Bio-mineralization has emerged as a promising strategy to enhance vaccine immunogenicity. This study optimized the calcium phosphate (CaP) mineralization process of foot-and-mouth disease virus-like particles (FMD VLPs) to achieve high mineralization efficiency and scalability. Key parameters, including concentrations of Ca²⁺, HPO₄^2-, NaCl, and VLPs, as well as stirring speed, were systematically optimized. Stability of the scaled-up reaction system and immunogenicity of the mineralized vaccine were evaluated. Optimal conditions [25.50 mmol/L Ca(NO₃)₂, 15 mmol/L Na₂HPO₄, 300 mmol/L NaCl, 0.75 mg/mL VLPs, and 1 500 r/min] yielded CaP-mineralized VLPs (VLPs-CaP) with high mineralization efficiency, uniform morphology, and a favorable particle size. Scaling up the reaction by 25 folds maintained consistent mineralization efficiency and particle characteristics. Immunization in mice demonstrated that VLPs-CaP induced higher titers of specific antibodies and neutralizing antibodies than unmineralized VLPs (P < 0.05). Higher IgG2a/IgG1 ratio and enhanced IFN-γ secretion (P < 0.05) further indicated robust cellular immune responses. We establish a stable and scalable protocol for VLPs-CaP, providing a theoretical and technical foundation for developing high-efficacy VLPs-CaP vaccines.
Vaccines, Virus-Like Particle/immunology* ; Immunogenicity, Vaccine ; Calcium Phosphates/chemistry* ; Foot-and-Mouth Disease Virus ; Biomineralization ; Particle Size ; Animals ; Mice ; Antibodies, Neutralizing/blood* ; Antibodies, Viral/blood* ; Immunity, Cellular

Vaccination is a crucial strategy for the prevention and control of infectious diseases. Virus-like particles (VLPs), composed of structural proteins, have garnered significant attention as a novel type of vaccine due to their excellent safety and immunogenicity. However, similar to most vaccine antigens, VLPs exhibit insufficient thermal stability, which not only restricts the widespread application of vaccines but also increases the risk of vaccine inactivation. This study aims to enhance the stability and shelf life of VLPs derived from type A foot-and-mouth disease virus (FMDV) by employing vacuum freeze-drying technology. The optimal lyoprotectant formulation was determined through single-factor and combinatorial screening. Subsequently, the correlation between the immunogenicity of the freeze-dried vaccine and the content of FMDV VLPs was evaluated via a mouse model. The stability of FMDV VLPs before and after freeze-drying was further assessed by storing them at 4, 25, and 37 ℃ for varying time periods. Results indicated that the lyoprotectant formulation No.1, composed of 7.5% trehalose, 0.1% Tween 80, 50 mmol/L glycine, 1% sodium glutamate, and 3% polyvinylpyrrolidone (PVP), effectively preserved the content of FMDV VLPs during the vacuum freeze-drying process. The immunization trial in mice revealed that the levels of specific antibodies, immunoglobulin G1 (IgG1), interleukin-4 (IL-4), and neutralizing antibodies induced by freeze-dried FMDV VLPs were comparable to those induced by non-freeze-dried FMDV VLPs. The heat treatment results showed that the storage periods of freeze-dried FMDV VLPs at 4, 25, and 37 ℃ were significantly longer than those of non-freeze-dried FMDV VLPs. In conclusion, the selected lyoprotectant formulation effectively improved the stability of FMDV VLPs vaccines. This study provides valuable insights for enhancing the stability of novel subunit vaccines.
Freeze Drying/methods* ; Animals ; Foot-and-Mouth Disease Virus/immunology* ; Mice ; Vaccines, Virus-Like Particle/chemistry* ; Foot-and-Mouth Disease/immunology* ; Vacuum ; Drug Stability ; Mice, Inbred BALB C ; Viral Vaccines/immunology*

Primers and probes were designed based on the conserved regions of Senecavirus A(SVA),foot-and-mouth disease virus(FMDV),and porcine teschovirus(PTV)and used to devel-op a TaqMan fluorescent quantitative PCR method for detecting the above-mentioned three viru-ses.The triplex fluorescent quantitative PCR system was developed using recombinant positive plasmids containing conserved sequences of the three viruses as templates.After optimizing the conditions,the specificity,sensitivity,repeatability,standard curve,and mixed infection model were evaluated,and the constructed triplex fluorescent quantitative PCR was used for clinical detection.The results showed that this method could specifically detect SVA,FMDV and PTV without cross-reactivity with other pathogens with the minimal detection concentrations for SVA,FMDV,and PTV as low as 1X101 copies/μL,respectively.The coefficients of variation within and between groups were less than 5％.Furthermore,none of the three viruses were detected in 126 samples.The above results indicate that this method is highly specific,sensitive,and stable,making it suit-able for clinical detection.

The objective of this study was to evaluate the protective effect and possible related mechanisms of Sophora subprostrate polysaccharide(SSP)on intestinal epithelial cell injury in-duced by Tert-Butyl hydroperoxide(TBHP).The optimal dose of TBHP and the safe concentra-tion range of SSP were determined using the MTT method.In this study,IPEC-J2 cells were divid-ed into five groups:the control group,the model group,the SSPL group,the SSPM group and the SSPH group,and the cell morphology,cell survival rate and LDH release rate were observed and measured.The content of intracellular reactive ROS was observed and determined by DCFH-DA staining.The content of MDA in the supernatant and the antioxidant index of cells were determined by the reagent kit.Transcriptome technology was employed to analyze the potential mechanisms by which SSP mitigates oxidative damage in IPEC-J2 cells.The results showed that treatment with 625 μmol/L TBHP for 2 h significantly reduced the activity of IPEC-J2 cells,markedly increased LDH release(P＜0.05),inhibited CAT superoxide SOD and glutathione GPX activities(P＜0.05),and significantly elevated MDA and ROS levels(P＜0.05).Compared to the model group,after SSP treatment,intracellular ROS levels were significantly reduced(P＜0.05),while CAT,SOD,and GPX activities were significantly increased(P＜0.05),and MDA content and LDH re-lease were significantly decreased(P＜0.05)in a dose-dependent manner.Transcriptome analysis revealed that TBHP treatment significantly altered the transcriptional profiles of IPEC-J2 cells,while SSP treatment could restore the transcriptional profiles of the damaged cells to a certain ex-tent.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)indicated that the differentially expressed genes between the CC and TBHP groups were significantly enriched in oxidative phosphorylation,ribosome,and other pathways.Meanwhile,the differentially expressed genes between the SSP and TBHP groups were mainly enriched in oxidative phosphorylation,ap-optosis,glyoxylate and dicarboxylate metabolism,and other pathways.These results suggest that TBHP may disrupt normal oxidative respiration in IPEC-J2 cells by affecting oxidative phospho-rylation and interfering with metabolism pathways involving glycine,serine,and threonine,leading to oxidative damage in intestinal epithelial cells.Conversely,SSP treatment may potentially restore oxidative phosphorylation processes,alleviate lysosomal damage,reduce cell apoptosis,and miti-gate oxidative damage in intestinal epithelial cells through modulation of oxidative phosphoryla-tion,apoptosis,and lysosomal pathways.This discovery provides a theoretical basis for the clinical application of SSP in alleviating oxidative damage in the porcine intestinal tract.

Transcranial electrical stimulation(tES)is a process,in which a specific pattern of low-intensity electrical currents is applied to the cerebral cortex through a combination of electrode sheets placed on the surface of scalp,modulating neural activity and corresponding human behaviors.In recent years,its application in the field of psychiatry has been gradually increasing.This paper reviews the clinical applications and latest research progress of tES technology in schizophrenia,depressive disorders,bipolar disorder,obsessive-compulsive disorder and sleep disorders,aiming to provide references for its application and further research in the field of psychiatric practice.

Transcranial electrical stimulation(tES)is a process,in which a specific pattern of low-intensity electrical currents is applied to the cerebral cortex through a combination of electrode sheets placed on the surface of scalp,modulating neural activity and corresponding human behaviors.In recent years,its application in the field of psychiatry has been gradually increasing.This paper reviews the clinical applications and latest research progress of tES technology in schizophrenia,depressive disorders,bipolar disorder,obsessive-compulsive disorder and sleep disorders,aiming to provide references for its application and further research in the field of psychiatric practice.

Primers and probes were designed based on the conserved regions of Senecavirus A(SVA),foot-and-mouth disease virus(FMDV),and porcine teschovirus(PTV)and used to devel-op a TaqMan fluorescent quantitative PCR method for detecting the above-mentioned three viru-ses.The triplex fluorescent quantitative PCR system was developed using recombinant positive plasmids containing conserved sequences of the three viruses as templates.After optimizing the conditions,the specificity,sensitivity,repeatability,standard curve,and mixed infection model were evaluated,and the constructed triplex fluorescent quantitative PCR was used for clinical detection.The results showed that this method could specifically detect SVA,FMDV and PTV without cross-reactivity with other pathogens with the minimal detection concentrations for SVA,FMDV,and PTV as low as 1X101 copies/μL,respectively.The coefficients of variation within and between groups were less than 5％.Furthermore,none of the three viruses were detected in 126 samples.The above results indicate that this method is highly specific,sensitive,and stable,making it suit-able for clinical detection.

The objective of this study was to evaluate the protective effect and possible related mechanisms of Sophora subprostrate polysaccharide(SSP)on intestinal epithelial cell injury in-duced by Tert-Butyl hydroperoxide(TBHP).The optimal dose of TBHP and the safe concentra-tion range of SSP were determined using the MTT method.In this study,IPEC-J2 cells were divid-ed into five groups:the control group,the model group,the SSPL group,the SSPM group and the SSPH group,and the cell morphology,cell survival rate and LDH release rate were observed and measured.The content of intracellular reactive ROS was observed and determined by DCFH-DA staining.The content of MDA in the supernatant and the antioxidant index of cells were determined by the reagent kit.Transcriptome technology was employed to analyze the potential mechanisms by which SSP mitigates oxidative damage in IPEC-J2 cells.The results showed that treatment with 625 μmol/L TBHP for 2 h significantly reduced the activity of IPEC-J2 cells,markedly increased LDH release(P＜0.05),inhibited CAT superoxide SOD and glutathione GPX activities(P＜0.05),and significantly elevated MDA and ROS levels(P＜0.05).Compared to the model group,after SSP treatment,intracellular ROS levels were significantly reduced(P＜0.05),while CAT,SOD,and GPX activities were significantly increased(P＜0.05),and MDA content and LDH re-lease were significantly decreased(P＜0.05)in a dose-dependent manner.Transcriptome analysis revealed that TBHP treatment significantly altered the transcriptional profiles of IPEC-J2 cells,while SSP treatment could restore the transcriptional profiles of the damaged cells to a certain ex-tent.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)indicated that the differentially expressed genes between the CC and TBHP groups were significantly enriched in oxidative phosphorylation,ribosome,and other pathways.Meanwhile,the differentially expressed genes between the SSP and TBHP groups were mainly enriched in oxidative phosphorylation,ap-optosis,glyoxylate and dicarboxylate metabolism,and other pathways.These results suggest that TBHP may disrupt normal oxidative respiration in IPEC-J2 cells by affecting oxidative phospho-rylation and interfering with metabolism pathways involving glycine,serine,and threonine,leading to oxidative damage in intestinal epithelial cells.Conversely,SSP treatment may potentially restore oxidative phosphorylation processes,alleviate lysosomal damage,reduce cell apoptosis,and miti-gate oxidative damage in intestinal epithelial cells through modulation of oxidative phosphoryla-tion,apoptosis,and lysosomal pathways.This discovery provides a theoretical basis for the clinical application of SSP in alleviating oxidative damage in the porcine intestinal tract.

Objective:To investigate the detection status and genotypes distribution characteristics of norovirus(NoV)in environmental sewage from three monitoring points in Fujian province, and to explore the significance of its application to NoV monitoring.Methods:Sewage samples were collected monthly at 5 sampling sites in representative monitoring cities, enriched and concentrated. Partial gene fragments of norovirus VP1 were amplified by reverse transcription-semi nested polymerase chain reaction (RT-snPCR), TA cloned and sequenced. Genotypes were identified based on the sequencing.Results:A total of 56 sewage samples were collected from July 2022 to June 2023. The detection rates of GⅠ and GⅡ were 89.29% (50/56) and 94.64% (53/56), respectively. A total of 7 NoV GⅠ genotypes and 13 GⅡgenotypes were identified. GⅠ.1, GⅠ.4, GⅡ.4 and GⅡ.17 were the dominant genotypes. NoV genotypes detected in different sampling sites were not exactly the same. The detection rate of NoV was low from August to November 2022, and the prevalence of the dominant genotypes was different in different seasons. GⅠ.1 and GⅡ.4 were highly prevalent from August to November 2022, but were replaced by GⅠ.4 and GⅡ.17 from December 2022 to June 2023, respectively. More NoV genotypes were detected in January-June 2023, comparing to the July-December 2022. The dominant genotype GII.17, has multiple clades and new variants have been discovered that are different from the 2014/2015 circulating strains.Conclusions:The detection rates of NoV in environmental sewage were very high, and genotypes were diverse. Environmental sewage surveillance could be an important complementary method for NoV cases surveillance.

The variable domain of heavy-chain antibody (VHH) has been developed widely in drug therapy, diagnosis, and research. Escherichia coli is the most popular expression system for VHH production, whereas low bioactivity occurs sometimes. Mammalian cells are one of the most ideal hosts for VHH expression at present. To improve the yield of VHH in Expi293F cells, we optimized the signal peptide (SP) and codons of VHH. Firstly, the fusion protein VHH1-Fc was used to screen SPs. The SP IFN-α2 showed the highest secretion as quantified by enzyme-linked immunosorbent assay (ELISA). Subsequently, codon optimization by improving GC3 and GC content doubled the yield of VHH1 and kept its binding activity to Senecavirus A (SVA). Finally, the mean yields of other 5 VHHs that fused with SP IFN-α2 and codon-optimized were over 191.6 mg/L, and these VHHs had high recovery and high purity in the culture supernatant. This study confirms that SP IFN-α2 and codon optimization could produce VHHs in Expi293F cells efficiently, which provides a reference for the large-scale production of VHHs.
Codon/genetics* ; Protein Sorting Signals/genetics* ; Escherichia coli/metabolism* ; Humans ; Recombinant Fusion Proteins/biosynthesis* ; Interferon-alpha/metabolism* ; Immunoglobulin Heavy Chains/immunology* ; Cell Line ; Immunoglobulin Variable Region/immunology*