CDK2 phosphorylation regulates the protein stability of KLF10 by interfering with binding of the E3 ligase SIAH1.

Downregulation of multiple cell cycle-regulatory molecules is a dominant event in TGF-ß1-mediated growth inhibition of human carcinoma cells. It is known that KLF10 mimics the anti-proliferative and apoptotic effects that TGF-ß1 has on epithelial cell growth and the growth of various tumor cells; based on these findings it is considered as a tumor suppressor. KLF10 protein expression is tightly associated with cell cycle-dependent events. However, the regulatory mechanism and its biological meaning have not been identified. In this study, we have demonstrated that KLF10 is a substrate of CDK2/cyclin E and can be phosphorylated. We also have shown that KLF10 efficiently binds to CDK2, while binding much less to CDK4, and displaying no binding to Cdk6. Using mass spectrometry, site direct mutagenesis, in vitro kinase assays and depletion assays, we have established that CDK2 phosphorylates Ser206, which subsequently affects the steady state level of KLF10 in cells. Our studies have also proved that CDK2 up-regulates the protein level of KLF10 through reducing its association with SIAH1, a KLF10 E3-ubiqutin ligase involved in proteasomal degradation. Taken all together, these findings indicate that CDK2-dependent phosphorylation regulates KLF10 stability and that this affects the role of KLF10 in cell.

Restoring Prohealing/Remodeling-Associated M2a/c Macrophages Using ON101 Accelerates Diabetic Wound Healing.

Diabetic wounds exhibit chronic inflammation and delayed tissue proliferation or remodeling, mainly owing to prolonged proinflammatory (M1) macrophage activity and defects in transition to prohealing/proremodeling (M2a/M2c; CD206+ and/or CD163+) macrophages. We found that topical treatment with ON101, a plant-based potential therapeutic for diabetic foot ulcers, increased M2c-like (CD163+ and CD206+) cells and suppressed M1-like cells, altering the inflammatory gene profile in a diabetic mouse model compared with that in the controls. An in vitro macrophage-polarizing model revealed that ON101 directly suppressed CD80+ and CD86+ M1-macrophage polarization and M1-associated proinflammatory cytokines at both protein and transcriptional levels. Notably, conditioned medium collected from ON101-treated M1 macrophages reversed the M1-conditioned medium‒mediated suppression of CD206+ macrophages. Furthermore, conditioned medium from ON101-treated adipocyte progenitor cells significantly promoted CD206+ and CD163+ macrophages but strongly inhibited M1-like cells. ON101 treatment also stimulated the expression of GCSF and CXCL3 genes in human adipocyte progenitor cells. Interestingly, treatment with recombinant GCSF protein enhanced both CD206+ and CD163+ M2 markers, whereas CXCL3 treatment only stimulated CD163+ M2 macrophages. Depletion of cutaneous M2 macrophages inhibited ON101-induced diabetic wound healing. Thus, ON101 directly suppressed M1 macrophages and facilitated the GCSF- and CXCL3-mediated transition from M1 to M2 macrophages, lowering inflammation and leading to faster diabetic wound healing.

The C-type lectin Clec12A present on mouse and human dendritic cells can serve as a target for antigen delivery and enhancement of antibody responses.

We have cloned the mouse and human C-type lectin Clec12A, expressed both, and produced mAb recognizing both. Mouse Clec12A is highly expressed on splenic CD8(+) dendritic cells (DC) and plasmacytoid DC. A proportion of CD8(-)DC also expresses lower levels of Clec12A, as do monocytes, macrophages, and B cells. Human CLEC12A, like the mouse counterpart, is expressed on blood monocytes and DC, including pDC and BDCA-3(+)DC, the proposed equivalent of mouse CD8(+)DC. To determine whether Ag targeted to Clec12A could induce immune responses, mice were injected with a rat mAb recognizing Clec12A, or a control rat mAb, then production of anti-rat Ig was measured. Anti-Clec12A mAb alone produced only moderate responses, but these were amplified by coinjecting only small amounts of LPS as a DC activation agent. Furthermore, when OVA was conjugated to anti-Clec12A mAb, OVA-specific T cells were induced to proliferate. This Ag presentation to naive T cells was due to targeting conventional DC, because their ablation eliminated T cell activation. The potent Ab responses induced using microgram amounts of anti-Clec12A and minimal amounts of adjuvant demonstrate that this molecule can be used as an Ag-delivery target to enhance Ab responses to vaccines.

Long-term Proton Pump Inhibitor Administration Caused Physiological and Microbiota Changes in Rats.

Proton pump inhibitors (PPIs) are used for the long-term treatment of gastroesophageal disorders and the non-prescription medicines for acid reflux. However, there is growing concerns about PPI misuse, overuse and abuse. This study aimed to develop an animal model to examine the effects of long-term use of PPI in vivo. Twenty one Wistar rats were given omeprazole orally or intravenously for 30 days, and caerulein as a positive control. After euthanization, the serum and stool were collected to perform MS-based quantitative analysis of metabolites. We carried out 16S-based profiling of fecal microbiota, assessed the expression of bile acid metabolism regulators and examined the immunopathological characteristics of bile ducts. After long-term PPI exposure, the fecal microbial profile was altered and showed similarity to those observed in high-fat diet studies. The concentrations of several metabolites were also changed in various specimens. Surprisingly, morphological changes were observed in the bile duct, including ductal epithelial proliferation, micropapillary growth of biliary epithelium, focal bile duct stricture formation and bile duct obstruction. These are characteristics of precancerous lesions of bile duct. FXR and RXRα expressions were significantly reduced, which were similar to that observed in cholangiocarcinoma in TCGA and Oncomine databases. We established a novel animal model to examine the effects of long-term use of omeprazole. The gut microbes and metabolic change are consequences of long-term PPI exposure. And the results showed the environment in vivo tends to a high-fat diet. More importantly, we observed biliary epithelial hyperplasia, which is an indicator of a high-fat diet.

Therapeutic Effect of Repurposed Temsirolimus in Lung Adenocarcinoma Model.

Lung cancer is one of the major cause of cancer-related deaths worldwide. The poor prognosis and resistance to both radiation and chemotherapy urged the development of potential targets for lung cancer treatment. In this study, using a network-based cellular signature bioinformatics approach, we repurposed a clinically approved mTOR inhibitor for renal cell carcinomans, temsirolimus, as the potential therapeutic candidate for lung adenocarcinoma. The PI3K-AKT-mTOR pathway is known as one of the most frequently dysregulated pathway in cancers, including non-small-cell lung cancer. By using a well-documented lung adenocarcinoma mouse model of human pathophysiology, we examined the effect of temsirolimus on the growth of lung adenocarcinoma in vitro and in vivo. In addition, temsirolimus combined with reduced doses of cisplatin and gemcitabine significantly inhibited the lung tumor growth in the lung adenocarcinoma mouse model compared with the temsirolimus alone or the conventional cisplatin-gemcitabine combination. Functional imaging techniques and microscopic analyses were used to reveal the response mechanisms. Extensive immunohistochemical analyses were used to demonstrate the apparent effects of combined treatments on tumor architecture, vasculature, apoptosis, and the mTOR-pathway. The present findings urge the further exploration of temsirolimus in combination with chemotherapy for treating lung adenocarcinoma.

Characterization of a transgenic mouse model exhibiting spontaneous lung adenocarcinomas with a metastatic phenotype.

Developing lung cancer in mouse models that display similarities of both phenotype and genotype will undoubtedly provide further and better insights into lung tumor biology. Moreover, a high degree of pathophysiological similarity between lung tumors from mouse models and their human counterparts will make it possible to use these mouse models for preclinical tests. Ovine pulmonary adenocarcinomas (OPAs) present the same symptoms as adenocarcinomas in humans and are caused by a betaretrovirus. OPAs have served as an exquisite model of carcinogenesis for human lung adenocarcinomas. In this study, we characterized the histopathology and transcriptome profiles of a jaagsiekte sheep retrovirus (JSRV)-envelope protein (Env) transgenic mouse model with spontaneous lung tumors, and associations of the transcriptome profiles with tumor invasion/metastasis, especially the phenomenon of the epithelial-mesenchymal transition (EMT). Genetic information obtained from an expression array was analyzed using an ingenuity pathways analysis (IPA) and human disease database (MalaCards). By careful examination, several novel EMT-related genes were identified from tumor cells using RT-qPCR, and these genes also scored high in MalaCards. We concluded that the JSRV-Env mouse model could serve as a spontaneous lung adenocarcinoma model with a metastatic phenotype, which will benefit the study of early-onset and progression of lung adenocarcinoma. In addition, it can also be a valuable tool for biomarkers and drug screening, which will be helpful in developing intervention therapies.

Phage display antibodies to allelic determinants of canine blood cells.

Techniques were developed to select useful allele-specific antibodies directed to canine red blood cell alloantigens from a phage display library in which antibody single chain variable fragments (scFv) were expressed on filamentous bacteriophage. First, techniques were developed to detect specific antigens displayed on red blood cells using flow cytometry. Next, techniques permitting the efficient selection of red blood cell binders from a large phage library were developed. Finally, the amplified library was depleted using the red blood cells of one animal and the remainder enriched using cells from a genetically different animal. A high frequency of clones derived from this population bound antigen(s) of the second animal but not the first. Sequence analysis of these clones revealed that at least 11 clonally distinct isolates were present within the selected population. The procedure used to obtain these reagents is simple and inexpensive and the techniques developed should find applications in canine transfusion medicine and parentage assignment.

Klf10 deficiency in mice exacerbates pulmonary inflammation by increasing expression of the proinflammatory molecule NPRA.

KLF10 is a transforming growth factor (TGF)-ß/Smad downstream regulated gene. KLF10 binds to the promoter of target genes and mimics the effects of TGF-ß as a transcriptional factor. In our laboratory, we noted that Klf10 deficiency in mice is associated with significant inflammation of the lungs. However, the precise mechanism of this association remains unknown. We previously identified NPRA as a target gene potentially regulated by KLF10 through direct binding; NPRA knockout have known that prevented lung inflammation in a mouse model of allergic asthma. Here, we further explored the regulatory association between KLF10 and NPRA on the basis of the aforementioned findings. Our results demonstrated that KLF10 acts as a transcriptional repressor of NPRA and that KLF10 binding reduces NPRA expression in vitro. Compared with wild-type mice, Klf10-deficient mice were more sensitive to lipopolysaccharide or ovalbumin challenge and showed more severe inflammatory histological changes in the lungs. Moreover, Klf10-deficient mice showed pulmonary neutrophil accumulation. These findings collectively reveal the precise site where KLF10 signaling affects pulmonary inflammation by attenuating NPRA expression. They also verify the importance of KLF10 and atrial natriuretic peptide/NPRA in exerting influences on chronic pulmonary disease pathogenesis.

KLF10 affects pancreatic function via the SEI-1/p21Cip1 pathway.

TGF-ß plays a significant role in regulating pancreas islet function and maintaining their mass. KLF10, a TGF-ß downstream gene, belongs to a group of Krüppel-like transcription factors that bind to the promoters of target genes and produce effects that mimic TGF-ß as a tumor suppressor. Using ChIP-chip screening, SEI-1 was identified as a target gene that may be regulated by KLF10. We conducted a series of assays to verify the presence of unknown regulation events between SEI-1 and KLF10. These showed that KLF10 transcriptionally activates the SEI-1 promoter and, furthermore, induces SEI-1 protein expression in pancreatic carcinoma cells. SEI-1 is one of the key factors involved in cell cycle control through the regulation of other transcription factors such as the p21(Cip1) gene. Interestingly, it has been shown previously that p21(Cip1) is indirectly activated by KLF10. Our results first demonstrated that KLF10 acts as a transcriptional activator on SEI-1, which can then result in increased p21(Cip1) expression. Furthermore, KLF10-deficiency in mice is associated with a decrease in the pancreatic islet mass, which is similar to the effects found in SEI-1 deficient mice. The KLF10-defect was also associated with the nuclear accumulation of the p21(Cip1) in islet cells. Based on our molecular and histological findings, we conclude that KLF10 plays an important role in pancreatic ß-cells and this supports a functional link between KLF10 and various cell cycle regulators, most notably in the context of the pancreas.

Heat shock protein 90: role in enterovirus 71 entry and assembly and potential target for therapy.

Although several factors participating in enterovirus 71 (EV71) entry and replication had been reported, the precise mechanisms associated with these events are far from clear. In the present study, we showed that heat shock protein 90 (HSP90) is a key element associated with EV71 entry and replication in a human rhabdomyosarcoma of RD cells. Inhibition of HSP90 by pretreating host cells with HSP90ß siRNA or blocking HSP90 with a HSP90-specific antibody or geldanamycin (GA), a specific inhibitor of HSP90, as well as recombinant HSP90ß resulted in inhibiting viral entry and subsequent viral replication. Co-immunprecipitation of EV71 with recombinant HSP90ß and colocalization of EV71-HSP90 in the cells demonstrated that HSP90 was physically associated with EV71 particles. HSP90 seems to mediate EV71 replication by preventing proteosomal degradation of the newly synthesized capsid proteins, but does not facilitate viral gene expression at transcriptional level. This was evident by post-treatment of host cells with GA, which did not affect the expression of viral transcripts but accelerated the degradation of viral capsid proteins and interfered with the formation of assembled virions. In vivo studies were carried out using human SCARB2-transgenic mice to evaluate the protection conferred by HSP90 inhibitor, 17-allyamino-17-demethoxygeldanamycin (17-AAG), an analog of geldanamycin, that elicited similar activity but with less toxicity. The results showed that the administration of 17-AAG twice conferred the resistance to hSCARB2 mice challenged with C2, C4, and B4 genotypes of EV71. Our data supports HSP90 plays an important role in EV71 infection. Targeting of HSP90 with clinically available drugs might provide a feasible therapeutic approach to treat EV71 infection.

Protective efficacy of VP1-specific neutralizing antibody associated with a reduction of viral load and pro-inflammatory cytokines in human SCARB2-transgenic mice.

Hand-foot-mouth diseases (HFMD) caused by enterovirus 71 (EV71) and coxsackievirus 16 (CVA16) in children have now become a severe public health issue in the Asian-Pacific region. Recently we have successfully developed transgenic mice expressing human scavenger receptor class B member 2 (hSCARB2, a receptor of EV71 and CVA16) as an animal model for evaluating the pathogenesis of enterovirus infections. In this study, hSCARB2-transgenic mice were used to investigate the efficacy conferred by a previously described EV71 neutralizing antibody, N3. A single injection of N3 effectively inhibited the HFMD-like skin scurfs in mice pre-infected with clinical isolate of EV71 E59 (B4 genotype) or prevented severe limb paralysis and death in mice pre-inoculated with 5746 (C2 genotype). This protection was correlated with remarkable reduction of viral loads in the brain, spinal cord and limb muscles. Accumulated viral loads and the associated pro-inflammatory cytokines were all reduced. The protective efficacy of N3 was not observed in animals challenged with CVA16. This could be due to dissimilarity sequences of the neutralizing epitope found in CVA16. These results indicate N3 could be useful in treating severe EV71 infections and the hSCARB2-transgenic mouse could be used to evaluate the protective efficacy of potential anti-enterovirus agent candidates.

Human SCARB2 transgenic mice as an infectious animal model for enterovirus 71.

Enterovirus 71 (EV71) and coxsackievirus (CVA) are the most common causative factors for hand, foot, and mouth disease (HFMD) and neurological disorders in children. Lack of a reliable animal model is an issue in investigating EV71-induced disease manifestation in humans, and the current clinical therapies are symptomatic. We generated a novel EV71-infectious model with hSCARB2-transgenic mice expressing the discovered receptor human SCARB2 (hSCARB2). The challenge of hSCARB2-transgenic mice with clinical isolates of EV71 and CVA16 resulted in HFMD-like and neurological syndromes caused by E59 (B4) and N2838 (B5) strains, and lethal paralysis caused by 5746 (C2), N3340 (C4), and CVA16. EV71 viral loads were evident in the tissues and CNS accompanied the upregulated pro-inflammatory mediators (CXCL10, CCL3, TNF-α, and IL-6), correlating to recruitment of the infiltrated T lymphocytes that result in severe diseases. Transgenic mice pre-immunized with live E59 or the FI-E59 vaccine was able to resist the subsequent lethal challenge with EV71. These results indicate that hSCARB2-transgenic mice are a useful model for assessing anti-EV71 medications and for studying the pathogenesis induced by EV71.

Estimated glomerular filtration rate as a useful predictor of mortality in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: This study evaluated the impact of estimated glomerular filtration rate (eGFR) on 30-day and 1-year mortalities in patients with an acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). METHODS: Between January 2002 and November 2009, 1432 consecutive patients who had experienced STEMI with an onset of chest pain <12 hours of undergoing primary PCI were prospectively enrolled. Patients were categorized into group 1 (eGFR <30 mL/min/1.73 m(2)), group 2 (eGFR = 30-60 mL/min/1.73 m(2)) and group 3 (eGFR >60 mL/min/1.73 m(2)). RESULTS: The incidence of a high Killip class (defined as class ≥3) upon presentation, a requirement for mechanical ventilatory support for respiratory failure and intra-aortic balloon pump support for hemodynamic instability, and duration of hospitalization were substantially higher in group 1 than in groups 2 and 3, and notably higher in group 2 compared with group 3 (all P < 0.001). Conversely, the procedural success of primary PCI was remarkably lower in group 1 compared with groups 2 and 3, and it was also notably lower in group 2 than in group 3 (all P < 0.001). Additionally, both 30-day and 1-year mortalities were markedly increased in group 1 than in groups 2 and 3, and significantly higher in group 2 than in group 3 (all P < 0.001). Multivariate analysis showed that eGFR <30 mL/min/1.73 m(2) was a significantly independent predictor of 30-day and 1-year mortalities (all P < 0.001). CONCLUSIONS: eGFR <30 mL/min/1.73 m(2) was strongly and independently predictive of poor short-term and long-term prognostic outcomes in patients with STEMI undergoing primary PCI.

Impact of chronic obstructive pulmonary disease on patient with acute myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: This study reported the incidence and prognostic outcome of chronic obstructive lung disease (COPD) patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). METHODS: Between January 2002 and May 2011, totally 1554 consecutive patients who experienced STEMI undergoing primary PCI were enrolled into the study. RESULTS: Of the 1554 patients, 124 (9.7%) with diagnosis of COPD and 1430 (90.3%) without COPD were categorized into group 1 and group 2. Although no difference in in-hospital mortality was noted between the two groups (p = 0.726). However, the hospitalization duration was notably longer (p = 0.003), the incidences of recurrent MI and re-hospitalization for congestive heart failure were significantly higher in group 1 than in group 2 (all p < 0.02). Although Kaplan-Meier analysis demonstrated that the incidence of freedom from one-year major adverse clinical outcome (MACO) (defined as recurrent MI, re-admission for congestive heart failure was significantly lower in group 1 than group 2 (p = 0.012), multivariate Cox regression analysis showed COPD was not an independent predictor of MACO-free time after adjusting traditional risk factors. CONCLUSION: COPD was not an independent predictor of short-term and medium-term MACO in patients with STEMI undergoing primary PCI.

Link between lipoprotein-associated phospholipase A2 gene expression of peripheral-blood mononuclear cells and prognostic outcome after acute ischemic stroke.

AIM: To evaluate the potential of the lipoprotein-associated phospholipase A(2) (Lp-PLA(2) level as a biomarker in the prediction of prognostic outcome in patients with acute ischemic stroke (IS). METHODS: From October 2008 to March 2010, 130 patients with acute IS were prospectively enrolled in the study and their medical records were reviewed. A blood sample was collected from each patient 48 hours after acute IS, as well as from 20 healthy volunteers as controls. Messenger-RNA (mRNA) expression of Lp-PLA(2) of peripheral-blood mononuclear cells (PBMNCs) relative to that of ß actin was measured using quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Patients with acute IS exhibited significantly higher Lp-PLA(2) mRNA expression of PBMNCs than the control group (p <0.0001). Lp-PLA(2) mRNA expression of PBMNCs in patients with a major adverse clinical outcome (MACO) (defined as recurrent stroke or death) within 90 days was significantly higher than in patients without MACO (p=0.006). Furthermore, elevated Lp-PLA(2) mRNA expression was strongly associated with old age, diabetes mellitus, a positive history of significant coronary arterial disease and significant stenosis of the extra-cranial carotid arteries (all p <0.04), and positively correlated with the body mass index, leukocyte count, and serum levels of total cholesterol and low-density lipoprotein cholesterol. Multivariate analysis revealed that Lp-PLA(2) mRNA expression of PBMNCs was a significant independent predictor of MACO within 90 days (p= 0.011). CONCLUSION: Elevated Lp-PLA(2) mRNA expression of PBMNCs seems to be a potential biomarker for predicting an unfavorable outcome in patients with acute IS.

Value and level of galectin-3 in acute myocardial infarction patients undergoing primary percutaneous coronary intervention.

AIM: This study investigated the impact of the circulating galectin-3 level on the 30-day prognostic outcome in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). METHODS: From May 2009 to March 2011, blood samples for assessment of the circulating galectin-3 level were collected from 196 consecutive STEMI patients treated by primary PCI and from 30 healthy volunteers. RESULTS: The galectin-3 level was determined using ELISA. Our results demonstrated that the circulating level of galectin-3 was significantly higher in STEMI patients than in healthy control subjects (p<0.001). As compared with patients with galectin-3 <7.67 ng/mL, patients with galectin-3 ≥7.67 ng/mL were significantly older, had significantly lower left ventricular ejection fraction and significantly higher frequency of elevated white blood cell count, advanced Killip score (defined as ≥ score 3), congestive heart failure (defined as ≥ New York Heart Association Functional Class III), respiratory failure, unstable hemodynamics requiring a mechanical ventilator and intra-aortic balloon pump support, multiple vessel diseases and 30-day mortality (all p<0.04). Furthermore, multivariate analysis showed that elevated circulating level of galectin-3 was the strongest independent predictor of the combined 30-day major adverse clinical outcome (MACO) (defined as advanced CHF or 30-day mortality) (p<0.0001). CONCLUSION: A high circulating galectin-3 level may serve as a useful biomarker for predicting 30-day MACO in patients with STEMI undergoing primary PCI.

Tonsillar CD4+FOXP3+ T-regulatory cell dynamics in primary EBV infection.

CD8(+) lymphocytosis is recognized as the primary immunopathological response generated in primary EBV infection that may manifest itself as a benign lymphoproliferative disorder, infectious mononucleosis (IM). While CD4(+)FOXP3(+) T-regulatory cells (Treg cells) are well accepted to inhibit T-cell responses, it is puzzling why massive expansion of CD8(+) lymphocytes still occurs despite CD4(+)FOXP3(+) Treg cells are localized in tonsils, which are the port of entry of the virus. Understanding the interplay between the virologic and immunologic events that take place in tonsils in primary EBV infection is necessary to comprehend why IM preferentially develops in adolescents and the dynamics of CD4(+) Treg cell change that may occur in virus/pathogen infection in a broader setting.

Generation of murine monoclonal antibodies which cross-neutralize human enterovirus genogroup B isolates.

A live enterovirus 71 (EV71) isolate designated, EV71/E59, with genotype B4 produced in Vero cells and purified over a sucrose gradient was used as the immunogen to generate EV71-specific murine monoclonal antibodies. Four hybridoma clones derived from the fusion of splenocytes of EV71/E59-preimmunized BALB/c (H-2(d)) mice and the NS-1 myeloma cells that exhibit stable growth were selected for detailed characterization. The proof that the hybridomas produced are indeed true independent clones was based on the obervations that they expressed different complementarity-determining regions (CDRs) in their κ light chain genes. Purified ascitic fluids produced by the individual clones reacted against the viral capsid protein, VP1, in Western blot; and recognized distinct sites of a common epitope localized at the C-terminal half of VP1. Each of the monoclonal antibodies exhibited potent neutralizing activities against the immunizing virus strain, as well as two other isolates namely, N0781-TW-01, and N2838, of subgenogroups B4 and B5, respectively, that were found commonly in recent outbreaks in Taiwan. It was also observed the monoclonal antibodies acted cooperatively in neutralizing the EV71/E59 virus.

Development of a quantitative enzyme linked immunosorbent assay for monitoring the Enterovirus 71 vaccine manufacturing process.

Enterovirus 71 (EV71), the etiologic agent causes outbreaks with significant mortality in young children in Asia and currently there is no vaccine available. In this study, we report a quantitative enzyme linked immunosorbent assay (Q-ELISA) to determine the concentration of the EV71 VP2 antigen. EV71 virus-like particles (VLPs) were produced in the baculovirus expression system and used as the EV71 antigen reference standard. Antisera from both EV71-immunized chickens and rabbits were very efficient and useful as capture antibodies to bind various forms of EV71 antigens, whereas a commercial VP2-specific virus neutralizing monoclonal antibody MAB979 was found to be suitable for quantifying the amount of VP2 antigen. This Q-ELISA was used successfully to determine VP2 content at each stage of EV71 vaccine manufacturing process, particularly during the upstream harvest, downstream purification and viral inactivation steps. The amount of VP2 antigen and the magnitude of neutralizing titers were found to be dose-dependent in mice immunized with vaccine candidates. These results indicate that Q-ELISA could provide off-line timely quantitative measurements of VP2 antigen throughout the production cycle to evaluate critical attributes and conditions that may affect virus yields in culture media, the quality of purification methods, the stability and potency of final vaccine formulations.

The cross-regulatory relationship between human dendritic and regulatory T cells and its role in type 1 diabetes mellitus.

Dendritic cells (DCs) and T regulatory (Treg) cells play a crucial role in maintaining the tolerance needed to prevent the onset of autoimmunity that leads to the development of type 1 diabetes mellitus (T1DM). Various experimental studies have shown that human DC subsets are involved in the induction of anergy in T cells and in the differentiation of conventional CD4(+) and CD8(+) lymphocytes into the respective subtypes of Treg cells. Treg cells, in turn, have been shown to modulate the function of DCs to exhibit tolerogenic properties. To evaluate whether T1DM development is related to abnormalities in DCs and Treg cells, many attempts have been made to characterize these cell types in diabetic individuals and in subjects at risk of developing the disease. This review aims to supply an update on the progress made in these aspects of T1DM research.