Objective To explore the effect and preliminary mechanism of the plant-derived immunostimulatory molecule,ophiopogonin,on enhancing the immune response of a subunit vaccine with the receptor-binding domain(RBD)of coronavirus spike protein as the antigen.Methods CCK-8 assay was used to determine the cytotoxicity of ophiopogonin D'(OPD')on bone marrow-derived dendritic cells(BMDCs).Female Balb/c mice were randomly divided into RBD,RBD/OPD',RBD/Alum,and control groups.The immunization dose was 5 μg of antigen per mouse and 100 μg of adjuvant per mouse,and immunization was carried out according to the intramuscular injection immunization procedure on days 0,21,and 42.The titers of specific IgG and its subtype antibodies were detected by ELISA.The cytokine levels in the supernatant of splenocytes were detected using ELISA.The number of splenocytes secreting IFN-γ was detected by ELISpot.Laser confocal microscopy was employed to observe the uptake of antigen by BMDCs.The phagocytic ability of BMDCs for antigen was quantitatively analyzed by flow cytometry.The mechanism of its enhanced immune effect was preliminarily explored using transcriptomics technology combined with bioinformatics research.Results When the concentration of OPD'was less than 5 μg/mL,the survival rate of BMDCs was 100%.After a single intramuscular injection in mice,except for a slight decrease in body weight,the other biochemical indicators were within corresponding normal ranges.After intramuscular injection immunization of the vaccine,the titers of serum-specific IgG,IgG1,and IgG2a in the RBD/OPD'group were significantly higher than those in the RBD group(P<0.05).Compared with the RBD group,the RBD/OPD'group induced a high-level Th1 cell immune response of IL-1β,TNF-α,and IFN-γ(P<0.01)and had more lymphocytes secreting IFN-γ(P<0.001).Laser confocal microscopy displayed that BMDCs took up more antigens after OPD'treatment,which was further confirmed with flow cytometry in quantitative analysis on antigen uptake rate(P<0.01).Transcriptomics results indicated that there was more significant enrichment of the PPAR signaling pathway in the RBD/OPD'group than the RBD group,suggesting that OPD'may activate the PPAR signaling pathway to exert its adjuvant effect.Conclusion OPD'effectively enhances the immune response of the RBD subunit vaccine,and its action mechanism may be related to the activation of the PPAR signaling pathway.

Objective To establish a mouse model of infection with the minimum lethal dose of Vibrio vulnificus(V.vulnificus)and to evaluate the protective efficacy of inactivated whole-cell(IWC)vaccine using this model.Methods A mouse model of lethal-dose infection was established by intraperitoneal injection of different doses of V.vulnificus.Bacterial colonization in the organs was detected with tissue homogenate plating,and pathological changes in the organs were observed after tissue section staining.Flow cytometry was used to detect immune cell responses after liver tissues were digested into single-cell suspension.IWC vaccine of V.vulnificus was prepared,and the mice were immunized through different routes to observe the protective efficacy of the vaccine.Results A mouse model of infection with the minimum lethal dose at 1×106 CFU of V.vulnificus was successfully established.After infection,the bacteria were mainly colonized in the liver of mice and caused severe pathological damages.Compared with the uninfected mice,the proportion of neutrophils in the liver was significantly increased in the infected mice,whereas the proportions of B cells and T cells were correspondingly decreased(P<0.05).A single intramuscular or intraperitoneal injection of the IWC vaccine could protect the mice effectively against lethal infection of V.vulnificus in 7 d later(P<0.01),although the level of serum IgG having no significant increase.Conclusion A mouse model of lethal-dose infection with V.vulnificus is successfully established,with histopathological characteristics.The IWC vaccine of V.vulnificus rapidly mediates immune protection in this model probably independent of IgG.

Objective To prepare tubeimoside Ⅲ nanoemulsion(TBMⅢ-NE)and evaluate its adjuvant effect in vaccines.Methods TBMⅢ-NE was prepared using low-energy emulsification.Dynamic light scattering was used to characterize the particle size and polydispersity index of the obtained TBMⅢ-NE,and transmission electron microscopy(TEM)was employed to observe the morphology.CCK-8 assay was utilized to determine the cytotoxicity of TBMⅢ-NE on bone marrow-derived dendritic cells(BMDCs).The in vitro safety of TBMⅢ-NE was evaluated using a hemolysis assay.The ability of TBMⅢ-NE to promote the phagocytosis of antigens by DC2.4 cells was observed using confocal laser microscopy.After co-incubation of TBMⅢ-NE with BMDCs,the expression levels of CD40,CD86,MHC-Ⅰ,and CCR7 on the surface of BMDCs were detected using flow cytometry,and the levels of cytokines in the supernatant of BMDCs were measured using enzyme-linked immunosorbent assay(ELISA).After female BALB/c mice were immunized with the SARS-CoV-2 antigen RBD in combination with TBMⅢ-NE,ELISA was conducted to determine the serum levels of specific IgG,IgG2a,and IgG1 antibodies.The number of specific IFN-γ-secreting cells in mouse splenocytes was detected using enzyme-linked immunospot(ELISpot)assay.Results The prepared blank nanoemulsion(BNE)and TBMⅢ-NE were in a particle size of 25.46 and 25.89 nm,and a polydispersity index of 0.214 and 0.125,respectively.TEM displayed that TBMⅢ-NE was in uniform sphere and well dispersed.When the TBMⅢ-NE adjuvant was diluted by 400-fold,the survival rate of BMDCs was approximately 86%.Compared with free TBMⅢ,the hemolytic toxicity of TBMⅢ-NE was significantly reduced(P<0.01).TBMⅢ-NE promoted the phagocytosis of antigens by DC2.4 cells and significantly increased the expression of CCR7 on the surface of BMDCs(P<0.05),indicating its potential to promote more dendritic cells to effectively migrate to lymph nodes.TBMⅢ-NE also promoted the expression of IL-6 and IL-1β in the supernatant of BMDCs(P<0.05).When combined with RBD,TBMⅢ-NE significantly increased the levels of specific IgG,IgG2a,and IgG1 antibodies in mouse serum(P<0.01)and promoted the secretion of specific IFN-γ in splenocytes(P<0.01),indicating that TBM Ⅲ-NE could enhance specific cellular immune responses.Conclusion A stable and highly effective TBMⅢ-NE that can induce humoral and cellular immune responses is successfully prepared.

OBJECTIVE To investigate a suspected hospital-acquired infection cluster of Enterococcus faecium(Efm)in a neonatal intensive care unit(NICU)of the First Medical Center of Chinese PLA General Hospital,identify the source of infection and transmission routes,and provide a reference for precise prevention and control of hospital-acquired infections.METHODS Epidemiological investigations and environmental microbiological sam-pling were conducted for two neonates with Efm bloodstream infections in the NICU in Jul.2024 to detect Efm in the ward environment.Whole-genome average nucleotide identity(ANI)and multilocus sequence typing(MLST)were used to analyze the homology,drug resistance,and virulence factors of Efm isolates from patients and envi-ronments.Targeted intervention measures were proposed.RESULTS Two cases of Efm bloodstream infection were detected.A total of 37 environmental specimens were collected,and 2 were cultured Efm(the wipe dispenser o-pening and incubator handle of the patients).The drug susceptibility testing results of 2 environmental specimens were consistent with those of the two patient specimens.Genomic analysis confirmed high homology(ANI＞99.99％)among the four Efm isolates.After implementing a series of measures including centralized isolation,strict hand hygiene,thorough environmental cleaning and disinfection,strict disinfection and management of inva-sive devices,enhanced grouping of medical staff for diagnosis and treatment,the incident was effectively con-trolled.CONCLUSIONS This incident can be determined as cluster of hospital-acquired infection with Enterococcus faecium in the neonatal intensive care unit.The wet wipes are the source or transmission medium of contamina-tion.Inadequate disinfection of items and the environment,and insufficient hand hygiene of medical staff are the main reasons for this infection outbreak.Early identification of abnormal cluster of infection,investigation of the source of infection and transmission routes and timely implementation of targeted measures are the keys for preventing infection outbreaks.

Objective:To explore risk factors for delayed onset of lactogenesis in prenatally overweight women and construct risk prediction models based on machine learning for early identification of high-risk individuals.Methods:Convenience sampling was adopted to select 338 prenatally overweight women who delivered in the Obstetrics Departments of four ClassⅢ Grade A hospitals in Hengyang City from October 2023 to June 2024 for the study. Delivery women were randomly divided into training set and test set in the ratio of 7∶3. The survey was conducted with the General Information Questionnaire, Breastfeeding Self-efficacy Scale Short Form, Edinburgh Postnatal Depression Scale, LATCH Scale and Pittsburgh Sleep Quality Index. One-way analysis and LASSO regression were used to screen predictors using delayed onset of lactogenesis as the outcome variable. Risk prediction models were constructed based on three machine learning algorithms of Logistic regression, support vector, and random forest, respectively. The models were tuned by ten-fold cross-validation to filter out the best models.Results:Delayed onset of lactogenesis occurred in 140 of 338 prenatally overweight women, an incidence of 41.4%. Among the three predictive model performances, the random forest model had the highest area under the receiver operating characteristic curve, accuracy, precision, recall, and F1 value. The importance of each predictor was ranked according to the fandom forest algorithm, and in descending order of importance, they were breastfeeding 1 h after the birth of the newborn, number of previous deliveries, age, feeding mode 3 d postpartum, pregnancy complications, mode of delivery, number of breastfeeding 24 h postpartum, and monthly household income.Conclusions:Risk prediction models for delayed onset of lactogenesis in prenatally overweight women are constructed based on three machine learning algorithms, aiming to help provide a scientific basis for clinical healthcare professionals to take relevant decisions.

OBJECTIVE To investigate a suspected hospital-acquired infection cluster of Enterococcus faecium(Efm)in a neonatal intensive care unit(NICU)of the First Medical Center of Chinese PLA General Hospital,identify the source of infection and transmission routes,and provide a reference for precise prevention and control of hospital-acquired infections.METHODS Epidemiological investigations and environmental microbiological sam-pling were conducted for two neonates with Efm bloodstream infections in the NICU in Jul.2024 to detect Efm in the ward environment.Whole-genome average nucleotide identity(ANI)and multilocus sequence typing(MLST)were used to analyze the homology,drug resistance,and virulence factors of Efm isolates from patients and envi-ronments.Targeted intervention measures were proposed.RESULTS Two cases of Efm bloodstream infection were detected.A total of 37 environmental specimens were collected,and 2 were cultured Efm(the wipe dispenser o-pening and incubator handle of the patients).The drug susceptibility testing results of 2 environmental specimens were consistent with those of the two patient specimens.Genomic analysis confirmed high homology(ANI＞99.99％)among the four Efm isolates.After implementing a series of measures including centralized isolation,strict hand hygiene,thorough environmental cleaning and disinfection,strict disinfection and management of inva-sive devices,enhanced grouping of medical staff for diagnosis and treatment,the incident was effectively con-trolled.CONCLUSIONS This incident can be determined as cluster of hospital-acquired infection with Enterococcus faecium in the neonatal intensive care unit.The wet wipes are the source or transmission medium of contamina-tion.Inadequate disinfection of items and the environment,and insufficient hand hygiene of medical staff are the main reasons for this infection outbreak.Early identification of abnormal cluster of infection,investigation of the source of infection and transmission routes and timely implementation of targeted measures are the keys for preventing infection outbreaks.

Objective:To explore risk factors for delayed onset of lactogenesis in prenatally overweight women and construct risk prediction models based on machine learning for early identification of high-risk individuals.Methods:Convenience sampling was adopted to select 338 prenatally overweight women who delivered in the Obstetrics Departments of four ClassⅢ Grade A hospitals in Hengyang City from October 2023 to June 2024 for the study. Delivery women were randomly divided into training set and test set in the ratio of 7∶3. The survey was conducted with the General Information Questionnaire, Breastfeeding Self-efficacy Scale Short Form, Edinburgh Postnatal Depression Scale, LATCH Scale and Pittsburgh Sleep Quality Index. One-way analysis and LASSO regression were used to screen predictors using delayed onset of lactogenesis as the outcome variable. Risk prediction models were constructed based on three machine learning algorithms of Logistic regression, support vector, and random forest, respectively. The models were tuned by ten-fold cross-validation to filter out the best models.Results:Delayed onset of lactogenesis occurred in 140 of 338 prenatally overweight women, an incidence of 41.4%. Among the three predictive model performances, the random forest model had the highest area under the receiver operating characteristic curve, accuracy, precision, recall, and F1 value. The importance of each predictor was ranked according to the fandom forest algorithm, and in descending order of importance, they were breastfeeding 1 h after the birth of the newborn, number of previous deliveries, age, feeding mode 3 d postpartum, pregnancy complications, mode of delivery, number of breastfeeding 24 h postpartum, and monthly household income.Conclusions:Risk prediction models for delayed onset of lactogenesis in prenatally overweight women are constructed based on three machine learning algorithms, aiming to help provide a scientific basis for clinical healthcare professionals to take relevant decisions.

Objective To evaluate the stability,safety and immune enhancement and anti-tumor effects of Wilms'tumor gene 1(WT1)peptide combined with AddaVaxTM emulsion vaccine for acute myeloid leukemia.Methods The stability of WT1 peptide in the adjuvant vaccine was evaluated using MALDI-TOF-MS time-of-flight mass spectrometry.Female C57BL/6 mice were randomly divided into PBS group,WT1 peptide group,and WT1 peptide+AddaVaxTMemulsion adjuvant vaccine group.The immunization was performed at a dose of 50 μg/mouse for antigen and 50 μg/mouse for adjuvant,with intramuscular injection on days 0,14,and 28.HE staining was used to assess the toxicity of intramuscular vaccination on mouse organ tissues.Cytokine levels were detected by ELISA,and the number of IFN-γ-secreting splenocytes was measured by ELISpot.Flow cytometry was employed to detect the maturation of bone marrow-derived dendritic cells(BMDCs)promoted by the vaccine in vitro and the promotion for lymphocyte activation,and H-2Db WT1 tetramer was utilized to detect the proportion of specific CD8+T cells.After establishing a mouse leukemia tumor model using the C1498-mWT1 stable cell line,the anti-tumor effects of the vaccine for prevention and treatment were evaluated.Results The WT1 peptide stably existed in the vaccine without causing significant organ tissue changes in mice after intramuscular injection.Compared to the mice immunized with WT1 aqueous solution,the mice after intramuscular injection of the WT1 peptide emulsion adjuvant vaccine showed stronger immune responses of Th1 cells,including IFN-γ and TNF-α,as well as Th17 cells of IL-17A(P＜0.05),and the mice had not only promoted number of IFN-γ secreting splenocytes(P＜0.01)but also enhanced maturation of BMDCs,as indicated by an increase in the proportions of CD40+/CD11c+and CD86+CD80+/CD11c+ cells(P＜0.05).Additionally,there were increases in both the proportion of CD4+/CD3+T and CD69+/CD8+T cells(P＜0.05)and the proportion of specific CD8+T cells(P＜0.05).In the anti-tumor effect study using the C1498-mWT1 mouse model,the median survival time of the WT1+AddaVaxTM group was extended by 6 d compared to the WT1 aqueous solution group.At day 50,the survival rate of mice in the WT1+AddaVaxTM group was still 28.5％,while all mice in the other groups had died(P＜0.05).Conclusion The vaccine with the WT1 peptide and AddaVaxTM emulsion adjuvant exhibits good immunological and anti-tumor effects.

Objective To investigate the antibacterial effect and its preliminary mechanism of lavender essential oil on multi-drug resistant Acinetobacter baumannii.Methods Micro-dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)of lavender essential oil against multi-drug resistant Acinetobacter baumannii,and bactericidal kinetic study was employed to determine the onset and maintenance time of lavender essential oil.Meanwhile,the promoting and therapeutic effects of lavender essential oil on wound healing were observed in a mouse model of infection.Subsequently,crystal violet staining was used to determine the inhibition and clearance of multi-drug resistant Acinetobacter baumannii biofilm by lavender essential oil,and laser confocal microscopy was utilized to observe the survival of bacteria in biofilms.NanoDrop instrument was utilized to quantify the leakage of bacterial DNA nucleic acid and protein after intervention with 3 and 6 mg/mL lavender essential oil,and the leakage of bacterial potassium ion was measured by potassium ion test kit.Proteomics technology combined with bio-informatics were applied to explore the action mechanism of lavender essential oil against multi-drug resistant Acinetobacter baumannii.Results The MIC and MBC of lavender essential oil were both 6 mg/mL,which could kill almost all multi-drug resistant Acinetobacter baumannii at the time point of 120 min,and showed an obvious dose-and time-dependent manner.The overall animal model evaluation showed that both 3 and 6 mg/mL lavender essential oil could promote wound healing,and the curative effect was obvious.Further studies confirmed that 3 mg/mL lavender essential oil had a certain biofilm inhibitory effect on multi-drug resistant Acinetobacter baumannii,and 6 mg/mL also had a certain biofilm clearance effect under the same conditions.Meanwhile,when incubated at 37℃ for 1 h,the dose of 3 mg/mL could increase the leakage of DNA nucleic acid and protein,and significantly promote the efflux of potassium ions.Proteomic analysis suggested that the antibacterial effect of lavender essential oil may be related to affecting the oxidorereductase activity and cell metabolic process of multi-drug resistant Acinetobacter baumannii,and interfering with the biosynthesis of cell wall/membrane/envelope and other structures.Conclusion Lavender essential oil at 3 mg/mL can play an antibacterial effect against multi-drug resistant Acinetobacter baumannii,and its mechanism may be related to the destruction of bacterial biofilm and interference with bacterial metabolism.

Tumor has become the major reasons cause of death,and its vaccine has become the effective tracts of treatment and prevention by enhancing the immune response of patients.However,most vaccines which are recombination subunit protein antigens are poorly immunogenic and difficult to induce a robust immune response in patients with compromised immune systems,resulting in poor marketing approval.The core component of the vaccine adjuvant can greatly enhance the strength,speed and duration of the immune response,thus becoming the key to the development of an ideal tumor vaccine.Most tumor vaccines are combined with tradition adjuvant such as aluminum,MF59 and AS adjuvant,but their products and patents are monopolized by large foreign companies.We found that natural adjuvants have many unique advantages,such as good biocompatibility and biodegradability,promoting the maturation of dendritic cell and the secretion of immune cytokines,significantly enhancing the tumor vaccine immune response,etc.In this paper,the application and future development of natural polysaccharides,saponins,flavonoid and plant virus-like particles in cancer vaccines were reviewed,which may lay a solid foundation for the development of the original and innovative adjuvants with domestic independent intellectual property rights.