The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.
Enzyme-Linked Immunosorbent Assay ; Epithelial Cells/metabolism ; Gastric Mucosa/*drug effects/metabolism/microbiology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/drug effects/*pathogenicity ; Humans ; Interleukin-8/genetics/*metabolism ; JNK Mitogen-Activated Protein Kinases ; Janus Kinase 1 ; Mitogen-Activated Protein Kinases/*biosynthesis ; NF-kappa B/*metabolism ; RNA, Messenger/isolation & purification/metabolism ; Reactive Oxygen Species/metabolism ; STAT3 Transcription Factor ; Stomach/metabolism/*microbiology ; Thioctic Acid/*pharmacology

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

We studied the immunogenicity of pseudorabies virus gC DNA vaccination by fusing the murine complement C3d receptor binding domain. First, pseudorabies virus gC gene was linked to four copies of C3d receptor binding domain (M284), and then cloned into the vector pcDNA3.1 to construct the recombinant plasmid sgC-M284. Through the experiment of immunized BALB/c mice, we found that the enzyme linked immunosorbent assay (ELISA) antibody titer for sgC-M284 was 17-fold higher than that for sgC alone, and protective rate of mice was augmented from 25% to 88% after lethal dose PrV (316 LD50) challenge. In addition, the IL-4 levels for sgC-M284 immunization approached that for the pseudorabies virus inactivated vaccine. In conclusion, we demonstrated murine C3d receptor binding domain fusion significantly increased Th2-biased immune response by inducing IL-4 production.
Adjuvants, Immunologic ; physiology ; Animals ; Antibody Formation ; immunology ; Binding Sites ; Cloning, Molecular ; Complement C3d ; genetics ; immunology ; Herpesvirus 1, Suid ; genetics ; immunology ; Interleukin-4 ; immunology ; Mice ; Mice, Inbred BALB C ; Pseudorabies Vaccines ; immunology ; Receptors, Complement 3d ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Vaccines, DNA ; immunology ; Viral Envelope Proteins ; pharmacology ; Viral Fusion Proteins ; immunology

OBJECTIVETo study the effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 and the mechanisms in asthmatic mice.

METHODSExperimental asthma was induced by ovalbumin (OVA) sensitization in 20 in female Balb/c mice with (dexamethasone group, n=10) or without dexamethasone treatment (model group, n=10), with another 10 serving as the control group. The levels of IL-17 in the bronchoalveolar lavage fluid (BALF) and serum of the mice were measured by enzyme-linked immunosorbent assay (ELISA), and the airway inflammation was evaluated by HE staining. The expressions of IL-17 and RORgammat mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR), and the expression of RORgammat protein was measured by immunohistochemical staining.

RESULTSThe levels of RORgammat and IL-17 mRNA and protein in the asthmatic model group were significantly higher than those in the control group (P<0.01), and the increased expressions of RORgammat and IL-17 mRNA and protein in the asthmatic mice were significantly reduced by dexamethasone treatment (P<0.05).

CONCLUSIONDexamethasone can inhibit the release of IL-17 probably by inhibiting RORgammat expression and blocking Th17 differentiation in asthmatic mice.

Animals ; Asthma ; chemically induced ; immunology ; metabolism ; Dexamethasone ; pharmacology ; Female ; Interleukin-17 ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; metabolism ; Ovalbumin ; RNA, Messenger ; biosynthesis ; genetics ; T-Lymphocyte Subsets ; immunology ; metabolism ; T-Lymphocytes, Helper-Inducer ; immunology ; metabolism

OBJECTIVETo study the antitumor effect GPI-CD80 fusion protein and its mechanisms.

METHODSA tumor vaccine was prepared by culturing HepG2 cells in the presence of purified GPI-CD80 followed by inactivation with mitomycin, with mitomycin-inactivated HepG2 cells as the control group. The two preparations were co-cultured with nude mouse splenic lymphocytes, and the changes of lymphocyte proliferation and the production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were detected by MTT assay. The cytotoxic T-lymphocyte (CTL) activity was evaluated by LDH-release assay, and the changes of gross tumor volume were measured in tumor-bearing nude mice after administration of different vaccines.

RESULTSThe application of GPI-CD80 tumor vaccine resulted in significantly increased optical density, IL-2 and IFN-gamma levels and CTL activity of the nude mouse splenic lymphocytes in comparison with the control groups. The average tumor volume in nude mice treated with GPI-CD80 tumor vaccine was significantly smaller than that in negative control and blank control groups.

CONCLUSIONGPI-CD80 fusion protein may inhibit the tumor growth velocity in nude mice, possibly by promoting lymphocyte proliferation, stimulating the production of the cytokines IL-2 and IFN-gamma, and enhancing of CTL activity.

Animals ; B7-1 Antigen ; biosynthesis ; genetics ; immunology ; isolation & purification ; CHO Cells ; Cancer Vaccines ; biosynthesis ; genetics ; immunology ; isolation & purification ; Cell Proliferation ; Cricetinae ; Cricetulus ; Glycosylphosphatidylinositols ; genetics ; metabolism ; Interferon-gamma ; biosynthesis ; Interleukin-2 ; biosynthesis ; Mice ; Mice, Nude ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification ; Spleen ; cytology ; immunology ; metabolism ; Tumor Burden ; immunology

Staphylococcus aureus may perform an crucial function in atopic dermatitis (AD), via the secretion of superantigens, including staphylococcal enterotoxins (SE) A or B, and toxic shock syndrome toxin-1 (TSST-1). Dysregulated cytokine production by keratinocytes (KCs) upon exposure to staphylococcal superantigens (SsAgs) may be principally involved in the pathophysiology of AD. We hypothesized that lesional KCs from AD may react differently to SsAgs compared to nonlesional skin or normal skin from nonatopics. We conducted a comparison of HLA-DR or CD1a expression in lesional skin as opposed to that in nonlesional or normal skin by immunohistochemistry (IHC). We also compared, using ELISA, the levels of IL-1alpha, IL-1beta, and TNF-alpha secreted by cultured KCs from lesional, nonlesional, and normal skin, after the addition of SEA, SEB and TSST-1. IHC revealed that both HLA-DR and CD1a expression increased significantly in the epidermis of lesional skin versus nonlesional or normal skin in quite a similar manner. IL-1alpha, IL-1beta, and TNF-alpha secretion was also significantly elevated in the cultured KCs from lesional skin after the addition of SsAgs. Our results indicated that KCs from lesional skin appear to react differently to SsAgs and increased proinflammatory cytokine production in response to SsAgs may contribute to the pathogenesis of AD.
Tumor Necrosis Factor-alpha/biosynthesis/genetics ; *Superantigens/administration & dosage/immunology ; Staphylococcus aureus/*immunology/pathogenicity ; Male ; Keratinocytes/immunology/*microbiology ; Interleukin-1/biosynthesis/genetics ; Inflammation Mediators/metabolism ; Humans ; HLA-DR Antigens/metabolism ; Enterotoxins/administration & dosage/immunology ; Dermatitis, Atopic/etiology/immunology/*microbiology ; DNA, Complementary/genetics ; Case-Control Studies ; Base Sequence ; Bacterial Toxins/administration & dosage/immunology ; Antigens, CD1/metabolism ; Adult

OBJECTIVETo explore the mechanism of endotoxin tolerance (ET) through observing the expression of interleukin 1 receptor associated kinase-4 (IRAK-4) during endotoxin tolerance development in Kupffer cells (KCs).

METHODSIsolated KCs of Balb/c mouse were divided into two groups: the non-endotoxin tolerance (NET) group and the endotoxin tolerance (ET) group, which were pretreated with 10 ng/ml lipopolysaccharide (LPS) for 24 h. Then, the two groups were treated with 100 ng/ml LPS. The expressions of IRAK-4 gene and protein level were determined by RT-PCR and Western blot. The activities of NF-kappaB of KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h after LPS stimulation.

RESULTSThe ultimate level of IRAK-4, the activities of NF-kappaB and the TNFalpha level were evidently lower in the ET group than those in the NET group (t = 12.4, 17.4 and 138.9 respectively, P<0.01).

CONCLUSIONSPretreatment with LPS on KCs could induce endotoxin tolerance of KCs and inhibition of IRAK-4 expression may be one of the reasons for its development.

Animals ; Cells, Cultured ; Endotoxins ; immunology ; Immune Tolerance ; Interleukin-1 Receptor-Associated Kinases ; biosynthesis ; genetics ; Kupffer Cells ; cytology ; immunology ; metabolism ; Lipopolysaccharides ; immunology ; Male ; Mice ; Mice, Inbred BALB C

The capsid of the foot and mouth disease (FMD) virus carries the epitopes that are critical for inducing the immune response. In an attempt to enhance the specific immune response, plasmid DNA was constructed to express VP1/interleukin-1alpha (IL-1alpha) and precursor capsid (P1) in combination with 2A (P1-2A)/IL-1alpha under the control of the human cytomegalovirus (HCMV) immediateearly promoter and intron. After DNA transfection into MA104 (monkey kidney) cells, Western blotting and an immunofluorescence assay were used to confirm the expression of VP1 or P1-2A and IL-1alpha. Mice were inoculated with the encoding plasmids via the intradermal route, and the IgG1 and IgG2a levels were used to determine the immune responses. These results show that although the immunized groups did not carry a high level of neutralizing antibodies, the plasmids encoding the VP1/ IL-1alpha, and P1-2A /IL-1alpha fused genes were effective in inducing an enhanced immune response.
Animals ; Antibodies, Viral/blood ; Capsid Proteins/biosynthesis/genetics/*immunology ; Cell Line ; DNA, Viral/genetics ; Enzyme-Linked Immunosorbent Assay ; Foot-and-Mouth Disease/*immunology/prevention&control ; Foot-and-Mouth Disease Virus/genetics/*immunology ; Haplorhini ; Immunization ; Interleukin-1/biosynthesis/genetics/*immunology ; Male ; Mice ; Mice, Inbred C57BL ; Plasmids/genetics ; Polymerase Chain Reaction ; Recombinant Fusion Proteins/biosynthesis/genetics/immunology ; Specific Pathogen-Free Organisms ; Transfection ; Vaccines, DNA/genetics/*immunology

OBJECTIVETo investigate the immune-functional epitopes and inflammation-inducing effects of the major outer envelope proteins of Leptospira interrogans.

METHODSNi-NTA affinity chromatography was established to extract the target recombinant proteins rOmpL1/1 and OmpL1/2, LipL32/1 and rLipL32/2, LipL41/1 and rLipL41/2 expressed by the different genotypes. By using Signal P-NN software in Signal P3.0 prediction server, EMBOSS software in propred MHC class-II binding peptide prediction-ProPred prediction server, the possible signal peptides, MHC-II binding peptides and lymphocyte B epitopes were analyzed. The IL-1, IL-8 and TNF-alpha secretion in human umbilical vein endothelial cell line EVC-304 induced by target recombinant proteins were measured by ELISA.

RESULTSUnder the inducement of IPTG, the constructed prokaryotic systems efficiently expressed rOmpL1/1 and rOmpL1/2, rLipL32/1 and rLipL32/2, and rLipL41/1 and rLipL41/2 with outputs of 30% and 15%, 40% and 35%, and 15% and 10% of the total bacterial proteins, respectively. Each of the purified target recombinant proteins showed a single protein band in SDS-PAGE. The signal peptides of OmpL1s, LipL32/1 and LipL32/2, and LipL41s were located at the N ends of 1-24, 1-21 and 1-24, and 1-24 amino acid residuals, respectively. OmpL1s, LipL32s and LipL41s displayed 2,2 and 1 same major epitopes of MHC-II binding peptides and lymphocyte B and OmpL1/2 had another one (59-78). The different dosages of rOmpL1s, rLipL32s and rLipL41s increased the secretion of IL-1alpha , IL-8 and TNF-alpha (P<0.05) in EVC-304 cells. The IL-1alpha levels reached the highest at the 24 h and then declined,while the IL-8 and TNF-alpha levels after 48 h treatment were higher that those after 24 h.

CONCLUSIONThe expression products in ompL1/1, lipL32 or lipL41 genotypes of L.interrogans contain similar immune functional epitopes. rOmpL1/1 and rOmpL1/2, rLipL32/1 and rLipL32/2, and rLipL41/1 and rLipL41/2 are able to directly induce inflammatory reaction in EVC-304 cells.

Bacterial Outer Membrane Proteins ; immunology ; pharmacology ; Cells, Cultured ; Endothelial Cells ; cytology ; Epitopes ; Genotype ; Humans ; Inflammation ; etiology ; Interleukin-1 ; biosynthesis ; Leptospira interrogans ; genetics ; immunology ; Lipoproteins ; immunology ; pharmacology ; Recombinant Proteins ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis ; Umbilical Veins ; cytology