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*

Pseudorabies (PR) is an infectious disease caused by the pseudorabies virus (PRV), affecting various domesticated and wild animals. Since pigs are the only natural hosts of PRV, PR poses a serious threat to the pig farming industry. Currently, PR is primarily prevented through vaccination with inactivated vaccines or genetically modified attenuated live vaccines. Developing safe and effective genetically engineered vaccines would facilitate the eradication and control of PR. In this study, the PRV vaccine strain Bartha-K61 was used as the reference strain. The gB protein was expressed via the baculovirus-insect cell expression system. Non-denaturing gel electrophoresis confirmed that the gB protein could form a trimeric structure. The purified gB protein was used to immunize mice, and the immune effect was evaluated by a challenge test. The results showed that the gB antigen induced a strong immune response in mice, with the serum-neutralizing antibody titer above 1:70. The lymphocyte stimulation index reached more than 1.29, and the level of (interferon gamma, IFN-γ) release was higher than 100 pg/mL. After immunization, mice were challenged with the virus at a dose of 10⁴ TCID₅₀/mL, 200 μL per mouse, and the clinical protection rate was 100%. Immunohistochemistry, histopathological section, and tissue viral load results showed that the pathological damage and viral load in the gB-immunized group were significantly lower than those in the PBS group. In summary, the gB protein obtained in this study induced strong humoral and cellular immune responses in mice, laying a foundation for developing a recombinant gB protein subunit vaccine.
Animals ; Mice ; Baculoviridae/metabolism* ; Viral Envelope Proteins/biosynthesis* ; Herpesvirus 1, Suid/genetics* ; Pseudorabies/immunology* ; Swine ; Pseudorabies Vaccines/genetics* ; Antibodies, Viral/blood* ; Insecta/cytology* ; Mice, Inbred BALB C ; Female ; Viral Vaccines/immunology*

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*

To further enhance the immune effect of the foot-and-mouth disease (FMD) virus-like particles (VLPs) vaccine, this study prepared FMDV VLPs-zeolitic imidazolate (framework-8, ZIF-8) complexes with different particle sizes. We used a biomimetic mineralization method with Zn²⁺ and 2-methylimidazole in different concentration ratios to investigate the effect of size on the immunization effect. The results showed that FMDV VLPs-ZIF-8 with three different sizes were successfully prepared, with an approximate size of 70 nm, 100 nm, and 1 000 nm, respectively. Cytotoxicity and animal toxicity tests showed that all three complexes exhibited excellent biological safety. Immunization tests in mice showed that all three complexes enhanced the titers of neutralizing and specific antibodies, and their immune effects improved as the size of the complexes decreased. This study showed that ZIF-8 encapsulation of FMDV VLPs significantly enhanced their immunogenic effect in a size-dependent manner.
Animals ; Mice ; Foot-and-Mouth Disease/prevention & control* ; Foot-and-Mouth Disease Virus ; Antibodies, Neutralizing ; Immunity, Humoral ; Immunization ; Vaccines, Virus-Like Particle ; Antibodies, Viral ; Viral Vaccines

Model-induced drug development （MIDD） is a mathematical and statistical method for constructing， validating and utilizing disease model， drug exposure-response model and pharmaceutical model to promote drug development. With the development of pharmaceutical technology， MIDD is widely used in the field of traditional Chinese medicine and has high practical value. This article summarizes the relevant literature at home and abroad， and finds that MIDD has the advantages of improving the research and development efficiency of traditional Chinese medicine， quickly identifying the applicable population of traditional Chinese medicine， predicting the interaction of drugs， and optimizing the dosage. MIDD has been applied in the studies of effective components of traditional Chinese medicine， quantitative design of prescription， dosage form and preparation process， pilot scale- up， quality and safety， regulatory decision-making and evaluation， etc.

ObjectiveTo explore the underlying mechanism of bran-fried Atractylodis Rhizoma （AR） in improving gastrointestinal function by comparing the effects of raw AR and bran-fried AR on the small intestine tissue structure and transport-related protein carriers in rats with spleen deficiency syndrome. MethodSeventy male SD rats were randomly divided into a normal group， a model group， high- and low-dose raw AR groups （10， 2.5 g·kg^-1）， high- and low-dose bran-fried AR groups （10， 2.5 g·kg^-1）， and a compound glutamine group （9 mg·kg^-1）， with 10 rats in each group. Except for the normal group， the other six groups were subjected to the spleen deficiency model induced by the method of bitter and cold breaking stagnated Qi and abnormal hunger and fullness for 21 days. After modeling， each treatment group was given medication orally according to the corresponding doses every day for a total of 14 days， and the normal group and the model group were given an equal volume of normal saline orally. During the treatment period， the general survival status， macroscopic syndrome score， daily increase in body weight and food intake， and rectal temperature of the spleen deficiency rats were evaluated， and after the treatment， the rats were sacrificed. The pathological changes in the small intestine tissues of each group were observed by hematoxylin-eosin （HE） staining. The content of serum 5-hydroxytryptamine （5-HT） was detected by enzyme-linked immunosorbent assay （ELISA）， and the content of serum D-xylose， lactate， and amylase was detected by colorimetry. The levels of free fatty acid receptor 3 （FFA3） and peptide transporter 1 （PepT1） in small intestinal tissues were detected by the Bradford method， and the protein expression of sodium-dependent glucose transporter 1 （SGLT1） and glucose transporter 1 （GLUT1） in small intestinal tissue was detected by immunohistochemistry. Real-time fluorescence-based quantitative PCR was used to detect the mRNA expression of glucose transporter 2 （GLUT2）， sodium/hydrogen exchanger 3 （NHE3）， and 5-hydroxytryptamine receptor 4 （5-HT4R）. ResultCompared with the normal group， the model group exhibited symptoms of spleen deficiency， such as sluggishness， squint， reduced food intake， and lethargy at the end of modelling， damaged basic structure of the small intestinal mucosal epithelium and lamina propria， increased serum lactate and 5-HT content， and decreased serum amylase and D-xylose （P<0.01）. Compared with the model group， all treatment groups showed varying degrees of improvement， with the small intestinal microstructure repaired to different degrees. The daily weight gain， anal temperature， and macroscopic syndrome score of spleen deficiency improved to varying degrees （P<0.05， P<0.01）. The serum lactate and 5-HT content decreased to varying degrees， while the serum amylase and D-xylose content increased to varying degrees （P<0.05， P<0.01）. The PepT1 content in the small intestinal tissues increased， while the FFA3 content decreased to varying degrees. The protein expression of SGLT1 and GLUT1 increased， while the mRNA expression of GLUT2 and NHE3 increased to varying degrees. The mRNA expression of 5-HT4R decreased to varying degrees （P<0.05， P<0.01）. Compared with the high- and low-dose raw AR groups， the high- and low-dose bran-fried AR groups showed significant improvement in general conditions and histopathological improvement of the small intestinal tissues. The daily weight gain， anal temperature， and macroscopic syndrome score of spleen deficiency also improved （P<0.05， P<0.01）. The serum lactate and 5-HT content decreased， while the serum amylase and D-xylose content increased （P<0.05， P<0.01）. The PepT1 content in the small intestinal tissues increased， while the FFA3 content decreased. The protein expression of SGLT1 and GLUT1 increased， while the mRNA expression of GLUT2 and NHE3 increased. The mRNA expression of 5-HT4R decreased significantly （P<0.05， P<0.01）. ConclusionBran-fried AR can improve the spleen deficiency-related symptoms and histopathology of the small intestinal tissues in spleen deficiency model rats. Its mechanism may be related to the regulation of the expression of various transport-related protein carriers and the secretion of various digestive enzymes after stir-frying of AR， thus restoring the absorption and transport function of the small intestine.

Objective:The study aims to analyze the problems faced in the clinical research and management of stem cells, explore the construction of the entire process of stem cells clinical research, and promote the healthy and orderly development of the clinical research of stem cells.Methods:By consulting the literature and retrieval of relevant policies and regulations, this study analyzed the problems faced by the supervision and management department, medical institutions and researchers, this study and discussed the countermeasures for strengthening the management of the entire process of clinical research of stem cells in medical institutions.Results:There were imperfect internal system and poor management process, insufficient quality control of cell products, low quality of project management, and insufficient clinical research consciousness of stem cell clinical research management in medical institutions.Conclusions:Combined with the current management measures, guidance principles and medical institutions, we should improve the internal system of medical institutions, promote the centralized management and informatization construction of projects, strengthen cell quality control in the hospital, cultivate talent echelons and improve academic and ethical review capabilities, actively explore the management model that is suitable for the entire process of stem cell clinical research for medical institutions in China.

Objective:To analyze and study the difficulties and countermeasures in the implementation of the Qualified Person(QP) system for stem cell clinical research, and share the experience of QP management practice in our hospital in order to promote and improve the construction of the QP management system in medical institutions.Methods:Comprehensive investigations were conducted to summarize and analyze the shortage of talents, unclear qualifications, unclear responsibilities, and lack of assessment standards in the QP system of medical institutions.Results:In view of the difficulties in the implementation of the current QP system, it is suggested to consider a combination of improving the system of laws and regulations, strengthening the top-level design of stem cell research institutions, clarifying the qualification threshold, refining QP responsibilities, continuing training and assessment system, establishing QP support system, etc.Conclusions:Medical institutions are responsible for stem cell clinical research, and the improvement of the QP system can promote the development of the cell industry in China.

AIM:To investigate the effect of liraglutide ( LG) on the expression of fibronectin type Ⅲdomain-containing protein 5 (FNDC5) in the C2C12 myotubes.METHODS:The C2C12 mouse myoblast cell line was induced to differentiation.Differentiated cells were stimulated with gradient concentrations (1 ~1000 nmol/L) of LG for different time (0 ~24 h).The effects of LG on the expression of FNDC5 and the activation of adenosine 5'-monophosphate ( AMP)-activated protein kinase ( AMPK) signaling pathway were determined .After pretreated with glucagon-like peptide-1 ( GLP-1 ) receptor antagonist exendin 9-39 , the inhibitor of Ca 2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2), STO609, or the inhibitor of AMPK, Compound C, the LG-induced FNDC5 expression in C2C12 myotubes was examined.The expression of FNDC5 and the activation of AMPK were determined by Western blot .RESULTS: In C2C12 myotubes, LG promoted the expression of FNDC5 in a dose-and time-dependent manner .LG also activated AMPK signaling pathway .These effects of LG were partly abolished by exendin 9-39 , STO609 and Compound C .CONCLUSION:LG promotes the expression of FNDC5 via GLP-1 receptor in the C2C12 myotubes possibly through activation of the CAMKK2/AMPK signaling pathways .