GMOIT: a tool for effective screening of genetically modified crops.

BACKGROUND: Advancement in agricultural biotechnology has resulted in increasing numbers of commercial varieties of genetically modified (GM) crops worldwide. Though several databases on GM crops are available, these databases generally focus on collecting and providing information on transgenic crops rather than on screening strategies. To overcome this, we constructed a novel tool named, Genetically Modified Organisms Identification Tool (GMOIT), designed to integrate basic and genetic information on genetic modification events and detection methods. RESULTS: At present, data for each element from 118 independent genetic modification events in soybean, maize, canola, and rice were included in the database. Particularly, GMOIT allows users to customize assay ranges and thus obtain the corresponding optimized screening strategies using common elements or specific locations as the detection targets with high flexibility. Using the 118 genetic modification events currently included in GMOIT as the range and algorithm selection results, a "6 + 4" protocol (six exogenous elements and four endogenous reference genes as the detection targets) covering 108 events for the four crops was established. Plasmids pGMOIT-1 and pGMOIT-2 were constructed as positive controls or calibrators in qualitative and quantitative transgene detection. CONCLUSIONS: Our study provides a simple, practical tool for selecting, detecting, and screening strategies for a sustainable and efficient application of genetic modification.

Electroacupuncture Improving Intestinal Barrier Function in Rats with Irritable Bowel Syndrome Through Regulating Aquaporins.

BACKGROUND: Intestinal mucosal barrier dysfunction plays a crucial role in the pathogenesis of irritable bowel syndrome with diarrhea (IBS-D). In order to explore the mechanism of electroacupuncture (EA) treatment on intestinal mucosal barrier, this study observed the effect of EA on aquaporins (AQPs), tight junctions (TJs), NF-κB pathway and the gut microbiota in IBS-D rats. METHODS: The IBS-D model was established by acetic acid enema combined with chronic restraint method. The effects of EA on the treatment of IBS-D were examined by the abdominal withdrawal reflex score, Bristol's fecal character score, fecal water content, small intestine propulsion rate and HE staining. AQPs, TJs and inflammation-related molecular mechanisms were explored. The fecal samples were applied for 16S rRNA sequencing to assess the effect of EA intervention to the intestinal bacterial abundance. RESULTS: EA reduced intestinal sensitization, restored intestinal motility and improved inflammatory cell infiltration. Furthermore, EA improved intestinal inflammation and flora environment significantly, inhibited NF-κB signaling and inflammatory factors (IL-1ß and TNF-α). It can also increase the gene and protein expression of AQPs (AQP1, AQP3, and AQP8) and the gene levels of TJs (ZO-1 and Occludin). CONCLUSION: EA has an inhibitory effect on the NF-κB signaling pathway, and regulates the proteins of AQP1, AQP3, AQP8, and TJs to restore the balance of water metabolism and intestinal permeability in IBS-D, which also restored the function of the intestinal mucosa by regulating the intestinal flora.

Effects of the Timing of Intense Physical Activity on Hypertension Risk in a General Population: A UK-Biobank Study.

PURPOSE OF REVIEW: It has recently been suggested that the timing of exercise is important in the subsequent development of hypertension. We used the UK Biobank database which prospectively collates data in over 500,000 people aged between 40 and 69 years to determine the relationship between the chronoactivity pattern of exercise and the risk of incident hypertension. RECENT FINDINGS: We analyzed data from 70,617 participants with 7-day Axivity AX3 triaxial accelerometry information available. Comparisons were made by a K-means clustering analysis separating groups according to the daily timing of physical activity and intensity. Subgroup, sensitivity analyses, and Cox proportional hazard model were performed. The mean age of the cohort was 61.17 (± 7.89) years with 40.05% men, and there was a mean follow-up of 7.54 (± 1.65) years. Participants were separated into 4 clusters with 6341 developing hypertension. Cluster 1 (early morning physical activity) and Cluster 2 (early morning and later physical activity) had a significantly reduced risk of incident hypertension (adjusted HR 0.870 [95%CI 0.812-0.932) vs. 0.895 [95%CI 0.825-0.972], respectively) when compared with Cluster 3 (physical activity intensity spread evenly throughout the day). Cluster 1 and Cluster 2 cases with High Intensity physical activity had a lower risk of hypertension; however, Low Intensity physical activity in Cluster 1 still reduced the risk of incident hypertension. There was a lower risk of hypertension in Cluster 1 and Cluster 2 in both morning and evening sleep chronotypes. The development of incident hypertension is significantly reduced in those who engage in some level of physical activity earlier in the day. Hypertension (high blood pressure) is a global problem with a high economic health burden that has been shown to be a major risk factor for diabetes, cardiovascular, and kidney disease. Our study has used a large maintained UK biological database to determine the impact of physical exercise on reducing the subsequent development of hypertension during follow-up from data provided by more than 70,000 participants. When we segregated patients into clusters of exercise timing, we found that the risk of developing hypertension over time was reduced for patients who performed exercise earlier in the morning than at other times of the day. This benefit was still evident even when the intensity of regular physical activity was low.

Associations between handgrip strength and skeletal muscle mass with all-cause mortality and cardiovascular mortality in people with type 2 diabetes: A prospective cohort study of the UK Biobank.

AIMS: To explore the associations between handgrip strength (HGS) and skeletal muscle mass (SMM) with all-cause and cardiovascular disease (CVD) mortality risk in type 2 diabetes (T2DM) patients. MATERIALS AND METHODS: Data were obtained from the UK Biobank. Baseline survey was conducted between 2006 and 2010, and followed up for a median of 12.52 years. HGS was measured using dynamometer, and SMM was measured using bioelectrical impedance method. Mortality was available via links to the National Health Service Information Centre. Sex-specific analyses were conducted. RESULTS: A total of 13 392 T2DM participants were included, with a mean age of 60.39 years and 52.35% men. During the follow-up, there were 3006 (22.45%) deaths, including 746 (5.57%) CVD deaths. The risk for all-cause mortality and CVD mortality among both men and women increased progressively with decreasing HGS quartiles (p trend <.05). A 1 SD decrease in HGS was found to both increase the all-cause risk (HR: 1.31 [95% CI: 1.24-1.38]) and CVD mortality risk (HR: 1.35 [95% CI: 1.22-1.50]) for men, and all-cause risk (HR: 1.26 [95% CI: 1.11-1.42]) and CVD mortality risk (HR: 1.43 [95% CI: 1.09-1.89]) for women. There was no statistically significant trend association between SMM/height2 and mortality risk, and the restricted cubic regression splines indicated that SMM/height2 showed a U-shaped nonlinear relationship (pnonlinear <.05). CONCLUSIONS: Grip strength displayed a linear downward trend with mortality risk among T2DM patients, whereas muscle mass showed a U-shaped relationship. Low grip strength seemed to be a better predictor for mortality compared to low muscle mass.

Daily higher tea consumption is associated with a reduced risk of type 2 diabetes: A cohort study and updated systematic review and meta-analysis.

Tea is abundant in phytochemicals (such as polyphenols and theaflavins), which have a hypoglycemic effect. Previous studies investigating the relationship between tea consumption and the risk of type 2 diabetes mellitus (T2DM) have yielded inconsistent results. We hypothesized that tea consumption would be associated with a reduced risk of T2DM. This cohort study used data from the China Health and Nutrition Survey, involving a total of 5199 participants initially recruited in 1997 and subsequently followed until 2009. Consumption of any variety of tea was tracked using structured questionnaires, and T2DM was diagnosed according to the American Diabetes Association's criteria. We also performed a systematic literature search of PubMed, Web of Science, and EMBASE for publications through September 2021, including 19 cohort studies comprising 1,076,311 participants. In our cohort study, the logistic regression model showed a relative risk (RR) of T2DM among tea drinkers of 1.02 (95% confidence interval [CI], 0.82-1.28) compared with non-tea drinkers. Although our updated meta-analysis showed no significant association between tea consumption and T2DM on the whole (pooled RR of 0.96 [0.91-1.00]), compared with the non-tea-drinking group, participants consuming 4 or more cups of tea per day had a 17% reduced risk of T2DM, with an RR of 0.83 (95% CI, 0.76-0.90). These data support our hypothesis that tea consumption at higher doses (e.g., ≥4 cups/day) is associated with a reduced risk of T2DM.

Associations between Consumption of Dietary Fibers and the Risk of Type 2 Diabetes, Hypertension, Obesity, Cardiovascular Diseases, and Mortality in Chinese Adults: Longitudinal Analyses from the China Health and Nutrition Survey.

Although many studies have explored the relationship between total dietary fiber intake and the risk of chronic non-communicable diseases, the results are mixed. There is also a lack of research on the association between dietary fiber intake from different food sources and disease. Using data from the China Nutrition and Health Database from 2004 to 2015, Cox proportional risk models were used to explore the associations between total dietary fiber and fiber intake from different food sources and the occurrence of type 2 diabetes, hypertension, obesity, cardiovascular disease, and all-cause mortality. After multi-factorial adjustment, the hazard ratios (95% confidence interval) of total dietary fiber intake (quartile 4 vs. quartile 1) in type 2 diabetes, hypertension, obesity, cardiovascular disease, and all-cause mortality cohorts were 1.20 (0.93, 1.55), 0.91 (0.75, 1.12), 0.93 (0.64, 1.35), 1.13 (0.60, 2.12), 1.13 (0.60, 2.12), and 1.13 (0.84, 1.52). Whole-grain fiber intake was positively associated with hypertension but not with the occurrence of other diseases. No association was observed between legume fibers, fruit fibers, and vegetable fibers in the cohorts of type 2 diabetes, hypertension, obesity, cardiovascular diseases and all-cause mortality. Our study did not find any association between total dietary fiber and dietary fiber intake from different food sources and type 2 diabetes, obesity, cardiovascular disease, and all-cause mortality in the Chinese population. The role of dietary fiber in the Chinese population may be overestimated. More extraordinary efforts are needed to further confirm the association between dietary fiber and these diseases in the Chinese population.

The Association Between Plant-Based Diet Indices and Obesity and Metabolic Diseases in Chinese Adults: Longitudinal Analyses From the China Health and Nutrition Survey.

Background: A wide range of health benefits are associated with consuming a diet high in plant-based foods. Diet quality can be accurately assessed using plant-based diet indices, however there is inadequate evidence that plant-based diet indices are linked to obesity, hypertension, and type 2 diabetes (T2D), especially in Chinese cultures who have traditionally consumed plant-rich foods. Methods: The data came from the China Nutrition and Health Survey. Overall, 11,580 adult participants were enrolled between 2004 and 2006 and followed up until 2009 or 2015 (follow-up rate: 73.4%). Dietary intake was assessed across three 24-h recalls, and two plant-based dietary indices [overall plant-based diet indice (PDI) and healthy plant-based diet indice (hPDI)] were calculated using China Food Composition Code and categorized into quintiles. The study's endpoints were overweight/obesity, hypertension, and T2D. The Hazard ratio (HR) and dose-response relationship were assessed using the Cox proportional risk model and restricted cubic splines. The areas under the curve of the receiver operating characteristic curve analyses were used to evaluate the predictive performance of the PDI and hPDI. Results: During the median follow-up period of more than 10 years, 1,270 (33.4%), 1,509 (31.6%), and 720 (11.5%) participants developed overweight / obesity, hypertension, and T2D, respectively. The higher PDI score was linked with a reduced risk of overweight/obesity [HR: 0.71 (95% CI: 0.55-0.93), P-trend <0.001], hypertension [HR: 0.63 (95% CI: 0.51-0.79), P-trend <0.001], and T2D [HR: 0.79 (95% CI: 0.72-0.87), P-trend <0.001]. The hPDI score was inversely associated with overweight/obesity [HR: 0.79 (95% CI: 0.62-0.98), P-trend = 0.02] and T2D [HR: 0.84 (95% CI: 0.75-0.93), P-trend = 0.001]. In the aged <55-year-old group, subgroup analysis indicated a significant negative association between PDI/hPDI and overweight/obesity, hypertension, and T2D. There was no significant difference in the areas under the curve of the fully adjusted obesity, hypertension, and diabetes prediction models between PDI and hPDI. Conclusion: The PDI and hPDI scores were very similar in application in Chinese populations, and our findings highlight that adherence to overall plant-based diet index helps to reduce the risk of T2D, obesity, and hypertension in Chinese adults who habitually consume plant-based foods, especially for those aged <55 year. Further understanding of how plant-based diet quality is associated with chronic disease will be needed in the future, which will help develop dietary strategies to prevent diabetes, hypertension, and related chronic diseases.

Development of Genomic DNA Certified Reference Materials for Genetically Modified Rice Kefeng 6.

The application of certified reference materials (CRMs) to genetically modified organism (GMO) detection is essential for guaranteeing the accuracy, comparability, and traceability of quantitative results over time and among laboratories. Clean leaves from GM rice Kefeng 6 were used as raw materials to develop a batch of genomic DNA (gDNA) CRMs. The optimized KF6/PLD duplex digital PCR was used for collaborative characterization of Kefeng 6 gDNA CRMs by eight qualified laboratories; this batch of gDNA CRMs was certified for two property values, namely, copy number ratio and copy number concentration, which were 1.03 ± 0.04 and (1.60 ± 0.11) × 105 copies/µL, respectively. The gDNA CRMs displayed good between-vial homogeneity when the minimum sample intake of 2 µL was taken into account. Stability studies indicated that the gDNA CRMs should be transported below 25 °C, and cold chain transport was recommended. Shelf life was assessed to be at least 12 months, and when using gDNA CRMs, freeze-thaw should not exceed 10 cycles. Compared to the available gDNA CRMs in the market, this batch of gDNA CRMs has accurate property values with combined uncertainties, providing user-friendly calibrators for GM rice Kefeng 6 inspection and monitoring. The development and characterization of Kefeng 6 gDNA CRMs contribute to the establishment of a copy number-based reference system for GMO detection.

Development of a certified genomic DNA reference material for detection and quantification of genetically modified rice KMD.

Qualitative and quantitative detection of genetically modified products is inseparable from the application of reference materials (RMs). In this study, a batch of genomic DNA (gDNA) certified reference materials (CRMs) was developed using genetically modified rice Kemingdao (KMD) homozygotes as the raw material. The gDNA CRMs in this batch showed good homogeneity; the minimum sample intake was determined to be 2 µL. The stability study showed that transportation by cold chain is preferable, no significant degradation trend was observed during a 12-month period when storing the gDNA CRMs at 4 °C and - 20 °C, and the number of freeze-thaw cycles cannot exceed 10. The property values of the copy number ratio of transgene and endogenous gene and the copy number concentration for gDNA CRMs were determined by a collaborative characterization of eight laboratories using the duplex KMD/PLD droplet digital PCR (ddPCR) assays. The uncertainty components of characterization, potential between-unit heterogeneity, and potential degradation during long-term storage were combined to estimate the expanded uncertainty of the certified value with a coverage factor k of 2.0. The certified value of copy number ratio for KMD gDNA CRM is 0.99 ± 0.05, and that of copy number concentration is (1.76 ± 0.10) × 105 copies/µL. Compared to the gDNA CRMs in availability, this batch of KMD gDNA CRMs is assigned accurate property values and can be directly used for qualitative and quantitative detection of GMOs as well as evaluation of the parameters of analytical methods with no need of further DNA concentration measurement. Graphical abstract.

Clinical significance of RAD51C and its contribution to ovarian carcinogenesis.

AIM: The underlying mechanisms of chemoresistance-induced recurrence of ovarian carcinoma are largely unknown. The purpose of this study was to investigate the clinical significance of RAD51C and its role in ovarian tumorigenesis and progression. METHODS: 60 cases of ovarian epithelial tumors (30 benign and 30 malignant tumors, respectively) were enrolled from 2014 to 2016. Immunohistochemistry was used to evaluate RAD51C expression in tumor tissues, and RT-PCR was employed to test RAD51C mRNA levels in SKOV3, A2780, and CAOV3 cell lines. Targeted knockdown of RAD51C was achieved with siRNA to explore the changes of cell proliferation, migration, and apoptosis. RESULTS: RAD51C protein level in carcinoma tissues, especially in the high-grade group (P<0.001), was significantly higher than that of benign tumors and associated with pathological type, stage, and overall survival (P<0.05). Downregulation of RAD51C promoted apoptosis and decreased cell survival rate and migration. CONCLUSIONS: Our results supported that RAD51C contributes to the progression of ovarian carcinoma, suggesting its promising application as an independent prognostic marker for diagnosis and treatment.

Mo Concentration Controls the Morphological Transitions from Dendritic to Semicompact, and to Compact Growth of Monolayer Crystalline MoS2 on Various Substrates.

The domain morphology in the growth of transition-metal dichalcogenides (TMDCs) is mostly triangular but rarely dendritic. Here, we report a robust chemical vapor deposition method to fabricate atomic-thin 2H-phase MoS2 dendrites on several single-crystalline substrates with different lattice structures, such as rutile-TiO2(001), SrTiO3(001), and sapphire(0001). It is found that by tuning the concentration of Mo adatoms, the morphology of MoS2 domains on these substrates evolves from tridentate dendrites at a low Mo concentration to semicompact fractal domains at an intermediate Mo concentration, and to a compact triangular shape at a high Mo concentration. First-principles calculations reveal that the edge diffusion barrier of Mo is comparable to the attachment barrier, inhibiting fast Mo atom diffusion along the edge. Kinetics Monte Carlo simulations with varying Mo concentrations well reproduce the experimental results. Our combined experimental and theoretical analyses evidently show that the growth of MoS2 dendritic domains at a low Mo concentration is a nonequilibrium process, which is dominated by the kinetics of Mo adatoms. Our study presents an effective route to control the morphology of TMDCs by simply tuning the transition-metal adatom concentration.

Development and strategy of reference materials for the DNA-based detection of genetically modified organisms.

The enforcement of GMO labeling regulations requires validated analytical methods and certified reference materials (CRMs). The early labeling regulations stipulated that the GMO content should be expressed as percentage, but did not specify what unit this percentage referred to. Two reference systems, using mass fraction and copy number ratio as measurement units, individually, are established for GMO analysis using different metrological traceability chains. Three types of CRMs, powder CRMs certified for mass fractions, genomic DNA CRMs, and plasmid DNA CRMs certified for copy number ratios, were developed for calibration and quality control. The type, certification, and measurement unit commutability of current GMO CRMs are presented and discussed in this paper. Both existing reference systems are facing a metrological challenge, although later EU regulations specified that the measurement unit of GMO content must be expressed in mass fraction and recommended to convert one unit into another by introducing a conversion factor, further efforts are required to explore which reference system is more metrologically sound. The determination of conversion factor per CRM batch is recommended to be based on the pure CRMs produced from pure GM materials, which is expected to be the best choice for calibration of PCR measurement results.

Development and Interlaboratories Validation of Event-Specific Quantitative Real-Time PCR Method for Genetically Modified Rice G6H1 Event.

The transgenic rice G6H1 was a new event with the traits of herbicide-tolerance and insect-resistant. Herein, we developed one event-specific real-time PCR method with high specificity and sensitivity for G6H1 event quantitative analysis, and validated its performance on practical samples quantification through a collaborative ring trial. A total of eight laboratories participated in this validation and quantified three blind G6H1 powder samples including DNA extraction and real-time PCR analysis. The statistically analyzed results from returned data confirmed its high PCR efficiency and good linearity, trueness, and precision, indicating that the developed G6H1 real-time PCR assay was accurate, reliable, and comparable for G6H1 identification and quantification.

Development of Certified Matrix-Based Reference Material as a Calibrator for Genetically Modified Rice G6H1 Analysis.

The accurate monitoring and quantification of genetically modified organisms (GMOs) are key points for the implementation of labeling regulations, and a certified reference material (CRM) acts as the scaleplate for quantifying the GM contents of foods/feeds and evaluating a GMO analytical method or equipment. Herein we developed a series of CRMs for transgenic rice event G6H1, which possesses insect-resistant and herbicide-tolerant traits. Three G6H1 CRMs were produced by mixing seed powders obtained from homozygous G6H1 and its recipient cultivar Xiushui 110 at mass ratios of 49.825%, 9.967%, and 4.986%. The between-bottle homogeneity and within-bottle homogeneity were thoroughly evaluated with consistent results. The potential DNA degradation in transportation and shelf life were evaluated with an expiration period of at least 12 months. The property values of three CRMs (G6H1a, G6H1b, G6H1c) were given as (49.825 ± 0.448) g/kg, (9.967 ± 1.757) g/kg, and (4.986 ± 1.274 g/kg based on mass fraction ratio, respectively. Furthermore, the three CRMs were characterized with values of (5.01 ± 0.08)%, (1.06 ± 0.22)%, and (0.53 ± 0.11)% based on the copy number ratio using the droplet digital PCR method. All results confirmed that the produced G6H1 matrix-based CRMs are of high quality with precise characterization values and can be used as calibrators in GM rice G6H1 inspection and monitoring and in evaluating new analytical methods or devices targeting the G6H1 event.

Negative Regulation of Hepatic Inflammation by the Soluble Resistance-Related Calcium-Binding Protein via Signal Transducer and Activator of Transcription 3.

Host immune response is tightly controlled by negative regulators to avoid excessive immune reactions for homeostasis. Some pathogens may take advantage of host negative regulating system to evade host defense. Our previous report showed that foot-and-mouth disease virus (FMDV) VP1 inhibited TNF-α- and SeV-induced type I interferon response via interaction with cellular protein soluble resistance-related calcium-binding protein (sorcin). Conversely, TNF-α- or SeV-induced type I interferon response increased when sorcin knocked down, leading to inhibition of vesicular stomatitis virus replication. However, the exact role of sorcin in regulation of the immune response is still not clear. Here, we show that mice deficient of sorcin (sorcin-/-) display enhanced ConA-induced hepatitis. Importantly, splenocytes from sorcin-/- mice produced more IL-2, IL-4, IL-17, and IFN-γ than that of littermate controls (sorcin+/+) in response to anti-CD3/28 stimulation. Furthermore, our data indicate that sorcin interacts with signal transducer and activator of transcription 3 (STAT3) and enhances its phosphorylation and that STAT3 acts as an immediate downstream molecule of sorcin in the negative regulation of NF-κB signaling. Thus, sorcin, in association with STAT3, negatively regulates hepatic inflammation.

[Study on prevalence of occupational musculoskeletal disorders and their risk factors among workers in three industries in Zhongshan, China].

OBJECTIVE: To determine the prevalence of occupational musculoskeletal disorders (OMSD) and its risk factors among workers in three manufacturing industries in Zhongshan, China by cross-sectional epidemiological investigation. METHODS: A total of 2 035 workers from the industries of metals (1001 persons), electrical appliances (455 persons), and furniture (579 persons), including 1 402 males and 633 females, were selected; the mean age was 32.9 ± 8.2 years, and the mean length of service was 6.4 ± 5.6 years. A revised Northern Europe Standardized Questionnaire was used for cross-sectional epidemiological investigation of OMSD. RESULTS: The results showed that OMSD in these workers was primarily located in the neck, waist, and shoulder, with annual prevalence rates of 23.1%, 20.1%, and 15.8%, respectively. The overall prevalence of OMSD was 43.1% in metal industry, 44.0% in electrical appliance industry, and 26.6% in furniture industry. OMSD prevalence showed significant differences between different industries (χ(2) = 54.2, P < 0.01). The prevalence of OMSD in the shoulder and back increased with working years (P < 0.05). Logistic regression analysis showed that the risk factors for OMSD were working age >10 years, safety behavior such as "bending down when lifting heavy things from the ground", and different types of industries. CONCLUSION: OMSD is mainly manifested by neck pain, waist pain, and shoulder pain among front-line manufacturing workers in Zhongshan, and working age, poor labor posture, and different types of industries were risk factors for waist pain.

A critical role of interferon-induced protein IFP35 in the type I interferon response in cells induced by foot-and-mouth disease virus (FMDV) protein 2C.

Foot-and-mouth disease virus (FMDV) protein 2C is one of the most highly conserved viral proteins among the serotypes of FMDV. However, its effect on host cell response is not very clear. In our previous report, we showed that FMDV protein 2C interacts with cellular protein N-myc and STAT interactor (Nmi), inducing moderate apoptosis in cells. Here, we show that transfection of HEK293T cells with pEGFP-N1-2C or pEGFP-N1-Nmi induces activation of type I interferon promoters, leading to delayed vesicular stomatitis virus (VSV) growth. Using immunoprecipitation and confocal microscopy assays, we found that interferon-induced protein IFP35 interacts with Nmi. Knockdown of IFP35 expression by siRNA abolished pEGFP-N1-2C and pEGFP-N1-Nmi-induced activation of type I interferon promoters and restored VSV growth, suggesting that IFP35 plays a critical role in the type I interferon response induced by FMDV protein 2C. These findings may help to further understand cell responses to FMDV infection.

[Preparation and identification of monoclonal antibodies against infectious bursal disease virus (IBDV) VP4].

Infectious bursal disease virus (IBDV) VP4 plays an important role in immunosuppression of host. In order to develop monoclonal antibodies (McAbs) against VP4, we vaccinated BALB/c mice with His-VP4, screened and subcloned positive clones. We established 4 hybridoma cell lines that stably secreted McAbs against VP4 and named these cell lines 3B3, 3H11, 4C8 and 4G6, respectively. We tested the dissociation constant (Kd) of these McAbs, and found that their K(d)s were 4.61 x 10(-11), 1.71 x 10(-10), 4.26 x 10(-11), 5.02 x 10(-11), respectively. The isotypes of these McAbs were determined to be IgG1, IgG1, IgG2b and IgG1. These McAbs specifically bound to VP4 in IBDV infected DF-1 cells as demonstrated by Western blotting analysis and fluorescence antibody assay. These McAbs would help to detect IBDV infection and to analyze the biological activities of IBDV VP4.

Engagement of soluble resistance-related calcium binding protein (sorcin) with foot-and-mouth disease virus (FMDV) VP1 inhibits type I interferon response in cells.

Foot-and-mouth disease (FMD) is an acute, highly contagious animal disease caused by FMD virus (FMDV). Although FMDV-induced immunosuppression in host has been well established, the exact molecular mechanism for such induction is not very clear. We report here the identification of FMDV VP1 as an interferon-suppressor by interacting with soluble resistance-related calcium binding protein (sorcin). We found that VP1 suppressed tumor necrosis factor (TNF)-α or Sendai virus (SeV)-induced type I interferon response in HEK293T cells, and that this suppression could be completely abolished by knockdown of sorcin by shRNA. Furthermore, overexpression of sorcin inhibited type I interferon response. Conversely, TNF- or SeV-induced type I interferon response increased when sorcin knocked down, leading to inhibition of vesicular stomatitis virus (VSV) replication. Thus, VP1-induced suppression of type I interferon is mediated by interacting with sorcin, a protein that appears to regulate cell response to viral infections.

Staphylococcus sciuri exfoliative toxin C is a dimer that modulates macrophage functions.

Staphylococcus sciuri causes multiple infections in humans. Recently, a strain of S. sciuri (HBXX06) carrying exfoliative toxin C (ExhC) was reported to cause fatal exudative epidermal skin pathology in piglets and might be considered as a potential zoonotic agent. However, little is known about the pathogenicity of this bacterium. In this study, we examined the activity of recombinant ExhC-his (rExhC) protein using newborn mice as the model and investigated the effect of rExhC on macrophage functions. Interestingly, we found that both rExhC and S. sciuri ExhC existed as dimers and that rExhC inhibited the phagocytosis of RAW264.7 cell lines but enhanced the production of proinflammatory mediators, such as interleukin-6, interleukin-12, tumor necrosis factor α, and nitric oxide, by murine peritoneal macrophages and RAW264.7 cells. These results suggest that ExhC may play an important role in innate immune response against S. sciuri infection.