Tumor immunity is primarily mediated by cells as CD8+ cytotoxic T lymphocytes (CTL) recognize tumor antigen by MHC class I molecules. But most tumors are associated with a decreased expression of MHC class I to escape the antitumor immunity of the host. Our previous data have demonstrated that MPL has an antitumor effect on metastatic lung cancer of B16 melanoma with enhancing cytotoxicity due to increase of IFN-gamma and IL-2, and decrease of IL-4, which indicates the stimulation of type 1 helper T cells (Th1). To determine the effects of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha on MHC class I expression of B16 melanoma cells, we evaluated the expression of MHC class I molecules with treatments of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha by flow cytometry. The supernatant of MPL-treated spleen cells in vitro upregulated the expression of MHC class I molecules of B16 melanoma cells compared to the control supernatant of spleen cells. The MHC class I expression of B16 melanoma cells treated with IFN-gamma, but not TNF-alpha or IL-1 alpha, increased in a time-dependent manner. In conclusion, MPL upregulated MHC class I expression of B16 melanoma cells by activating spleen cells via IFN-gamma. These data suggest that increased IFN-gamma by MPL is responsible for the upregulation of MHC class I expression to augment cytotoxicity. Therefore, we suggest that MPL could play an important role in immunotherapy.
Adjuvants, Immunologic/pharmacology* ; Animal ; Histocompatibility Antigens Class I/biosynthesis* ; Interferon Type II/pharmacology ; Interferon Type II/biosynthesis* ; Lipid A/pharmacology ; Lipid A/analogs & derivatives* ; Mice ; Mice, Inbred C57BL ; Tumor Cells, Cultured ; Up-Regulation (Physiology)

A soluble factor which augments the expression of major histocompatibility complex class I (MHC I) antigens on a number of murine tumor cell lines, has been isolated from the culture supernatants of mixed lymphocyte reaction of spleen cells derived from C57B1/6, Balb/c and Swiss mice. The factor, termed MHC-augmenting factor (MHC-AF) has been partially purified by Sephadex G-100 column chromatography and reverse phase HPLC. MHC-AF activity is associated with an 18 kDa molecule. MHC-AF activity was resistant to pH 2.0 treatment and partially purified MHC-AF preparations did not have any activity in L929 cell/vesicular stomatitis virus (VSV) interferon bioassay system. Antibodies to IFN-gamma did not block the activity of MHC-AF. These results indicate that a MHC-AF distinct from IFN-gamma, is produced by mouse spleen cells undergoing a mixed lymphocyte reaction.
Animal ; Antibodies/pharmacology ; Chymotrypsin/metabolism ; Chymotrypsin/chemistry ; Comparative Study ; Concanavalin A/pharmacology ; Heat ; Histocompatibility Antigens Class I/metabolism* ; Histocompatibility Antigens Class I/drug effects ; Interferon Type II/pharmacology ; Interferon Type II/metabolism ; Interferon Type II/immunology ; Lymphocytes/physiology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Proteins/pharmacology* ; Proteins/metabolism ; Proteins/isolation & purification* ; Spleen/cytology ; Trypsin/metabolism ; Trypsin/chemistry ; Tumor Cells, Cultured/immunology ; Tumor Cells, Cultured/drug effects

Killer cell Ig-like receptor (KIR) binds to HLA class I molecules on the surface of target cells, and it confers inhibitory signals to NK cells. Although NK cytotoxicity can be affected by the change of the surface expression of KIR on NK cells, the effect of cytokines on the regulation of KIR expression has not been thoroughly investigated. Here in our study, we investigated the effect of several cytokines, including IL-2, TGF-beta, IFN-gamma, IL-12 and IL-18, on the surface expression of CD158 KIR, which binds to HLA-C, by the use of FACS analysis. In the isolated NK cells, IL-2 obviously increased the surface expression of CD158 KIR after 72 hr in vitro culture, and this was evidenced by the increased percentage of CD158+ NK cells and the increased mean fluorescence intensity of CD158 in CD158+ NK cells. In contrast, TGF-beta decreased the surface expression of CD158 KIR after 72 hr culture. However, IFN-gamma, IL-12 and IL-18 did not change the expression of CD158 KIR. The modulated expression of KIR by IL-2 and TGF-beta can be associated with the changed NK-cytotoxic target-discriminating ability of NK cells upon their exposure to IL-2 and TGF-beta.
Antineoplastic Agents/*pharmacology ; Cells, Cultured ; Human ; Interferon Type II/pharmacology ; Interleukin-12/pharmacology ; Interleukin-18/pharmacology ; Interleukin-2/*pharmacology ; Killer Cells/cytology/*drug effects/*metabolism ; Receptors, Immunologic/*metabolism ; Support, Non-U.S. Gov't ; Transforming Growth Factor beta/*pharmacology

The cytokine pattern on viral antigen recognition is believed to exert a profound influence on the resolution of viral infections and viral clearance. This study was initiated to investigate whether a cytokine imbalance oriented toward Th2 type response plays a role in chronic hepatitis B. Cytokine profiles of peripheral blood mononuclear cells associated with chronic hepatitis B were analysed by RT-PCR. Upon HBsAg stimulation, expression of IFN-gamma, IL-2, IL-4, and IL-10 was detected in 41%, 8%, 41%, and 50% of the patients, respectively. Among these cytokines, the expression of IFN-gamma was associated with high levels of serum AST/ALT. However, we could not prove that Th2 type cytokines had a protective effect on hepatocytes. Upon HBxAg stimulation, there was no recognizable association of cytokine patterns with AST/ALT levels. In conclusion, production of a Th1 cytokine, IFN-gamma, by HBsAg-reactive cells was associated with hepatocyte damage in chronic hepatitis B, while no counteracting effect of Th2 cytokines produced by those cells was observed.
Cytokines/genetics ; Cytokines/biosynthesis* ; Hepatitis B Surface Antigens/pharmacology ; Hepatitis B Surface Antigens/immunology* ; Hepatitis B, Chronic/immunology* ; Human ; Interferon Type II/genetics ; Interferon Type II/biosynthesis ; Leukocytes, Mononuclear/immunology ; Liver/cytology ; Recombinant Fusion Proteins/pharmacology ; Recombinant Fusion Proteins/immunology ; Th1 Cells/immunology* ; Th1 Cells/drug effects ; Th2 Cells/immunology* ; Th2 Cells/drug effects ; Trans-Activators/pharmacology ; Trans-Activators/immunology*

Two human malignant melanoma cell lines, Malme-3M and SK-Mel-28, were analyzed for their ability to induce the expression of intercellular adhesion molecule 1 (ICAM-1) and human leukocyte antigen (HLA)-DR molecules on their cell surfaces as well as at the transcriptional level before and after treatment with interferon (IFN)-gamma. Both cell lines demonstrated a high percentage(> 99%) of ICAM-1 expression regardless of IFN-gamma treatment. Before IFN-gamma treatment, Malme-3M cells barely expressed HLA-DR molecules (< 2%) and SK-Mel-28 cells demonstrated a relatively high percentage(> 50%) of HLA-DR expression. Both cell lines displayed elevated levels of HLA-DR expression in a time dependent manner after IFN-gamma treatment. However, these two cell lines have been shown to respond differentially to IFN-gamma. The molecular mechanism underlying such a differential behavior was investigated, and HLA-DR gene regulation was studied at the transcriptional level. Treatment with IFN-gamma led to the steady-state mRNA augmentation of the HLR-DR gene. The HLA-DRA mRNA augmentation was similar in both cell lines, whereas in Malme-3M, IFN-gamma did not augment the rate of transcription of the HLA-DRB gene as much as in SK-Mel-28. Data from this study established the fact that the melanoma cell lines displayed a differential susceptibility to IFN-gamma on the modulation of HLA-DR molecules, and this modulation was transcriptionally regulated.
Genes, MHC Class II ; HLA-DR Antigens/*metabolism ; Human ; Intercellular Adhesion Molecule-1/*metabolism ; Interferon Type II/*pharmacology ; Melanoma/*metabolism/pathology ; Support, Non-U.S. Gov't ; Transcription, Genetic ; Tumor Cells, Cultured

OBJECTIVETo investigate the vascular effect of acute and chronic treatment of interferon-alpha (IFN-alpha) in rat aortic rings.

METHODSIsolated thoracic aortic rings were mounted on the organ bath and the tension of the vessel was recorded.

RESULTSIFN-alpha(10, 100, 1,000 and 10,000 U/ml) caused concentration -dependent relaxation of endothelium-intact aorta rings preconstricted with phenylephrine (PE,10(-6)mol/L), to(90.1+/-0.91)%, (65.1+/-5.21)%, (39.5+/-8.22)% and (35.3+/-8.27)% of pre-drug control, respectively. Removal of the endothelium inhibited the relaxation by IFN-alpha. The vasorelaxant effect of IFN-alpha (100 U/ml ) was attenuated by pretreatment with L-NAME (10(-4)mol/L), methylene blue (10(-5)mol/L) or AMG (10(-4)mol/L), to (97.2+/-5.34)%, (95.1+/-6.25)% and (93.7+/-8.82)% of the control, respectively. Pretreatment with IFN-alpha (1,000,000 U/d, i.p.) for five days markedly inhibited the endothelium-dependent relaxation of the aortic rings to acetylcholine. But the endothelium-dependent relaxation to acetylcholine was not changed by pretreatment of IFN-alpha (10,000 U/ml) with the isolated aorta rings for 2 h.

CONCLUSIONThe vasorelaxation induced by IFN-alpha in rat aorta rings is endothelium-dependent and is possibly mediated by inducible nitric oxide synthase. Chronic treatment of IFN-alpha may impair the endothelium or NO-sGC pathway.

Acetylcholine ; pharmacology ; Animals ; Aorta, Thoracic ; drug effects ; physiology ; Endothelium, Vascular ; physiology ; Guanylate Cyclase ; physiology ; Interferon-alpha ; pharmacology ; Male ; Nitric Oxide ; physiology ; Nitric Oxide Synthase ; physiology ; Nitric Oxide Synthase Type II ; Phenylephrine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Vasodilation ; drug effects

TNF-related apoptosis inducing ligand (TRAIL) expressions were studied in primary human brain astrocytes in response to pro-inflammatory cytokines. When astrocytes were treated with IL-1beta TNF-alphaor IFN-gamma TRAIL was induced in cultured fetal astrocytes. In particular, IFN-gammainduced the highest levels of TRAIL in cultured astrocytes. When astrocytes were pre-reated with IFN-gamma they induced apoptosis in TRAIL-sensitive Peer cells. Our results suggest that IFN-gamma modulates the expression of TRAIL in astrocytes, which may enhance cytotoxic sensitivity of infiltrating immune cells or brain cells other than astrocytes during inflammation of brain.
Tumor Necrosis Factor-alpha/genetics/*metabolism ; TNF-Related Apoptosis-Inducing Ligand ; Membrane Glycoproteins/genetics/*metabolism ; Interferon Type II/*pharmacology ; Humans ; Cells, Cultured ; Astrocytes/*cytology/drug effects/metabolism ; Apoptosis Regulatory Proteins/genetics/*metabolism ; Apoptosis/*drug effects/physiology ; Antineoplastic Agents/*pharmacology

TNF-related apoptosis inducing ligand (TRAIL) expressions were studied in primary human brain astrocytes in response to pro-inflammatory cytokines. When astrocytes were treated with IL-1beta TNF-alphaor IFN-gamma TRAIL was induced in cultured fetal astrocytes. In particular, IFN-gammainduced the highest levels of TRAIL in cultured astrocytes. When astrocytes were pre-reated with IFN-gamma they induced apoptosis in TRAIL-sensitive Peer cells. Our results suggest that IFN-gamma modulates the expression of TRAIL in astrocytes, which may enhance cytotoxic sensitivity of infiltrating immune cells or brain cells other than astrocytes during inflammation of brain.
Tumor Necrosis Factor-alpha/genetics/*metabolism ; TNF-Related Apoptosis-Inducing Ligand ; Membrane Glycoproteins/genetics/*metabolism ; Interferon Type II/*pharmacology ; Humans ; Cells, Cultured ; Astrocytes/*cytology/drug effects/metabolism ; Apoptosis Regulatory Proteins/genetics/*metabolism ; Apoptosis/*drug effects/physiology ; Antineoplastic Agents/*pharmacology

Phagocytosis of serum- and IgG-opsonized zymosan (SOZ and IOZ, respectively) particles into J774A.1 macrophages induced apoptosis of the cells, accompanied by the expression of p21(WAF1), one of cyclin-dependent protein kinase (CDK) inhibitors. Furthermore, phagocytosis of SOZ and IOZ particles into macophages induced superoxide formation. Tat-superoxide dismutase (SOD), which is readily transduced into the cells using Tat-domain, protected the cells from the apoptosis induced by phagocytosis of SOZ and IOZ particles. lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma) also caused the apoptosis of the cells. However, Tat-SOD could not protect the cells from LPS/IFN-gamma induced apoptosis, suggesting that apoptosis mechanisms involved are different from each other. In the present study, we determined the amounts of nitric oxide (NO) produced by SOZ, IOZ, and LPS/IFN-gamma, and found that SOZ and IOZ did not induce the generation of NO in macrophages, whereas LPS/ IFN-gamma did. The apoptosis due to phagocytosis was accompanied with the release of cytochrome c from mitochondrial membrane to cytosolic fraction. Furthermore, SOZ and IOZ induced the cleavage of procasapase-3 (35 kDa) to give rise to an active caspase-3 (20 kDa), which was blocked by Tat- SOD but not by 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO), a scavenger of NO. On the other hand, LPS/IFN-gamma caused the activation of procaspase-3, which was blocked by PTIO but not by Tat-SOD. Taken together, phagocytosis of SOZ and IOZ particles induced apoptosis through superoxide but not NO in macrophages, accompanied with the release of cytochrome c and the activation of caspase-3.
Apoptosis/*immunology ; Caspases/metabolism ; Cell Line ; Cyclins/biosynthesis ; Cytochromes c/metabolism ; Immunoglobulin G/*immunology ; Interferon Type II/pharmacology ; Lipopolysaccharides/pharmacology ; Macrophages/*immunology/metabolism ; Nitric Oxide/*metabolism ; Opsonins/immunology ; Phagocytosis/*physiology ; Superoxide Dismutase/metabolism ; Superoxides/*metabolism ; Zymosan

Receptor activator of NFkappaB ligand (RANKL) is known as a key regulator of osteoclastogenesis. However, the fact that fibroblasts and periodontal ligament cells express RANKL in response to bacterial substances, suggests that RANKL may have evolved as a part of the immunity to infection. As RANKL increases the survival and activity of dendritic cells, it may have similar effects on macrophages. To address this issue, we studied the effect of RANKL on various functions of macrophages using mouse bone marrow derived macrophages. RANKL enhanced the survival of macrophages and up-regulated the expression of CD86. RANKL-treated macrophages showed increased allogeneic T cell activation and phagocytic activity compared to control cells. In addition, RANKL increased the expression of TNFalpha, MCP-1, and IL-6 but not of IL-10, IL-12, IFN-gamma, and iNOS. Collectively, RANKL augmented the activity of macrophages especially as antigen presenting cells, suggesting its new role in immune regulation.
Animals ; Antigen-Presenting Cells/cytology/*drug effects/immunology/*metabolism ; Antigens, CD86/metabolism ; Carrier Proteins/*pharmacology ; Cell Death/drug effects ; Cell Survival/drug effects ; Cells, Cultured ; Cytokines/metabolism ; Flow Cytometry ; Histocompatibility Antigens Class II/metabolism ; Inflammation Mediators ; Interferon Type II/pharmacology ; Lipopolysaccharides/pharmacology ; Macrophages/cytology/*drug effects/immunology/*metabolism ; Membrane Glycoproteins/*pharmacology ; Mice ; Mice, Inbred C57BL ; Mice, Inbred ICR ; Nitric Oxide Synthase Type II/metabolism ; Phagocytosis/drug effects ; Research Support, Non-U.S. Gov't ; T-Lymphocytes/immunology/metabolism ; Up-Regulation/drug effects/genetics