OBJECTIVEThe study was aimed to investigate the inhibitory effect and mechanism of astragaloside IV (ASI) on the activation of microglial cells.

METHODAfter pre-incubated with ASI for 2 h, microglial cells BV-2 were stimulated with interferon-γ (IFN-γ) for 1. 5 h and 24 h, respectively. Secretion of nitric oxide (NO) in the medium was measured by Griess method. Production of tumor necrosis factor alpha (TNF-α) was detected by ELISA approach. Cellular gene expressions of CD11b, TNF-α, interleukin 1β (IL-1β) and induced nitric oxide synthase (iNOS) were examined by quantitative-PCR analysis. Total and phosphorylation of STAT1, IκB and NF-κB was analyzed by Western blot method.

RESULTASI could significantly inhibit the increased secretion of TNF-α and NO from BV-2 cells upon IFN-γ stimulation (P < 0.001). Further study showed that ASI significantly down-regulated gene expression of IL-1β and TNF-α (P < 0.01, P < 0.05) and exhibited a trend to reduce that of iNOS. IFN-γ and ASI have no obvious effect on gene expression of CD11b. Moreover, ASI inhibited the phosphorylation of STAT1, IκB and NF-κB elicited by IFN-γ stimulation.

CONCLUSIONASI could restrain microglial activation through interfering STAT1/IκB/NF-κB signaling pathway, reducing gene expres- sion of IL-1β and TNF-α, and thus inhibiting the production of proinflammatory mediators such as NO and TNF-α.

Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; I-kappa B Proteins ; genetics ; metabolism ; Interferon-gamma ; genetics ; metabolism ; Mice ; NF-kappa B ; genetics ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Triterpenes ; pharmacology

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

OBJECTIVETo study possible immunobiological potential of Osmunda japonica Thunb.

METHODSImmunomodulatory effects of ethanol extracts prepared from rhizomes of O. japonica and phenolic compounds isolated from the extracts were investigated under the in vitro conditions using the rat peritoneal cells (2×10(6)/mL; 24 h culture). Biosynthesis of nitric oxide (NO) was assayed by Griess reagent, production of prostaglandin E2 (PGE2) and secretion of cytokines were determined by enzyme-linked immunoabsorbent assay.

RESULTSThe extracts activated dose dependently, with the onset at 2.5-5 μmol/L concentrations, the high output NO production, and secretion of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Mild enhancement of NO was produced by the aldehyde-type phenolics 4-hydroxybenzaldehyde and 3,4-hydroxybenzaldehyde. In contrasts, the acetone-type phenolics 4-hydroxybenzalacetone and 3,4-hydroxybenzalacetone inhibited production of immune mediators including cytokines (TNF-α, IL-1β, IL-6), NO, and PGE2. The 3,4-hydroxybenzalacetone was more effective than 4-hydroxybenzaldehyde. The IC50s estimates ranged within the interval of 5-10 μmol/L. No signs of cytotoxicity were observed up to the 50 μmol/L concentration of the compounds.

CONCLUSIONPhenolic compounds contained in medicinal herb Osmunda japonica possess distinct immunomodulatory activity.

Animals ; Cell Survival ; drug effects ; Cells, Cultured ; Dinoprostone ; biosynthesis ; Female ; Ferns ; chemistry ; Immunologic Factors ; pharmacology ; Interferon-gamma ; pharmacology ; Lipopolysaccharides ; pharmacology ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Peritoneum ; cytology ; drug effects ; Phenols ; chemistry ; isolation & purification ; pharmacology ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Polymyxin B ; pharmacology ; Proline ; analogs & derivatives ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Thiocarbamates ; pharmacology

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 demonstrated previously that Coptidis rhizoma extract (CRE) prevented S-nitroso-N-acetylpenicillamine-induced apoptotic cell death via the inhibition of mitochondrial membrane potential disruption and cytochrome c release in RINm5F (RIN) rat insulinoma cells. In this study, the preventive effects of CRE against cytokine-induced beta-cell death was assessed. Cytokines generated by immune cells infiltrating pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. The treatment of RIN cells with IL-1beta and IFN-gamma resulted in a reduction of cell viability. CRE completely protected IL-1beta and IFN-gamma-mediated cell death in a concentration-dependent manner. Incubation with CRE induced a significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding which correlated well with reduced levels of the iNOS mRNA and protein. The molecular mechanism by which CRE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappa B activation. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappa B binding activity and p65 subunit levels in nucleus, and IkappaBalpha degradation in cytosol compared to unstimulated cells. Furthermore, the protective effects of CRE were verified via the observation of reduced NO generation and iNOS expression, and normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated islets.
Animals ; Cell Death/drug effects ; Cell Line ; Cell Nucleus/metabolism ; Cell Survival/drug effects ; Drugs, Chinese Herbal/*pharmacology ; Gene Expression Regulation, Enzymologic/drug effects ; Glucose/pharmacology ; I-kappa B Proteins/metabolism ; Insulin/secretion ; Insulin-Secreting Cells/*cytology/*drug effects/enzymology ; Interferon-gamma/*pharmacology ; Interleukin-1beta/*pharmacology ; Male ; NF-kappa B/*metabolism ; Nitric Oxide/biosynthesis ; Nitric Oxide Synthase Type II/genetics/metabolism ; Protein Transport/drug effects ; RNA, Messenger/genetics/metabolism ; Rats ; Rats, Sprague-Dawley

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

We examined the effect of class II transactivator (CIITA) down-modulation on allograft rejection. To inhibit the function of CIITA, we constructed a series of CIITA mutants and found one exhibiting the dominant-negative effect on the regulation of major histocompatibility complex (MHC) class II expression. To test whether the CIITA dominant-negative mutant reduces immunogenecity, CIITA-transfected melanoma cells were injected into allogeneic host and assessed for immune evading activity against host immune cells. We demonstrated that the CIITA dominant-negative mutant allowed tumor nodules to develop earlier in the lung than control by this tumor challenge study. Furthermore, skin grafts deficient for CIITA also survived longer than wild-type in allogeneic hosts. Both the tumor challenge and skin graft studies suggest the inhibition of CIITA molecules in donor tissue would be beneficial to the control of allo-response.
Transplantation, Homologous ; Transfection ; Trans-Activators/genetics/*immunology/metabolism ; Trans-Activation (Genetics)/genetics/immunology ; Skin Transplantation ; Nuclear Proteins/genetics/*immunology/metabolism ; Mutation ; Mice, Transgenic ; Mice, Knockout ; Mice, Inbred C57BL ; Mice, Inbred BALB C ; Mice ; Melanoma, Experimental/genetics/immunology/pathology ; Male ; Interferon Type II/pharmacology ; Humans ; Histocompatibility Antigens Class II/genetics/*immunology/metabolism ; Graft Survival/genetics/immunology ; Graft Rejection/genetics/*immunology ; Genes, MHC Class II/genetics/immunology ; Flow Cytometry ; DNA, Complementary/genetics ; Cell Proliferation/drug effects ; Cell Line, Tumor ; Animals

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

GITR (glucocorticoid-induced TNF receptor) is a recently identified member of the TNF receptor superfamily. The receptor is preferentially expressed on CD4+CD25+ regulatory T cells and GITR signals break the suppressive activity of the subset. In this study, we wanted to reveal the in vivo function of GITR in herpes simplex virus type 1 (HSV-1) infection. A single injection of anti-GITR mAb (DTA-1) immediately after viral infection significantly increased the number of CD4+ and CD8+ T cells expressing CD25, an activation surface marker, and secreting IFN-gamma. We confirmed these in vivo observations by showing ex vivo that re-stimulation of CD4+ or CD8+ T cells with a CD4+ or CD8+ T-cell-specific HSV-1 peptide, respectively, induced a significant elevation in cell proliferation and in IFN-gamma secretion. Our results indicate that GITR signals play a critical role in the T-cell immunity to HSV-1.
Animals ; Antibodies, Monoclonal/pharmacology ; CD4-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cell Proliferation ; Female ; Glucocorticoids/*pharmacology ; Herpes Simplex/*immunology ; Herpesvirus 1, Human/pathogenicity ; *Immunity, Cellular ; Interferon Type II/secretion ; *Lymphocyte Activation ; Mice ; Mice, Inbred BALB C ; Peptide Fragments/metabolism ; Receptors, Interleukin-2/metabolism ; Receptors, Nerve Growth Factor/genetics/immunology/*metabolism ; Receptors, Tumor Necrosis Factor/genetics/immunology/*metabolism ; Research Support, Non-U.S. Gov't ; T-Lymphocytes/*immunology/metabolism/virology