Objective: To analyze the bioinformatics of domestic Clostridium difficile toxin B(TcdB) and prepare it to provide data support for the development of effective vaccines. Methods: Using bioinformatics software such as Snippy, Blast, Muscle, and the dist.alignment() and hclust() functions in R, 1 355 strains of Clostridium difficile from NCBI GenBank in China were compared and analyzed, and TcdB were grouped. The maximum likelihood tree and phylogenetic tree were beautified and displayed using iTOL. An online bioinformatics analysis website was used to predict and analyze the spatial structure and antigenic epitopes of the two largest subgroups, TcdB1 and TcdB2. The antigen protein TcdB was expressed and purified by prokaryotic system. Results: According to the genotype of toxin B, the 1 355 prevalent strains of Clostridium difficile in China could be roughly divided into 12 subtypes, among which TcdB1 and TcdB2 were the main subtypes, accounting for more than 93.94% of all isolated strains, and about 17.20% of the strains were nontoxigenic or lack TcdB. The antigen epitope prediction of TcdB1 and TcdB2 showed that their antigen epitope distributions were basically the same, and many of them were distributed outside the C-terminal combined repetitive oligopeptides domains. Conclusion A specialized typing system for C. difficile TcdB in China has been established, and its main subtypes have been predicted for antigenic epitopes. The screened TcdB has been expressed for recombinant preparation.

C-type lectin receptors DC-SIGN is a transmembrane protein that mainly express on dendritic cell surface and its carbohydrate recognition domain can be combined with a variety of pathogens.In recent years,with deepening of research on viral infection immunity,multifaceted role played by DC-SIGN is gradually being mined.As a kind of pattern recognition molecules,DC-SIGN plays a crucial part in both innate and adaptive immune response,and can be mediated cis and trans viral infections.Starting with structure,function,expression and ligand of DC-SIGN,this review introduces molecular homologue in different species and finally summarizes role of DC-SIGN in influenza virus infections,which in order to find a new idea to study and treatment of viral infections associated with DC-SIGN.

To formulate an expert consensus on the principles of preoperative hair removal and provide scientific guidance for standardized removal of hair before surgical procedures so as to reduce the incidence of surgical site infections.METHODS Led by the Hospital Management Institute of National Health Commission of the People's Republic of China,this consensus was reached with the joint efforts from the expects of relevant fields such as surgeries,interventional therapies,nursing,and infection prevention and control.The consensus facilitates the classification and evaluation of literatures by following the evidence grade formulated by Oxford Evidence-based Medicine Center and focuses on the association of preoperative hair removal with surgical site infection,it reaches the evidence grade of expert consensus and recommendation intensity by integrating with discussions on meetings and clinical experience of the expects from relevant fields.RESULTS A total of 6 items of consensus were reached by summarizing the latest evidence on the aspects including the indications for preoperative hair removal,tools,range,timing and places.CONCLUSION The consensus,to some extent,make supplements to and complete the exiting regulations and standards.It provides guidance for the medical institutions to carry out the preoperative hair removal.

To formulate an expert consensus on the principles of preoperative hair removal and provide scientific guidance for standardized removal of hair before surgical procedures so as to reduce the incidence of surgical site infections.METHODS Led by the Hospital Management Institute of National Health Commission of the People's Republic of China,this consensus was reached with the joint efforts from the expects of relevant fields such as surgeries,interventional therapies,nursing,and infection prevention and control.The consensus facilitates the classification and evaluation of literatures by following the evidence grade formulated by Oxford Evidence-based Medicine Center and focuses on the association of preoperative hair removal with surgical site infection,it reaches the evidence grade of expert consensus and recommendation intensity by integrating with discussions on meetings and clinical experience of the expects from relevant fields.RESULTS A total of 6 items of consensus were reached by summarizing the latest evidence on the aspects including the indications for preoperative hair removal,tools,range,timing and places.CONCLUSION The consensus,to some extent,make supplements to and complete the exiting regulations and standards.It provides guidance for the medical institutions to carry out the preoperative hair removal.

C-type lectin receptors DC-SIGN is a transmembrane protein that mainly express on dendritic cell surface and its carbohydrate recognition domain can be combined with a variety of pathogens.In recent years,with deepening of research on viral infection immunity,multifaceted role played by DC-SIGN is gradually being mined.As a kind of pattern recognition molecules,DC-SIGN plays a crucial part in both innate and adaptive immune response,and can be mediated cis and trans viral infections.Starting with structure,function,expression and ligand of DC-SIGN,this review introduces molecular homologue in different species and finally summarizes role of DC-SIGN in influenza virus infections,which in order to find a new idea to study and treatment of viral infections associated with DC-SIGN.

The aim of this study was to prepare a self-assembled nanoparticle monkeypox vaccine candidate and study its immune response characteristics,so as to provide reference test data for its vaccine design.The antigen protein A29L-SpyTag and the backbone protein Mi3-SpyCatcher were expressed and purified by prokaryotic system,and nanoparticles A29L-Mi3 were prepared by chemical assembly,then the antibody titers were determined by ELISA,the antibody neutralization was determined by plaque test,and the cytokine secretion of lymphocytes was determined by flow cytometry to describe the immune response characteristics.Data showed that A29L-Mi3 nanoparticles were successfully prepared,and the particles were uniformly distributed in hollow cages,with an average particle size of(29±0.19)nm.After the A29L-Mi3 nanoparticle vaccine candidate was combined with SP01 adjuvant,the neutralizing antibody titer was stronger than that of the A29L protein candidate,and the A29L-Mi3 nanoparticle vaccine candidate could obtain neutralizing antibodies with similar titers after two immunizations.The level of mouse T lymphocyte immune response activated by the A29L-Mi3 nanoparticle vaccine candidate was higher than that of the A29L protein vaccine candidate.In conclusion,A29L-Mi3 protein nanoparticles with uniform structure have successfully assembled in vitro,which has strong immunogenicity and improved neutralization ability after combination with SP01 adjuvant,thus provided reference data for the optimization of immune programs.In addition,the level of cellular immune response is higher than that of A29L protein alone,which provides a reference for the design and development of monkeypox vaccine.

Objective To prepare and identify CS-PLGA microspheres carrying bilayer antigen protein.Methods Porous microspheres were prepared by emulsion polymerization combined with solvent evaporation.The antigen was loaded in a water bath at 4 ℃,and the antigen was promoted to enter the microspheres by physical diffusion media-ted by antigen concentration gradient and combined with the outer surface of the microspheres by electrostatic ac-tion,forming an inner and outer double-layer antigen carrier.Then,according to the glass transition temperature of PLGA material,the pores on the surface of porous microspheres were promoted to heal at 48 ℃ to form a closed microsphere preparation,and then the obtained microsphere preparation was suspended with chitosan solution for cationic modification to reverse the negative potential on the surface of microspheres.In this study,the morphology,particle size distribution and potential changes of microspheres were detected by scanning electron microscope and dynamic light scattering particle size analyzer.In addition,sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)was used to identify whether the antigen was loaded into the microsphere preparation.The fluorescent labeled BSA and fluorescent labeled PLGA materials were used to observe the distribution of the antigen after load-ing by laser confocal microscope.The encapsulation efficiency and drug loading rate of the microsphere preparation were detected by BCA method.Results The results of scanning electron microscope and optical microscope showed that the porous microspheres had good pore formation,the particle size was(73.94±0.81)nm,and the Polydisper-sity index was 0.038±0.004.Zeta potential changed from negative to positive,which indicated that chitosan had been successfully coated on the surface of microspheres.SDS-PAGE,laser confocal microscope and other detection methods confirmed that BSA had been successfully carried.The encapsulation rate of porous microspheres was(3.01±0.04)％and the drug loading rate was(1.50±0.02)％after detection by micro BCA kit.Conclusion CS-PLGA preparation carrying bilayer antigen was successfully prepared,which provided a new idea for the subse-quent study of sustained and controlled release preparations.

N ⁶-methyladenosine (m⁶A) modification is critical for mRNA splicing, nuclear export, stability and translation. Fat mass and obesity-associated protein (FTO), the first identified m⁶A demethylase, is critical for cancer progression. Herein, we developed small-molecule inhibitors of FTO by virtual screening, structural optimization, and bioassay. As a result, two FTO inhibitors namely 18077 and 18097 were identified, which can selectively inhibit demethylase activity of FTO. Specifically, 18097 bound to the active site of FTO and then inhibited cell cycle process and migration of cancer cells. In addition, 18097 reprogrammed the epi-transcriptome of breast cancer cells, particularly for genes related to P53 pathway. 18097 increased the abundance of m⁶A modification of suppressor of cytokine signaling 1 (SOCS1) mRNA, which recruited IGF2BP1 to increase mRNA stability of SOCS1 and subsequently activated the P53 signaling pathway. Further, 18097 suppressed cellular lipogenesis via downregulation of peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and C/EBPβ. Animal studies confirmed that 18097 can significantly suppress in vivo growth and lung colonization of breast cancer cells. Collectively, we identified that FTO can work as a potential drug target and the small-molecule inhibitor 18097 can serve as a potential agent against breast cancer.

Scaffold hopping refers to computer-aided screening for active compounds with different structures against the same receptor to enrich privileged scaffolds, which is a topic of high interest in organic and medicinal chemistry. However, most approaches cannot efficiently predict the potency level of candidates after scaffold hopping. Herein, we identified potent PDE5 inhibitors with a novel scaffold via a free energy perturbation (FEP)-guided scaffold-hopping strategy, and FEP shows great advantages to precisely predict the theoretical binding potencies ΔG _FEP between ligands and their target, which were more consistent with the experimental binding potencies ΔG _EXP (the mean absolute deviations | Δ G FEP - Δ G EXP |  < 2 kcal/mol) than those ΔG _MM-PBSA or ΔG _MM-GBSA predicted by the MM-PBSA or MM-GBSA method. Lead L12 had an IC₅₀ of 8.7 nmol/L and exhibited a different binding pattern in its crystal structure with PDE5 from the famous starting drug tadalafil. Our work provides the first report via the FEP-guided scaffold hopping strategy for potent inhibitor discovery with a novel scaffold, implying that it will have a variety of future applications in rational molecular design and drug discovery.

Our recent studies demonstrated that the natural product nobiletin (NOB) served as a promising multidrug resistance (MDR) reversal agent and improved the effectiveness of cancer chemotherapy . However, low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent. To tackle these challenges, NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy. All the compounds showed improved sensitivity to paclitaxel (PTX) in P-glycoprotein (P-gp) overexpressing MDR cancer cells. Among them, compound exhibited water solubility 280-fold higher than NOB. A drug-resistance A549/T xenograft model showed that at a dose of 50 mg/kg co-administered with PTX (15 mg/kg), inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors P-gp inhibition. Moreover, Western blot experiments revealed that inhibited expression of NRF2, phosphorylated ERK and AKT in MDR cancer cells, thus implying of multiple mechanisms to reverse MDR in lung cancer.