Establishment of a mouse model of IgA nephropathy induced by superantigen staphylococcal enterotoxin B / 中国比较医学杂志

Objective To establish a mouse model of IgA nephropathy and to observe its biochemical and pathological characteristics. Methods Twelve BALB/c mice were randomly divided into the normal group and model group, with 6 mice in each group. Mice in the model group received an intravenous injection of 0. 8 mg/kg superantigen staphylococcal enterotoxin B (SEB) into the tail vein once a week for three weeks. At the end of the 4th week, the mice were sacrificed, and the 24 h-urinary protein, urinary microalbumin, the renal function indicators BUN, Scr and UA were measured, levels of liver function indicators ALT, AST, ALP, and the blood lipid levels of TC, TG, and LDL were determined, the renal morphological changes were examined by pathology using HE, PAS, PASM and Masson staining, and by electron microscopy, the IgA deposition in the renal tissue was observed with immunofluorescence, and the liver and small intestine were observed by pathology using HE staining. Results Compared with the normal group, the mice of model group showed increased 24-hour urinary protein and urinary microalbumin (P<0. 01), increased CREA and UA (P<0. 05), but not significantly changed BUN, TP and ALB. The liver function indicator AST was significantly increased (P<0. 05), but ALT and ALP were not significantly changed. The blood lipid TG was significantly decreased (P<0. 05) and LDL increased (P<0. 01), while the TC was not significantly changed. The kidney tissues had moderate histological changes, and immunofluorescence observation showed granular or massive IgA deposition in the renal glomerular mesangium. The liver tissue had some inflammatory cell infiltration and hepatocyte necrosis. The small intestine showed slender and shortened villi with widened inter-villous space and sloughed off epithelial cells, dilated central lacteal, and lymphocyte infiltration. Conclusions A mouse model of IgA nephropathy can be successfully established by tail vein injection of superantigen staphylococcal entrotoxin B.

Prevalence of enterotoxin a and b genes in Staphylococcus aureus isolated from clinical samples and healthy carriers in Gorgan City, North of Iran.

Background: Infections due to Staphylococcus aureus, a nosocomial and community-acquired pathogen, is a major public health problem. Wide range of diseases caused by S. aureus from mild infections of the skin and soft tissue to life threatening diseases which is due to having several virulence factors such as enzymes, toxins and also enterotoxins. Enterotoxin A (SEA) and enterotoxin B (SEB) are superantigens and gasterointestinal toxins causing food poisoning. The sea and seb genes encode SEA and SEB, respectively. The goal of this study was determine the prevalence of sea and seb genes in S. aureus isolated from patients and healthy carriers in Gorgan city, north of Iran. Materials and Methods: 170 isolates of S. aureus (95 from patients and 75 healthy carriers) were collected during 1 year. After identifi cation and purifi cation, DNA extraction was done by phenol — chloroform method. Amplification of sea and seb genes was done by specific primers and polymerase chain reaction method. Results: Among the 170 isolates of S. aureus, 60.6% and 27.1% contained sea and seb genes, respectively. The frequencies of isolates containing sea and seb genes were 58.8% and 61.3%, respectively, in methicillin-resistant Staphylococcus aureus (MRSA) isolates and 23.5% and 28.6%, respectively, in methicillin-sensitive Staphylococcus aureus (MSSA) isolates which were not statistically signifi cant. The frequency of these genes was not related to age, sex and source of isolation in the patients. Conclusion: This study showed that a high proportion of S. aureus isolates carried sea gene, whereas the frequency of seb gene in this region was predictable.

Evaluation of systemic and mucosal immune responses in mice administered with novel recombinant Salmonella vaccines for avian pathogenic Esherichia coli / 대한수의학회지

Avian pathogenic Escherichia coli (APEC) is a causative agent for a number of extra intestinal diseases and account for significant losses to the poultry industry. Since protective immunity against APEC is largely directed to virulence antigens, we have individually expressed four different viulence antigens, papA, papG, IutA, and CS31A, using an attenuated Salmonella Typhimurium and a plasmid pBB244. Following oral immunization of mice with combination of two or four of these strains, serum IgG and mucosal IgA responses were elicited against each antigen represented in the mixture. The antigen-specific mucosal IgA responses were significantly higher in the group of mice immunized with the heat-labile Escherichia coli enterotoxin B subunit (LTB) strain than those in the group of mice immunized without the LTB strain. While, there was no significant difference between these two groups in antigen-specific serum IgG responses. The results showed that LTB could act as mucosal immune adjuvant. To assess the nature of immunity, the distribution of antigen-specific IgG isotypes was analyzed. All groups promoted Th1-type immunity as determined by the IgG2a/IgG1 ratio. Thus, our findings provided evidence that immunization with a combination of several vaccine strains is one of the strategies of developing effective vaccines against APEC.

The immunological effect of group A and C meningococcal conjugate vaccine with double protein carriers / 中华微生物学和免疫学杂志

Objective To evaluate the immunogenicity of group A and C meningococcal polysaccharides conjugates using different proteins as carriers. Methods Heat-labile enterotoxin B subunit (LTB)pentamer form was expressed in E. coli. The target protein was identified and purified by cation-exchange chromatography. Then biological activity of rLTB was tested using GM1-ELISA. GCMP was conjugated to rLTB with the chemical method (ADH). Furthermore, the mice were immunized with GAMp-TT/GCMP-TT conjugates and GAMP-TT/GCMP-rLTB conjugates via peritoneal. Finally the anti-polysaccharide antibody was detected. Results The GAMP-TT/GCMP-rLTB conjugate elicits remarkably higher serum antibodies in mice than GAMP-TT/GCMP-TT conjugate. Conclusion These results indicated that polysaccharide conjugates using different proteins as carriers were superior to those using only one protein as carrier.

Perfil de producción de citoquinas en linfocitos T de sangre periférica de pacientes con poliposis nasal y asma bronquial en respuesta a la estimulación con enterotoxina estafilocócica B / Cytokine production profile in peripheral blood T lymphocytes from patients with nasal poliposis and bronchial asthma in response to staphylococcal enterotoxin B

Introducción: La poliposis nasal (PN) se presenta frecuentemente asociada a asma bronquial (AB). La enterotoxina estafilocócica B (SEB) jugaría un papel en su patogenia. No se ha estudiado si el perfil de citoquinas inducido por SEB en linfocitos T (LT) de pacientes con PNyAB difiere del de controles sanos. Objetivo: Comparar el perfil de citoquinas de LT de sangre periférica de pacientes con PN-AByde controles, estimulados con SEB o concanavalina A (ConA). Material y método: Células mononucleares de sangre periférica de 9 pacientes con PN-AB y de 6 controles se estimularon con SEB o ConA. El porcentaje LT CD4+ productores de interferón (IFN)-y, interleuquina (IL) IL-4, IL-5, IL-17 e IL-21 se determinó mediante citometrfa de flujo. Resultados: El grupo PN-AB presentó un menor porcentaje de LT productores de IL-5 que los controles al estimularse con SEB y con ConA. No hubo diferencia en las otras citoquinas estudiadas. Discusión: Nuestros resultados en sangre periférica difieren de lo descrito en tejido de pólipos nasales. Conclusión: Se sugiere que la respuesta inflamatoria de la PN se originaría localmente ya que los LT de sangre de pacientes con PN-AB no muestran una polarización hacia perfiles proinflamatorios con los estímulos utilizados.

Introduction: Nasal poliposis (NP) is frequently associated with bronchial asthma (BA) and its pathogenesis is still unknown. Staphylococcal enterotoxin B (SEB) has been implicated in the development of NP, however if the SEB-induced cytoklne profile of peripheral blood T lymphocytes (TL) of PN-BA patients differs from that of normal controls has not been studied. Aim: To compare the cytoklne profile of CD4+ TL from NP-BA and controls stimulated with SEB or concanavalin A (ConA). Material and method: Peripheral blood mononuclear cells from 9 NP-BA patients and from 6 controls were stimulated with SEB or ConA. The percentage of interferon (IFN)-y, interleukin {II) 11-4,11-5,11-17, and 11-21 producing TL was analyzed by flow cytometry Results: The percentage of SEB and ConA stimulated CD4+ IL-5-producing TLs was lower in the NP-BA group compared to the control group. There were no differences in the other cytokine-producing populations. Discussion: Unlike what is described in nasal polyp tissue, our findings show a diminished production of IL-5 by peripheral TL from the NP-AB group. Conclusion: A local sinonasal origin of the chronic inflammation is suggested since peripheral blood TL of NP-BA patients do not show a pro-inflammatory polarization with the tested stimuli.

Effect of Staphylococcal Enterotoxin on the Development of Allergic Rhinitis in Mice

BACKGROUND AND OBJECTIVES: The aim of this study is to investigate the role of staphylococcal enterotoxin B (SEB) in the development of allergic rhinitis. MATERIALS AND METHODS: Nasal mucosa and serum were obtained from sensitized mice and control groups, and the frequencies of allergic symptoms, such as sneezing and nasal rubbing, were counted. Eosinophil counts in the nasal mucosa were compared between the study groups. The serum levels of ovalbumin-specific IgE were measured by ELISA. Differences between the sensitized and control groups were statistically analyzed using the Kruskal-Wallis test and the Mann-Whitney U test. RESULTS: The frequencies of sneezing and serum levels of ovalbumin-specific IgE were significantly higher in the groups locally sensitized with SEB than in the control group. On the other hand, they sneezed less frequently and showed lower serum levels of ovalbumin-specific IgE than those in the group locally sensitized with ovalbumin. CONCLUSION: SEB may participate in the pathogenesis of allergic rhinitis although it is a less potent inducer than ovalbumin.

Rat Model of Staphylococcal Enterotoxin B-Induced Rhinosinusitis

OBJECTIVES: It has been proposed that microbial persistence, superantigen (SA) production, and host T-cell response may be involved in the development of chronic rhinosinusitis. According to the SA hypothesis, a single intranasal application of SA such as staphylococcal enterotoxin B (SEB) may induce chronic eosinophilic rhinosinusitis. This study aimed to develop a rat model of rhinosinusitis induced by intranasally applied SEB. METHODS: Forty microliter of SEB (100 microgram/mL) or phosphate buffered saline was applied intranasally through each naris in 4 weekold Sprague-Dawley test rats (N=36) and controls (N=16), respectively. Following sacrifice at 1, 5, 14, and 28 days, the obtained nasal cavity and sinuses were prepared for histologic investigation. The histologic sections were examined in a blind manner for the ratio of the sinus spaces occupied by inflammatory cell clusters and the number of inflammatory cells in the lamina propria. RESULTS: Infiltration of neutrophils in the lamina propria and appearance of neutrophil clusters in the sinus spaces were observed in the SEB-applied rats. The ratio of the sinus spaces occupied by neutrophil clusters and the number of neutrophils infiltrated in the lamina propria increased significantly at day 1 as compared with the control rats. CONCLUSION: Intranasally applied SEB induces acute neutrophilic rhinosinusitis in rats. Eosinophilic inflammation was not demonstrated. The mere presence of SA in the nose does not necessarily induce SA-induced inflammation, as suggested by the SA hypothesis.

Rat Model of Staphylococcal Enterotoxin B-Induced Rhinosinusitis

OBJECTIVES: It has been proposed that microbial persistence, superantigen (SA) production, and host T-cell response may be involved in the development of chronic rhinosinusitis. According to the SA hypothesis, a single intranasal application of SA such as staphylococcal enterotoxin B (SEB) may induce chronic eosinophilic rhinosinusitis. This study aimed to develop a rat model of rhinosinusitis induced by intranasally applied SEB. METHODS: Forty microliter of SEB (100 microgram/mL) or phosphate buffered saline was applied intranasally through each naris in 4 weekold Sprague-Dawley test rats (N=36) and controls (N=16), respectively. Following sacrifice at 1, 5, 14, and 28 days, the obtained nasal cavity and sinuses were prepared for histologic investigation. The histologic sections were examined in a blind manner for the ratio of the sinus spaces occupied by inflammatory cell clusters and the number of inflammatory cells in the lamina propria. RESULTS: Infiltration of neutrophils in the lamina propria and appearance of neutrophil clusters in the sinus spaces were observed in the SEB-applied rats. The ratio of the sinus spaces occupied by neutrophil clusters and the number of neutrophils infiltrated in the lamina propria increased significantly at day 1 as compared with the control rats. CONCLUSION: Intranasally applied SEB induces acute neutrophilic rhinosinusitis in rats. Eosinophilic inflammation was not demonstrated. The mere presence of SA in the nose does not necessarily induce SA-induced inflammation, as suggested by the SA hypothesis.

The Study of SEB/OVA Allergic Rhinitis Mice Model / 医学研究杂志

Objective To establish mice modle of allergic rhinitis(AR) and to study the role of Staphylococcal enterotoxin B(SEB) and ovalbumin(OVA) in the modle.Methods Forty Balb/c mice were evenly randomized into OVA group,SEB group,OVA+SEB group and normal sodium group and AR modle was established.The symptom scores,total serum IgE concentration,IL-4 concentration were analyzed by factorial design.Meanwhile,the morphology change of nasal mucosa was observed.Results The symptom scores in OVA group,SEB group,OVA+SEB group and normal sodium group were 6.80?1.03,0.90?0.99,0.70?0.82,0.60?0.70 respectirely.The interaction of OVA and SEB had statistical significance(P

Effect of regulatory T cell in SEB/OVA allergic rhinitis of animal model / 中国耳鼻咽喉头颈外科

OBJECTIVE To establish mice model of allergic rhinitis(AR) and study the role of Staphylococcal enterotoxin B(SEB)and ovalbumin(OVA)in the model,and investigate the change of regulatory T cell(Treg)in the nasal mucosa of mice.METHODS Forty Balb/c mice were randomized into OVA group(A),SEB group(B),OVA+SEB group(C)and normal solution group(D).AR model was established.The symptom scores and count of Foxp3 positive cells in nasal mucosa were analyzed by factorial design.RESULTS The symptom scores in Group A,B,C,D were 0.90?0.99,0.70?0.82,6.80?1.03,0.60?0.70 respectively.Group C was successfully established as AR model.OVA and SEB had interaction(P

Role of Staphylococcal Superantigen in Atopic Dermatitis: Influence on Keratinocytes

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.

Expression of Toll-like Receptors on the Macrophages Activated by Bacterial Superantigens / 감염과화학요법

BACKGROUND: Staphylococcal enterotoxin B (SEB) as a prototype superantigen is known to play a pivotal role in toxic shock syndrome and severe sepsis. However, the precise mechanism initiating the activation of innate effector cells by SEB is unclear. Recently, Toll-like receptors (TLRs), the sensor of pathogen associated molecular pattern (PAMP), have been reported to be expressed abundantly in monocytic lineage-cells. The purpose of this study is to investigate whether TLRs are involved in the SEB-induced immune cell activation and to prove the differential TLRs expression in response to SEB and/or lipopolysaccharide (LPS). MATERIALS AND METHODS: SEB was purified by dye ligand affinity chromatography. The mRNA expression of TLR1-9 in human peripheral blood mononuclear cells (PBMC) and human monocyte- like THP-1 cell line stimulated by SEB and/or LPS was detected by RT-PCR. RESULTS: The treatment of PBMC with SEB elicited significant changes in the expression of several TLRs. Interestingly, the mRNAs of TLR1 and TLR5 were clearly up-regulated in PBMC, whereas mRNA of TLR4 was down-regulated in the very early period of stimulation within 1-2 hours, and subsequently up-regulated 3 hours later after the stimulation. The up-regulation of mRNA of TLR4 was detected in PBMC stimulated by LPS. The up-regulation was more prominent in the cells exposed concomitantly to SEB and LPS. The mRNA expression pattern of TLR4 in THP-1 cell line stimulated by SEB or LPS was comparable to those of PBMC. CONCLUSION: This study indicates that SEB triggers inflammatory signals on macrophages and PBMC by engaging TLRs, particularly TLR4. The combination of LPS and SEB synergistically modulates TLR4 signaling.

Expression of Toll-like Receptors on the Macrophages Activated by Bacterial Superantigens / 감염과화학요법

BACKGROUND: Staphylococcal enterotoxin B (SEB) as a prototype superantigen is known to play a pivotal role in toxic shock syndrome and severe sepsis. However, the precise mechanism initiating the activation of innate effector cells by SEB is unclear. Recently, Toll-like receptors (TLRs), the sensor of pathogen associated molecular pattern (PAMP), have been reported to be expressed abundantly in monocytic lineage-cells. The purpose of this study is to investigate whether TLRs are involved in the SEB-induced immune cell activation and to prove the differential TLRs expression in response to SEB and/or lipopolysaccharide (LPS). MATERIALS AND METHODS: SEB was purified by dye ligand affinity chromatography. The mRNA expression of TLR1-9 in human peripheral blood mononuclear cells (PBMC) and human monocyte- like THP-1 cell line stimulated by SEB and/or LPS was detected by RT-PCR. RESULTS: The treatment of PBMC with SEB elicited significant changes in the expression of several TLRs. Interestingly, the mRNAs of TLR1 and TLR5 were clearly up-regulated in PBMC, whereas mRNA of TLR4 was down-regulated in the very early period of stimulation within 1-2 hours, and subsequently up-regulated 3 hours later after the stimulation. The up-regulation of mRNA of TLR4 was detected in PBMC stimulated by LPS. The up-regulation was more prominent in the cells exposed concomitantly to SEB and LPS. The mRNA expression pattern of TLR4 in THP-1 cell line stimulated by SEB or LPS was comparable to those of PBMC. CONCLUSION: This study indicates that SEB triggers inflammatory signals on macrophages and PBMC by engaging TLRs, particularly TLR4. The combination of LPS and SEB synergistically modulates TLR4 signaling.

The Influence of Superantigen Staphylococcal Enterotoxin B on the Proliferation of TILs from Rectum Adenocacinoma / 中国医师杂志

Objective To study the effects of staphylococcal enterotoxin B(SEB) on the proliferation of tumor infiltrating lymphocytes(TILs) from rectum adenocacinoma.Methods The TILs from patients with rectum adenocacinoma were stimulated with SEB and interleukin 2(IL-2) respectively,and then the proliferation of TILs,the secretion of IL-2 and tumor necrosis factor-?(TNF-?) were determined.Results SEB presented profound stimulating effect on the TILs from rectum adenocarcinoma both the proliferation of TILs and the secretion of cytokines.Compared with the IL-2,SEB stimulated TILs more quickly,and SEB acted more effectively in the early stage but weakly in the late stage.Conclution SEB was an effective TIL stimulator.

Purification of SEB by McAb affinity chromatography and activity analysis / 中国免疫学杂志

Objective:To prepare highly purified Staphylococcal enterotoxin B(SEB) by affinity chromatography and test its activities.Methods:Anti-SEB McAb(1D2) purified by precipitation method with caprylic acid was coupled to Sepharose 4B. And then the SEB was isolated using an affinity chromatography column. In addition, we analyzed the superantigen activity and antigen activity of SEB.Results:The purification efficiency of SEB was 60.71% by affinity chromatography. Its purity was higher than those of standard preparation and the SEB purified by ion change chromatography. At the same time, the purified SEB by affinity chromatography possesses favourable activities of superantigen and antigen.Conclusion:McAb affinity chromatography could be used for purification of SEB with high efficiency.

Specific Antibodies to Staphylococcal Enterotoxin B in Children with Atopic Dermatitis / 소아알레르기및호흡기학회지

PURPOSE: Exotoxin secreted by Staphylococcus aureus has been identified as a possible trigger factor in atopic dermatitis(AD). We investigated the production and the role of circulating antibodies with specificity to staphylococcal enterotoxin B(SEB) in children with AD, and compared with those of healthy controls. METHODS: Forty children with AD and 40 nonatopic healthy children were studied. The severity was determined by the criteria of Rajka. The serum levels of specific antibodies(IgG, IgM, IgE) against SEB were determined by ELISA. The levels and positive rates were compared between the two groups. The correlation between the levels of specific antibodies and the severity of AD or their ages was studied. RESULTS: The children with AD had significantly higher levels of serum SEB specific IgG(P=0.0193), IgM(P=0.011) and IgE(P=0.0001) than the nonatopic children. The proportions of children with AD showing positive to IgG, IgM and IgE were 52.5%(21/40), 62.5%(25/40) and 67.5%(27/40), respectively. The levels of SEB-specific IgE were correlated with the severity of AD(P=0.0004), but no such correlation was seen with IgG or IgM. CONCLUSION: SEB may be involved in exacerbation of AD. The SEB-specific IgE may be an important index of the clinical severity of AD. The SEB-specific IgG or IgM may be produced during the exposure to the SEB antigen, but may not be protective against SEB in AD.

Association of the proliferation of CD4(+)/Vbeta17(+) cells and peripheral blood mononuclear cells in response to staphylococcal enterotoxin B(SEB) in atopic dermatitis / 천식및알레르기

BACKGROUND AND OBJECTIVE: Atopic dermatitis(AD) is a chronic inflammatory skin disease with a high incidence in early childhood. Staphylococcus aureus(SA) is found at high concentrations in over 90% of AD skin lesions compared with 5-37% of age-matched controls. SA isolates from AD subjects have a high prevalence(37-57%) of superantigen-producing strains. And staphylococcal enterotoxin B(SEB) has been shown to induce inflammatory reactions following application to intact skin of normal and atopic subjects. These findings suggest that SA toxin produced by SA may be linked with initiation or aggravation of AD, but the role of satphylococcal enterotoxin to the T cell in the pathogenesis of AD has not been determined clearly. This study was conducted to determine whether staphylococcal enterotoxin might have a role as a superantigen in the pathogenesis of AD. Materials and Method: We investigated the proliferative responses of peripheral blood mononuclear cell(PBMC) from 8 patients with AD and 10 age-matched normal controls. We also assessed T cell markers and T cell receptor(TCR) Vbeta chain expression by flow cytometry with and without SEB stimulation. RESULTS: PBMC from AD patients showed increased proliferation to SEB 100 pg/ml and 1000 pg/ml compared to controls. There were no differences of CD3(+), CD4(+), and CD8(+) cells after SEB stimulation between the two groups. And there were also no differences of TCR Vbeta2(+) and TCR Vbeta8(+) cells with and without SEB stimulation, but TCR Vbeta17(+) cells were increased after SEB stimulation not only in AD patients but also in controls compared to culture without SEB. The expressions of TCR Vbeta17 chain of CD3(+) and CD4(+) cells after SEB stimulation were increased in AD patients compared to controls. Furthermore, there was positive correlation between the enhanced PBMC proliferative responses to SEB and increased expressions of SEB reactive TCR Vbeta17(+)/CD4(+) cells in AD patients and controls. CONCLUSION: These findings suggest that SEB is important in the pathogenesis of atopic dermatitis and also provide evidence that the increased use of certain TCR Vbeta families is of functional significance.

Immunohistochemical Characterization of Dendritic Cells after Systemic Administration of Staphylococcal Enterotoxin B / 대한해부학회지

This study was performed to investigate the effects of Staphylococcal enterotoxin B (SEB) on dendritic cells (DCs) and other immune cells in the major lymphoid organs. A single dose of SEB (25 microgram/kg) was administered to BALB/c mice by intraperitoneal injection. After the mice were sacrificed in groups of three at 2 h, 6 h, 1 day, 2 days, 3 days, 1 week and 2 weeks, the spleen, lymph node and thymus were removed. The immunocytochemical characterization of the cells was carried out using various monoclonal antibodies in cryostat-cut sections. We demonstrated in this study the distribution patterns of DCs and their major costimulatory and adhesive molecules in the murine spleen, lymph node and thymus after SEB administration. We obtained the evidence for maturation of DCs in vivo in response to SEB. DCs were found in increased number in the periarterial lymphatitc sheath (PALS) of spleen, paracortex of lymph nodes and thymic medulla. CD86, ICAM-1 and MHC class II molecules were upregulated on the activated and matured DCs after SEB injection. The most salient feature of the present study was the differential expression pattern of the costimulatory and adhesive molecules on the activated DCs. In addition to DCs, T cells expressing T cell receptor Vbeta8 were increased in number after SEB treatment. In conclusion, SEB exhibited a potent and effective stimulative effect on DCs in vivo.

Fermentation technology in heat-labile enterotoxin B subunit of genetic recombinant E. coli / 第三军医大学学报

Objective To investigate the fermentation conditions for the heat-labile enterotoxin B subunit (LTB) of genetic recombinant E.coli. Methods The effects of different kinds of media, the range of pH, the induction time, the glucose concentration, and the fed-batch on LTB level in 10-liter fermenter under the condition of cascade controlling dissolved oxygen content were analyzed. Results Under the established conditions, the cell output per liter was 40.5g, and the expression level was 30.6%. Conclusion The results indicate that the stable fermentation technology with high efficiency has been established.