CD43 (sialophorin, leukosialin) is a heavily sialylated surface protein expressed on most leukocytes and platelets including T cells. Although CD43 antigen is known to have multiple and complex structure, exact function of CD43 in each cell type is not completely understood. Here we evaluated the role of CD43 in Fas (CD95)-induced cell death in human T lymphoblastoid cell line, Jurkat. Crosslinking CD43 antigen by K06 mAb increased the Fas-mediated Jurkat cell apoptosis and the augmentation was inhibited by treatment with caspase inhibitors. Further, CD43 signaling of Jurkat cells induced Fas oligomerization on the cell surfaces implying that CD43 ligation have effects on early stage of Fas-induced T cell death. These also suggest that CD43 might play an important role in contraction of the immune response by promotion of Fas-induced apoptosis in human T cells.
Receptor Aggregation/immunology ; Jurkat Cells ; Humans ; Caspases/metabolism ; Apoptosis/*immunology ; Antigens, Surface/metabolism ; Antigens, CD95/metabolism/*physiology ; Antigens, CD43/metabolism/*physiology ; Antibodies, Monoclonal/metabolism

Apoptosis is responsible for the loss of thyrocytes in autoimmune thyroiditis. Recent investigations into the pathogenesis of apoptosis have revealed that the important roles of suicide molecules expression on both thyrocytes and cytotoxic T-lymphocytes. To study the mechanism of thyrocyte loss in various forms of thyroiditis, we evaluated in situ expression patterns of CD40, Fas, and Fas-L on thyrocytes and infiltrating inflammatory cells by immunohistochemical staining of thyroid samples obtained from 49 patients (Graves' disease, n=10 : Hashimoto's thyroiditis, n=14; nonspecific lymphocytic thyroiditis, n=11; subacute granulomatous thyroiditis, n=11; normal, n=3). The role of cytotoxic T-lymphocytes was also evaluated by analyzing the expression of granzyme B along with their phenotypic characteristics. CD40 was not expressed on thyrocytes of normal controls while they showed a diffuse expression of Fas and a scattered focal expression of Fas-L. The plump thyrocytes proximal to the inflammatory infiltrates showed more intense expressions of these three molecules in various forms of thyroiditis and a close correlation was found between CD40 and Fas-L expression on thyrocytes. Unlike Fas, which was expressed on infiltrating lymphocytes in all groups, Fas-L was not expressed on infiltrating lymphocytes, except those in subacute granulomatous thyroiditis. Granzyme B expressing activated cytotoxic T-lymphocytes occupied a negligible proportion of CD8+ T-lymphocytes in various forms of thyroiditis, and no difference was found in terms of their proportions according to the type of thyroiditis. These results show the acquisition of CD40, Fas and Fas-L molecules on thyrocytes proximal to inflammatory cell aggregates and the negligible expression of granzyme B and Fas-L on the infiltrating lymphocytes, and suggest that Fas and Fas-L mediated apoptosis of thyrocytes (fratricide) may be more important than T cell-mediated cytotoxicity in various forms of thyroiditis.
Antigens, CD40/*metabolism ; Antigens, CD95/metabolism ; Apoptosis/*physiology ; Graves' Disease/*metabolism/pathology ; Human ; Membrane Glycoproteins/metabolism ; Reference Values ; Thyroiditis, Autoimmune/*metabolism/pathology

Neutrophils are also known to acquire the characteristics of dendritic cells (DCs) under the appropriate conditions. In this study, neutrophils were cultivated in vitro in the presence or absence of compounds modulating their survival in an attempt to characterize the expression profile of the DC markers. Higher MHC-II, CD80, CD86, CD83, and CD40 expression levels were detected on the surface of the cultured neutrophils for 24 h than on the freshly isolated cells. The annexin V-positive cells showed a higher expression level of the DC markers than the annexin V-negative cells. The population of neutrophils double stained with annexin V and the DC markers increased after being incubated with agonistic anti-Fas Ab. LPS, the anti-apoptotic compound, decreased the CD86 and MHC-II expression levels but 50-60% of the DC marker-positive cells were detected in the annexin V-positive cells. In contrast, CD80, CD86, CD83, and HLA-DR mRNA levels increased in the GM-CSF-treated neutrophils but not in the anti-Fas Ab-treated neutrophils. T cell proliferation was inhibited by co-culturing them with anti-Fas Ab- or LPS-treated neutrophils at a high neutrophil:T cell ratio. However, the superantigen-mediated T cell proliferation was increased by the LPS-treated neutrophils but decreased by the anti-Fas Ab-treated neutrophils. There was a lower level of interferon-gamma production in the T cells co-cultured with anti-Fas Ab-treated neutrophils than with the LPS-treated neutrophils. This suggests that apoptotic neutrophils express DC markers on their surface and the differential expression of DC markers might have a detrimental effect on the immune reaction.
Antigen Presentation ; Antigens, CD/biosynthesis ; Antigens, CD95/pharmacology ; Antigens, Differentiation/*biosynthesis ; *Apoptosis ; Cells, Cultured ; Dendritic Cells/*metabolism ; Humans ; Lipopolysaccharides/pharmacology ; Lymphocyte Activation ; Neutrophils/*metabolism/physiology ; T-Lymphocytes/immunology

The cell-surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34+ cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF + FL could up-regulate the expression of CD95 in vitro culture and tumor necrosis factor-alpha (TNF-alpha) and interon-gamma (IFN-gamma) further increased the CD95 expression induced by positive cytokines. The functional status of CD95-mediated apoptosis were analyzed by incubation of CD34+ CB cells in the presence of anti-CD95 monoclonal antibodies (McAbs). The effects of anti-CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU-C assays. A decrease of viable cells, CFU-C and LTIC numbers were observed in the presence of anti-CD95 McAbs and TNF-alpha or IFN-gamma. However, growth factor deprivation or the early-acting cytokine such as SCF and FL cross-linking to CD95 caused low apoptosis of CD34+ cells. The correlation of increased intracytoplasmic levels of bcl-2 and the presence of CD95 on fresh CB CD34+ cells suggested that bcl-2 might be involved in protecting against CD95-mediated apoptosis of CB CD34+ cells.
Antigens, CD34 ; Antigens, CD95/*metabolism ; Apoptosis ; Fetal Blood/*cytology ; Hematopoiesis ; Hematopoietic Stem Cells/*metabolism ; Leukocytes, Mononuclear/metabolism ; Proto-Oncogene Proteins c-bcl-2/*metabolism

Various cytokines and chemokines play a role in carcinogenesis. However, no study has previously been undertaken to investigate comprehensively the expressions of cytokines and chemokines in hepatoma cells. In this study, we determined which cytokines and chemokines are expressed in hepatoma cells. Recently, it was reported that the expressions of several chemokines could be increased by Fas stimulus in many normal and cancer cells. Therefore, we also investigated whether chemokines expression is regulated by Fas ligation. To address this issue, we performed RNase protection assays upon 13 cytokines and 8 chemokines genes in 10 human hepatoma cell lines, comprising 8 hepatitis B virus (HBV)-associated hepatoma cell lines. Transforming growth factor-beta2 (TGF-beta2) was found to be expressed in 8 HBV-associated hepatoma cell lines, and to be potently expressed in 5 cell lines; however, the mRNA expressions of interleukin-10 (IL-10), IL-12, interferon-gamma(IFN-gamma) and tumor necrosis factor-alpha(TNF-alpha) were not detected in any cell lines examined. Among the chemokines investigated in this study, IL-8 was expressed by 8 HBV- associated hepatoma cell lines, and monocyte chemoattractant protein-1 (MCP-1) by 7 HBV-associated hepatoma cell lines. However, the mRNA expressions of macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-beta, interferon-inducible protein-10 (IP-10), RANTES, lymphotactin and I-309 were either very weak or undetectable. Fas ligation did not increase chemokines expression in hepatoma cells. Conclusively, TGF-beta2, IL-8 and MCP-1 were overexpressed in HBV-associated hepatoma cells, and the expressions of chemokines were not increased by Fas ligation in human hepatoma cells.
Antigens, CD95/physiology ; Carcinoma, Hepatocellular/*metabolism ; Chemokines/*genetics ; Cytokines/*genetics ; Gene Expression Profiling ; Human ; Liver Neoplasms/*metabolism ; RNA, Messenger/analysis ; Tumor Cells, Cultured

Deregulation of soluble apoptosis stimulating fragment (sFas) plays an important role in glomerulonephritis (GN). The study assed the influence of immunosuppressive treatment on serum and urine sFas in patients with proliferative (PGN) and non-proliferative (NPGN) GN, and evaluated the potential of sFas measurements in predicting outcomes. Eighty-four patients with GN (45 males and 39 females) were included. Serum concentration (ng/mL) and urinary excretion (ng/mg of urinary creatinine) of sFas were measured before and after the treatment. After 12 months of therapy with steroids and cyclophosphamide, patients were divided into two subgroups according to the treatment results: Responders (R) and Non-Responders (NR). The sFas urinary excretion was reduced after treatment in both PGN and NPGN (from 17.12 +/- 15 to 5.3 +/- 4.2, P = 0.008 and from 10.11 +/- 6.1 to 3.4 +/- 3.0, P = 0.039; respectively) whereas the sFas serum concentration remained unchanged. In PGN, pre-treatment urinary sFas concentration was significantly lower in the Responders than in Non-Responders (2.3 +/- 3.1 vs 19.4 +/- 14.1, P = 0.003), and was lower still than in both R (P = 0.044) and NR (P = 0.042) subgroups with NPGN. The immunosuppressive treatment reduced sFas urinary excretion in proliferative and non-proliferative GN and results suggest that the lower urinary sFas may be linked with favorable therapy outcomes in patients with PGN.
Adult ; Antigens, CD95/blood/*urine ; Cyclophosphamide/therapeutic use ; Female ; Glomerulonephritis/*drug therapy/metabolism/pathology ; Humans ; Immunosuppressive Agents/*therapeutic use ; Male ; Middle Aged ; Steroids/therapeutic use ; Treatment Outcome

The changes of phospholipase D (PLD) activity were investigated during the courses of apoptotic process induced by tumor necrosis factor (TNF)-alpha or anti-Fas/Apo1 antibody in human premyelocyte HL-60 and murine B cell lymphoma A20 cells. The treatment of recombinant TNF-alpha to HL-60 cells resulted in the increased PLD activity as determined by the phosphatidylethanol formation in the presence of 1% ethanol. The enhancement of PLD activity was also observed in the anti-Fas/Apo1 monoclonal antibody-treated A20 cells. However, the activity of PLD was maximized when HL-60 and A20 cells were treated with either TNF-alpha or anti-Fas/Apo1 monoclonal antibody for 6 h. Both TNF-alpha and anti-Fas/Apo1 monoclonal antibody increased PLD activity in a dose-dependent manner up to 200 U/ml and 200 ng/ml, respectively. When the intracellular activity of protein kinase C (PKC) was interrupted by treatment of calphostin-C, both the PLD activation and the apoptosis induced by TNF-alpha and anti-Fas/Apo1 monoclonal antibody appeared to be inhibited. Since PKC is reported to activate PLD, the results indicate that the intracellular signaling cascade via PLD may play a role in the induction of apoptosis induced by TNF-alpha and anti-Fas/Apo1 monoclonal antibody.
Animal ; Antibodies, Monoclonal/pharmacology ; Antigens, CD95/metabolism* ; Antigens, CD95/immunology ; Apoptosis* ; DNA Fragmentation ; Dose-Response Relationship, Drug ; Enzyme Activation ; HL-60 Cells ; Human ; Leukemia, Promyelocytic, Acute ; Lymphoma, B-Cell ; Mice ; Naphthalenes/pharmacology ; Phospholipase D/metabolism* ; Protein Kinase C/antagonists & inhibitors ; Receptors, Tumor Necrosis Factor/metabolism* ; Signal Transduction ; Tumor Necrosis Factor/pharmacology*

Cyclopentenone prostaglandins (PGs) have antiproliferative activity on various tumor cell growth in vitro. Particularly, 9-deoxy-(9,12)-13,14-dihydro PGD2( delta12-PGJ2) was reported for its antineoplastic and apoptotic effects on various cancer cells, but its mechanism inducing apoptosis is still not clear. In this study, we have characterized apoptosis induced by delta12-PGJ2in HeLa cells. Treatment of delta12-PGJ2induced apoptosis as indicated by DNA fragmentation, chromatin condensation, and formation of apoptotic body. We also observed release of cytochrome c from mitochondria and activation of caspase cascade including caspase-3, -8, and -9. And the pan-caspase inhibitor z-Val-Ala-Asp (OMe) fluoromethyl-ketone (z-VAD-fmk) and Q-Val-Asp (OMe)-CH2-OPH (Q-VD (OMe)-OPH) prevented cell death induced by delta12-PGJ2 showing participation of caspases in this process. However, protein expression level of Bcl-2 family was not altered by delta12-PGJ2, seems to have no effect on HeLa cell apoptosis. And ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase 8 indicating that Fas receptor-ligand interaction was not involved in this pathway. Treatment of delta12-PGJ2 also leads to suppression of nuclear factor kappaB (NF-kappaB) as indicated by nuclear translocation of p65/RelA and c-Rel and its DNA binding ability analyzed by EMSA. Taken together, our results suggest that delta12-PGJ2-induced apoptosis in HeLa cell utilized caspase cascade without Fas receptor-ligand interaction and accompanied with NF-kappaB inactivation.
Antigens, CD95/metabolism ; Apoptosis/*physiology ; Caspases/metabolism ; Cytochromes c/*metabolism ; Hela Cells ; Human ; NF-kappa B/metabolism ; Prostaglandin D2/*analogs & derivatives/*metabolism ; Proto-Oncogene Proteins c-bcl-2/metabolism

Although the apoptosis of chondrocytes plays an important role in endochondral ossification, its mechanism has not been elucidated. In this study, we show that guanosine induces chondrocyte apoptosis based on the results of acridine orange/ ethidium bromide staining, caspase-3 activation, and sub-G1 fraction analysis. The potent inhibitory effect of dipyridamole, a nucleoside transporter blocker, indicates that extracellular guanosine must enter the chondrocytes to induce apoptosis. We found that guanosine promotes Fas-Fas ligand interaction which, in turn, leads to chondrocyte apoptosis. These findings indicate a novel mechanism for endochondral ossification via metabolic regulation.
Tumor Necrosis Factors/metabolism ; Signal Transduction/drug effects ; Receptors, Tumor Necrosis Factor/*metabolism ; Rats, Sprague-Dawley ; Rats ; Nucleoside Transport Proteins/metabolism ; Membrane Glycoproteins/metabolism ; Guanosine/*pharmacology/physiology ; Fas Ligand Protein ; Chondrocytes/*drug effects/metabolism ; Apoptosis/*drug effects ; Antigens, CD95 ; Animals

To investigate the expressions of Fas and Fas ligand (FasL) in human placenta, we studied the expressions of Fas and FasL in placenta with RT-PCR, immunoblotting and immunostaining. We observed amplified products of Fas and FasL transcripts, the band of Fas (52 kDa) and multiple bands of FasL (42-52 kDa) in pla-centa. Fas and FasL localized mainly on fetal vessels and on syncytiotrophoblasts respectively. The differential distribution of Fas and FasL in human placenta may reflect intrinsic expressions of them by trophoblasts during differentiation. The increased expression of Fas in trophoblasts may promote apoptosis of placenta in pathologic condition such as preeclampsia.
Antigens, CD95/biosynthesis/*genetics ; Fas Ligand Protein ; *Gene Expression ; Gene Expression Profiling ; Glycosylation ; Humans ; Immunoblotting/methods ; Membrane Glycoproteins/biosynthesis/*genetics ; Placenta/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Trophoblasts/cytology/metabolism