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

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*

This study investigated the presence of cytokines interferon (IFN)-gamma, interleukins (IL) -6 and -8 in serum of cattle and buffaloes infected with Fasciola gigantica from one to 16 weeks post-infection to determine their T cell response during infection. The concentration of these cytokines was determined by sandwich enzyme-linked immunosorbent assay (ELISA). No IFN-gamma was detected in these animals while IL-6 was elevated from one to 16 weeks postinfection. Levels of IL-8 were also elevated in infected buffaloes from one to 16 weeks post-infection. A predominantly T helper (Th) 2 response which started early in the infection was apparently present in cattle and buffaloes in this study which was characterised by IL-6. IL-8 production could be another mechanism of immune response in buffaloes during infection with F. gigantica.
Animals ; Buffaloes/blood/immunology/*parasitology ; Cattle ; Cattle Diseases/*immunology/*parasitology ; Cytokines/*blood/immunology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Fasciola/*immunology ; Fascioliasis/immunology/parasitology/*veterinary ; Interferon Type II/blood ; Interleukin-6/blood ; Interleukin-8/blood ; Random Allocation

Bacillus Calmette-Guerin (BCG) is reported to suppress Th2 response and asthmatic reaction. Dendritic cells (DCs), the major antigen-presenting cells, infections with BCG are known to result in inducing various cytokines. Thus, DCs are likely to play a role in the effects of BCG on asthma. This study aims at investigating that cytokine milieu secreted by BCG-treated DCs directly enhances allergen-specific Th1 response and/or suppresses Th2 response in allergic asthma. DCs and CD3+ T cells were generated from Dermatophagoides farinae-sensitive asthmatics. DCs were cultured with and without BCG and subjected to flow cytometric analysis. IL-12 and IL-10 were determined from the culture supernatants. Some DCs were cocultured with T cells in the presence of D. farinae extracts after adding the culture supernatants from BCG-treated DCs, and IL-5 and IFN-gamma were determined. BCG-treated DCs enhanced significantly the expressions of CD80, CD86, and CD40, and the productions of IL-12 and IL-10. Addition of culture supernatants from BCG-treated DCs up-regulated production of IFN-gamma by T cells stimulated by DCs and D. farinae extracts (p<0.05), but did not down-regulate production of IL-5 (p>0.05). The cytokine milieu secreted by BCG-treated DCs directly enhanced allergen-specific Th1 response, although did not suppress Th2 response.
Antigens, Dermatophagoides/*immunology ; Asthma/*immunology ; Cells, Cultured ; Coculture Techniques ; Culture Media ; Cytokines/*immunology/secretion ; Dendritic Cells/cytology/*immunology/secretion ; Humans ; Hypersensitivity/immunology ; Interferon Type II/immunology/secretion ; Interleukin-10/immunology/secretion ; Interleukin-12/immunology/secretion ; Interleukin-5/immunology/secretion ; Lymphocyte Activation/immunology ; Mycobacterium bovis/*immunology ; Research Support, Non-U.S. Gov't ; Th2 Cells/cytology/immunology/secretion ; Up-Regulation/immunology

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

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

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

OBJECTIVETo investigate the effect of activated greater omental milky spots and peritoneal macrophages in mice on tumoricidal activity against gastric carcinoma SGC-7901, following intraperitoneal (i.p.) injection of INF-gamma, staphylococcin aureus or NDV-L.

METHODSThe quantitative changes of milky spots were determined by activated carbon, the number of the macrophage in milky spots was assessed by nonspecific esterase stain and the number of peritoneal macrophages was counted by trypan blue exclusion. The morphology of peritoneal macrophages was observed by scanning electron microscope, the amount of TNF-alpha and iNOS mRNA expressed by peritoneal macrophages was measured by fluorescence quantitative PCR and the cytotoxicity of peritoneal macrophages supernatant against SGC-7901 was evaluated by MTT assay.

RESULTSIt was found in the treated groups that: 1. The amount of greater omental milky spots and the macrophages in milky spots increased, 2. The number of peritoneal macrophages increased. The peritoneal macrophages were in activated status. The effect TNF-alpha and iNOS mRNA expression increased and 3. The cytotoxicity against in vitro SGC-7901 increased.

CONCLUSIONIntraperitoneal injection of IFN-gamma, staphylococcin aureus or NDV-L could activate the milky spots of the greater omentum and the macrophages in peritoneal cavity in mice, with IFN-gamma being the best. The supernatant of activated peritoneal macrophages has cytotoxicity against SGC-7901. Administration of LPS to macrophages cultured in vitro could amplify the activation and enhance the cytotoxicity of the supernatant against SGC-7901.

Animals ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; Female ; Interferon-gamma ; pharmacology ; Macrophages, Peritoneal ; drug effects ; immunology ; ultrastructure ; Mice ; Nitric Oxide Synthase Type II ; genetics ; Omentum ; drug effects ; immunology ; ultrastructure ; RNA, Messenger ; analysis ; Stomach Neoplasms ; immunology ; Tumor Necrosis Factor-alpha ; genetics

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

Although there are many reports on the splenic (systemic) T cell response after Toxoplasma gondii infection, little information is available regarding the local T cell responses of peritoneal exudate cells (PEC) and gut intraepithelial lymphocytes (IEL) following peroral infection with bradyzoites. Mice were infected with 40 cysts of the 76K strain of T. gondii, and then sacrificed at days 0, 1, 4, 7 and 10 postinfection (PI). The cellular composition and T cell responses of PEC and IEL were analyzed. The total number of PEC and IEL per mouse increased after infection, but the ratio of increase was higher in IEL. Lymphocytes were the major component of both PEC and IEL. The relative percentages of PEC macrophages and neutrophils/eosinophils increased significantly at day 1 and 4 PI, whereas those of IEL did not change significantly. The percentage of PEC NK1.1 and gamma delta T cells peaked at day 4 PI (p < 0.0001), and CD4 and CD8 alpha T cells increased continuously after infection. The percentages of IEL CD8 alpha and gamma delta T cells decreased slightly at first, and then increased. CD4 and NK1.1 T cells of IEL did not change significantly after infection. IFN-gamma-producing PEC NK1.1 T cells increased significantly from day 1 PI, but the other T cell subsets produced IFN-gamma abundantly thereafter. The proportion of IEL IFN-gamma-producing CD8 alpha and gamma delta T cells increased significantly after infection, while IEL NK1.1 T cells had similar IFN-gamma production patterns. Taken together, CD4 T cells were the major phenotype and the important IFN-gamma-producing T cell subsets in PEC after oral infection with T. gondii, whereas CD8 alpha T cells had these roles in IEL. These results suggest that PEC and IEL comprise different cell differentials and T cell responses, and according to infection route these factors may contribute to the different cellular immune responses.
Acute Disease ; Animals ; Ascitic Fluid/cytology/*metabolism ; Female ; Interferon Type II/*biosynthesis ; Intestinal Mucosa/cytology ; Lymphocytes/*metabolism ; Mice ; Mice, Inbred C57BL ; Support, Non-U.S. Gov't ; T-Lymphocyte Subsets/*immunology ; Toxoplasmosis/*immunology