The continuously evolving PRRSV has been plaguing pig farms worldwide for over 30 years, with conventional vaccines suffering from insufficient protection and biosecurity risks. To address these challenges, we identified 10 PRRSV-specific CTL epitopes through enzyme-linked immunospot assay (ELISPOT) and constructed a multi-epitope peptide (PTE) by linking them in tandem. This PTE was then fused with a modified porcine Fc molecule to create the recombinant protein pFc-PTE. Our findings indicate that pFc-PTE effectively stimulates PRRSV-infected specific splenic lymphocytes to secrete high levels of interferon-gamma (IFN-γ) and is predicted to be non-toxic and non-allergenic. Compared to PTE alone, pFc-PTE not only induced a comparable cellular immune response in mice but also extended the duration of the immune response to at least 10 weeks post-immunization. Additionally, pFc-PTE predominantly induced a Th1 immune response, suggesting its potential advantage in enhancing cellular immunity. Consequently, pFc-PTE holds promise as a novel, safe, and potent candidate vaccine for PRRSV and may also provide new perspectives for vaccine design against other viral diseases.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that infect pigs’ intestinal epithelial cells, causing high morbidity and mortality. Due to the rapid mutation of PEDV, vaccine efficacy is uncertain, prompting exploration of alternative treatments. Nanobodies, also known as variable heavy chain domains of heavy chain-only antibodies (VHHs), offer significant potential in biomedical applications due to their small size and high specificity. In this study, yeast two-hybrid technology was employed to screen for eight specific VHH sequences targeting the PEDV S protein from a synthetically constructed nanobody yeast library. The VHH genes were then cloned into expression plasmids for recombinant protein production, and the resulting VHHs (termed PEDV S-VHHs) were purified. Indirect immunofluorescence assay (IFA) and Western blotting analysis confirmed that these VHHs specifically bind to both PEDV and its S protein. Neutralization assays demonstrated that seven PEDV S-VHHs exhibited potent neutralizing activity against PEDV. Additionally, a combination of these seven antibodies showed enhanced antiviral effects. Preliminary predictions were also made regarding the binding sites between these VHHs and PEDV. The PEDV S-VHHs described in this study hold potential as candidates for the prevention and treatment of PEDV infection.

Pseudorabies virus (PRV) is a highly contagious pathogen in swine that can cross species barriers and infect other mammals, including humans. Given the potential for interspecies transmission and its threat to public health, understanding the molecular biology of PRV strains is essential for developing effective control measures and preparing for future pandemics. In this study, a novel PRV strain, PRV-HL-2021, was isolated from an outbreak in Heilongjiang Province, China. The viral genome was used to establish a reverse genetics system based on a fosmid library of the PRV-HL-2021 genome. This system facilitated the creation of recombinant PRV, including one expressing EGFP and another with deletions in the US9, gI, and gE genes. PRV-HL-2021 was found to be highly lethal to mice in vivo. The recombinant PRV strains, such as rPRV-US9-EGFP and rPRV-delgI/gE/US9, exhibited growth characteristics similar to the parental PRV-HL-2021 strain. The isolation and characterization of PRV-HL-2021 contribute to a better understanding of the genetic diversity of PRV strains. The developed reverse genetics system provides valuable tools for investigating viral functions, creating genetically modified PRV strains, and advancing the development of safer vaccines. These findings will enhance strategies for controlling PRV outbreaks and mitigating its impact on both animal and public health.

Sujiang pigs, a high-quality local Chinese breed, represent a valuable model for investigating muscle development and improving meat production through genetic selection. Skeletal muscle satellite cells (MuSCs) are essential regulators of muscle growth, with differentiation tightly controlled by specific genes and signaling pathways. In this study, MuSCs were isolated from the gastrocnemius muscle and subjected to mRNA sequencing during proliferation (GM) and differentiation stages (DM1, DM2, and DM4, collectively referred to as DM). A total of 2790 differentially expressed genes (DEGs) were identified, including 1551 upregulated and 1239 downregulated genes. Time-series analysis revealed 16 significant expression patterns. These DEGs were primarily associated with muscle development and differentiation and were enriched in Wnt, PI3K–Akt, JAK–STAT, p53, Hippo, and Apelin signaling pathways. Among them, phosphoribosyl transferase domain containing 1 (PRTFDC1) exhibited pronounced downregulation during differentiation. Functional validation demonstrated that PRTFDC1 overexpression promoted myotube formation and upregulated MYOD1, MYOG, and MYH1 expression, whereas knockdown significantly inhibited differentiation. Furthermore, PRTFDC1 enhanced phosphorylation of key proteins in the cGAS–STING signaling pathway. Collectively, this study elucidates the temporal transcriptional regulation of MuSC differentiation in Sujiang pigs and identifies PRTFDC1 as a novel regulatory factor, providing a molecular foundation for breeding strategies and meat quality improvement.

African swine fever (ASF) poses a catastrophic and ongoing threat to the global swine industry. The rapid intercontinental spread of ASF, compounded by the absence of licensed vaccines and the structural complexity of African swine fever virus (ASFV), renders disease control and eradication extraordinarily challenging. Serological diagnosis is central to long-term ASF surveillance and control, with current assays predominantly based on well-validated antigens such as p30 (CP204L), p54 (E183L), and p72 (B646L), which form the backbone of OIE/WOAH-recommended testing. To expand and complement this established diagnostic repertoire with additional, less-explored targets. In this study, three ASFV proteins, B169L, A151R, and KP177R, were identified through systematic bioinformatic screening and successfully expressed using a prokaryotic expression system. Three individual indirect ELISA methods were subsequently established, optimized, and comprehensively evaluated. All three assays demonstrated high specificity, with no cross-reactivity detected against antisera to PRRSV, CSFV, or PCV2. Intra-assay coefficients of variation (CVs) were below 6% and inter-assay CVs were below 8%, confirming excellent repeatability and reproducibility. These assays provide sensitive, specific, and practically deployable tools that expand the available options for ASF serological surveillance and may serve as useful complements to existing diagnostic methods in epidemiological investigations of this devastating disease.