Ferritin, a ubiquitous protein in living organisms, plays a crucial role in storing and converting iron, as well as maintaining cellular iron metabolism balance. Due to the ability of self-assembling into unique nanocage-like structures in vitro and the special physicochemical properties, ferritin has garnered extensive attention in the biomedical field. This paper provides a brief overview of the structure and cargo loading strategies of ferritin, with a specific focus on its applications in various biological fields such as nanomedicine, bioimaging, and nanoparticle vaccine carriers. The aim is to offer a valuable reference for the future research involving ferritin nanoparticles.
Ferritins/chemistry* ; Nanoparticles/chemistry* ; Humans ; Nanomedicine/methods* ; Animals

The study aims to investigate the impacts of prolyl oligopeptidase (POP) on the replication of foot-and-mouth disease virus (FMDV) in BHK-21 cells. Firstly, the effects of FMDV replication on POP expression in BHK-21 cells were analyzed by Western blotting and Real-time reverse transcription polymerase chain reaction (RT-qPCR). Secondly, a eukaryotic expression plasmid for POP was constructed, and the effects of POP overexpression on the replication of two different serotypes of FMDV were assessed by Western blotting, RT-qPCR, and virus titer assays. Thirdly, specific small interfering RNAs (siRNAs) targeting POP were synthesized, and their efficiency in interfering with endogenous POP expression was identified by RT-qPCR. The impacts of downregulating endogenous POP expression on FMDV replication were further evaluated by Western blotting, RT-qPCR, and virus titer assays. The results indicated that FMDV infection did not significantly affect POP expression in BHK-21 cells. Overexpression of POP dose-dependently enhanced the replication of both FMDV/O and FMDV/A serotypes. Conversely, siRNA-mediated downregulation of endogenous POP expression markedly suppressed FMDV/O replication. This study is the first to demonstrated that the role of the host POP protein in promoting FMDV replication in BHK-21 cells, thereby providing a critical theoretical foundation and potential molecular targets for developing efficient candidate cell strains for foot-and-mouth disease inactivated vaccines.
Foot-and-Mouth Disease Virus/genetics* ; Virus Replication/genetics* ; Prolyl Oligopeptidases ; Serine Endopeptidases/physiology* ; Animals ; Cell Line ; RNA, Small Interfering/genetics* ; Foot-and-Mouth Disease/virology* ; Cricetinae

This study developed ferritin-based nanoparticles carrying the African swine fever virus (ASFV) p30 protein and evaluated their immunogenicity, aiming to provide an experimental basis for the research on nanoparticle vaccines against ASFV. Initially, the gene sequences encoding the p30 protein and SpyTag were fused and inserted into the pCold-I vector to create the pCold-p30 plasmid. The gene sequences encoding SpyCatcher and ferritin were fused and then inserted into the pET-28a(+) vector to produce the pET-F-np plasmid. Both plasmids were expressed in Escherichia coli upon induction. Subsequently, the affinity chromatography-purified p30 protein was conjugated with ferritin in vitro, and the p30-ferritin (F-p30) nanoparticles were purified by size-exclusion chromatography. The morphology and structural integrity of F-p30 nanoparticles were examined by a particle size analyzer and transmission electron microscopy. Mice were immunized with F-p30 nanoparticles, and the humoral and cellular immune responses were assessed. The results showed that F-p30 nanoparticles were successfully prepared, with the particle size of approximately 20 nm. F-p30 nanoparticles were efficiently internalized by bone marrow-derived dendritic cells (BMDCs) cells in vitro. Compared with the p30 protein alone, F-p30 nanoparticles induced elevated levels of specific antibodies and cytokines in mice and stimulated the proliferation of follicular helper T cell (T_FH) and germinal center B cell (GCB) in lymph nodes as well as CD4⁺ and CD8⁺ T cells in the spleen. In conclusion, we successfully prepared F-p30 nanoparticles which significantly enhanced the immunogenicity of p30 protein, giving insights into the development of vaccines against ASFV.
Animals ; Nanoparticles/chemistry* ; Mice ; African Swine Fever Virus/genetics* ; Ferritins/chemistry* ; Swine ; Viral Vaccines/genetics* ; African Swine Fever/immunology* ; Mice, Inbred BALB C ; Viral Proteins/genetics* ; Escherichia coli/metabolism* ; Dendritic Cells/immunology* ; Immunogenicity, Vaccine ; Antibodies, Viral/blood* ; Female ; Capsid Proteins/genetics*

The aim of this study was to produce recombinant porcine interferon gamma (rPoIFN-γ) by Chinese hamster ovarian (CHO) cells expression system and to analyze its antiviral activity. Firstly, we constructed the recombinant eukaryotic expression plasmid pcDNA3.1-PoIFN-γ and transfected into suspension cultured CHO cells for secretory expression of rPoIFN-γ. The rPoIFN-γ was purified by affinity chromatography and identified with SDS-PAGE and Western blotting. Subsequently, the cytotoxicity of rPoIFN-γ was analyzed by CCK-8 test, and the antiviral activity of rPoIFN-γ was evaluated using standard procedures in VSV/PK-15 (virus/cell) test system. Finally the anti-Seneca virus A (SVA) of rPoIFN-γ activity and the induction of interferon-stimulated genes (ISGs) and cytokines were also analyzed. The results showed that rPoIFN-γ could successfully expressed in the supernatant of CHO cells. CCK-8 assays indicated that rPoIFN-γ did not show cytotoxicity on IBRS-2 cells. The biological activity of rPoIFN-γ was 5.59×10⁷ U/mg in VSV/PK-15 system. Moreover, rPoIFN-γ could induced the expression of ISGs and cytokines, and significantly inhibited the replication of SVA. In conclusion, the high activity of rPoIFN-γ was successfully prepared by CHO cells expression system, which showed strong antiviral activity on SVA. This study may facilitate the investigation of rPoIFN-γ function and the development of novel genetically engineered antiviral drugs.
Swine ; Animals ; Cricetinae ; Interferon-gamma/pharmacology* ; Cricetulus ; CHO Cells ; Sincalide ; Recombinant Proteins/pharmacology* ; Antiviral Agents/pharmacology*

The aim of this study was to produce E^rns protein of bovine viral diarrhea virus (BVDV) by using suspensively cultured CHO cells expression system and to analyze the immunogenicity of the purified E^rns protein. In this study, the recombinant eukaryotic expression plasmid pcDNA3.1-BVDV-E^rns was constructed based on the gene sequence of BVDV-1 NADL strain. The E^rns protein was secreted and expressed in cells supernatant after transfecting the recombinant expression plasmid pcDNA3.1-BVDV-E^rns into CHO cells. The expression and purification of the E^rns protein was analyzed by SDS-PAGE, the reactivity was determined with anti-His monoclonal antibodies and BVDV positive serum with Western blotting. Immunogenicity analysis of the E^rns protein was determined after immunizing New Zealand white rabbits, and the serum antibodies were tested by indirect ELISA (iELISA) and indirect immunofluorescence (IFA). The serum neutralizing titer of the immunized rabbits was determined by virus neutralization test. The concentration of the purified E^rns protein was up to 0.886 mg/mL by BCA protein quantification kit. The results showed that the E^rns protein could be detected with anti-His monoclonal antibodies and anti-BVDV sera. Serum antibodies could be detected by iELISA on the 7th day post-prime immunization, and the antibody level was maintained at a high titer until the 28th day post-immunization. The antibody titer was 1:128 000. Furthermore, the expression of the E^rns protein in BVDV-infected MDBK cells could be detected with immunized rabbits sera by IFA. Moreover, antigen-specific neutralizing antibodies of 2.71 log₁₀ was induced in rabbits. In this study, purified BVDV E^rns protein was successfully produced using CHO suspension culture system, and the recombinant protein was proved to have a good immunogenicity, which may facilitate the development of BVD diagnosis method and novel subunit vaccine.
Rabbits ; Animals ; Cricetinae ; Cricetulus ; CHO Cells ; Antibodies, Viral ; Diarrhea Viruses, Bovine Viral/genetics* ; Antibodies, Monoclonal/genetics* ; Diarrhea ; Viral Vaccines/genetics*

We researched the mechanism of African swine fever virus (ASFV) protein E248R in regulating the cGAS-STING pathway. First, we verified via the dual-luciferase reporter assay system that E248R protein inhibited the secretion of IFN-β induced by cGAS-STING or HT-DNA in a dose-dependent manner. The relative quantitative PCR analysis indicated that the overexpression of E248R inhibited HT-DNA-induced transcription of IFN-b1, RANTES, IL-6, and TNF-α in PK-15 cells. Next, we found that E248R interacted with STING by co-immunoprecipitation assay and laser confocal microscopy. Finally, we demonstrated that E248R inhibited the expression of STING protein by using Western blotting. We demonstrated for the first time that the E248R protein of ASFV suppressed the host innate immune response via inhibiting STING expression. The results are pivotal in extending the understanding of the ASFV immune escape and can guide the design of vaccines against ASFV.
African Swine Fever Virus/genetics* ; Animals ; DNA ; Immunity, Innate ; Nucleotidyltransferases/metabolism* ; Signal Transduction ; Swine

ObjectiveTo explore the meridian tropism of components in Bupleuri Radix （Chaihu， CH） based on the model of nonalcoholic steatohepatitis （NASH） and clarify the substance basis of the meridian tropism of CH in Xiaoyaosan （XYS） by means of principal component analysis. MethodEighty SPF male C57BL/6 mice were randomly assigned into 8 groups， with 10 mice in each group. Except that the blank group was fed with the methionine choline-sufficient （MCS） diet， the other mice were fed with methionine choline-deficient （MCD） diet for 4 weeks to establish the nonalcoholic steatohepatitis （NASH） model. After the established model was confirmed by hematoxylin-eosin （HE） staining， the mice were administrated with corresponding drugs by gavage once a day for 4 weeks. Specifically， the 8 groups were XYS group （2.874 g·kg^-1）， XYS-CH group （2.445 g·kg^-1）， XYS-CH+volatile oils （Vol， 0.163 mg·kg^-1） group， XYS-CH+polysaccharides （Pol， 24.067 mg·kg^-1） group， XYS-CH+flavones （Fla， 2.241 mg·kg^-1） group， and XYS-CH+saponins （Sap， 2.746 mg·kg^-1） group. The model group and the blank group were administrated with the same volume of normal saline. After the last administration， the mice were sacrificed for the collection of blood and liver tissue. The pathological changes of liver were observed by HE staining and oil red O staining. Enzyme linked immunosorbent assay （ELISA） kits were used to determine the levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， triglyceride （TG）， total cholesterol （TC）， high-density lipoprotein （HDL）， and low-density lipoprotein （LDL） in serum as well as malondialdehyde （MDA）， superoxide dismutase （SOD）， catalase （CAT）， and glutathione peroxidase （GSH-Px） in liver. SPSS Statistics 23 was used for principal component analysis and comprehensive evaluation to determine the substance basis of the meridian tropism of CH in NASH mice. ResultCompared with the blank control group， the modeling led to hepatocyte swelling， increased fat vacuoles， and appearance of inflammatory cells. Further， the modeling elevated the levels of ALT， AST， TG， TC， and LDL and lowered the HDL level in serum， and it increased the MDA level and decreased the SOD， CAT， and GSH-Px levels in liver. Compared with the model group， the administration of XYS and XYS-CH in combination with the components of CH alleviated the oxidative damage in liver （P<0.05）. The comprehensive score of the pharmacological efficacy was in a descending order as follows： XYS > XYS-CH+Sap > XYS-CH+Fla > XYS-CH+Pol > XYS-CH+Vol > XYS-CH. Among the chemical components of CH， Sap had the best effect. ConclusionSap lowers the blood lipid level， regulates the abnormal lipid metabolism， and alleviates the oxidative damage of liver， which is the substance basis for CH to exert the meridian tropism in liver.

OBJECTIVE To establish H PLC fingerprint of Rheum palmatum before and after steaming with wine ，and to determine the contents of 3 differential components. METHODS HPLC method was used to establish the fingerprints of 15 batches of R. palmatum （before wine-steaming ）and prepared rhubarb （after wine-steaming ）and the similarity evaluation was conducted. The chemical pattern recognition analysis was carried out by principal component analysis ，cluster analysis ，partial least squares- discriminant analysis and orthogonal partial least squares-discriminant analysis. The contents of gallic acid ，resveratrol-4′-O- glucoside and resveratrol- 4′-O-（6″-galloyl）-glucoside in 30 batches of samples were determined. RESULTS In the fingerprint study，48 common peaks were demarcated for R. palmatum and 47 for prepared rhubarb as well as 17 common peaks were identified by reference substance. Cluster analysis and principal component analysis showed that R. palmatum derived from Qinghai before and after steaming with wine could be distinguished from those from Sichuan and Gansu. The results of content determination showed that the contents of 3 differential components in R. palmatum derived from Qinghai before and after steaming with wine were higher than those from other two production areas ；the contents of gallic acid in prepared rhubarb derived from those production areas were higher than R. palmatum ；the contents of resveratrol- 4′-O-glucoside and resveratrol- 4′-O- （6″-galloyl）-glucoside in R. palmatum derived from those production areas were higher than prepared rhubarb. CONCLUSIONS Fingerprint and content determination method established in this study can quickly ，scientifically and accurately evaluate the quality of R. palmatum from different producing areas before and after wine steaming ，which provide a basis for the processing specification and quality control of R. palmatum .

To develop Senecavirus A (SVA) virus-like particles (VLPs), a recombinant prokaryotic expression plasmid pET28a-SVA-VP031 was constructed to co-express SVA structural proteins VP0, VP3 and VP1, according to the genomic sequence of the field isolate CH-FJ-2017 after the recombinant proteins were expressed in E .coli system, and purified by Ni+ ion chromatographic method. The SVA VLPs self-assemble with a high yield in vitro buffer. A typical VLPs with an average diameter of 25-30 nm which is similar to native virions by using TEM detection. Animals immunized by SVA VLPs shown that the VLPs induced high titers neutralizing antibodies in Guinea pigs. This study indicated that the VLPs produced with co-expressing SVA structural proteins VP0, VP3 and VP1 in prokaryotic system is a promising candidate and laid an important foundation for the development of a novel SVA VLPs vaccine.
Animals ; Antibodies, Neutralizing ; Escherichia coli/genetics* ; Genomics ; Guinea Pigs ; Picornaviridae/genetics*

Objective:To explore the latest progress of oncology drug clinical trials in China under COVID-19, as well as to provide decision-making evidence for related stakeholders. Research progress of oncology drug trials and approved cancer drugs in China in 2020 were systematically summarized and compared with 2019.Methods:Information Disclosure Platform for Drug Clinical Studies and China Food and Drug Administration Query System for Domestic and Imported Drug were searched for registered clinical trials and approved oncology drugs, respectively. The trial scope, stage, drug type, effect and mechanism of domestic and global pharmaceutical enterprises were compared between 2019 and 2020.Results:A total of 722 cancer drug trials registered in China in 2020, with an annual growth rate of 52.3%, accounting for 28.3% of all registered trials. Among them, 603 (83.5%) trials were initiated by domestic pharmaceutical enterprises, and 105 (14.5%) were international multicenter trials, phase I trials accounted for 44.5%. For all those trials, there were 458 cancer drug varieties, with an annual growth rate of 36.7%, and 361 (85.8%) were developed by domestic enterprises. Most of the investigational products were therapeutic innovative drugs (77.1%), major in tumor treatment (92.8%). In terms of mechanism, targeted drugs were the most popular, accounting for 76.6%, and programmed cell death-1 (PD-1) and epithelial growth factor receptor (EGFR) were the most common targets. In addition, there were 19 anticancer drugs from 17 companies approved in China in 2019, with 10 drugs from domestic companies. Lung cancer and breast cancer are the most common indications for both registered trials and marketed drugs. No statistically significant differences were found between 2020 and 2019 in terms of the distribution of trial sponsor, scope and stage, as well as the distribution of drug type, effect and mechanism ( P>0.05). Conclusions:During the Covid-19 epidemic period, clinical trials of oncology drugs in China progress smoothly and maintain a high growth rate. Series of innovative products obtained by domestic enterprises in 2020 is the main driving force of development of oncology drug clinical trials in China.