Background: Canine distemper virus (CDV), which is highly infectious, has caused outbreaks of varying scales in domestic and wild animals worldwide, so the development of a high-efficiency vaccine has broad application prospects. Currently, the commercial vaccine of CDV is an attenuated vaccine, which has the disadvantages of a complex preparation process, high cost and safety risk. It is necessary to develop a safe and effective CDV vaccine that is easy to produce on a large scale. In this study, sequences of CDV haemagglutinin (HA) from the Yanaka strain were aligned, and three potential linear sequences, termed YaH₃, YaH₄, and YaH₅, were collected. To increase the immunogenicity of the epitopes, ferritin was employed as a self-assembling nanoparticle element. The ferritin-coupled forms were termed YaH₃F, YaH₄F, and YaH₅F, respectively. A full-length HA sequence coupled with ferritin was also constructed as a DNA vaccine to compare the immunogenicity of nanoparticles in prokaryotic expression. Result: The self-assembly morphology of the proteins from prokaryotic expression was verified by transmission electron microscopy. All the proteins self-assembled into nanoparticles. The expression of the DNA vaccine YaHF in HEK-293T cells was also confirmed in vitro. After subcutaneous injection of epitope nanoparticles or intramuscular injection of DNA YaHF, all vaccines induced strong serum titres, and long-term potency of antibodies in serum could be detected after 84 days. Strong anti-CDV neutralizing activities were observed in both the YaH₄F group and YaHF group. According to antibody typing and cytokine detection, YaH₄F can induce both Th1 and Th2 immune responses. The results of flow cytometry detection indicated that compared with the control group, all the immunogens elicited an increase in CD3. Simultaneously, the serum antibodies induced by YaH₄F and YaHF could significantly enhance the ADCC effect compared with the control group, indicating that the antibodies in the serum effectively recognized the antigens on the cell surface and induced NK cells to kill infected cells directly. Conclusions: YaH₄F self-assembling nanoparticle obtained by prokaryotic expression has no less of an immune effect than YaHF, and H₄ has great potential to become a key target for the easy and rapid preparation of epitope vaccines. Graphical

We investigated the functions of microRNAs in the therapeutic effects of noni (Morinda citrifolia L.) fruit juice on mouse models of acute gouty arthritis induced with monosodium urate (MSU). Compared with the model group (treated with MSU), mice in both the positive control group (treated with both MSU and colchicine) and noni fruit juice group (treated with MSU and noni fruit juice) showed a significantly decreased degree of paw swelling in 5 days, as well as the contents of two types of proinflammatory cytokines (i.e., NALP3 and TNF-α). Based on the next-generation sequencing technology, a total of 3896 microRNAs (234 known and 3662 novel) were identified in mice treated with noni fruit juice. A large amount of differentially expressed miRNAs were identified in the noni fruit juice group, suggesting the significant effects of noni fruit juice on the mice with acute gouty arthritis, while the different patterns of change in the numbers of both upregulated and downregulated miRNAs in both noni fruit juice and positive control groups indicated that the mice of acute gouty arthritis may be regulated by differential mechanisms between the treatments of noni fruit juice and colchicine. The target genes of microRNAs involved in the pathogenesis and pathology of acute gouty arthritis in mice were identified and further annotated by both Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Our results revealed the therapeutic effects of noni fruit juice on acute gouty arthritis in mice with a group of microRNAs involved in the pharmacological mechanisms of noni fruit juice, providing scientific evidence to support both the agricultural cultivation and pharmacological significance of noni plants.

(1) Background: Antibiotic resistance in bacteria is an urgent global threat to public health. Migratory birds can acquire antibiotic-resistant and pathogenic bacteria from the environment or through contact with each other and spread them over long distances. The objectives of this study were to explore the relationship between migratory birds and the transmission of drug-resistant pathogenic Escherichia coli. (2) Methods: Faeces and swab samples from migratory birds were collected for isolating E. coli on the Inner Mongolia Plateau of northern China from 2018 to 2023. The resistant phenotypes and spectra of isolates were determined using a BD Phoenix 100 System. Conjugation assays were performed on extended-spectrum β-lactamase (ESBL)-producing strains, and the genomes of multidrug-resistant (MDR) and ESBL-producing isolates were sequenced and analysed. (3) Results: Overall, 179 isolates were antibiotic-resistant, with 49.7% MDR and 14.0% ESBL. Plasmids were successfully transferred from 32% of ESBL-producing strains. Genome sequencing analysis of 91 MDR E. coli strains identified 57 acquired resistance genes of 13 classes, and extraintestinal pathogenic E. coli and avian pathogenic E. coli accounted for 26.4% and 9.9%, respectively. There were 52 serotypes and 54 sequence types (STs), including ST48 (4.4%), ST69 (4.4%), ST131 (2.2%) and ST10 (2.2%). The international high-risk clonal strains ST131 and ST10 primarily carried bla_CTX-M-27 and bla_TEM-176. (4) Conclusions: There is a high prevalence of multidrug-resistant virulent E. coli in migratory birds on the Inner Mongolian Plateau. This indicates a risk of intercontinental transmission from migratory birds to livestock and humans.

Objectives: Research on the immunocastration vaccine is of great significance for animal management. In this study, the gonadotropin-releasing hormone (GnRH) ferritin nanoparticle vaccine was constructed using Spy Catcher-Spy Tag (SC-ST) as a delivery system; Methods: The Spy Catcher was constructed to fuse with the expression vector pET-30a-SF of ferritin nanoparticles. Two polypeptides, STG1: Spy Tag-GnRH I-PADRE and STG2: Spy Tag-GnRH I-GnRH II, coupled to SF in vitro to form two nanoparticles, were designed and synthesized to detect castration effects in mice. We mixed them with the adjuvant MONTANIDE ISA 206 VG to explore the adjuvant’s effect on immunogenicity; Results: All immunized groups produced anti-GnRH specific antibodies after the second immunization, which was significantly higher in the immunized group and the combined adjuvant group than in the control group, and the immune response could still be detected at the 12th week. The concentrations of testosterone, follicle-stimulating hormone, and luteinizing hormone in serum were significantly decreased. The number of sperm in the epididymis of mice in each immune group was significantly reduced, and the rate of sperm deformity was high; Conclusions: The two ferritin-based GnRH nanoparticles developed in this study can significantly cause testicular atrophy, decreased gonadal hormone concentration, decreased sperm count, and increased deformity rate in male mice. These findings provide experimental evidence supporting their potential application in animal immunocastration.

Li S, et al. J Vet Sci. 2021 Jan;22(1):e8. https://doi.org/10.4142/jvs.2021.22.e8