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)

This study was performed to observe the therapeutic effects of interferon-gamma(IFN-gamma) and gamma-globulin(gamma-globulin) in experimental Pneumocystis carinii pneumonia of immune suppressed mice. After 9 weeks, trimethoprim-sulfamethoxazole(TMP-SMZ; 10-50 mg/mouse/day), mouse IFN-gamma(5 x 10(4) units/mouse/day) and mouse gamma-globulin(20 mg/mouse/day) were administered to the mice for 3 weeks by the experimental group. The therapeutic efficacy was evaluated by body weights, histopathologic and electron microscopic findings of the lungs, and number of P. carinii cysts by Gomori's methenamine silver stain. Body weights of the mice were significantly increased in the group of combination therapy of TMP-SMZ with IFN-gamma or gamma-globulin, and in the group of TMP-SMZ treatment (p < 0.05), however, little effect was found in the group of gamma-globulin alone. Histopathologic findings of P. carinii pneumonia were much improved in the group of combination therapy of TMP-SMZ with IFN-gamma. Treatment with either TMP-SMZ or IFN-gamma significantly reduced the number of cysts in the P. carinii pneumonia, but gamma-globulin alone was ineffective. In electron microscopic findings of P. carinii pneumonia, the number of trophozoites and cysts were reduced by treatment with either TMP-SMZ or IFN-gamma, and most of the cysts were empty or containing one or two intracystic bodies. The present results suggested, that combination therapy of TMP-SMZ with IFN-gamma had synergistic effects in treatment of P. carinii pneumonia in experimental mice.
Drug-Synergism ; Drug-Therapy,-Combination ; English-Abstract ; Gamma-Globulins-administration-and-dosage ; Interferon-Type-II-administration-and-dosage ; Mice- ; Trimethoprim-Sulfamethoxazole-Combination-administration-and-dosage ; *Gamma-Globulins-therapeutic-use ; *Interferon-Type-II-therapeutic-use ; *Pneumonia,-Pneumocystis-carinii-therapy ; Gamma-Globulins ; Trimethoprim-Sulfamethoxazole-Combination ; Interferon-Type-II

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

The avoidance of incriminated foods is one of the principal therapies for atopic dermatitis (AD). Recently, interferon (IFN)-gamma therapy has been tried in AD with limited success. The necessity of diet therapy for the success of IFN-gamma therapy in AD was evaluated. A total of 524 AD patients participated in this study and 316 patients among them were entered into open food challenge tests. As the first step, an elimination diet was administered to 43 AD patients and 30 AD patients were enrolled as an untreated control group. As the second step, 45 AD patients were treated by both IFN-gamma therapy and elimination diet alone, 30 AD patients by elimination diet alone, 50 AD patients by IFN-gamma therapy, and 43 AD patients as controls. Clinical severity reduced significantly by using only the elimination diet in 58.1% patients with varying degrees of AD. Elimination diet improved the clinical results of IFN-gamma therapy in AD. In regard to the food challenge test, 77.8% of AD patients showed an adverse reaction to at least one food. Diet therapy itself had therapeutic effects on AD and an elimination diet might be essential for the success of IFN-gamma therapy in AD.
Adolescence ; Adult ; Child ; Child, Preschool ; Dermatitis, Atopic/drug therapy* ; Dermatitis, Atopic/diet therapy* ; Female ; Food Hypersensitivity/diet therapy ; Human ; Interferon Type II/therapeutic use* ; Male ; Treatment Outcome

Proliferative enteropathy was reproduced in IFN-gamma receptor knockout (IFN-gamma R-) mice by experimental infection with Lawsonia intracellularis (L. intracellularis). The cecum and the colon of the infected mice were evidently enlarged 2 weeks post infection. The presence of L. intracellularis was identified in the stool and the cecum of the mice after infection. However, high levels of IFN-gamma were detected in the sera of the infected mice 2 weeks PI. These data indicated that the IFN-gamma produced in the infected mice should have been utilized by it's receptor to elicit protective immune responses against L. intracellularis infections.
Animals ; DNA, Viral ; Desulfovibrionaceae Infections/*immunology/microbiology ; Interferon Type II/*immunology ; Intestinal Diseases/*immunology/microbiology ; Intestinal Mucosa/immunology ; Lawsonia Bacteria/*immunology/isolation&purification ; Mice ; Mice, Knockout ; Polymerase Chain Reaction ; Receptors, Interferon/physiology

BACKGROUNDAlthough the onset of anemia during infectious disease is commonly correlated with production of inflammatory cytokines, the mechanisms by which cytokines induce anemia are poorly defined. This study focused on the mechanism research.

METHODSDifferent types of mice were infected perorally with Toxoplasma gondii strain ME49. At the indicated times, samples from each mouse were harvested, processed, and analyzed individually. Blood samples were analyzed using a Coulter Counter and red blood cell (RBC) survival was measured by biotinylation. Levels of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), and inducible protein 10 (IP-10) mRNA in liver tissue were measured by real-time polymerase chain reaction.

RESULTST. gondii-infected mice exhibited anemia due to a decrease in both erythropoiesis and survival time of RBC in the circulation (P < 0.02). In addition, infection-stimulated anemia was associated with fecal occult, supporting previous literature that hemorrhage is a consequence of T. gondii infection in mice. Infection-induced anemia was abolished in interferon gamma (IFNγ) and IFNγ receptor deficient mice (P < 0.05) but was still evident in mice lacking TNF-α, iNOS, phagocyte NADPH oxidase or IP-10 (P < 0.02). Neither signal transducer and activator of transcription 1 (STAT1) deficient mice nor 129S6 controls exhibited decreased erythropoiesis, but rather suffered from an anemia resulting solely from increased loss of circulating RBC.

CONCLUSIONSInfection-stimulated decrease in erythropoiesis and losses of RBC have distinct mechanistic bases. These results show that during T. gondii infection, IFNγ is responsible for an anemia that results from both a decrease in erythropoiesis and a STAT1 independent loss of circulating RBC.

Anemia ; genetics ; metabolism ; Animals ; Erythrocytes ; pathology ; Interferon-gamma ; metabolism ; Male ; Mice ; Mice, Knockout ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Receptors, Interferon ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; Toxoplasma ; pathogenicity ; Tumor Necrosis Factor-alpha ; genetics ; metabolism

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

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*

OBJECTIVETo investigate the effect of interferon regulatory factors (IRFs) on neointimal formation after vascular injury in the mouse, and its possible mechanism.

METHODSVascular injury was induced by polyethylene cuff placement around the left femoral artery of IRF-1-deficient mice and C57BL/6J mice. The mRNA expressions of IRF-1, IRF-2, angiotensin II type 2 (AT2) receptor, interleukin-1 beta converting enzyme (ICE), inducible nitric oxide synthase (iNOS) were detected by RT-PCR and immunohistochemical staining.

RESULTSNeointimal formation after vascular injury was significantly greater in IRF-1-deficient mice than that in C57BL/6J mice (P<0.05). In contrast, TUNEL-positive nuclei to total nuclei in the neointima and media in vascular smooth muscle cell (VSMC) in the injured artery significantly attenuated in IRF-1-deficient mice compared to C57BL/6J mice (P<0.05). The expressions of AT2 receptor as well as pro-apoptotic genes such as ICE and iNOS in C57BL/6J mice were up-regulated in response to vascular injury, but this upregulation was attenuated in IRF-1-deficient mice.

CONCLUSIONSOur results suggest that IRF-1 induces VSMC apoptosis and inhibits neointimal formation after vascular injury at least partly due to the upregulation of AT2 receptor, ICE and iNOS expressions. These results indicate that IRF-1 exerts an inhibitory effect on neointimal formation through the induction of apoptosis in VSMCs.

Animals ; Apoptosis ; physiology ; Caspase 1 ; genetics ; metabolism ; Femoral Artery ; anatomy & histology ; pathology ; Interferon Regulatory Factor-1 ; genetics ; metabolism ; Interferon Regulatory Factor-2 ; genetics ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Muscle, Smooth, Vascular ; cytology ; metabolism ; pathology ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; Receptor, Angiotensin, Type 2 ; genetics ; metabolism ; Tunica Intima ; pathology ; physiology

We have investigated in vitro proliferative responses of peripheral blood mononuclear cells and productions of interferon-gamma and soluble interleukin-2 receptors by these cells from 6 patients with chronic active hepatitis B immediately before and 24 hours after a single intravenous injection of 100 mg of polyadenylic.polyuridylic acid. Cell proliferations were assessed by the technique of tritiated-thymidine incorporation and productions of interferon-gamma and soluble interleukin-2 receptors were measured by enzyme-linked immunosorbent assay. The administration of polyadenylic.polyuridylic acid to the patients has resulted in significant increases of in vitro proliferations of their peripheral blood mononuclear cells as well as productions of interferon-gamma by these cells. However, in vitro productions of soluble interleukin-2 receptors were not changed significantly. These results suggest that the enhanced cellular responses by polyadenylic.polyuridylic acid might be due to the increased sensitivity rather than the increased expression of cellular interleukin-2 receptor.
Adult ; Hepatitis B/*immunology ; Hepatitis, Chronic/*immunology ; Human ; Immunity, Cellular/drug effects ; Interferon Type II/biosynthesis ; Leukocytes, Mononuclear/*drug effects/immunology ; Male ; Middle Age ; Poly A-U/*pharmacology ; Receptors, Interleukin-2/biosynthesis ; Solubility