Adjuvant screening of the Senecavirus A inactivated vaccine in mice and evaluation of its immunogenicity in pigs.

BACKGROUND: Senecavirus A (SVA) causes an emerging vesicular disease (VD) with clinical symptoms indistinguishable from other vesicular diseases, including vesicular stomatitis (VS), foot-and-mouth disease (FMD), and swine vesicular disease (SVD). Currently, SVA outbreaks have been reported in Canada, the U.S.A, Brazil, Thailand, Vietnam, Colombia, and China. Based on the experience of prevention and control of FMDV, vaccines are the best means to prevent SVA transmission. RESULTS: After preparing an SVA inactivated vaccine (CH-GX-01-2019), we evaluated the immunogenicity of the SVA inactivated vaccine mixed with Imject® Alum (SVA + AL) or Montanide ISA 201 (SVA + 201) adjuvant in mice, as well as the immunogenicity of the SVA inactivated vaccine combined with Montanide ISA 201 adjuvant in post-weaned pigs. The results of the mouse experiment showed that the immune effects in the SVA + 201 group were superior to that in the SVA + AL group. Results from pigs immunized with SVA inactivated vaccine combined with Montanide ISA 201 showed that the immune effects were largely consistent between the SVA-H group (200 µg) and SVA-L group (50 µg); the viral load in tissues and blood was significantly reduced and no clinical symptoms occurred in the vaccinated pigs. CONCLUSIONS: Montanide ISA 201 is a better adjuvant choice than the Imject® Alum adjuvant in the SVA inactivated vaccine preparation, and the CH-GX-01-2019 SVA inactivated vaccine can provide effective protection for pigs.

Drug-Eluting Balloon Versus Plain Balloon Angioplasty For The Treatment of Failing Hemodialysis Access: A Systematic Review and Meta-analysis.

BACKGROUND: Hemodialysis access dysfunction is the major cause of hospitalization for patients undergoing hemodialysis due to stenosis at the anastomotic site. Our purpose is to perform a meta-analysis comparing target lesion primary patency rates at 6 months and one year, and major procedure-associated complications between drug-eluting balloon (DEB) and plain balloon angioplasty (PBA) for the treatment of arteriovenous fistula (AVF) or synthetic arteriovenous graft (AVG) stenosis. METHODS: PubMed, Embase, and MEDLINE databases were screened up to December 2018 to compare target lesion primary patency and complications between DEB and PBA. Two independent reviewers identified studies fulfilling our inclusion/exclusion criteria, extracted relevant data, and assessed quality. Fixed- or random-effects models were used to calculate overall effect estimates. RESULTS: Our literature search identified 10 articles eligible for inclusion in the review and analysis. DEB provided significantly higher target lesion primary patency rates for failing hemodialysis access than did PBA at 6 months [70% vs. 54%; odds ratio (OR), 2.71, 95% confidence interval (CI), 1.51 to 4.85; P < 0.01] and one year (59% vs. 37%; OR, 3.12, 95% CI, 2.14 to 4.55; P < 0.01). No major procedure-associated complications were observed in the 2 groups. CONCLUSIONS: DEB is an effective and safe technology that can significantly prolong 6-month and one-year target lesion primary patency for failing hemodialysis access when compared to PBA.

R848 Adjuvant Laden With Self-Assembled Nanoparticle-Based mRNA Vaccine Elicits Protective Immunity Against H5N1 in Mice.

In order to perfect the design strategy of messenger RNA (mRNA) vaccines against the H5N1 influenza virus, we investigated whether different antigen designs and the use of adjuvants could improve the immune effect of mRNA vaccines. We designed three different forms of antigen genes, including Flu [H1/H3/H5/B-HA2(aa90~105)-M2e(24aa)], Flu-Fe (Fe, ferritin), and CD5-Flu-Fe (CD5, a secretion signal peptide). Meanwhile, R848 (Requimod) was selected as the adjuvant of the mRNA vaccine. We prepared cationic lipid nanoparticles for mRNA delivery, named LNP-Man (mannose-modified lipid nanoparticles). Cell transfection results showed that Flu-Fe/CD5-Flu-Fe containing ferritin could express the target antigens HA2 and M2e more efficiently than Flu. In the mice immune experiment, five immune groups (LNP-Man/Flu, LNP-Man/Flu-Fe, LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848) and two control groups (LNP-Man, PBS) were set up. After being infected with the 1×LD50 H5N1 avian influenza virus, the survival rate of the mice in the LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848 were 100%. More importantly, in LNP-Man/Flu-Fe+R848 and LNP-Man/CD5-Flu-Fe+R848 groups, there was no residual virus detected in the mice lung tissue on the 5th day postchallenge. Overall, this study provides a new idea for the design of H5N1 avian influenza virus mRNA vaccines in terms of antigen designs and adjuvant selection.

Growth of outgrowth endothelial cells on aligned PLLA nanofibrous scaffolds.

Tissue engineering holds great promise in providing vascular grafts as substitutes for damaged small-diameter blood vessels. Two of the key factors in vascular tissue engineering are biocompatible scaffolds that mimic the effects of extracellular matrix and the source of seeding cells. Synthetic poly-L-lactic acid (PLLA) nanofibers has been shown to be excellent scaffolds for tissue engineering. Outgrowth endothelial cells (OECs) isolated from human peripheral blood could also be expanded in vitro and stably maintain the differentiated phenotypes and could be used as the seeding cells for engineering autologous vascular crafts. Here we tested the possibility of combining these two together. We found that PLLA nanofibers are not only biocompatible with OECs originally isolated from rabbit peripheral blood, the aligned PLLA fibers actually promoted and guided their sustained proliferation. These results suggest that aligned PLLA could be excellent both as the scaffolds and as a promoter of cell growth during vascular tissue engineering.

Immune responses of swine inoculated with a recombinant fowlpox virus co-expressing P12A and 3C of FMDV and swine IL-18.

Two recombinant fowlpox viruses (rFPV-P1 and rFPV-IL18-2AP12A) containing foot-and-mouth disease virus (FMDV) capsid polypeptide, 3C coding regions of O/NY00 were evaluated to determine their abilities to induce humoral and cellular responses in the presence or absence of swine IL-18 as genetic adjuvant. The ability to protect swine against homologous virus challenge was examined. All swine were given booster vaccinations at 21 days after the initial inoculation and were challenged 10 days after the booster vaccination. Control groups were inoculated with wild-type fowlpox virus (wtFPV). All animals vaccinated with rFPV-P12A and rFPV-IL18-P12A developed specific anti-FMDV ELISA antibody and neutralizing antibody and T-lymphocyte proliferation was observed. Cellular immune function was evaluated via examination of IFN-gamma production in swine peripheral blood serum. The results demonstrate the potential viability of a fowlpox virus-based recombinant vaccine in the control and prevention of FMDV infections.

Construction and immunogenicity of a recombinant fowlpox virus containing the capsid and 3C protease coding regions of foot-and-mouth disease virus.

Foot-and-mouth disease virus (FMDV) is an important pathogen with worldwide economic consequences. Consequently, an important goal is the development of a vaccine that can provide rapid protection while overcoming the potential risk associated with the production of conventional inactivated vaccines. An important secondary feature of the vaccine would be the ability to distinguish vaccinated from infected animals. A recombinant fowlpox virus (vUTAL3CP1) containing FMDV capsid polypeptide and 3C coding regions of O/NY00 was constructed and evaluated for its ability to induce humoral and cellular responses in mice and guinea pigs. In addition, the ability to protect guinea pigs against homologous virus challenge was examined. Mice and guinea pigs were given booster vaccinations twice and once, respectively, and guinea pigs were challenged 20 days after the booster vaccination. Control groups included animals inoculated with commercial vaccine, fowlpox virus or phosphate-buffered saline (PBS). All animals vaccinated with vUTAL3CP1 developed specific anti-FMDV antibody and neutralizing antibody, as well as T lymphocyte proliferation response and CTL cytotoxic activity. Three of four guinea pigs vaccinated with vUTAL3CP1 were completely protected from viral challenge. The results demonstrated the potential of a fowlpox virus-based recombinant FMD vaccine.

Immune responses to the oral administration of recombinant Bacillus subtilis expressing multi-epitopes of foot-and-mouth disease virus and a cholera toxin B subunit.

Bacillus subtilis has been engineered successfully to express heterologous antigens for use as a vaccine vehicle that can elicit mucosal and systemic immunity response. In this study, a recombinant B. subtilis expressing the B subunit of cholera toxin (CT-B) and an epitope box constituted with antigen sites from foot-and-mouth disease virus (FMDV) type Asia 1 was constructed and named 1A751/CTB-TEpiAs. Its capability to induce mucosal, humoral, and cellular responses in mice and guinea pigs was evaluated after oral administration with vegetative cells of 1A751/CTB-TEpiAs. In addition, its capability to protect guinea pigs against homologous virus challenge was examined. All animals were given booster vaccination at day 21 after initial inoculation and guinea pigs were challenged 3 weeks after booster vaccination. The control groups were inoculated with a commercial vaccine or administered orally with 1A751/pBC38C or an oral buffer. All animals vaccinated with 1A751/CTB-TEpiAs developed specific anti-FMDV IgA in lung and gut lavage fluid, serum ELISA antibody, neutralizing antibody as well as T lymphocyte proliferation, and IFN-γ secretory responses. Three of the five guinea pigs vaccinated with 1A751/CTB-TEpiAs were protected completely from the viral challenge. The results demonstrate the potential viability of a B. subtilis-based recombinant vaccine for the control and prevention of FMDV infections.

The influence of type-I collagen-coated PLLA aligned nanofibers on growth of blood outgrowth endothelial cells.

Nanofibrous scaffolds have been applied widely in tissue engineering to simulate the nanostructure of natural extracellular matrix (ECM) and promote cell bioactivity. The aim of this study was to design a biocompatible nanofibrous scaffold for blood outgrowth endothelial cells (BOECs) and investigate the interaction between the topography of the nanofibrous scaffold and cell growth. Poly(L-lactic acid) (PLLA) random and aligned nanofibers with a uniform diameter distribution were fabricated by electrospinning. NH(3) plasma etching was used to create a hydrophilic surface on the nanofibers to improve type-I collagen adsorption; the conditions of the NH(3) plasma etching were optimized by XPS and water contact angle analysis. Cell attachment, proliferation, viability, phenotype and morphology of BOECs cultured on type-I collagen-coated PLLA film (col-Film), random fibers (col-RFs) and aligned fibers (col-AFs) were detected over a 7 day culture period. The results showed that collagen-coated PLLA nanofibers improved cell attachment and proliferation; col-AFs induced the directional growth of cells along the aligned nanofibers and enhanced endothelialization. We suggest that col-AFs may be a potential implantable scaffold for vascular tissue engineering.

[Molecular design and immunogenicity of a multiple-epitope foot-and-mouth disease virus antigen, adjuvants, and DNA vaccination].

We designed and constructed a fuse expression gene OAAT and staphylococcal enterotoxin A (SEA) on the basis of the OAAT designed and constructed which consists of the structural protein VP1 genes from serotypes A and O FMDV, 5 major VP1 immunodominant epitopes from two genotypes of Asia1 serotype, and 3 Th2 epitopes originating from the non-structural protein, 3ABC gene and structural protein VP4 gene. The recombinant plasmids pEA was constructed using SEA as a genetic adjuvant. Expressions of target gene from the pEA in Hela cell were verified by IFA and Western blotting. The experiment of BALB/c mice immunized with the DNA vaccines showed that pA and pEA could induce simultaneously specific antibodies against serotypes A, Asia1, and O FMDV, and the highest antibody titres were found in the pEA and inactivated vaccine groups compared to pA vaccinating mice. Compared with the control, the levels of IL-2, IFN-gamma, IL-4, and IL-10 expression by splenic lymphocytes from mice immunized with pA and pEA were significantly increased. In addition, we found that the levels of IL-2, IFN-gamma and IL-4 from the mice immunized with pEA was higher than mice immunized with pA did. The results of viral challenge in guinea pigs showed the pA, pEA and inactivated vaccine provided full protection in 2/4, 2/4, 3/4, 3/4 and 4/4, 4/4 guinea pigs from challenge with FMDV O/NY00 and Asial/YNBS/58, respectively. The results demonstrated fuse protein OAAT and SEA may be potential immunoge against FMDV, furthermore, SEA may be an effective genetic adjuvant for DNA vaccine.