OBJECTIVETo investigate the influence of the LPS of Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal individuals, so as to elucidate the mechanism of the infection by Bacteroides fragilis.

METHODSLPS was obtained from both the strains isolated from patients and from standard NCTC9343. Peripheral blood mononuclear cells (PBMCs) were treated with different concentrations of LPS thus obtained. The supernatants from the cell culture of the PBMCs were harvested at 24 PBHs and were subjected to the determination of the IL-2 and IL-4 contents by ELISA method. RESULTS The IL-2 secretion from the PBMCs of normal volunteers was obviously inhibited by the LPS from Bacteroides fragilis (P < 0.01), and the inhibitory effect was dose-dependent. Nevertheless, the IL-4 secretion from the PBMCs of normal volunteers was significantly stimulated by the LPS from Bacteroides Fragilis (P < 0.05), and it was not concentration dependent. There was no difference between the effects of the LPSs from patients and standard strains (P < 0.05).

CONCLUSIONThe LPS from Bacteroides fragilis was inhibitory to the secretion of IL-2 from PBMCs and was stimulative to that of IL-4 from PBMCs of normal human persons.

Bacteroides fragilis ; metabolism ; Cells, Cultured ; Humans ; Interleukin-2 ; immunology ; secretion ; Interleukin-4 ; immunology ; secretion ; Lipopolysaccharides ; pharmacology ; Monocytes ; drug effects ; immunology

OBJECTIVETo prepare the polyclonal antibody of human endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1), and to determine the expression of EOLA1 in human umbilical vein endothelial cell (HUVEC).

METHODSThe protein samples (sample 1 and 2) expressing EOLA1 were purified and renatured. The protein concentrations were determined with bicinchoninic acid assay. The protein samples were identified with peptide mass fingerprinting (PMF) analysis. Protein sample with higher coincidence rate of amino acid sequence with theoretic protein was used to inoculate 4 mice; another 4 mice inoculated with adjuvant were used as control. Serum was isolated from collected mice blood. Polyclonal antibody of EOLA1 was purified with saturated ammonium sulfate precipitation, and was determined with ELISA for the titer (data were denoted by absorbance value). The expression of EOLA1 in HUVEC was determined with Western blot.

RESULTSThe concentration of protein sample 1 and 2 was respectively 0.124 16 mg/mL and 0.132 15 mg/mL. According to PMF analysis, the coincidence rate of amino acid sequence between protein samples and theoretic protein were 32% (protein sample 1) and 24% (protein sample 2). The polyclonal antibody of EOLA1 with titer more than 1:10 000 was obtained from mice inoculated with protein sample 1. The expression of EOLA1 protein in HUVEC was determined with polyclonal antibody of EOLA1.

CONCLUSIONSThe polyclonal antibody of EOLA1 can be prepared by inoculating mice with EOLA1 prokaryotic expressing protein, which can be used for determination of EOLA1 protein.

Animals ; Antibodies ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; metabolism ; Humans ; Lipopolysaccharides ; metabolism ; Membrane Proteins ; immunology ; metabolism ; Mice

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

OBJECTIVETo investigate whether hepatitis B e antigen (HBeAg) can modulate the ability of dendritic cells (DCs) to produce inflammatory cytokines (IL-12/IL-6) upon stimulation in vitro.

METHODSPurified adherent mononuclear cells isolated by Ficoll-hypaque density gradient centrifugation were cultured in complete medium containing granulocyte macrophage colony-stimulating factor plus interleukin (IL)-4 to generate immature (i)DCs. Microscopic analysis and flow cytometry were performed to define the phenotypic characteristics of the iDCs. Then, different concentrations (1, 2 and 5 mug/ml) of HBeAg were added to the culture medium and for 24 hrs of incubation. To induce iDCs' maturation, the various groups of cells were incubated for 24 hrs in differentiation culture with lipopolysaccharide (LPS). Effects on secreted inflammatory cytokines were determined by enzyme-linked immunosorbent assay of the cells' supernatants.

RESULTSAll concentrations of HBeAg led to significant reductions in IL-6 (all P less than 0.05). Similar significant reduction trends were seen for IL-12 at the HBeAg concentrations of 2 and 5 mug/ml (both P less than 0.05), but not at the 1 mug/ml concentration.

CONCLUSIONHBeAg may suppress the production of cytokines from DCs; this mechanism may contribute to the immune escape of HBV that supports persistent infection.

Cells, Cultured ; Dendritic Cells ; immunology ; metabolism ; Hepatitis B e Antigens ; immunology ; Humans ; Interleukin-12 ; metabolism ; Interleukin-6 ; metabolism ; Lipopolysaccharides ; adverse effects

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

BACKGROUNDCorticosteroid treatment of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) has been one of the most controversial clinical issues in critical care. Although the administration of high-dose corticosteroids does not benefit patients with early septic shock and ARDS, recent clinical trials have indicated that treatment with relatively low-dose corticosteroids (2 to 3 mg/kg/day of methylprednisolone or equivalent) may improve outcome when used for late ARDS or persistent septic shock. The underlying mechanism was not fully clarified. Whether the administration of corticosteroids can arrest neutrophil-driven organ injury once started remains to be elucidated.

OBJECTIVETo observe the effects of hydrocortisone (HC, 6 mg/kg) on oxygen free radicals (OFR) released by PMN and pulmonary pathological changes in rat ALI model induced by lipopolysaccharide (LPS), to investigate the possible mechanism through which corticosteroids exert protective effect on ALI.

METHODSA rat model of ALI was induced by peritoneal injection of 2 x 10(12) Escherichia coli/kg. Fifty-six rats were randomly divided into three groups: normal control group, LPS group and HC group (6 mg/kg). Samples were collected 2 h, 4 h and 6 h after giving LPS to LPS and HC group (6 h after giving normal saline in normal control group) to measure the level of OFR released by PMN using chemiluminescence method based on lumino, and to compae of pulmonary pathological changes among the three groups.

RESULTSPathological examination with light microscope in LPS group showed thickened pulmonary interstitia, inflammatory cell infiltration, edema and hemorrhage, which were in accordance with the features of ALI. There were significant differences in the release of OFR by PMN among the three groups (P < 0.01). The level of OFR released by PMN in LPS group was significantly higher than that of the control group, and continued to increase during the observation period (2 - 6 h after LPS). The release of OFR by PMN in HC group was significantly suppressed as compared with LPS group, which was peaked at 4 h after LPS injection (to 98.2%); there were also significant differences in the grades of ALI pathologic changes among the three groups (P < 0.01). The grades of ALI pathologic changes in LPS group were significantly increased when compared with the normal control group (P < 0.05) while significantly decreased in HC group as compared with LPS group (P < 0.05).

CONCLUSIONIt was demonstrated in the LPS induced ALI model that OFR might play an important role in onset of ALI. Intervening with HC (6 mg/kg) treatment could ameliorate the lung injury and exert significant and sustained suppression on the release of OFR by PMN, showing that HC has a protective effect on LPS induced ALI and its theraputic effect occurs possibly through suppression on the release of OFR by PMN.

Acute Lung Injury ; etiology ; immunology ; Animals ; Disease Models, Animal ; Free Radicals ; metabolism ; Glucocorticoids ; pharmacology ; Hydrocortisone ; pharmacology ; Lipopolysaccharides ; adverse effects ; Lung ; immunology ; pathology ; Mice ; Neutrophils ; drug effects ; metabolism

OBJECTIVESTo investigate the role of TLR-NF-κB signaling pathway in pathogenesis of allergic rhinitis (AR) and the mechanism of TLR to modulate innate immunity and adaptive immunity.

METHODSOne hundred rats were divided into 5 groups by simple randomization, normal group(group A), modle group(group B), AR+LPS20 group(group C), AR+LPS10 group(group D), AR+LPS5 group(group E). Model of AR in B group was established by intraperitoneal injection and nasal topic delivery of ovalbumin (OVA). A group was delivered of same volume physiological saline instated of OVA, C,D,E group were interfered by nasal delivery of LPS in different concentration (including LPS 20 µg, 10 µg, 5 µg per 100 µl). Changes of nasal mucosa tissues and inflammatory cell infiltration were observed by HE staining, while neutrophil and eosinophil counted under high power microscope.Expression of IL-4, IFN-γ, and IgE in nasal mucosa tissues were measured with immunohistochemical method.Realtime-PCR and Western-blot were used to evaluate the expression level of TLR-4 and NF-κB in nasal mucosa tissues.SPSS 13.0 software was used to analyze the data.

RESULTSGroup B was observed to have developed AR injury of nasal mucosa. Eosinophil count and the expression of IL-4, IFN-γ, and IgE were significantly higher in B group than those in A group (all P < 0.05), neutrophil count was significantly higher in C, D, E groups than that in B group (all P < 0.05).

RESULTSof immunohistochemical staining showed that, expression level of IFN-γ, TLR-4 and NF-κB were significantly higher than group B (all P < 0.05), while IL-4 and IgE were significantly decreased than group B (all P < 0.05) . The protein expression of TLR-4 and NF-κB was 0.888 9 ± 0.032 9 and 0.913 3 ± 0.031 1 in group C, and 0.419 2 ± 0.038 0 and 0.447 8 ± 0.033 0 in group A, 0.616 1 ± 0.025 1 and 0.748 1 ± 0.034 3 in group B, the difference was significant(all P < 0.05).

CONCLUSIONSTLR plays an important role of modulation between innate immunity and adaptive immunity in the pathogenesis of AR. The higher concentration of TLR doping may activate the higher expression of NF-κB then intervene the development of AR with immune deviation.

Animals ; Female ; Immunoglobulin E ; immunology ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Lipopolysaccharides ; adverse effects ; Male ; NF-kappa B ; metabolism ; Rats ; Rats, Wistar ; Rhinitis, Allergic ; immunology ; metabolism ; pathology ; Signal Transduction ; Toll-Like Receptors ; metabolism

Bacterial Translocation ; physiology ; Humans ; Intestinal Mucosa ; pathology ; physiology ; Lipopolysaccharides ; metabolism ; physiology ; Liver Failure, Acute ; etiology ; immunology ; physiopathology ; Lymphocytes ; immunology ; metabolism ; Macrophages ; immunology ; metabolism ; Signal Transduction ; genetics ; physiology ; Toll-Like Receptor 4 ; metabolism ; physiology

Lipooligosacharide (LOS) of Neisseria gonorrhoeae (gonococci, GC) is involved in the interaction of GC with host cells. Deletion of the alpha-oligosaccharide (alpha-OS) moiety of LOS (lgtF mutant) significantly impairs invasion of GC into epithelial cell lines. GC opacity (Opa) proteins, such as OpaI, mediate phagocytosis and stimulate chemiluminescence responses in neutrophils in part through interaction with members of the carcinoembryonic antigen (CEA) family, which includes CEACAM3 (CD66d), a human neutrophil specific receptor for phagocytosis of bacteria. In the present work, we examined the effects of OpaI-expressing lgtF mutant on phagocytosis by HeLa-CEACAM3 cells and chemiluminescence responses in neutrophils. The results showed that lgtF mutant even expressing OpaI completely lost the ability to promote either phagocytosis mediated by CEACAM3 interaction in HeLa cells or chemiluminescence responses in neutrophils. These data indicated that Opa proteins in the lgtF mutant, which might result from the conformational change, cannot be functional.
Antigens, Bacterial ; chemistry ; genetics ; immunology ; metabolism ; Carbohydrate Sequence ; Carcinoembryonic Antigen ; genetics ; immunology ; Gene Expression Regulation ; HeLa Cells ; Host-Pathogen Interactions ; Humans ; Lipopolysaccharides ; chemistry ; immunology ; Luminescent Measurements ; Mutation ; Neisseria gonorrhoeae ; genetics ; metabolism ; pathogenicity ; Neutrophils ; immunology ; microbiology ; Phagocytosis

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