No anstract available.
Animal ; Binding Sites ; Histocompatibility Antigens Class II/chemistry/immunology/*metabolism ; Human ; Superantigens/chemistry/immunology/*metabolism

OBJECTIVETo separate and identify the exosomes derived from a mouse hepatoma carcinoma cell line (H22) and to detect their protein composition, and to investigate the possibility of using these exosomes as a kind of tumor vaccine.

METHODSExosomes were purified by serial ultracentrifugation and sugar density ultracentrifugation, and then they were observed and identified by electron microscopy. Exosomes underwent peptide mass fingerprint and Western blot analyses.

RESULTSH22 cell-derived exosomes were 20-90 nm round or oval vesicles. The exosomes expressed HSP70, ICAM-1, EF-G2, DLC-A, C-myc protein and Vav-2 protein.

CONCLUSIONSerial ultracentrifugation and sugar density ultracentrifugation can be used to purify H22 cell-derived exosomes. H22 cell-derived exosomes express a distinct set of proteins involving in and/or relating to antigen presentation (HSP70, ICAM-1), migration (DLC-A), adhesion (ICAM-1), cytoskeleton (EF-G2) and tumour antigens (C-myc, Vav-2). The exosomes have immunogenicity.

Animals ; Carcinoma, Hepatocellular ; immunology ; metabolism ; Cell Line, Tumor ; Exosomes ; immunology ; secretion ; Histocompatibility Antigens Class II ; immunology ; Liver Neoplasms ; immunology ; metabolism ; Mice ; Peptide Mapping

To examine the self-association of CD4 molecules and preliminary studies on its biological function by several indirect methods. A series of CD4 chimeras were generated including truncated CD4 lacking the short cytoplasmic tail, deleted mutantsD1/D2 devoid of D3 and D4 and D3/D4 devoid of D1 and D2 by PCR techniques, as well as another three CD4 chimeric genes by fused human Fas cytoplasmic death domain to the downstream of the above chimeras respectively. All these molecules were subcloned into pEGFP-N1, forming the corresponding expression vectors. After introducing into HEK293 cells, gene-modified cell morphological changes and target protein subcellular localization were observed and analyzed by a confocal microscopy. Moreover, stable 293/CD4 clones were obtained by transfecting the truncated CD4 recombinant plasmid into the HEK293 cell line and selected by G418. The fluorescene intensity and rosette formation of different clones was each analyzed by a confocal microscopy and cell adhesive assays. It's seen that CD4-Fas fusion gene could induce approximately 80% cell apoptosis of transfected HEK293 cells, compared to FKBP12-Fas is about 30% and CD4 gene only is 7%. Furthermore, both D1/D2-Fas and D3/D4 Fas chimeras could trigger nearly all transfected HEK293 cells to death. Cell adhesion assays showed that neither the D1/D2 nor D3/D4 chimeras when expression in HEK293 cells binds to MHC class II + Raji B cells. Interestedly, there were two type stable clones among 293/CD4. Fluorescence intensity analysis displayed that one' mean fluorescence intensity value is about twice of the other while cell-cell binding examination showed that the former is capable of forming rosette with Raji cells but the latter. All these results suggest that CD4 molecules most likely could exist as a dimer or even an oligomer on transfected HEK293 cell surface, which constitute a functional form for stable binding to MHC class II molecules.
Antigen-Presenting Cells ; immunology ; metabolism ; CD4 Antigens ; chemistry ; genetics ; metabolism ; CD4-Positive T-Lymphocytes ; immunology ; metabolism ; Cell Line ; Dimerization ; Fas Ligand Protein ; metabolism ; Histocompatibility Antigens Class II ; genetics ; immunology ; metabolism ; Humans ; Mutagenesis, Site-Directed ; Protein Binding ; genetics ; Protein Multimerization

Animals ; Antigens, Differentiation, B-Lymphocyte ; immunology ; Gene Expression ; Hepacivirus ; immunology ; Histocompatibility Antigens Class II ; immunology ; Mice ; Mice, Inbred BALB C ; Th1 Cells ; immunology ; metabolism ; Viral Hepatitis Vaccines ; genetics ; immunology

OBJECTIVETo study the mechanism of macrophage injury after trauma-hemorrhagic shock.

METHODSWistar male rats underwent trauma (closed bone fracture) and hemorrhage (mean arterial blood pressure of 35 mm Hg+/-5 mm Hg for 60 minutes, following fluid resuscitation). Rats without trauma, hemorrhage or fluid resuscitation served as controls. Peritoneal macrophages were harvested at 6 hours and 1, 2, 3, 7 days after traumatic hemorrhagic shock to determine the effects of pertussis toxin (PTX, as a specific inhibitor to Gi(alpha) and cholera toxin (CTX, as a stimulant to Gs(alpha) on macrophage-Ia expression and TNF-alpha production and levels of Gi(alpha) and Gs(alpha).

RESULTSThe macrophages from the injured rats revealed a significant decrease of Ia positive number and TNF-alpha release in response to LPS. Wi th pretreatment with PTX 10-100 ng/ml Ia positive cells and LPS-induced TNFalpha production in both control and impaired macrophages populations were dos e dependently increased. Both macrophages populations were not responding to CTX treatment (10-100 ng/ml). Western blot analyses showed that the levels of Gi(alpha) protein expression increased as much as 116.5%-148.8% of the control level fro m 6 hours through 7 days after traumatic hemorrhage. The levels of Gs protein expression were reduced at 6 hours and decreased to the lowest degree; 36% o f the control at day 1, began to return at day 2 and returned to the normal level at day 7, following traumatic hemorrhagic shock.

CONCLUSIONSPTX-sensitive G-protein may participate in th e modulation of macrophage-Ia expression and TNF-alpha release following traumatic hemorrhagic shock. Analyses of the alteration of Gi(alpha) and Gs protein express ions further supports the concept that G-protein is involved in trauma-induced macrophage signal transduction pathways.

Analysis of Variance ; Animals ; GTP-Binding Proteins ; immunology ; metabolism ; Histocompatibility Antigens Class II ; immunology ; Immunoblotting ; Lipopolysaccharides ; pharmacology ; Macrophages, Peritoneal ; immunology ; metabolism ; Male ; Rats ; Rats, Wistar ; Shock, Hemorrhagic ; blood ; immunology ; Signal Transduction ; Tumor Necrosis Factor-alpha ; biosynthesis

OBJECTIVETo construct a dendritic cell vaccine transduced by murine alpha-fetoprotein (mAFP) gene, and evaluate its immunoprotective effect on C57BL/6J mice during the induction of hepatocellular carcinoma by diethylnitrosamines, carbon tetrachloride and ethanol.

METHODSDendritic cells (DCs) were induced and augmented by murine IL-4 and GM-CSF, and transfected by recombinant adenovirus engineered with mAFP gene. Major MHC class I and II, B7.1 (CD80), B7.2 (CD86), CD18a, and CD54 molecules on DC were analyzed by FACS. 80 C57BL/6J male mice were randomly divided into 4 groups (20 mice per group): Simple DC inoculated group, pAdBM5-mAFP-DC inoculated group, pAdBM5-mAFP plasmid inoculated group, and PBS control group. They were immunized once with 5 x 10(5) DCs (0.1 ml)/mouse administered s. c. in the left flank or 100 mg pAdBMS-mAFP plasmid/mouse administered i. m. in the left tibialis anterior muscle. Inoculation was conducted once a week for 4 weeks after 3 times consecutive immunization initially. At the same time of immunization, DEN/CCl4/ethanol were given to induce hepatocellular carcinoma. Tumor incidence was assessed after 20 weeks.

RESULTSA transgenic DC vaccine was successfully constructed and the mAFP transgenic DCs expressed high level molecules of major MHC class I and II , B7.1, B7.2, CD18a, and CD54. After the 20-week induction, the incidence of primary hepatocellular carcinoma (PLC) was 70.0% in simple DC inoculated group, 25.0% in pAdBMS-mAFP-DC inoculated group, 65.0% in pAdBM5-mAFP plasmid inoculated group, and 75.0% in PBS control group. There was a significant difference between group B and other groups (P < 0.05).

CONCLUSIONmAFP transgenic DC tumor vaccine inoculation may induce strong immunoprotection against liver carcinogenesis and tumor development and reduce PLC incidence induced by DEN/CCl4/ethanol.

Adenoviridae ; genetics ; Animals ; B7-1 Antigen ; metabolism ; Cancer Vaccines ; Carbon Tetrachloride ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; metabolism ; Diethylnitrosamine ; Ethanol ; Genetic Vectors ; Histocompatibility Antigens Class I ; metabolism ; Histocompatibility Antigens Class II ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Liver Neoplasms, Experimental ; chemically induced ; immunology ; prevention & control ; Male ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Recombinant Proteins ; genetics ; metabolism ; Transfection ; alpha-Fetoproteins ; genetics ; metabolism

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 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

OBJECTIVETo study the ex vivo effect of sirolimus on capacity of splenic dendritic cells (DC) from traumatized mice in inducing T cell responses.

METHODSTwenty-four BALB/c mice were divided into control group and trauma group according to the random number table, with 12 mice in each group. Mice in trauma group were bled followed by closed femur fracture after anaesthesia, while mice in control group were only anaesthetized without injury. Twenty-four hours later DC were isolated from spleens and divided into 4 subgroups: sirolimus devoid control (trauma) groups [consisted of cells from control (trauma) groups, without sirolimus treatment] and sirolimus treated control (trauma) groups [consisted of cells from control (trauma) groups, treated with 10 microg/L sirolimus for 6 hours]. Then their autophagic activity, DC-induced mixed lymphocyte reaction (MLR) were measured and recorded as fluorescence intensity (FI) value and absorbance value respectively. The expression of major histocompatibility complex class (MHC) II and costimulatory molecules CD40, CD80, and CD86 on DC surface were measured with flow cytometry. IL-12p40, IL-12p70 and IL-10 levels in lipopolysaccharide-stimulated DC supernatants were determined by ELISA. Data were processed with one-way analysis of variance.

RESULTS(1) Compared with those of sirolimus devoid control group (FI value = 22 +/- 6), DC autophagic activity (FI value = 13 +/- 2) and DC-induced MLR in mice from sirolimus devoid trauma group were significantly weakened (F = 212.836, P < 0.05). Compared with those of sirolimus devoid control (trauma) groups, DC autophagic activity in mice from sirolimus treated control (trauma) groups (FI = 45 +/- 8, 44 +/- 8 respectively) were significantly strengthened (F = 212.836, P < 0.05 or P < 0.01). MLR in mice from sirolimus treated trauma group was stronger than that from sirolimus devoid trauma group (with F value respectively 101.426, 86.533, P values all below 0.05). (2) Compared with those of sirolimus devoid control group [MHC II (85 +/- 6)%, CD40 (8 +/- 1)%], the expressions of MHCII [(60 +/- 9)%] and CD40 [(4 +/- 1)%] on DC surface from sirolimus devoid trauma group were significantly reduced (with F value respectively 37.918, 40.426, P values all below 0.05). The expression of MHCII from sirolimus treated trauma group [(78 +/- 7)%] was higher than that from sirolimus devoid trauma group (F = 37.918, P < 0.05). (3) IL-12p40, IL-12p70 secretion by DC from sirolimus devoid trauma group [(120 +/- 13), (10 +/- 3) pg/mL] were significantly reduced as compared with those from sirolimus devoid control group [(200 +/- 25), (20 +/- 6) pg/mL, with F value respectively 218.646, 310.253, P values all below 0.05]. Compared with those from sirolimus devoid control (trauma) groups, IL-12p40 [(560 +/- 34), (540 +/- 29) pg/mL], IL-12p70 [(55 +/- 8), (60 +/- 11) pg/mL] secretion by DC from sirolimus treated control (trauma) groups were obviously enhanced (with F value respectively 218.646, 310.253, P values all below 0.01), while IL-10 secretion levels were significantly decreased (F = 246.108, P < 0.01).

CONCLUSIONSSirolimus can partially ameliorate DC functions ex vivo in traumatized mice, and further enhance the capacity of DC in inducing T cell responses.

Animals ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; CD40 Antigens ; metabolism ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Histocompatibility Antigens Class II ; immunology ; Interleukin-12 Subunit p40 ; metabolism ; Lymphocyte Culture Test, Mixed ; Male ; Mice ; Mice, Inbred BALB C ; Sirolimus ; pharmacology ; Spleen ; cytology ; immunology ; T-Lymphocytes ; immunology ; Wounds and Injuries ; immunology

OBJECTIVETo investigate if granulocyte-macrophage colony stimulating factor (GM-CSF) gene-modified dendritic cells (DC) enhance antitumor immunity in vitro.

METHODSMice were injected with chemokine ligand 3 (CCL3) via the tail vein. Fresh B220(-)CD11c(+) cells were sorted from the peripheral blood mononuclear cells (PBMCs) and cultured into DCs by cytokines.DCs were transfected with AdGM-CSF gene at different ratios of multiplicity of infection (MOI) to determine the optimal gene transfection conditions, and the expression of GM-CSF was detected after transfection. The variation of GM-CSF gene-modifiedDCs were analyzed by morphological examination, phenotype analysis, and mixed lymphocyte reaction (MLR).DCs were loaded with gastric cancer antigen obtained by freezing and thawing method. The killing effect of DCs vaccine-stimulated T lymphocytes on gastric cancer cells was assessed by MTT assay. INF-gamma production was determined with the INF-gamma ELISA kit.

RESULTSB220(-)CD11c(+) cells increased obviously after CCL3 injection. The ELISA results showed that after GM-CSF gene modification, DCs could produce high level of GM-CSF. When DCs were transfected with AdGM-CSF gene at MOI equal to 100, the GM-CSF level in culture supernatants reached saturation [(130.00 +/- 12.61) pg/ml]. After GM-CSF gene-modification, DCs tend to be more maturated as detected by morphological observation and phenotype analysis. At the same time, the capacity of activating the proliferation of allogeneic T lymphocytes was enhanced greatly. T lymphocytes stimulated by DCs transfected with GM-CSF gene showed a specific killing effect on gastric carcinoma cells and produced high level of INF-gamma [(1245.00 +/- 13.75) pg/ml].

CONCLUSIONAfter GM-CSF gene modification, DCs can produce high level of GM-CSF, which tend to be more maturated, and the capacity of activating the proliferation of allogeneic T lymphocytes is enhanced greatly. GM-CSF gene modified DCs can induce specific CTL to target tumor cells in vitro.

Adenoviridae ; genetics ; Animals ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; CD40 Antigens ; metabolism ; Cancer Vaccines ; immunology ; Cell Line, Tumor ; Cell Proliferation ; Cytotoxicity, Immunologic ; Dendritic Cells ; cytology ; immunology ; metabolism ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; metabolism ; Histocompatibility Antigens Class II ; metabolism ; Interferon-gamma ; secretion ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; Stomach Neoplasms ; immunology ; metabolism ; pathology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology ; Transfection