Serum Levels Of sFasL Research Articles

Soluble FAS Ligand: A Discriminating Feature between Drug-Induced Skin Eruptions and Viral Exanthemas

The clinical spectrum of cutaneous eruptions comprises benign variants like maculopapular rashes (MPRs) and potentially life-threatening events such as toxic epidermal necrolysis (TEN). Apoptosis of keratinocytes is a common histopathological feature of all these drug eruptions. As in skin lesions of TEN and Stevens-Johnson syndrome patients, apoptosis of keratinocytes is often accompanied by an only sparse cellular infiltrate, a soluble fatty acid synthetase ligand (sFASL)-mediated mechanism of keratinocyte cell death is postulated. In MPR patients, evidence for the occurrence of a similar process could not be established so far. We therefore examined sera and lesional skin sections from patients with clinical variants of drug eruptions for FASL expression using a sandwich ELISA and immunohistochemistry, respectively. As controls, healthy persons and patients with other inflammatory skin diseases such as viral exanthema were analyzed. Elevated levels of FASL were detected not only in TEN patients but also in sera and lesional skin of patients with MPR. In contrast, sFASL was repeatedly negative in all viral exanthemas and healthy controls tested. Thus, determination of sFASL serum concentration may represent a discriminating tool between drug rashes and viral exanthemas.

Elevated levels of soluble Fas (APO-1, CD95), soluble Fas ligand, and matrix metalloproteinase-3 in sera from patients with active untreated adult onset Still’s disease

To investigate serum levels of soluble Fas (sFas), soluble Fas ligand (sFas-L), and matrix metalloproteinase-3 (MMP-3) in patients with active untreated adult onset Still's disease (AOSD). Serum levels of sFas, sFas-L, and MMP-3 were determined by enzyme-linked immunosorbent assays in 20 patients with active untreated AOSD, 20 patients with active rheumatoid arthritis (RA), and 20 healthy controls. Linear regression was used to evaluate the correlation between clinical activity scores and serum levels of sFas, sFas-L, and MMP-3 in AOSD patients. Significantly higher levels of sFas, sFas-L, and MMP-3 in sera were found in active untreated AOSD patients compared to healthy controls. Serum levels of sFas, sFas-L, and MMP-3 correlated well with clinical activity scores of AOSD patients (r=0.467, 0.694, and 0.798, respectively). There was a significant correlation between CRP values and serum levels of sFas-L as well as MMP-3 (r=0.583 and r=0.582, respectively, both p<0.01), and a positive correlation between serum sFas-L levels and serum MMP-3 levels (r=0.726, p<0.001) in AOSD patients. Significantly higher levels of serum sFas-L were found in AOSD patients than in RA patients. Serum levels of sFas, sFas-L, and MMP-3 fluctuated and were found to be parallel to disease activity of AOSD. sFas, sFas-L, and MMP-3, which were significantly elevated in sera of active untreated AOSD patients and paralleled disease activity, may be involved in the pathogenesis of this disease. Further studies are needed to determine the pathophysiologic role of sFas, sFas-L, and MMP-3 in AOSD.

Fas and Fas ligand: Expression and soluble circulating levels in bile duct carcinoma

Alteration of the Fas receptor (Fas)-/ligand (FasL) system including their soluble forms (sFas and sFasL) is thought to be one of the mechanisms preventing the immune system from rejecting the tumor cells. We investigated the tissue expression of Fas, FasL, and the alteration of sFas and sFasL in patients with bile duct carcinoma. Thirty-four samples were immunostained for Fas and FasL, and levels of sFas and sFasL in the serum of 62 patients were determined using an enzyme-linked immunoadsorbent assay. Patients with strongly positive Fas levels showed significantly better prognosis than those with weakly positive or negative Fas levels. The mean serum levels of sFas in healthy individuals were significantly higher in patients with carcinoma. However, the mean serum levels of sFasL were significantly lower in the patients with carcinoma. Serum levels of sFas and sFasL might be a significant and independent prognostic parameter in patients with bile duct carcinoma.

Role of soluble Fas ligand in autoimmune diseases.

To investigate the role of soluble Fas ligand in autoimmune diseases. RT-PCR was performed to amplify sFasL cDNA from the total RNA extracted from activated human peripheral blood lymphocytes. DNA fragments were cloned into PCR vector. After sequenced, sFasL gene fragments were inserted into pQE-31 vector and expressed in E. Coli M15 respectively. Proteins were purified through affinity chromatography column with ligand of 6XHis tag and identified by SDS-PAGE and Western blot. Mice were immunized with sFasL protein and specific anti-serum was harvested 6 wk after immunization. Monoclonal anti-human FasL antibody was made from the immunized mice. Serum level of sFasL in different patients was detected using anti-FasL antibodies from the immunized mice. The protein expressed was 24 ku by SDS-PAGE electrophrosis. The protein was specially bound to anti-human FasL antibody by Western blot analysis. The sFasL protein could induce Jurket cell apoptosis in vitro. The concentration of serum sFasL in patients with autoimmune diseases was higher than that in normal individuals. sFasL could reduce arthritis in collagen induced arthritis (CIA) mice model by subcutaneous injection. sFasL may be involved in either induction of apoptosis or autoimmune diseases. Furthermore, sFasL may have potential application in treatment of autoimmune diseases.

Significance of serum soluble fas ligand in patients with bladder carcinoma

Objective To study the significance of serum soluble Fas ligand in patients with bladder carcinoma. Methods Sandwich enzyme linked immuno-sorbent assay (ELISA) was used to detect the level of sFasL in sera of 48 bladder carcinoma patients and 25 healthy donors. Results The level of sFasL in patients with bladder carcinoma pre-operation was 12.25 ± 1.16 μg/L. It was higher than that in patients after operation and that in healthy donors( P 0.05 ). The level of serum sFasL in patients with muscle-invasive bladder carcinoma(T_ 2～4 ) was higher than that in patients with superficial bladder carcinoma (T_ 0～1 ) ( P 0.05 ); The serum level of sFasL in patients with bladder carcinoma in grade 3 was higher that in grade1 and grade 2 bladder carcinoma respectively ( P 0.05 ). Conclusion Serum sFasL is correlated with both disease progression and increase in the tumor grade of bladder carcinoma.

Increased circulating levels of soluble Fas ligand are correlated with disease activity in patients with fibrosing lung diseases

The Fas-Fas ligand (FasL) pathway is one of the important apoptosis-signalling molecule systems. We previously determined that this pathway may be involved in the pathogenesis of fibrosing lung diseases. In the present study, we evaluated the clinical significance of the levels of soluble forms of Fas (sFas) and FasL (sFasL) in serum from patients with fibrosing lung diseases. We measured sFas, sFasL, KL-6 (a measure of alveolar type II cell damage), surfactant protein D (SP-D), and surfactant protein A (SP-A) levels in serum from 35 patients with idiopathic pulmonary fibrosis (IPF), 17 patients with interstitial pneumonia associated with collagen vascular diseases (CVD-IP), and 13 normal healthy controls using enzyme-linked immunosorbent assays (ELISA). The serum levels of sFasL were significantly increased in patients with active IPF and CVD-IP, compared with those with inactive disease and controls. There was no significant difference in sFasL levels between patients with inactive disease and controls. Serum sFasL levels were significantly correlated with lactate dehydrogenase and KL-6 levels in IPF. The decrease in sFasL levels following corticosteroid therapy was not correlated with the clinical course of IPF. There was no significant difference in serum sFas levels between IPF or CVD-IP patients and controls. Although further studies need to be performed on a large number of patients with histologically proven IPF or CVD-IP, it would seem that serum sFasL levels may reflect the activity of IPF and CVD-IP.

Soluble Fas ligand released by colon adenocarcinoma cells induces host lymphocyte apoptosis: an active mode of immune evasion in colon cancer.

Expression of membrane-bound Fas ligand (mFasL) on colon cancer cells serves as a potential mechanism to inhibit host immune function by inducing apoptosis of host lymphocytes. Membrane-bound FasL can be cleaved and released as a soluble mediator (sFasL), which may spread the apoptosis induction effect. Our study examined whether colon adenocarcinoma cells release sFasL, and induce apoptosis of host lymphocytes without direct cell–cell contact. In 12 consecutive patients with colon adenocarcinoma mFasL was identified in the tumours, sFasL was measured in the sera and apoptosis identified in tumour-infiltrating and peripheral blood lymphocytes. To analyse the function of sFasL, colon cancer cells were primarily cultured; sFasL was isolated from supernatants, measured, incubated with Fas-bearing Jurkat cells, and the resulting apoptosis was analysed. Serum levels of sFasL were significantly elevated in all colon cancer patients with mFasL expression in tumour tissues (n = 8). In these patients, the number of apoptotic lymphocytes was significantly increased within tumour and peripheral blood. Furthermore, sFasL was present in the corresponding supernatants and induced apoptosis of Jurkat cells in a dose-dependent manner. These findings suggest that mFasL-positive colon cancer cells release sFasL, and thus may induce apoptosis of host lymphocytes as a potential mechanism for immune evasion. © 2001 Cancer Research Campaignhttp://www.bjcancer.com

Increased F as ligand expression in the tumor tissue and serum of patients with testicular germ cell tumors with seminomatous elements

Objectives. To measure the expression levels of Fas and Fas ligand (FasL) in testicular germ cell tumor (TGCT) and to determine whether the serum level of soluble FasL (sFasL) could be used as a marker for patients with TGCT. Methods. The expression of Fas and FasL in 51 specimens obtained from patients with TGCT was examined by reverse transcriptase-polymerase chain reaction, and the results were confirmed by Western blot analysis. The serum levels of sFasL in 24 patients with TGCT were measured using an enzyme-linked immunosorbent assay system. Results. Of 33 TGCT specimens that included seminomatous elements, Fas and FasL was expressed in 24 (73%) and 24 (73%), respectively. On the other hand, 10 (56%) and 2 (11%) specimens expressed Fas and FasL, respectively, in 18 TGCT specimens without seminomatous elements. Moreover, the serum levels of sFasL were significantly higher in patients with TGCT with a seminomatous element than in those without it. Conclusions. These results indicate that FasL is strongly expressed in tumor tissue and is present at high levels in the serum of patients with TGCT with a seminomatous element compared with those without it and that the serum levels of sFasL could be used as a novel diagnostic marker for TGCT with seminomatous elements.

Soluble Fas ligand released by colon adenocarcinoma cells induces host lymphocyte apoptosis: an active mode of immune evasion in colon cancer

Expression of membrane-bound Fas ligand (mFasL) on colon cancer cells serves as a potential mechanism to inhibit host immune function by inducing apoptosis of host lymphocytes. Membrane-bound FasL can be cleaved and released as a soluble mediator (sFasL), which may spread the apoptosis induction effect. Our study examined whether colon adenocarcinoma cells release sFasL, and induce apoptosis of host lymphocytes without direct cell–cell contact. In 12 consecutive patients with colon adenocarcinoma mFasL was identified in the tumours, sFasL was measured in the sera and apoptosis identified in tumour-infiltrating and peripheral blood lymphocytes. To analyse the function of sFasL, colon cancer cells were primarily cultured; sFasL was isolated from supernatants, measured, incubated with Fas-bearing Jurkat cells, and the resulting apoptosis was analysed. Serum levels of sFasL were significantly elevated in all colon cancer patients with mFasL expression in tumour tissues (n = 8). In these patients, the number of apoptotic lymphocytes was significantly increased within tumour and peripheral blood. Furthermore, sFasL was present in the corresponding supernatants and induced apoptosis of Jurkat cells in a dose-dependent manner. These findings suggest that mFasL-positive colon cancer cells release sFasL, and thus may induce apoptosis of host lymphocytes as a potential mechanism for immune evasion. © 2001 Cancer Research Campaign http://www.bjcancer.com

Significance of serum soluble Fas ligand in patients with bladder carcinoma.

The interaction of Fas and Fas ligand (FasL) plays an important role in cytotoxic T-lymphocyte-mediated and natural killer cell-mediated apoptosis against tumor cells. Circulating soluble FasL (sFasL) has been suggested to provide protection from Fas-mediated apoptosis. The current study examined this possibility in patients with bladder carcinoma. The levels of sFasL in the serum of 163 patients with bladder carcinoma were determined using an enzyme-linked immunoadsorbent assay. Antiautologous tumor cytotoxic activity was assessed by the 12-hour chromium isotope ((51)Cr) release assay. The mean serum level of sFasL in patients with bladder carcinoma was 2.5-fold higher than that in healthy donors. The level of serum sFasL in patients with muscle-invasive bladder carcinoma was 2.5-fold higher than that in patients with superficial bladder carcinoma. In addition, serum sFasL levels in patients with T1 and Tis bladder carcinoma was 2-fold and 2.7-fold higher, respectively, than levels in patients with Ta bladder carcinoma. The serum level of patients with sFasL in Grade 3 bladder carcinoma were 2.4-fold and 1.7-fold higher than that in patients with Grade 1 and Grade 2 bladder carcinoma, respectively. Patients with Ta bladder carcinoma with a low level of serum sFasL (less than the median value) had a longer postoperative tumor-free interval than patients with a high sFasL level (greater than the median value) in the 5-year follow-up. There was an apparent inverse correlation between the level of serum sFasL and antiautologous tumor cytotoxic activity. The results of the current study demonstrated that the level of serum sFasL is correlated with both disease progression and increase in the tumor grade, and that an elevated serum sFasL level predicted early recurrence in patients with Ta bladder carcinoma. These findings suggest that elevated serum sFasL levels might be associated with a greater risk of disease progression and recurrence in patients with bladder carcinoma.

Circulating levels of soluble Fas ligand and soluble Fas in patients with chronic obstructive pulmonary disease

Fas- and tumour necrosis factor (TNF) receptor-mediated apoptosis are known to be two principal apoptotic mechanisms in humans. Although there are several distinctions between these two systems, in vitro studies have demonstrated similar hypoxic activation and a functional relationship. Since patients with chronic obstructive pulmonary disease (COPD) show chronic hypoxaemia and the activation of the TNF- α system, we investigated whether these pathophysiological changes influence the Fas–Fas ligand system. We measured the circulating soluble Fas ligand (sFas-L) level, an inducer of apoptosis, and the soluble Fas receptor (sFas) level, an inhibitor of apoptosis, in 34 COPD patients and 35 age-matched healthy controls. In addition, we investigated the relationships between the levels of sFas-L or sFas and clinical variables including the TNF- α system; circulating TNF- α and soluble TNF-receptor (sTNF-Rs: sTNF-R55 and R75) levels, in the COPD patients. Although circulating TNF- α, sTNF-R55 and R75 levels were significantly higher in the COPD patients than in the healthy controls, serum level of sFas-L (Fisher's exact probability test;P=0·26) and plasma level of sFas [COPD patients vs. controls; mean (SD); 3·74 (0·63) vs. 3·67 (0·48) ng/ml;P=0·89) were not increased in the COPD patients. There was no significant correlation between the levels of sFas-L or sFas and clinical variables in COPD patients. These results suggest that the Fas–Fas ligand system does not independently play an important role in the pathophysiology of patients with COPD.

Soluble Fas/Apo-1 (CD95) levels during T cell activation in the presence of acute myelogenous leukemia accessory cells; contributions from local release and variations in systemic levels.

Fas (CD95/Apo-1) exists both in membrane-bound and in biologically active soluble (s) forms. Ligation of membrane-expressed Fas can induce apoptosis, and Fas-mediated signaling seems to be involved in T-cell-induced apoptosis of human acute myelogenous leukemia (AML) blasts. The local release of sFas by AML blasts may then function as a protective mechanism by competing with membrane-bound Fas for binding sites on the common Fas ligand (FasL). sFas was released by AML blasts during in vitro culture, and this release was modulated by several cytokines that can be secreted by activated T cells. Increased levels of sFas could be detected during in vitro activation of T cells in the presence of native AML accessory cells, and this was observed both for (i) mitogenic activation of CD4+ and CD8+ T cell clones derived from acute leukemia patients with therapy-induced leukopenia and (ii) allostimulated activation of T cells derived from normal donors. However, local in vivo levels of sFas will also be influenced by variations in systemic levels. High serum levels of sFas were detected in acute leukemia patients during chemotherapy-induced cytopenia, but these levels decreased during complicating bacterial infections. In contrast, serum levels of sFasL were normal in leukopenic patients. The present results support the hypothesis that local release of sFas can function as a protective mechanism against AML-reactive T cells, but the effects of this local release are, in addition, modulated by variations in systemic levels of sFas (but not sFasL).

Serum levels of soluble Fas ligand in patients with acute and fulminant hepatitis: relationship with soluble Fas, tumor necrosis factor α and TNF receptor-1

We measured the serum levels of soluble Fas ligand (sFasL) using a newly developed ELISA system in patients with acute hepatitis (AH), acute severe hepatitis (ASH) and fulminant hepatitis (FH). In addition, we also evaluated the relationship between the serum levels of sFasL, soluble Fas (sFas), soluble tumor necrosis factor α (sTNFα), and soluble TNF receptor-1 (sTNFR1). The median serum sFasL level was significantly increased in patients with acute liver disease compared to that in normal subjects; however, there were no significant differences among patients with AH, ASH, and FH. The serum sFasL levels varied according to the cause of hepatitis and were particularly high in patients with hepatitis A viral infection. On the other hand, the median serum sFas level was also significantly increased in patients with acute liver disease compared to that in normal subjects; however, there were no significant differences among patients with the three clinical forms or various causes of hepatitis. The serum sFasL levels decreased rapidly following improvement in liver functions, whereas the serum sFas levels decreased more gradually and remained abnormally high even at follow-up. The serum sFasL levels were not correlated with the levels of serum transaminases or sFas, but were significantly correlated with those of sTNFα ( r=0.483, P<0.001) and sTNFR1 ( r=0.324, P<0.05). On the other hand, serum sFas levels were significantly correlated with those of sTNFR1 ( r=0.319, P<0.05) alone. Our results suggest that the serum sFasL level increases in the acute phase of hepatitis and the level varies according to the cause of hepatitis. Our findings also suggest that the Fas-FasL system and cytokine networks may be closely associated with early process of hepatic necrosis.

Soluble Fas ligand expression in the ocular fluids of uveitis patients

Purpose. The expression of Fas ligand (FasL) in ocular tissues is thought to play a critical role in maintaining immune privilege in the eye. In this study, to clarify the involvement of the Fas-FasL system in inflammatory processes of the eye,we examined soluble FasL (sFasL) in ocular inflammation. Methods. Using ELISA systems recently developed, sFasL concentrations in aqueous humor (AH) and/or vitreous fluid (VF) were measured. AH was obtained from 17 eyes of 17 uveitis patients and from 12 eyes of 12 non-uveitis (cataract) patients. VF was obtained from 22 eyes of 22 uveitis patients and 7 eyes of 7 non-uveitis (macular hole) patients. Serum levels of sFasL were also determined. Results. sFasL in AH and VF was below the detection limit of the ELISA systems in all non-uveitis eyes. On the other hand, sFasL was detected in AH from uveitis patients where it measured 367.0 ± 154.7 pg/ml (mean ± SEM). sFasL was also detected in VF from uveitis patients where it measured 1132.2 ± 281.7 pg/ml. None of the sera from patients with or without uveitis contained a detectable level of sFas L. Conclusions. sFasL levels in AH and VF are elevated in the eye during ocular inflammation. Fas-FasL mediated apoptosis may play an important role in the regulation of inflammation during uveitis.