Evaluation of the immunogenicity of auxotrophic Lactobacillus with CRISPR-Cas9D10A system-mediated chromosomal editing to express porcine rotavirus capsid protein VP4.

Porcine rotavirus (PoRV) is an important pathogen, leading to the occurrence of viral diarrhoea . As the infection displays obvious enterotropism, intestinal mucosal immunity is the significant line of defence against pathogen invasion. Moreover, as lactic acid bacteria (LAB) show acid resistance, bile salt resistance and immune regulation, it is of great significance to develop an oral vaccine. Most traditional plasmid delivery vectors use antibiotic genes as selective markers, easily leading to antibiotic accumulation. Therefore, to select a food-grade marker in genetically engineering food-grade microorganisms is vital. Based on the CRISPR-Cas9D10A system, we constructed a stable auxotrophic Lactobacillus paracasei HLJ-27 (Lactobacillus △Alr HLJ-27) strain. In addition, as many plasmids replicate in the host bacteria, resulting in internal gene deletions. In this study,we used a temperature-sensitive gene editing plasmidto insert the VP4 gene into the genome, yielding the insertion mutant strains VP4/△Alr HLJ-27, VP4/△Alr W56, and VP4/W56. This recombinant bacterium efficiently induced secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses. These oral mucosal vaccines have the potential to act as an alternative to the application of antibiotics in the future and induce efficient immune responses against PEDV infection.

Correlates of the Veterans Visiting Emergency Departments in Taiwan: A Comparison Before and After the Coronavirus Disease 2019 Pandemic.

BACKGROUND: Taiwan has a substantial number of veterans, but knowledge regarding their emergency department (ED) visits during the coronavirus disease 2019 (COVID-19) pandemic remains limited. This study examined the characteristics of veterans' ED visits during Taiwan's COVID-19 epidemic. METHODS: This was a cross-sectional study conducted at the ED of a large veteran medical center located in Taipei, Taiwan, from May 2018 to October 2021. We analyzed the numbers and features of visits in summer and autumn according to the first wave of the COVID-19 epidemic in Taiwan in 2021. RESULTS: Medical institutions were positively associated with veteran status. Emergency department complaints of trauma (adjusted odds ratio [AOR] = 1.15, 95% CI: 1.06-1.25; summer P < .01) and chest pain/tightness (AOR = 1.65, 95% CI: 1.45-1.87; summer P < .01; AOR = 1.4, 95% CI: 1.26-1.55; P < .01) were associated with increased odds of being a veteran. Triage levels above 2 were positively associated with veteran status in the autumn model (AOR = 1.14, 95% CI: 1.07-1.22; P < .01). Patients hospitalized after ED visits were associated with reduced odds of veteran status (P < .01). Those who spent a long time in the ED were more likely to be veterans than those who spent a shorter time in the ED (P < .01). Veterans were less likely to visit the ED regardless of the time frame of the study period (P < .01), except during the COVID-19 outbreak in the autumn (2019-2020). CONCLUSIONS: The distinctions in ED visits highlighted the individuality of veterans' medical needs. Our findings suggest that the veteran medical system can add to the focus on improving senior-friendly care, fall prevention, quality of life of institutionalized veterans, access for homeless veterans, and care for ambulatory care-sensitive conditions.

Entangling of Peptide Nanofibers Reduces the Invasiveness of SARS-CoV-2.

The viral spike (S) protein on the surface of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to angiotensin-converting enzyme 2 (ACE2) receptors on the host cells, facilitating its entry and infection. Here, functionalized nanofibers targeting the S protein with peptide sequences of IRQFFKK, WVHFYHK and NSGGSVH, which are screened from a high-throughput one-bead one-compound screening strategy, are designed and prepared. The flexible nanofibers support multiple binding sites and efficiently entangle SARS-CoV-2, forming a nanofibrous network that blocks the interaction between the S protein of SARS-CoV-2 and the ACE2 on host cells, and efficiently reduce the invasiveness of SARS-CoV-2. In summary, nanofibers entangling represents a smart nanomedicine for the prevention of SARS-CoV-2.

The risk of COVID-19 can be predicted by a nomogram based on m6A-related genes.

BACKGROUND: The expression of m6A-related genes and their significance in COVID-19 patients are still unknown. METHODS: The GSE177477 and GSE157103 datasets of the Gene Expression Omnibus were used to extract RNA-seq data. The expression of 26 m6A-related genes and immune cell infiltration in COVID-19 patients were analyzed. Finally, we built and validated a nomogram model to predict the risk of COVID-19 infection. RESULTS: There were significant differences in 11 m6A regulatory factors between patients with COVID-19 and healthy individuals. The classification of disease subtypes based on m6A-related gene levels can be distinguished. COVID-19 patients in GSE177477 were classified into two categories based on m6A-related genes. The patients in cluster A were all symptomatic, while those in cluster B were asymptomatic. A significant correlation was also found between immune cells and m6A-related genes. Finally, seven m6A-related disease-characteristic genes, HNRNPA2B1, ELAVL1, RBM15, RBM15B, YTHDC1, HNRNPC, and WTAP, were screened to construct a nomogram model for predicting risk. The calibration curve, decision curve analysis, and clinical impact curve analysis were used to show that the nomogram model was effective and had a high net efficacy for risk prediction. CONCLUSIONS: m6A-related genes were correlated with immune cells. The nomogram model effectively predicted COVID-19 risk. Moreover, m6A-related genes may be associated with the presence or absence of symptoms in COVID-19 patients.

Delivery of antigen to porcine dendritic cells by fusing antigen with porcine dendritic cells targeting peptide.

Dendritic cells (DCs) are professional antigen-presenting cells that can recognize, capture, and process antigens. Fusing molecules targeting DCs with antigens can effectively improve the efficiency with which antigens are recognized and captured by DCs. This targeting strategy can be used for vaccine development to effectively improve the efficiency of antigen recognition and capture by DCs. The targeting sequence of porcine cytotoxic T-lymphocyte associated protein 4 (CTLA4), which binds porcine DCs, was identified in this study. Recombinant Lactobacillus reuteri (L. reuteri) expressing CTLA4-6aa (LYPPPY) and CTLA4-87aa fused to the porcine epidemic diarrhea virus (PEDV) protective antigen core neutralizing epitope (COE) were used to evaluate the ability of the two targeting motifs to bind the B7 molecule on DCs. Our results demonstrate that CTLA4-6aa could bind porcine DCs, and recombinant Lactobacillus expressing the CTLA4-6aa captured by porcine DCs was more efficient than those expressing CTLA4-87aa. In addition, the expression of DC markers, toll-like receptors, and cytokines was significantly higher in the 6aa-COE/L. reuteri-stimulated porcine DCs compared to DCs treated with 87aa-COE/L. reuteri (p<0.01) and recombinant Lactobacillus expressing CTLA4-6aa enhanced the ability of porcine DCs to activate T-cell proliferation. Our analysis of the protein structure revealed that CTLA4-87aa contains intramolecular hydrogen bonds, which may have weakened the intermolecular force between the residues on porcine CTLA4 and that on B7. In conclusion, recombinant Lactobacillus expressing CTLA4-6aa were more efficiently captured by porcine DCs and had a stronger ability to promote DC maturation and enhance T-cell proliferation. The LYPPPY motif is the optimal sequence for binding to porcine DCs. Piglets immunized with recombinant Lactobacillus showed that recombinant Lactobacillus expressing CTLA4-6aa induced significant levels of anti-PEDV-specific IgG and IgA antibody responses. Our study may promote research on DC-targeting strategies to enhance the effectiveness of porcine vaccines.

Evaluation of the Immunogenicity in Mice Orally Immunized with Recombinant Lactobacillus casei Expressing Porcine Epidemic Diarrhea Virus S1 Protein.

Porcine epidemic diarrhea (PED), characterized by diarrhea, vomiting, and dehydration, is an acute enteric infectious disease of pigs. The disease is caused by porcine epidemic diarrhea virus (PEDV), which infects the intestinal mucosal surface. Therefore, mucosal immunization through the oral route is an effective method of immunization. Lactic acid bacteria, which are acid resistant and bile-salt resistant and improve mucosal immunity, are ideal carriers for oral vaccines. The S1 glycoprotein of PEDV mediates binding of the virus with cell receptors and induces neutralizing antibodies against the virus. Therefore, we reversely screened the recombinant strain pPG-SD-S1/Δupp ATCC 393 expressing PEDV S1 glycoprotein by Lactobacillus casei deficient in upp genotype (Δupp ATCC 393). Mice were orally immunized three times with the recombinant bacteria that had been identified for expression, and the changes of anti-PEDV IgG and secreted immunoglobulin A levels were observed over 70 days. The results indicated that the antibody levels notably increased after oral administration of recombinant bacteria. The detection of extracellular cytokines on the 42nd day after immunization indicated high levels of humoral and cellular immune responses in mice. The above results demonstrate that pPG-SD-S1/Δupp ATCC 393 has great potential as an oral vaccine against PEDV.

Effects of recombinant porcine Lactobacillus reuteri secreting expression of bovine lactoferrin peptides on growth performance of newborn piglets and protective effect against diarrhea virus infection

This experiment was conducted to investigate the effects of recombinant porcine Lactobacillus reuteri secreting bovine lactoferrin peptide (LFCA) on growth performance of newborn piglets and the protective effect on porcine transmissible gastroenteritis virus (TGEV)infection which caused piglet diarrhea. Experiment 1:thirty-six one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 3 groups, which were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group and control group, each group with 12 piglets. Piglets in each group were orally administered recombinant porcine Lactobacillus reuteri expressing LFCA pPG-LFCA/LR-CO21, containing empty vector plasmid PPG/LR-CO21 and equal volume phosphate buffer (PBS);oral administration continued for 3 days, and the observation time after oral administration was 14 d. During the period, piglets were fed freely, and the changes of body weight and diarrhea were recorded. Experiment 2:thirty one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 5 groups and given TGEV with a half tissue culture infection dose (TCID50) of 10-7.50/mL by oral administration of 1, 3, 6, 9 and 12 mL, respectively. The observation period of 7 d was set to analyze the conditions of half lethal dose. Experiment 3:another thirty-two newborn piglets with an average body weight of about 1.5 kg were selected as experimental animals and randomly divided into 4 groups, with 8 piglets in each group. The groups were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group, control group and TGEV infect group. There were 8 replicates in each group and 1 piglet in each replicate. Each head of the experimental group was orally fed ppG-LFCA/LR-CO21, pPG/LR-CO21 and equal volume of PBS at a dose of 2..1010 CFU per day for 1 consecutive week. At 8 days of age, TGEV was infected by oral administration at half lethal dose, and samples were collected after 7 days of infection. The weight change and diarrhea of each group of piglets were recorded;hematoxylin-eosin staining was used to detect the length of intestinal villi and the depth of crypts;enzyme linked immunosorbent assay (ELISA) was used to determine total serum total immunoglobulin G (IgG) and total secretory immunoglobulin A (sIgA) antibody contents. RT-qPCR was used to detect the mRNA relative expression levels of Claudin-1, Occludin, tight junction protein-1 (ZO-1), inflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), interferon-P (IFN-P), tumor necrosis factor-a (TNF-a) and Toll-like receptor 2 (TLR2). The flora structure of the contents of the piglet's cecum was analyzed. After oral recombinant porcine Lactobacillusreuteri, compared with the control group, the average daily gain of newborn piglets in the pPG-LFCA/LR-CO21 group was significantly increased (P < 0.01), while the diarrhea rate was significantly decreased (P < 0.01). Compared with TGEV infection group, the average daily gain of piglets in pPG-LFCA/LR-CO21 group was increased and diarrhea rate was decreased, and the differences were significant (P < 0.05). Villus height and the ratio of villus height to crypt depth in jejunum and ileum were significantly increased (P < 0.05). The contents of total IgG and intestinal mucosal total sIgA antibody in serum of piglets were significantly increased (P < 0.05);the mRNA relative expression levels of tight junction protein-related genes Claudin-1, Occludin and ZO-1 in intestinal mucosal tissue were extremely significantly increased (P < 0.01), and the serum TNF-a content was extremely significantly decreased (P < 0.01). Serum IFN-P, IL-6, IL-8 and TLR2 contents were significantly increased (P < 0.01), and the survival rate of piglets was improved. The analysis of the bacterial diversity in the contents of the piglets' cecum showed that the proportion of normal intestinal flora of piglets decreased after TGEV infection. Compared with the TGEV infect group, the proportion of pathogenic bacteria Bacteroides in piglet's intestinal flora decreased by o

PCSK9 inhibitor recaticimab for hypercholesterolemia on stable statin dose: a randomized, double-blind, placebo-controlled phase 1b/2 study.

BACKGROUND: Recaticimab (SHR-1209, a humanized monoclonal antibody against PCSK9) showed robust LDL-C reduction in healthy volunteers. This study aimed to further assess the efficacy and safety of recaticimab in patients with hypercholesterolemia. METHODS: In this randomized, double-blind, placebo-controlled phase 1b/2 trial, patients receiving stable dose of atorvastatin with an LDL-C level of 2.6 mmol/L or higher were randomized in a ratio of 5:1 to subcutaneous injections of recaticimab or placebo at different doses and schedules. Patients were recruited in the order of 75 mg every 4 weeks (75Q4W), 150Q8W, 300Q12W, 150Q4W, 300Q8W, and 450Q12W. The primary endpoint was percentage change in LDL-C from the baseline to end of treatment (i.e., at week 16 for Q4W and Q8W schedule and at week 24 for Q12W schedule). RESULTS: A total of 91 patients were enrolled and received recaticimab and 19 received placebo. The dose of background atorvastatin in all 110 patients was 10 or 20 mg/day. The main baseline LDL-C ranged from 3.360 to 3.759 mmol/L. The least-squares mean percentage reductions in LDL-C from baseline to end of treatment relative to placebo for recaticimab groups at different doses and schedules ranged from -48.37 to -59.51%. No serious treatment-emergent adverse events (TEAEs) occurred. The most common TEAEs included upper respiratory tract infection, increased alanine aminotransferase, increased blood glucose, and increased gamma-glutamyltransferase. CONCLUSION: Recaticimab as add-on to moderate-intensity statin therapy significantly and substantially reduced the LDL-C level with an infrequent administration schedule (even given once every 12 weeks), compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov , number NCT03944109.

Emergency department response to coronavirus disease 2019 outbreak with a fever screening station and "graded approach" for isolation and testing.

BACKGROUND: Ever since coronavirus disease 2019 (COVID-19) emerged in Wuhan, China, in December 2019, it has had a devastating effect on the world through exponential case growth and death tolls in at least 146 countries. Rapid response and timely modifications in the emergency department (ED) for infection control are paramount to maintaining basic medical services and preventing the spread of COVID-19. This study presents the unique measure of combining a fever screening station (FSS) and graded approach to isolation and testing in a Taiwanese medical center. METHODS: An FSS was immediately set up outside the ED on January 27, 2019. A graded approach was adopted to stratify patients into "high risk," "intermediate risk," and "undetermined risk" for both isolation and testing. RESULTS: A total of 3755 patients were screened at the FSS, with 80.3% visiting the ED from home, 70.9% having no travel history, 21.4% having traveled to Asia, and 10.0% of TVGH staff. Further, 54.9% had fever, 35.5% had respiratory symptoms, 3.2% had gastrointestinal symptoms, 0.6% experienced loss of smell, and 3.1% had no symptoms; 81.3% were discharged, 18.6% admitted, and 0.1% died. About 1.9% were admitted to the intensive care unit, 10.3% to the general ward, and 6.4% were isolated. Two patients tested positive for COVID-19 (0.1%) and 127 (3.4%) tested positive for atypical infection; 1471 patients were tested for COVID-19; 583 were stratified as high-risk, 781 as intermediate-risk, and 107 as undetermined-risk patients. CONCLUSION: Rapid response for infection control is a paramount in the ED to confront the COVID-19 outbreak. The FFS helped divide the flow of high- and intermediate-risk patients; it also decreased the ED workload during a surge of febrile patients. A graded approach to testing uses risk stratification to prevent nosocomial infection of asymptomatic patients. A graded approach to isolation enables efficient allocation of scarce medical resources according to risk stratification.

Cloning, Prokaryotic Soluble Expression, and Analysis of Antiviral Activity of Two Novel Feline IFN-ω Proteins

Cats are becoming more popular as household companions and pets, forming close relationships with humans. Although feline viral diseases can pose serious health hazards to pet cats, commercialized preventative vaccines are lacking. Interferons (IFNs), especially type I IFNs (IFN-α, IFN-ß, and interferon omega (IFN-ω)), have been explored as effective therapeutic drugs against viral diseases in cats. Nevertheless, there is limited knowledge regarding feline IFN-ω (feIFN-ω), compared to IFN-α and IFN-ß. In this study, we cloned the genes encoding feIFN-ωa and feIFN-ωb from cat spleen lymphocytes. Homology and phylogenetic tree analysis revealed that these two genes belonged to new subtypes of feIFN-ω. The recombinant feIFN-ωa and feIFN-ωb proteins were expressed in their soluble forms in Escherichia coli, followed by purification. Both proteins exhibited effective anti-vesicular stomatitis virus (VSV) activity in Vero, F81 (feline kidney cell), Madin-Darby bovine kidney (MDBK), Madin-Darby canine kidney (MDCK), and porcine kidney (PK-15) cells, showing broader cross-species antiviral activity than the INTERCAT IFN antiviral drug. Furthermore, the recombinant feIFN-ωa and feIFN-ωb proteins demonstrated antiviral activity against VSV, feline coronavirus (FCoV), canine parvovirus (CPV), bovine viral diarrhea virus (BVDV), and porcine epidemic diarrhea virus (PEDV), indicating better broad-spectrum antiviral activity than the INTERCAT IFN. The two novel feIFN-ω proteins (feIFN-ωa and feIFN-ωb) described in this study show promising potential to serve as effective therapeutic agents for treating viral infections in pet cats.