB1 fusion. This report expands the clinicopathologic spectrum of angiomatoid malignant fibrous histiocytoma and underscores the value of integrating morphologic, immunophenotypic, and molecular findings in the identification of its unusual morphologic variants.     

B cells produce less IL-10, IL-6 and TNF-α in myasthenia gravis

Abstract

B cells from myasthenia gravis (MG) patients with autoantibodies (Aab) against acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or with no detectable Aab were investigated as cytokine producing cells in this study. B cells were evaluated for memory phenotypes and expressions of IL-10, IL-6 and IL-12A. Induced productions of IL-10, IL-6, IL-12p40, TNF-α and LT from isolated B cells in vitro were measured by immunoassays. MG patients receiving immunosuppressive treatment had higher proportions of memory B cells compared with healthy controls and untreated patients. With CD40 stimulation MG patients produced significantly lower levels of IL-10, IL-6. With CD40 and B cell receptor stimulation of B cells, TNF-α production also decreased in addition to these cytokines. The lower levels of these cytokine productions were not related to treatment. Our results confirm a disturbance of B cell subpopulations in MG subgroups on immunosuppressive treatment. B cell derived IL-10, IL-6 and TNF-α are down-regulated in MG, irrespective of different antibody productions. Ineffective cytokine production by B cells may be a susceptibility factor in dysregulation of autoimmune Aab production.     

Angiomatoid malignant fibrous histiocytoma

Angiomatoid malignant fibrous histiocytoma (MFH), is a rare but distinct fibrohistiocytic tumour of children and young adults, simulating a vascular neoplasm. A case of angiomatoid malignant fibrous histiocytoma in a 12 year old male is reported.     

TNF-alpha Production by Peripheral Blood Monocytes in Multiple Sclerosis Patients and Healthy Controls

Background: Aberrant immune responses are evident in the pathogenesis of multiple sclerosis (MS) and it has been proposed that the spectrum of cytokines influence disease outcomes. Leptin and lipopolysaccharide (LPS) of Gram-negative bacteria are both potent cellular stimulators for production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). The aim of this study was to compare the TNF-α production by peripheral blood monocytes from MS patients with healthy controls.

Methods: Peripheral blood samples were stimulated with LPS or leptin. After blocking the Golgi apparatus, intracellular cytokine production was assessed using a monoclonal antibody against human TNF-α by the flow cytometry technique. Moreover, plasma level measurement of cytokines was performed using enzyme-linked immunosorbent assay (ELISA).

Results: Intracellular levels of TNF-α were 16.80?±?8.21 and 16.52?±?8.23in MS patients and healthy controls which showed no statistically significant difference between them (p?=?0.850). Leptin-stimulated and LPS-stimulated TNF-α production showed no significant difference between MS patients and the control group (p?=?0.263 and p?=?0.191, respectively). However, after treatment with leptin, a weak significant difference was shown between cases and control group (p?=?0.049). There were significant differences between cases and controls regarding serum levels of IL-6 and Toll-like receptor-4 (TLR-4) before and after stimulation with leptin and LPS, separately (p?<?0.05).

Conclusion: Taken together, we cannot definitely conclude that TNF-α does not play an important role in pathogenesis of MS. However, other characteristics of monocyte activation such as IL-6 or TLRs can elucidate implication of peripheral blood monocytes in MS pathogenesis.     

Two inhibitors of pro-inflammatory cytokine release,interleukin-10 and interleukin-4, have contrasting effects on release of soluble p75 tumor necrosis factor receptor by cultured monocytes

The biological activity of the pro-inflammatory cytokine, tumor necrosis factor (TNF)-α depends on the level of TNF-α itself, the expression of the p55 and p75 cell surface receptors for TNF on target cells and the concentrations of the natural inhibitors of TNF-α, the soluble p55 and p75 TNF receptors (TNF-R). Interleukin (IL)-10 and IL-4 are known to inhibit TNF-α production by monocytes. We, therefore, investigated the effects of IL-10 and IL-4 on the cell surface expression and release of TNF-R by human monocytes to determine whether these cytokines also indirectly modulated the biological activity of TNF-α. Exposure to IL-10 (1-10 U/ml) for 24 or 48 h increased soluble p75 TNF-R expression and concomitantly reduced surface expression of p75 TNF-R. Further, IL-l α-stimulated production of TNF-α was diminished by IL-10 and only a small proportion of this TNF-α was bioactive, consistent with increased production of inhibitory soluble TNF-R. IL-10 also induced down-regulation of surface p55 TNF-R on monocytes, and increased release of soluble p55 TNF-R. However, the expression of soluble p55 TNF-R was much lower than soluble p75 TNF-R, indicating that it contributed less importantly to neutralization of TNF-α under these conditions. Like IL-10, IL-4 supressed the release of TNF-α by monocytes. In contrast to IL-10, however, IL-4 (0.1-10 ng/ml) supressed the release of soluble p75 TNF-R from monocytes in a dose-dependent manner. Release of soluble p55 TNF-R was also supressed by IL-4. IL-10, therefore, reduces the pro-inflammatory potential of TNF in three ways: by down-regulating surface TNF-R expression whilst increasing production of soluble TNF-R and inhibiting the release of TNF-α itself. This suggests that IL-10 may be useful in the treatment of diseases where overexpression of TNF-α occurs.     

Induction of tumour necrosis factor-alpha during haemodialysis. Influence of the membrane type.

Some of the secondary clinical effects induced by long-term haemodialysis in patients with end-stage renal failure have been related to an increased production of interleukin-1 (IL-1). We investigated the role of another cytokine which shares a number of biological properties with IL-1, tumour necrosis factor-alpha (TNF-alpha). In long-term haemodialysed patients, we found at the beginning of the dialysis increased plasma TNF-alpha levels and enhanced monocyte capacity to produce TNF-alpha spontaneously ex vivo. Non-haemodialysed uraemic patients also presented increased plasma TNF-alpha levels. During dialysis with cellulose acetate (CA) or polysulphone (PS) membranes, plasma TNF-alpha levels and the spontaneous and lipopolysaccharide-induced production of TNF-alpha by monocytes remained at predialysis levels. In contrast, when cuprophane membranes were used, there was a significant increase in plasma TNF-alpha levels and in both spontaneous (10-fold) and lipopolysaccharide-induced (seven-fold) ex vivo TNF-alpha production by monocytes. These results suggest that monocytes are stimulated during haemodialysis with the poorly biocompatible cuprophane membrane.     

Cytokine Inhibition by A Novel Steroid,Mometasone Furoate

Abstract

Mometasone furoate (9α, 21 dichloro-11β, 17α dihydroxy-16α methyl-1, 4 pregnadiene-3, 20 dione-17–[2′] furoate) was an unexpectedly potent inhibitor of the in vitro production of three inflammatory cytokines, IL-11, IL-6, and TNF-α. the potency of mometasone furoate in inhibiting cytokine production was compared to that of hydrocortisone, betamethasone, dexamethasone, and beclomethasone.

IL-6 and TNF-α were both produced by WEHI-265.1 (murine myelomonocytic leukemia) cells following stimulation by lipopolysaccharide (LPS). Twenty-four hours after stimulation by LPS, the cell-free supernatant fluids were removed. Their cytokine content was analyzed using ELISAs specific for each cytokine.

IL-1 synthesis was induced in the harvested peritoneal macrophages of BALB/c mice by incubation with LPS for twenty-four hours. the IL-1 content in the cell-free supernatant fluids was determined by the thymocyte-costimulator bioassay.

Using these systems, mometasone furoate was found to be the most potent steroid tested for inhibiting the production of the three cytokines. the IC50′s were 0.05 nM (IL-1), 0.15 nM (IL-6), and 0.25 nM (TNF-α). the inhibition of the production of proinflammatory mediators by extremely low concentrations of mometasone furoate suggests that this steroid should be highly effective in various disorders.