OBJECTIVE: The aim of this study was to determine the expression of GATA-3 and the level of Th1 and Th2 cytokines upon repeated exposure to staphylococcal enterotoxin B(SEB) of different concentrations in the maxillary sinus mucosa of rabbits. METHOD: The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEB group and high-dose SEB group. The low-dose SEB group and high-dose SEB group received daily injections of 0.6 ng of SEB (2 ml) and 60 ng of SEB (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as a control. Six rabbits chosen randomly in two groups were killed on days 3, 7, 14, and 28, and to obtain the sinus mucosa from the two-side maxillary sinuses for measurement. Mucosal levels of IL-2, IL-4, IL-5, and IFN-γ were measured using ABC-ELISA. Tissue expression of GATA-3 were examined using Real-time PCR and immunohistochemistry. RESULT: IFN-γ and IL-2 levels were significantly elevated in the high-dose SEB group compared with the low-dose SEB and control groups on days 7, 14, and 28 (P < 0.05). However, IL-4 and IL-5 levels were markedly enhanced in the low-dose SEB group compared with the high-dose SEB and control groups on days 14 and 28 (P < 0.05). Real-time PCR showed that the expression of GATA-3 mRNA in the low-dose SEB group was markedly enhanced, and immunohistochemical staining illustrated that the number of GATA-3 positive cells was markedly increased in the low-dose SEB group as compared with the high-dose SEB group (P < 0.05). No significant differences were observed in GATA-3 expression between the high-dose SEB and the control groups (P > 0.05). CONCLUSION SEB promoted Th1 cytokines production at high concentrations, and enhanced Th2 cytokines expression and Th2 immune response at low concentrations.
Animals ; Cytokines ; metabolism ; Enterotoxins ; administration & dosage ; pharmacology ; Enzyme-Linked Immunosorbent Assay ; Interferon-gamma ; metabolism ; Interleukin-2 ; metabolism ; Interleukin-4 ; metabolism ; Interleukin-5 ; metabolism ; Male ; Maxillary Sinus ; drug effects ; metabolism ; Nasal Mucosa ; metabolism ; RNA, Messenger ; metabolism ; Rabbits ; Th1 Cells ; Th2 Cells ; Transcription Factors ; metabolism

This study was aimed to investigate the effect of clostridium difficile toxin A (Tcd A) on proliferation of K562 cells and its mechanism. The proliferative activity of K562 cells exposed to Tcd A was tested by MTT assay; cell cycle distribution and mitochondrial membrane potential were analyzed by flow cytometry; the protein expression of cytochrome C and DNA fragmentation were observed by immunohistochemistry staining and agarose gel electrophoresis respectively. The results indicated that Tcd A inhibited proliferation of K562 cells in a time-and concentration-dependent manner. Cells were arrested at G(0)/G(1) phase. Peak of apoptosis appeared. The protein expression of cytochrome C increased as compared with control group (p < 0.05). Agarose gel electrophoresis of DNA from K562 treated with Tcd A revealed a "ladder" pattern. It is concluded that clostridium difficile toxin A can inhibit proliferation and induce apoptosis of K562 cells. The mechanism may be in relation to decrease of mitochondrial membrane potential and the release of cytochrome C from mitochondria matrix.
Apoptosis ; drug effects ; Bacterial Toxins ; pharmacology ; Cell Proliferation ; drug effects ; Enterotoxins ; pharmacology ; Humans ; K562 Cells

This study was purposed to investigate the growth inhibition and apoptosis-inducing effect of Clostridium difficile toxin A (TcdA) on the leukemia cell line K562. The proliferative activity of K562 cells exposed to Tcd A was tested by MTT assay, cell apoptosis was detected by flow cytometry; immunocytochemistry and colorimetric assay were employed to detect the protein expressions of BCL-2/BAX and the activity of Caspase-3, respectively. The results indicated that the proliferation of K562 cells was inhibited in a time-and dose-dependent manner after exposure to Tcd A for 24, 48 and 72 hours, the cells displayed the typical apoptotic, morphological changes, the expression of BCL-2 protein was down-regulated but the expression of BAX protein was signficantly increased, compared with control group (p < 0.05). In addition, caspase-3 was activated in a concentration-dependent manner. It is concluded that Tcd A inhibits cell growth of K562 by inducing apoptosis, and the up-regulation of BAX protein and activation of caspase-3 may play important roles in these processes.
Apoptosis ; drug effects ; Bacterial Toxins ; pharmacology ; Caspase 3 ; metabolism ; Enterotoxins ; pharmacology ; Gene Expression Regulation, Leukemic ; Humans ; K562 Cells ; drug effects ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

Clinical application of staphylococcal enterotoxin C2 (SEC2) was restricted during the cure of malignant tumor due to its side-effects. The aim of this study was to obtain SEC2 mutant, preserving the important functional sites responsible for the T-cell stimulatory activities but removing the sites responsible for emetic activity, through truncation of SEC2. It would efficiently solve the question of SEC2 side-effect. According to the results of methyl thiazol tetrazolium (MTT) assay in vitro, novel truncated SEC2 mutant (NSM) efficiently stimulated T-cell proliferation and inhibited the growth of such tumor cells as human colorectal cancer cells (Cx-1) and human breast cancer cells (MCF-7) in vitro. Activities of T cell stimulating and anti-tumor of NSM were similar to those of SEC2. According to results of animal experiments, the mutant no longer induced emetic response even if the dose was a 10-fold excess of the amount of SEC2 required. And also, NSM obviously inhibited the tumor growth in tumor-bearing mice. Therefore, we obtained novel truncated staphylococcal enterotoxin C2 mutant, which could efficiently inhibit the growth of tumor cells. It will become novel anti-tumor agents with the lowest side-effects and best treatment effects in clinic.
Animals ; Antineoplastic Agents ; adverse effects ; pharmacology ; Breast Neoplasms ; immunology ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; immunology ; pathology ; Enterotoxins ; genetics ; immunology ; Humans ; Mice ; Mutant Proteins ; immunology ; Staphylococcus aureus ; immunology ; Superantigens ; immunology ; T-Lymphocytes ; immunology ; Vomiting ; prevention & control

BACKGROUND AND OBJECTIVEImmunocompromised patients with malignant tumor always lack of strong anti-tumor immune response, because the antigenicity of tumor cells is weak, and antigen-presenting cell function is low, so that can not be effectively presenting tumor antigens to the lymphocytes. Therefore, how to effectively induce anti-tumor immune response is the key issue. Through the study on establishing a method to culture dendritic cells (DC) in vitro and to observe the anti-lung cancer immunological effect induced by DC, we provided definite experiment basis for the clinic application of vaccine based on DC.

METHODSThrough the experiment we get the soluble antigen polypeptide from lung cancer cells GLC-82 by 3 mol/L potassium chloride. DCs are cultured and obtained from peripheral blood mononuclear cell by GM-CSF, IL-4 and TNF-a. DCs are identified by flow cytometer (FCM) and immunostaining. DCs modified by lung cancer tumor soluble antigen (TSA) and staphylococcal enterotox in A (SEA), DCs modified by TSA or DCs modified by SEA or DCs modified by nothing were cultivated together with T lymphocyte, and the obtained cells are named TSA-SEA-DCL or TSA-DCL or SEA-DCL or DCL as effector cells. The anti-tumor activity of every effector cells against target cells was assayed with MT method. Shape of DCs and effector cells, and the process of killing target cells were observed in microscope.

RESULTSInduced DCs expressed more CD1a, CD80 and HLA-DR, which had typical cell traits such as tree branch. The killing ratio of the TSA-SEA-DCL in vitro to GLC-82 is larger than TSA-DCL, SEA-DCL and DCL, also larger than to K562. When the effector cells cultivate with target cells, we can observe the CTL approach and gather to the cancer cell, induce it necrosis and apoptosis.

CONCLUSIONRipe DCs that have typical characteristic and phenotype could be induced successfully. High potency and relatively specific antilung caner effect can be prepared in virtue ofDC Bacterin Induced by lung caner TSA and SEA.

Antigens, Neoplasm ; immunology ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; Enterotoxins ; immunology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Immunotherapy ; Interleukin-4 ; pharmacology ; Lung Neoplasms ; immunology ; therapy ; Superantigens ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

It has been well established that bacterial superantigens lead to the induction and aggravation of chronic inflammatory skin diseases. We investigated the clinical significance of serum specific immunoglobulin E (lgE) to the staphylococcal superantigens staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB), and toxic shock syndrome toxin (TSST)-1 in patients with chronic urticaria (CU), focusing on the differences in these prevalences between aspirin-intolerant CU (AICU) and aspirin-tolerant CU (ATCU) patients. Aspirin sensitivity was confirmed by oral aspirin provocation test. There were 66 patients AICU and 117 patients ATCU in the study. Serum IgE antibodies specific for SEA, SEB, and TSST-1 were measured by the ImmunoCAP test and the patients were compared with 93 normal controls (NC). The prevalences of serum specific IgE to staphylococcal superantigens were significantly higher in CU than in NC patients (IgE to SEA, 13.7% vs. 5.4%; IgE to SEB, 12.0% vs. 4.3%; IgE to TSST-1, 18.0% vs. 6.5%; p<0.05, respectively). The patients with specific IgE to SEA, SEB, and TSST-1 had higher serum total IgE levels and higher rates of atopy. Significant associations were noted between the prevalence of specific IgE to SEA and SEB and the HLA DQB1*0609 and DRB1*1302 alleles in the AICU group. We confirmed that a sub-population of patients with CU possesses serum IgE antibodies to SEA, SEB, and TSST- 1. Particularly, the IgE immune response to TSST-1 is associated with aspirin sensitivity in CU patients.
Adolescent ; Adult ; Aged ; Anti-Inflammatory Agents, Non-Steroidal/pharmacology ; Antigens/*chemistry ; Aspirin/pharmacology ; Bacterial Toxins/metabolism ; Chronic Disease ; Enterotoxins/metabolism ; Female ; Humans ; Immunoglobulin E/*chemistry/metabolism ; Male ; Middle Aged ; Phenotype ; Staphylococcus/*genetics/immunology ; Superantigens/metabolism ; Urticaria/*immunology

BACKGROUND: Recently the association between the virulence factors of Staphylococcus aureus and the outcome of the patients infected with the organism appears to be the subject of active investigation. Toxic shock syndrome toxin-1 (TSST-1) is thought to be a clinically more significant virulence factor than other staphylococcal toxins. We attempted to produce and characterize monoclonal antibodies to staphylococcal TSST-1. METHODS: An important epitope of TSST-1, amino acids 1-15 region, was synthesized into a peptide antigen, and Balb/c mice were immunized by intraperitoneal injection of the synthetic antigen. Hybridomas were produced by fusing immunized murine splenocytes with immortal myeloma cells. Hybridomas were cloned through a limiting dilution method. Stable cultured hybridoma was injected into the peritoneal cavity of Balb/c mice, and peritoneal fluid containing the monoclonal antibody was produced. RESULTS: One IgG2b type monoclonal antibody and two IgM type monoclonal antibodies were obtained. The IgG2b type monoclonal antibody was able to detect 5 microgram of TSST-1 with Western blot analysis and showed a strong reactivity to TSST-1 with ELISA. CONCLUSIONS: Highly immunoreactive anti-TSST-1 monoclonal antibody was produced by the use of synthesized peptide antigen. Diagnostic and protective capacity of this monoclonal antibody should be evaluated in the future.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal/biosynthesis/*immunology/isolation & purification ; Bacterial Toxins/*immunology ; Blotting, Western ; Enterotoxins/*immunology ; Enzyme-Linked Immunosorbent Assay ; Hybridomas/metabolism ; Mice ; Molecular Sequence Data ; Peptides/chemical synthesis/pharmacology ; Superantigens/*immunology

OBJECTIVETo investigate the contamination of Staphylococcus aureus isolates in ice cream by phenotypic typing and molecular typing.

METHODSThe Staphylococcus aureus isolates were separated from ice cream, filler, cutter, salves and material. The separated isolates were characterized by drug-resistance, staphylococcal enterotoxin (SEA-E), SE (A-E, G-J) genes and pulsed-field gel electrophoresis (PFGE) types.

RESULTTwo Staphylococcus aureus isolates were separated, one from ice cream, another from cutter. Their characteristics of drug-resistance, staphylococcal enterotoxin (SEA-E), SE (A-E,G-J) genes and PFGE type were the same.

CONCLUSIONThe two Staphylococcus aureus isolates were the same clone. The contaminated Staphylococcus aureus isolates could be traced to the contaminated cutters.

Anti-Bacterial Agents ; pharmacology ; Bacterial Typing Techniques ; Electrophoresis, Gel, Pulsed-Field ; Enterotoxins ; genetics ; Food Microbiology ; Ice Cream ; microbiology ; Microbial Sensitivity Tests ; Staphylococcus aureus ; classification ; drug effects ; isolation & purification

Hydrophilic low molecular drugs, peptides and proteins, which are always poor in bioavailability, are mainly absorbed through the paracellular way in which the tight junction is the elementary framework. The tight junctions are a multiple unit structure composed of multiprotein complex that affiliates with the underlying apical actomyosin ring. Tight junction proteins are identified including transmembrane proteins (occludin, claudin and JAM) , cytoplasmic plaque proteins (ZO-1, ZO-2, ZO-3 and cingulin) and cytoskeleton. Traditional absorption enhancers can usually impair mucous membranes which constraint the utilization of these enhancers. Recently, with the increasing knowledge of the structure and function of tight junctions, many new absorption enhancers have been developed such as NO donor, CPE, Zot, and so on. In vivo and in vitro studies have shown that these enhancers could be effectively used to increase the absorption of paracellular markers and low bioavailable drug across intestinal epithelium with lower side effect. In short, the transient opening of the tight junctions by these enhancers provides new ideas that could help in novel drug delivery of therapeutic agents.
Animals ; Biological Availability ; Cell Adhesion Molecules ; metabolism ; Cholera Toxin ; pharmacology ; Claudin-1 ; Cytoskeleton ; metabolism ; Decanoic Acids ; pharmacology ; Drug Delivery Systems ; Enterotoxins ; pharmacology ; Humans ; Intestinal Absorption ; drug effects ; Membrane Proteins ; metabolism ; Nitric Oxide Donors ; pharmacology ; Occludin ; Phosphoproteins ; metabolism ; Receptors, Cell Surface ; metabolism ; Tight Junctions ; metabolism ; physiology ; Zonula Occludens-1 Protein

OBJECTIVETo evaluate the effects of Staphylococcus aureus enterotoxin B (SEB) on proinflammatory cytokine/chemokine releases in primary human nasal epithelial cell (HNEC).

METHODSEpithelial cells of nasal polyps (NP) and inferior turbinate (IT) were cultured without serum under stimulus of SEB 1, 10, 100 ng/ml, IL-1beta 20 ng/ml and SEB 10 ng/ml + dexamethasone 13 ng/ml for 12,24 and 48 h, respectively. The expression of IL-5 and Granulocyte-macrophage colony stimulating factor (GM-CSF) mRNA derived from epithelial cells was detected by in situ hybridization.

RESULTS(1) The expression of IL-5 and GM-CSF mRNA was time and dose-dependent, and reached to a peak under SEB 10 ng/ml for 24 h (P < 0.05). The mRNA expressed more intensively in epithelial cells from NP than IT (P < 0.05). (2) The expression of IL-5 and GM-CSF mRNA increased less under the stimulus of IL-1beta than SEB 10 ng/ml (P < 0.05). (3) The mRNA level of IL-5 and GM-CSF decreased under the stimulus of SEB + dexamethasone 13 ng/m when compared with the stimulus of SEB 10 ng/ml (P < 0.05).

CONCLUSIONSEB showed proinflammatory effects on HNEC.

Cells, Cultured ; Dexamethasone ; pharmacology ; Enterotoxins ; pharmacology ; Epithelial Cells ; metabolism ; Granulocyte-Macrophage Colony-Stimulating Factor ; metabolism ; Humans ; Interleukin-1beta ; metabolism ; Interleukin-5 ; metabolism ; Nasal Mucosa ; cytology ; metabolism ; pathology ; RNA, Messenger ; metabolism