In order to characterize the immunogenicity and immunoprotection of the Staphylococcus aureus (S. aureus) surface protein Clumping factor A (ClfA), we amplified clfa genes from S. aureus Newman strain, Wood46 strain and HLJ23-1. The clfa gene from Newman strain was subsequently inserted into pQE-30 vector and the recombinant plasmid was transformed into Escherichia coli strain M15 (pREP4). The recombinant ClfA protein was expressed and purified. Then, we immunized mice with the purified recombinant protein. The antibody level and the concentration of cytokines were measured by enzyme-linked immunosorbent assay. Finally, immunized mice were challenged with S. aureus Newman, Wood46 and HLJ23-1. These results suggested that clfa gene sequences were highly conserved, and the recombinant ClfA was expressed correctly with good antigenicity. The antibody titer and the concentration of cytokines in the immunized groups increased significantly (P < 0.05) compared with control, and the mice in the immunized groups were protected against the challenge strains to some extent. These results showed that the ClfA had high immunogenicity and immunoprotective potential.
Animals ; Coagulase ; genetics ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Immunization ; Mice ; Recombinant Proteins ; genetics ; immunology ; metabolism ; Staphylococcus aureus ; metabolism ; pathogenicity

Fibronectin-binding protein (FnBPA) is a protein that expresses on cell surface of Staphylococcus aureus during early stage of infection. FnBPA was capable of promoting Staphylococcus aureus to invade cells and was viewed as a potential immune target. Based on the FnBPA-A gene two recombinant expression vectors with or without Kozak sequence were constructed. After identified and confirmed by restriction enzyme digestion and sequencing they were used to immunize C57BL/6 mice. Then induced antibody titer, T lymphocyte proliferative response and experiment mice challenge test were measured. Our result indicates that humoral immune responses and challenge experiment induced by recombinant DNA with Kozak sequence were better than those without Kozak sequence (P < 0.05). For T lymphocyte proliferative response the induced effect of recombinant DNA with Kozak sequence was higher than that without Kozak sequence, but there was no significant difference (P > 0.05). We conclude that Kozak sequence could play an important role in immune response induced by FnBPA-A recombinant DNA.
Adhesins, Bacterial ; genetics ; immunology ; Animals ; Immunization ; Mice ; Mice, Inbred C57BL ; Recombinant Proteins ; immunology ; Staphylococcus aureus ; immunology ; T-Lymphocytes ; immunology ; Vaccines, DNA ; genetics ; immunology

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

OBJECTIVETo analyse the relationship between superantigens produced by Staphylococcus aureus and the mRNA expression of T-cell receptor V beta region (TCR Vbeta), and to investigate the possible role of Staphylococcal superantigens in the pathogenesis of nasal polyps.

METHODSSinonasal mucus and polyp/mucosa tissue were obtained from patients with chronic rhinosinusitis (22 patients with bilateral nasal polyps, 15 without nasal polyps) and 12 normal subjects as comparative negative controls. Mucus specimens were assayed by enzyme-linked immunosorbent assay (ELISA) for Staphylococcal exotoxins,and analyzed for the expression of TCR Vbeta genes using the technique of reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTSThe percentages of Staphylococcus exotoxins in nasal polyps were 54.54% (21/22) for chronic rhinosinusitis with nasal polyp (CRSwNP) subjects. There were no positive results in the CRSsNP or control groups. The expressional intensity of Vbeta3 (10.02), Vbeta14 (3.54), Vbeta15 (2.39), Vbeta17 (3.48), and Vbeta20 (2.94) was increased significantly for Staphylococcal exotoxin B (SEB) positive subjects (P < 0.05). Vbeta2 (13.8) and Vbeta6. 1-3 (6.53) were significantly highly expressed for toxic shock syndrome toxin-1 (TSTf-1) positive subjects in CRSwNP group (P < 0.05). There were no dominantly used Vbeta fragments in ELISA- negative specimens. In the group of chronic rhinosinusitis without nasal polyp (CRSsNP), most of TCR Vbeta gene subfamilies demonstrated a trend toward higher expressional levels compared with those of normal controls, although there was no statistical difference (P > 0.05).

CONCLUSIONSThere was relationship between Staphylococcal superantigens and the excursion of TCR Vbeta gene spectra in nasal polyp, and superantigens possibly play an important role in the pathogenesis of CRSwNP.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Female ; Genes, T-Cell Receptor beta ; Humans ; Male ; Middle Aged ; Nasal Polyps ; genetics ; immunology ; Receptors, Antigen, T-Cell ; genetics ; Sinusitis ; genetics ; immunology ; Staphylococcus aureus ; immunology ; Superantigens ; immunology ; Young Adult

OBJECTIVEMouse factor VII (mfVII), ligand of tissue factor (TF) which is frequently over-expressed during neovascularization activated by tumor growth, was fused to staphylococcus enterotoxin A (SEA) that mediates greater intensity of T-cell activation against tumor cells. The anti-tumor effects of the mfVII-SEA chimeric protein were evaluated.

METHODSFusion of SEA and mfVII cDNA was constructed using adenovirus vector and produced in 293 packaging cell lines. The 293 cells containing the adenovirus were administered subcutaneously to mice. Fluorescence studies at the injection site and the liver were performed 3 days later. Mouse prostatic tumor RM-1 cells and mouse sarcoma MCA 205 H12 cell lines were then used in mice to create lung metastasis and subcutaneous tumor to carry out efficacy evaluation, respectively.

RESULTSAdenovirus released from the injected 293 cells only infected the subcutaneous tissue at the injection site. The in vivo experiments in mice revealed that formation of lung metastasis was strongly inhibited by the mfVII-SEA (23 +/- 8) compared to the vacant vector control group (193 +/- 38) and PBS control group (211 +/- 42) (P < 0.01). The mfVII-SEA also strongly suppressed tumor growth at the subcutaneous injection site (342.6 +/- 107.1) mm(3) compared to that of vacant vector control (2244.3 +/- 350) mm(3) and SEA (1208.3 +/- 210) mm(3) by the 23rd day.

CONCLUSIONThe chimeric protein mfVII-SEA significantly inhibits lung metastasis formation and local tumor growth.

Animals ; Antigens, Bacterial ; genetics ; immunology ; pharmacology ; Antineoplastic Agents ; pharmacology ; Enterotoxins ; genetics ; immunology ; pharmacology ; Factor VII ; genetics ; pharmacology ; Female ; Lung Neoplasms ; secondary ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Prostatic Neoplasms ; pathology ; Recombinant Fusion Proteins ; genetics ; pharmacology ; Staphylococcus ; Thromboplastin ; genetics ; pharmacology

In order to characterize the Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity, immunogenicity and immunoprotection of the Staphylococcus aureus (S. aureus) surface protein GapC, gapC gene of S. aureus was amplified from strain BMSA/855/23-1 by PCR, and was inserted into pQE-30 vector subsequently. The recombinant plasmid, designated as pQE/gapC, was transformed into E. coli strain M15 (pREP4). The recombinant GapC fusion proein was successfully expressed in E. coli M15 induced with IPTG and its GAPDH activity was confirmed by GAPDH activity assay. Then, the recombinant GapC protein, inactivated S. aureus whole cell and placebo (PBS) were administrated to healthy rabbits respectively. The IgG antibody titers, concentration of IFN-gamma and IL-4 cytokines in immunized rabbit sera were measured with Enzyme-Linked Immunosorbnent Assay (ELISA). Finally, immunized rabbits were challenged with S. aureus strain Wood46 to evaluate the immunoprotection. The IgG antibody titers against GapC and whole cell in rabbit sera reached their peaks at day 28 after boost immunization (1:64,000). The concentration of IL-4 and IFN-gamma in GapC groups rabbit sera increased significantly (P<0.05) at day 14 after boost immunization, while the concentration of those in whole cell group did not increase (P>0.05) compared with the placebo group. 4 rabbits in 5 of the protein immunized group were protected against challenge with 1 x 10(8) CFU S. aureus. The results above indicate that the expressed recombinant GapC protein have high GAPDH activity and immunogenicity, can also protect against S. aureus challenge to some extent. S. aureus GapC protein could be an attractive target for further genetic engineering vaccine.
Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Glyceraldehyde-3-Phosphate Dehydrogenases ; biosynthesis ; genetics ; immunology ; Immunization ; Male ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Staphylococcal Vaccines ; immunology ; Staphylococcus aureus ; enzymology ; genetics ; immunology ; Vaccines, Synthetic ; 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

We previously demonstrated that stimulation of bovine peripheral blood mononuclear cells (PBMCs) with staphylococcal enterotoxin C (SEC), led to an inversion of the CD4(+):CD8(+) T cell ratio and generation of an atypical CD8(+) T cell subpopulation expressing CD26. In the present study, we examined T cell apoptosis and proliferation profiles of PBMC subpopulations in cultures stimulated with SEC. Unlike when stimulated with concanavalin A, nucleic acid synthesis in bovine PBMC cultures stimulated with SEC was low during the first four days but increased greatly on day 5. In contrast, nucleic acid synthesis in human PBMC cultures stimulated with SEC increased continuously. To investigate the mechanism of delayed bovine T cell proliferation, various cell phenotypes were monitored. The inversion of the bovine CD4(+):CD8(+) T cell ratio in PBMC cultures stimulated by SEC was associated with higher proliferation and lower apoptosis of CD8(+) T cells compared to CD4(+) T cells. The mRNA levels for interleukin (IL)-4 and IL-13 were sustained over 4 days but IL-12 mRNA levels dropped to background on day 2. These data suggest that SEC induces a prolonged Th-2- biased microenvironment, and together with the inversion of the bovine CD4(+):CD8(+) T cell ratios in bovine PBMC cultures with SEC, may in part explain the inability of the mammary immune system to establish an effective response to Staphylococcus aureus infections.
Animals ; Apoptosis/drug effects/immunology ; CD4-CD8 Ratio/veterinary ; CD4-Positive T-Lymphocytes/drug effects/*immunology/microbiology ; CD8-Positive T-Lymphocytes/drug effects/*immunology/microbiology ; Cattle ; Concanavalin A/pharmacology ; Cytokines/genetics/immunology ; Enterotoxins/*pharmacology ; Female ; Lymphocyte Activation/drug effects ; Mastitis, Bovine/immunology/*microbiology ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Staphylococcal Infections/immunology/microbiology/*veterinary ; Staphylococcus aureus/*immunology

This study is to clone the gene of staphylococcal enterotoxins O, obtain recombinant protein (rSEO) and investigate its activity on mice lymphocyte. Staphylococcus aureus O gene is cloned into GST gene fusion vector pGEX-4T-1. The resultant plasmid pGEX-4T-SEO was used to transform E. coLi BL21, where the GST-SEO fusion protein was expressed efficiently. Then SEO was purified by Glutathione Sepharose 4B affinity column and digested with thrombin. The bioactivity of SEO was analyzed by MTT assay on mice lymphocyte and tumor cells. The nucleotide sequence was confirmed to code for the protein correctly, and soluble SEO was expressed efficiently in E. coli BL21 with pGEX-4T-SEO. The protein purified by affinity chromatography resulted to be one single band by SDS-PAGE detection. The MTT assay of the purified rSEO demonstrated that its abilities of stimulating T cells and inhibiting the proliferation of K562, K562-ADM and B16 cells were equivalent to that of SEC in vitro. The expression plasmid pGEX-4T-SEO was constructed and the recombinant superantigen was expressed successfully, which may provide a foundation for the further research of the anticancer activity of SEO.
Animals ; Cell Proliferation ; Cloning, Molecular ; Enterotoxins ; genetics ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Female ; Genetic Vectors ; Humans ; K562 Cells ; Lymphocytes ; cytology ; Male ; Melanoma, Experimental ; pathology ; Mice ; Mice, Inbred ICR ; Plasmids ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism ; Spleen ; cytology ; Staphylococcus aureus ; genetics ; Superantigens ; genetics ; immunology ; metabolism

BACKGROUND: Burn wounds lack normal barriers that protect against pathogenic bacteria, and burn patients are easily colonized and infected by Staphylococcus aureus. Toxic shock syndrome (TSS) is a rare but fatal disease caused by S. aureus. A lack of detectable antibodies to TSS toxin-1 (TSST-1) in serum indicates susceptibility to TSS. METHODS: A total of 207 patients (169 men and 38 women; median age, 42.5 yr) admitted to a burn center in Korea were enrolled in this study. The serum antibody titer to TSST-1 was measured by sandwich ELISA. S. aureus isolates from the patients' nasal swab culture were tested for TSST-1 toxin production by PCR-based detection of the TSST-1 toxin gene. RESULTS: One hundred seventy-four (84.1%) patients showed positive results for antibody against TSST-1. All patients aged > or =61 yr (n=28) and <26 months (n=7) were positive for the anti-TSST-1 antibody. S. aureus was isolated from 70 patients (33.8%), and 58.6% of the isolates were methicillin resistant. Seventeen patients were colonized with TSST-1-producing S. aureus. The antibody positivity in these 17 carriers was 88.2%, and the positivity in the non-carriers was 83.7%. CONCLUSIONS: Most burn patients had antibody to TSST-1, and nasal colonization with TSST-1-producing S. aureus was associated with positive titers of anti-TSST-1 antibody. Additionally, patients with negative titers of anti-TSST-1 antibody might be susceptible to TSS.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antibodies, Bacterial/*blood ; Bacterial Toxins/genetics/immunology/*metabolism ; Burns/blood/*immunology/*microbiology/pathology ; Child ; Child, Preschool ; Enterotoxins/genetics/immunology/*metabolism ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Infant ; Male ; Middle Aged ; Nasal Cavity/microbiology ; Polymerase Chain Reaction ; Prevalence ; Staphylococcal Infections/epidemiology ; Staphylococcus aureus/isolation & purification/*metabolism ; Superantigens/genetics/immunology/*metabolism ; Young Adult