Identification of Cell Types and Transcriptome Landscapes of Porcine Epidemic Diarrhea Virus-Infected Porcine Small Intestine Using Single-Cell RNA Sequencing.

Swine coronavirus-porcine epidemic diarrhea virus (PEDV) with specific susceptibility to pigs has existed for decades, and recurrent epidemics caused by mutant strains have swept the world again since 2010. In this study, single-cell RNA sequencing was used to perform for the first time, to our knowledge, a systematic analysis of pig jejunum infected with PEDV. Pig intestinal cell types were identified by representative markers and identified a new tuft cell marker, DNAH11. Excepting enterocyte cells, the goblet and tuft cells confirmed susceptibility to PEDV. Enrichment analyses showed that PEDV infection resulted in upregulation of cell apoptosis, junctions, and the MAPK signaling pathway and downregulation of oxidative phosphorylation in intestinal epithelial cell types. The T cell differentiation and IgA production were decreased in T and B cells, respectively. Cytokine gene analyses revealed that PEDV infection downregulated CXCL8, CXCL16, and IL34 in tuft cells and upregulated IL22 in Th17 cells. Further studies found that infection of goblet cells with PEDV decreased the expression of MUC2, as well as other mucin components. Moreover, the antimicrobial peptide REG3G was obviously upregulated through the IL33-STAT3 signaling pathway in enterocyte cells in the PEDV-infected group, and REG3G inhibited the PEDV replication. Finally, enterocyte cells expressed almost all coronavirus entry factors, and PEDV infection caused significant upregulation of the coronavirus receptor ACE2 in enterocyte cells. In summary, this study systematically investigated the responses of different cell types in the jejunum of piglets after PEDV infection, which deepened the understanding of viral pathogenesis.

Nonstructural Protein 1 of Variant PEDV Plays a Key Role in Escaping Replication Restriction by Complement C3.

Zoonotic coronaviruses represent an ongoing threat to public health. The classical porcine epidemic diarrhea virus (PEDV) first appeared in the early 1970s. Since 2010, outbreaks of highly virulent PEDV variants have caused great economic losses to the swine industry worldwide. However, the strategies by which PEDV variants escape host immune responses are not fully understood. Complement component 3 (C3) is considered a central component of the three complement activation pathways and plays a crucial role in preventing viral infection. In this study, we found that C3 significantly inhibited PEDV replication in vitro, and both variant and classical PEDV strains induced high levels of interleukin-1ß (IL-1ß) in Huh7 cells. However, the PEDV variant strain reduces C3 transcript and protein levels induced by IL-1ß compared with the PEDV classical strain. Examination of key molecules of the C3 transcriptional signaling pathway revealed that variant PEDV reduced C3 by inhibiting CCAAT/enhancer-binding protein ß (C/EBP-ß) phosphorylation. Mechanistically, PEDV nonstructural protein 1 (NSP1) inhibited C/EBP-ß phosphorylation via amino acid residue 50. Finally, we constructed recombinant PEDVs to verify the critical role of amino acid 50 of NSP1 in the regulation of C3 expression. In summary, we identified a novel antiviral role of C3 in inhibiting PEDV replication and the viral immune evasion strategies of PEDV variants. Our study reveals new information on PEDV-host interactions and furthers our understanding of the pathogenic mechanism of this virus. IMPORTANCE The complement system acts as a vital link between the innate and the adaptive immunity and has the ability to recognize and neutralize various pathogens. Activation of the complement system acts as a double-edged sword, as appropriate levels of activation protect against pathogenic infections, but excessive responses can provoke a dramatic inflammatory response and cause tissue damage, leading to pathological processes, which often appear in COVID-19 patients. However, how PEDV, as the most severe coronavirus causing diarrhea in piglets, regulates the complement system has not been previously reported. In this study, for the first time, we identified a novel mechanism of a PEDV variant in the suppression of C3 expression, showing that different coronaviruses and even different subtype strains differ in regulation of C3 expression. In addition, this study provides a deeper understanding of the mechanism of the PEDV variant in immune escape and enhanced virulence.

Identification of four patterns for self-management behaviors in clients with schizophrenia: A cross-sectional study.

This study aimed to describe different patterns of self-management behaviors among clients with schizophrenia in China. Two hundred twenty-eight clients with schizophrenia living in eight communities of Beijing were investigated using the Self-Management Instrument for Persons with Schizophrenia and a Demographic and Clinical Characteristics Questionnaire. Cluster analysis was performed to categorize the data. Four distinct self-management behavior patterns and variables of clients associated with non-adherent self-management were identified. The self-management behaviors and demographic characteristics were similar in each pattern but different among patterns. These findings could guide the development of more personalized and cost-effective self-management interventions for different patterns of clients in the future.

Broadband perfect transparency-to-absorption switching in tilted anisotropic metamaterials based on the anomalous Brewster effect.

Dynamically switchable light transmission/absorption functionality is highly desirable in sensing and functional devices. However, the operating bandwidth of the newly emerging schemes using resonant meta-structures is inherently limited. In this work, we design and numerically demonstrate a non-resonant tilted anisotropic metamaterial consisting of phase-change materials. When the phase transition of the phase-change material from amorphous phase to crystalline phase occurs, the functionality of the metamaterial can be switched from perfect transparency to perfect absorption for transverse-magnetic polarization under oblique incidence over a broad spectrum. Such a remarkable phenomenon originates in the anomalous Brewster effect, which enables broadband reflectionless transmission/absorption of light under the anomalous Brewster's angle. Moreover, gradient metamaterials exhibiting dynamically controllable functionality for incident light with an almost arbitrary wavefront are demonstrated. The proposed metamaterials are simple but highly efficient, which may find applications in sensing and advanced and intelligent optical devices.

Expression of sirtuins in ovarian follicles of postnatal mice.

Mammalian ovarian follicular development is an intricate, elaborate, and well-organized phenomenon regulated by various signaling pathways; however, the underlying mechanism remains unclear. Mammalian sirtuins (sirtuin 1 to sirtuin 7) are a group of NAD+ -dependent deacetylases implicated in various physiological processes including cell proliferation, apoptosis, cell cycle progression, and insulin signaling. Mammalian ovarian sirtuins have been studied using adult and aged bovine, porcine, and murine models. However, limited information is available regarding their precise expression patterns and the localization of follicle development in mice. This study aimed to assess the dynamic expression and localization of all seven sirtuins in early postnatal mouse ovaries through real-time polymerase chain reaction analysis and immunohistochemistry, respectively. During postnatal ovarian follicle development, sirtuin 1, sirtuin 4, and sirtuin 6 were downregulated compared with those in 1-day postnatal mouse ovaries (p < .05), indicating that these three sirtuin genes may be markers of follicular development. Combining their localization in granulosa cells through immunohistochemical studies, sirtuin 1, sirtuin 4, and sirtuin 6 are suggested to play negative regulatory roles in mammal ovarian follicular granulosa cell development. Furthermore, we found that sirtuin 2 (p < .05) and sirtuin 7 (p < .05) mRNA were constantly upregulated relative to sirtuin 1, although limited information is available regarding sirtuin 7. Among all sirtuins in mouse ovaries, sirtuin 1 was relatively and steadily downregulated. Upon sirtuin 1 overexpression in 1-day postnatal mouse ovaries via sirtuin 1-harboring adenoviruses in vitro, the emergence of primary follicles was delayed, as was the emergence of secondary follicles in 4-day postnatal ovaries. Further studies on KGN cell lines reported that interfering with sirtuin 1 expression in granulosa cell significantly affected granulosa cell proliferation and the expression of mitochondrial genes. This study presents the first systemic analysis of dynamic patterns of sirtuin family expression in early postnatal mice ovaries, laying the foundation for further studies on less discussed sirtuin subtypes, such as sirtuin 5 and sirtuin 7.

Quantitative Proteomics Reveals Changes in Vero Cells in Response to Porcine Epidemic Diarrhea Virus.

Outbreaks of porcine epidemic diarrhea virus (PEDV) have caused significant lethality rates in neonatal piglets, which pose a serious threat to the swine industry worldwide. Available commercial vaccines fail to protect against the emergence of high virulence of PEDV variants. Therefore, the endemic state of the PEDV infection in suckling piglets highlights the urgent need for uncovering the molecular determinants of the disease pathogenesis. In this study, stable isotope labeling by amino acids in cell culture (SILAC), combined with high-performance liquid chromatography/tandem mass spectrometry was performed to determine proteomic differences between PEDV-infected and mock-infected Vero cells at 18 h postinfection. The SILAC-based approach identified 4508 host-cell proteins, of which 120 were significantly up-regulated and 103 were significantly down-regulated at ≥95% confidence. Alterations in the expression of selected proteins were verified by Western blot. Several signaling metabolic pathways including mevalonate pathway I and the superpathway of cholesterol biosynthesis were triggered by the infection of the highly virulent strain and are linked to host innate immunity. 25-HC, an inhibitor of the mevalonate pathway, exhibited potent antiviral activity against PEDV infection. Meanwhile, the cell-cycle-related functions were significantly regulated, which may likely be responsible for the viral replication and pathogenicity of PEDV.

Development of Serotype-Specific PCR Assays for Typing of Haemophilus parasuis Isolates Circulating in Southern China.

The bacterium Haemophilus parasuis is the specific pathogenic cause of Glässer's disease in swine. Fifteen serotypes of H. parasuis have been reported. A method to serotype H. parasuis isolates accurately would help to prevent and control Glässer's disease outbreaks through appropriate vaccination and to understand the epidemiology in specific geographic areas. However, according to traditional serotyping, the rate of nontypeable (NT) strains is 10 to 40%, which gives low accuracy. In the present study, we developed a set of PCR assays that are able to identify all the currently known H. parasuis serotypes, with a detection limit of 5 CFU. This PCR method is particularly useful to distinguish serotype 5 from serotype 12. We then surveyed the serotype prevalence of H. parasuis isolates from southern China using both the traditional indirect hemagglutination (IHA) and current PCR methods. Of the 298 isolates tested, 228 (76.51%) and 281 (94.30%) were serotyped by the IHA and PCR tests, respectively, with a concordance rate of 80.87% (241/298). The most prevalent serotypes obtained by PCR were 4, 5, 12, 13, NT, and 2, and the most prevalent obtained by IHA were NT, 5, 4, 12, 13, and 2. In conclusion, the PCR assays developed in this study provide a rapid and specific method for the molecular serotyping of H. parasuis.

Trapped spoof surface plasmons with structured defects in textured closed surfaces.

We demonstrate that a defect unit in periodic textured closed surfaces is able to trap spoof surface plasmons (SPs) into a deep subwavelength scale. The resonant frequency of a trapped spoof SP can be tuned freely by properly tailoring the dimension of the defect unit. By introducing multiple defect units with different dimensions at different positions of the textured closed surfaces, the spoof SPs with different frequencies trapped effectively at desired places are also demonstrated. In addition, we further design a graded defect structure with continuously variable dimensions to trap the spoof SPs over an ultrawide spectral band. The interval between the trapped waves on the closed surfaces can be tuned conveniently by changing the grade of the defect dimensions. The designer structures may indicate potential applications in the optical switch and storage in the microwave and terahertz frequencies.

Knowledge structure and future research trends of body-mind exercise for mild cognitive impairment: a bibliometric analysis.

Background: Mild cognitive impairment (MCI) is a common neurodegenerative disorder that poses a risk of progression to dementia. There is growing research interest in body-mind exercise (BME) for patients with MCI. While we have observed a rapid growth in interest in BME for MCI over the past 10 years, no bibliometric analysis has investigated the knowledge structure and research trends in this field. Consequently, the objective of this research is to conduct a bibliometric analysis of global publications of BME for MCI from 2013 to 2022. Methods: A total of 242 publications in the field of BME for MCI were retrieved from the Web of Science Core Collection. Bibliometric analysis, including performance analysis, science mapping, and visualization, was performed using CiteSpace, VOSviewer, and Microsoft Excel. Results: Publications and citations in the field of BME for MCI have shown a rapidly increasing trend over the last decade. Geriatrics & Gerontology, and Neurosciences were the most frequently involved research categories. China (78 documents) and the USA (75 documents) contributed to the largest number of publications and had the strongest international collaborative networks. Fujian University of Traditional Chinese Medicine contributed to the largest number of publications (12 documents), and Chen, L of this institution was the most prolific author (12 documents). Frontiers in Aging Neuroscience (16 documents), and JOURNAL OF ALZHEIMER'S DISEASE (12 documents) were the most prolific journals. Tai Chi and Baduanjin, as specific types of BME, were the hotspots of research in this field, while evidence synthesis and guidelines might be future research trends. Conclusion: In the last decade, there has been a rapid growth in scientific activities in the field of BME for MCI. The results of this study provide researchers and other stakeholders with knowledge structure, hotspots, and future research trends in this field.

Vigorous physical activity and weight status in school-aged children: a cross-sectional study.

Aim: To explore the association between VPA and weight status in adolescents. Methods: The 2017/2018 Health Behavior in School-aged Children survey (HBSC) targeted children and adolescents aged 11, 13 and 15. A systematic multistage stratified cluster randomized sampling method was used in each participating country. The 2017/2018 survey enrolled over 240,951 adolescents across 45 countries and regions. Frequency of VPA, weight status and confounding factors were collected using a self-reported questionnaire. Results: Compared to daily VPA, less frequent VPA was linked to higher odds of obesity. For example, those who participating in VPA for 4-6 times a week (OR = 1.10, 95% CI = 1.06-1.13), 2-3 times a week (OR = 1.21, 95% CI = 1.17-1.25), or once a week (OR = 1.21, 95% CI = 1.16-1.25) all have higher odds of abnormal weight status. For boys, the frequency of 4-6 times a week (OR = 1.09, 95% CI = 1.04-1.13), 2-3 times a week (OR = 1.22, 95% CI = 1.17-1.27), or once a week (OR = 1.25, 95% CI = 1.19-1.32) were associated with higher odds of abnormal weight status. For girls, those who participating in VPA 4-6 times a week (OR = 1.11, 95% CI = 1.06-1.16), 2-3 times a week (OR = 1.20, 95% CI = 1.14-1.25), or once a week (OR = 1.17, 95% CI = 1.11-1.23) all have higher odds of abnormal weight status (i.e., overweight or obesity). Conclusion: This population-based study suggests that infrequent VPA participation is associated with unhealthy weight status in adolescents compared to their physically active counterparts. Additionally, this association remains consistent in both boys and girls.

Status and influencing factors of knowledge, attitude and self-reported practice regarding hospice care among nurses in Hainan, China: A cross-sectional study.

AIM: This study is to investigate the current status of knowledge, attitude and self-reported practice in hospice care among nurses in Hainan, China, and then to analyse its influencing factors and mediating effects. This provides a basis for formulating scientific and standardized hospice care training programmes for nurses. METHODS: This cross-sectional study investigated knowledge, attitude and self-reported practice in hospice care among 1819 nurses in Hainan, China. Convenience sampling was used to select participants from 45 hospitals and nursing homes in 14 cities and counties from October to December 2021. A scale of knowledge, attitude and self-reported practice of healthcare providers in hospice care (Chinese version) was administered to collect data during the study period. Statistical analyses, including t-tests, one-way ANOVA, post-hoc analysis and multiple linear regression, assessed the status of knowledge, attitude and self-reported practice of hospice care in nurses and identified influencing factors. The PROCESS macro program model 4.0 was employed to explore the mediating effect of attitude on knowledge and self-reported practice in hospice care. RESULTS: Nurses in Hainan displayed low knowledge (mean = 7.68, SD = 3.53), moderate attitudes (mean = 88.13, SD = 12.10) and self-reported practice (mean = 51.81, SD = 9.82) in hospice care. Current employment and willingness to engage in hospice care were significant factors influencing knowledge, attitude and self-reported practice in hospice care. Attitude partially mediated the relationship between knowledge and self-reported practice. PATIENT OR PUBLIC CONTRIBUTION: This study focuses on nurses' knowledge, attitude and self-reported practice in hospice care and does not directly involve patients or the public. However, the findings enhance hospice care provided to patients and the broader community by improving nurses' knowledge and skills. This study informs evidence-based training programmes and interventions, benefiting those in need of hospice care services.

Association between sports participation and resilience in school-attending students: a cross-sectional study.

Aim: This research sought to identify the association between sports participation and resilience in children and adolescents as a means to enhance mental health. Methods: A comprehensive survey was carried out, encompassing primary, middle, and high school students from chosen educational institutions. The analytical sample comprised 67,281 students of school age. Sports participation and resilience were evaluated using validated assessment tools, while relevant covariates, such as sex and school grade, were assessed through self-reported questionnaires. Generalized Linear Models were applied to ascertain the association between sports participation and resilience for the entire sample, and separately for subgroups divided by gender or school grade, after controlling for covariates. Results: Among the 67,281 school students, males constituted 51.9% of the sample. Approximately 47.1% of the entire sample reported no sports participation, and the average resilience score was 24.7. The regression model analysis revealed that, in the entire sample, increased in sports participation was linked to higher resilience scores (odds ratio [OR] for 1-3 times per month: 1.20, 95%CI: 1.16-1.24; OR for 1-2 times per week: 1.38, 95%CI: 1.33-1.43; OR for 3 times or more per week: 1.72, 95%CI: 1.65-1.79). Analyses stratified by gender and school grade indicated that sports participation was consistently associated with greater resilience. Conclusion: This study provides cross-sectional evidence supporting the positive association between sports participation and the resilience of children and adolescents, underscoring the potential of encouraging sports participation as a strategy for promoting mental health resilience. The findings presented herein should be subject to further confirmation or refutation in future research endeavors.

A single immunization with H5N1 virus-like particle vaccine protects chickens against divergent H5N1 influenza viruses and vaccine efficacy is determined by adjuvant and dosage.

The H5N1 subtype highly pathogenic avian influenza virus (HPAIV) reveals high variability and threatens poultry production and public health. To prevent the spread of H5N1 HPAIV, we developed an H5N1 virus-like particle (VLP) vaccine based on the insect cell-baculovirus expression system. Single immunization of the H5N1 VLP vaccines induced high levels of HI antibody titres and provided effective protection against homologous virus challenge comparable to the commercial inactivated vaccine. Meanwhile, we assessed the relative efficacy of different adjuvants by carrying out a head-to-head comparison of the adjuvants ISA 201 and ISA 71 and evaluated whether the two adjuvants could induce broadly protective immunity. The ISA 71 adjuvanted vaccine induced significantly higher levels of Th1 and Th2 immune responses and provided superior cross-protection against antigenically divergent H5N1 virus challenge than the ISA 201 adjuvanted vaccine. Importantly, increasing the vaccine dose could further enhance the cross-protective efficacy of H5N1 VLP vaccine and confer completely sterilizing protection against antigenically divergent H5N1 virus challenge, which was mediated by neutralizing antibodies. Our results suggest that the H5N1 VLP vaccine can provide broad-spectrum protection against divergent H5N1 influenza viruses as determined by adjuvant and vaccine dose.

Influence of PepF peptidase and sporulation on microcin J25 production in Bacillus subtilis.

The lasso peptide microcin J25 (MccJ25) possesses strong antibacterial properties and is considered a potential effective component of bacterial disease treatment drugs and safe food preservatives. Although MccJ25 can be heterologously expressed in Bacillus subtilis as we have previously reported, its regulation and accumulation are yet to be understood. Here, we investigated the expression level and stability of MccJ25 in B. subtilis strains with disruption in peptidase genes pepA, pepF, and pepT. Oligoendopeptidase F (PepF) was found to be involved in reduction of the production of MccJ25 by degradation of its precursor peptide. In the pepF mutant, the MccJ25 reached a concentration of 1.68 µM after a cultivation time exceeding 60 hours, while the wild-type strain exhibited a concentration of only 0.14 µM. Moreover, the production of MccJ25 in B. subtilis downregulated the genes associated with sporulation, and this may contribute to its accumulation. Finally, this study provides a strategy to improve the stability and production of MccJ25 in B. subtilis. IMPORTANCE: MccJ25 displays significant antibacterial activity, a well-defined mode of action, exceptional safety, and remarkable stability. Hence, it presents itself as a compelling candidate for an optimal antibacterial or anti-endotoxin medication. The successful establishment of exogenous production of MccJ25 in Bacillus subtilis provides a strategy for reducing its production cost and diversifying its utilization. In this study, we have provided evidence indicating that both peptidase PepF and sporulation are significant factors that limit the expression of MccJ25 in B. subtilis. The ΔpepF and ΔsigF mutants of B. subtilis express MccJ25 with higher production yield and enhanced stability. To sum up, this study developed several better engineered strains of B. subtilis, which greatly reduced the consumption of MccJ25 during the nutrient depletion stage of the host strain, improved its production, and elucidated factors that may be involved in reducing MccJ25 accumulation in B. subtilis.

Additional Insertion of gC Gene Triggers Better Immune Efficacy of TK/gI/gE-Deleted Pseudorabies Virus in Mice.

In recent years, pseudorabies virus (PRV) variants have resulted in an epidemic in swine herds and huge economic losses in China. Therefore, it is essential to develop an efficacious vaccine against the spread of PRV variants. Here, the triple-gene-deletion virus and the triple-gene-deletion plus gC virus were constructed by homologous recombination (HR). And then, their growth capacity, proliferation ability, and immune efficacy were evaluated. The results showed that the growth kinetics of the recombinant viruses were similar to those of the parental strain PRV-AH. Compared with the triple-gene-deletion virus group, the more dominant level of neutralizing antibody (NA) can be induced in the triple-gene-deletion plus gC virus group with the same 106.0 TCID50 dose after 4 and 6 weeks post-initial immunization (PII) (p < 0.0001). In addition, the antibody titers in mice immunized with the triple-gene-deletion plus gC virus were significantly higher than those immunized with triple-gene deletion virus with the same 105.0 TCID50 dose after 6 weeks PII (p < 0.001). More importantly, in the triple-gene-deletion plus gC virus group with 105.0 TCID50, the level of NA was close to that in the triple-gene deletion virus group with 106.0 TCID50 at 6 weeks PII. Meanwhile, the cytokines IL-4 and IFN-γ in sera were tested by enzyme-linked immunosorbent assay (ELISA) in each group. The highest level of IL-4 or IFN-γ was also elicited in the triple-gene deletion plus gC virus group at a dose of 106.0 TCID50. After challenge with PRV-AH, the survival rates of the triple-gene deletion plus gC virus immunized groups were higher than those of other groups. In immunized groups with 105.0 TCID50, the survival rate shows a significant difference between the triple-gene deletion plus gC virus group (75%, 6/8) and the triple-gene deletion virus group (12.5%, 1/8). In general, the immune efficacy of the PRV TK/gI/gE-deleted virus can be increased with additional gC insertion in mice, which has potential for developing an attenuated vaccine candidate for PRV control.

Quantitative proteomics by amino acid labeling in foot-and-mouth disease virus (FMDV)-infected cells.

Foot-and-mouth disease virus (FMDV) is an important disease agent that can be difficult to effectively eradicate from herds. Because it is an obligate intracellular parasite, the virus has multiple effects on the host cell during infection. Here, a high-throughput quantitative proteomic approach was used to develop an unbiased holistic overview of the protein changes in IBRS-2 cells infected with FMDV. Stable isotope labeling with amino acids in cell culture (SILAC) combined with LC-MS/MS was performed to identify and quantify 1260 cellular and 2 viral proteins after 6 h of infection of IBRS-2 cells with FMDV. Of these identified and measured cellular protein pairs, 77 were significantly up-regulated, and 50 were significantly down-regulated based on significance B ≤ 0.05. The differentially altered proteins included a number of proteins involved in endolysosomal proteases system, cell cycle, cellular growth and proliferation, and immune cell trafficking. Selected data were validated by Western blot. Ingenuity Pathway Analysis revealed that proteins that changed in response to infection could be assigned to defined canonical pathways and functional groupings, such as integrin signaling. The obtained data might not only improve the understanding of the dynamics of FMDV and host interaction but may also help elucidate the pathogenic mechanism of FMDV infection.

Complete genome sequence of a novel porcine epidemic diarrhea virus in south China.

Since early 2010, outbreaks of porcine epidemic diarrhea (PED) have been observed frequently in immunized swine herds in southern China. The suckling piglets are particularly susceptible to porcine epidemic diarrhea virus (PEDV), with a high mortality rate (90%). Recently, a virulent PEDV strain, GD-A, was isolated from an immunized-swine breeding farm in Guangdong, China. This report describes the complete genome sequence of GD-A, and the data will provide important insights into the variation of PEDV field isolates in southern China.

Complete genome sequence of a highly prevalent isolate of porcine epidemic diarrhea virus in South China.

A widespread porcine epidemic diarrhea virus (PEDV) occurred in southern China during 2010 to 2012. A virulent field PEDV strain, GD-B, was isolated from a sucking piglet suffering from severe diarrhea in Guangdong, China. We sequenced and analyzed the complete genome of strain GD-B, which will promote a better understanding of the molecular epidemiology and genetic diversity of PEDV field isolates in southern China.

Induction of robust immunity response in mice by dual-expression-system-based recombinant baculovirus expressing the capsid protein of porcine circovirus type 2.

BACKGROUND: Porcine circovirus type 2 (PCV2) is associated with post-weaning multisystemic wasting syndrome (PMWS), an emerging swine disease that causes progressive weight loss, dyspnea, tachypnea, anemia, jaundice, and diarrhea in piglets. Although baculovirus is an enveloped virus that infects insects in nature, it has emerged as a vaccine vector, and we used it to develop a novel candidate vaccine for a preventive or therapeutic strategy to control PCV2 infections. METHODS: Immunoblotting analysis of recombinant baculovirus and immunofluorescent staining of baculovirus-infected cells were followed using anti-ORF2 monoclonal antibodies. The BALB/c mice were immunized intramuscularly with this baculovirus. The titers of antibodies were mensurated with a Cap-protein-specific enzyme-linked immunosorbent assay (ELISA) and a serum neutralization assay. The IFN-γ response in splenocytes harvested from immunized mice was measured by ELISA. Student's t-test was used to compare immune responses of different groups. RESULTS: In this study, we successfully constructed a dual-expression-system-based recombinant baculovirus BV-GD-ORF2, which can display the PCV2 capsid (Cap) protein and VSV-G protein on the viral envelope and also expressing Cap protein on transduced mammalian cells, thereby functioning as both a subunit and a DNA vaccine. After infection, the Cap protein was expressed and displayed on the viral surface, as demonstrated with an indirect fluorescence assay and immunoblotting. The vaccination of mice with recombinant baculovirus BV-GD-ORF2 successfully induced robust Cap-protein-specific humoral and cellular immune responses. CONCLUSIONS: Our findings collectively demonstrate that the recombinant baculovirus BV-GD-ORF2 is a potential vaccine against PCV2 infections.

Influenza H7N9 Virus Hemagglutinin with T169A Mutation Possesses Enhanced Thermostability and Provides Effective Immune Protection against Lethal H7N9 Virus Challenge in Chickens.

H7N9 avian influenza virus (AIV) has caused huge losses in the poultry industry and impacted human public health security, and still poses a potential threat. Currently, immune prevention and control of avian influenza relies on traditional inactivated vaccines; however, they have some limitations and genetically engineered avian influenza subunit vaccines may be potential candidate vaccines. In this study, a T169A mutation in the HA protein derived from H7N9 AIV A/Chicken/Guangdong/16876 (H7N9-16876) was generated using the baculovirus expression system (BVES). The results showed that the mutant (HAm) had significantly increased thermostability compared with the wild-type HA protein (HA-WT). Importantly, immunizing chickens with HAm combined with ISA 71VG elicited higher cross-reactive hemagglutination inhibition (HI) antibody responses and cytokine (IFN-γ and IL-4) secretion. After a lethal challenge with heterologous H7N9 AIV, the vaccine conferred chickens with 100% (10/10) clinical protection and effectively inhibited viral shedding, with 90% (9/10) of the chickens showing no virus shedding. The thermostability of HAm may represent an advantage in practical vaccine manufacture and application. In general, the HAm generated in this study represents a promising subunit vaccine candidate for the prevention and control of H7N9 avian influenza.