1.Construction and biological characterization of a dual sagA/aroA gene deletion mutant strain of donkey-derived Streptococcus equi subsp. equi
Bing LIU ; Guangyuan LIU ; Nannan GAO ; Zhaoliang DING ; Jie YU ; Chuanlu WEI ; Haijing LI ; Hua WANG ; Shishan DONG ; Jianbao DONG
Chinese Journal of Veterinary Science 2025;45(11):2365-2371
Strangles,caused by Streptococcus equi subsp.equi,remains one of the most prevalent and high-incidence infectious diseases in intensive donkey farms,posing a significant threat to the healthy development of the donkey industry.Vaccination serves as an effective measure for the pre-vention and control of the disease,however,there is currently no attenuated vaccine against this disease in China.To provide a candidate strain for the development of a live attenuated strangles vaccine,this study focused on a wild-type S.equi subsp.equi strain isolated from donkeys.Using homologous recombination gene knockout technology,the aroA gene(encoding 5-enolpyru-vylshikimate-3-phosphate synthase)and the sag A gene(encoding the precursor of streptolysin S toxin)were sequentially deleted to construct a double-gene-deletion strain(ΔsagA/aroA).The virulence and key biological characteristics of the mutant strain were systematically evaluated.TheΔsagA/aroA strain was successfully generated,exhibiting complete loss of hemolytic activity and maintaining stable genetic inheritance over 60 consecutive passages.Electron microscopy revealed that the mutant retained morphological characteristics compared to the wild-type strain,and its growth rate was significantly slower(P<0.000 1).Virulence assessment using a challenge dose of 1× 105 CFU/0.2 mL(the minimum fully lethal dose of the wild-type strain)demonstrated markedly attenuated virulence in the mutant.Immunization trials with 1 ×104 CFU/0.2 mL of theΔsagA/aroA strain revealed a increase in ELISA antibody titers by day 7 post-vaccination,and higher levels at days 14 and 21.Notably,antibody levels in the experimental group were significant-ly higher than those in the control group(P<0.000 1).These findings confirm that the double-gene-deletion strain S.equi subsp.equi ΔsagA/aroA exhibits reduced virulence while retaining im-munogenicity,which suggested it can be used as a promising candidate strain for further develop-ment of a live attenuated strangles vaccine.
2.Construction and biological characterization of a dual sagA/aroA gene deletion mutant strain of donkey-derived Streptococcus equi subsp. equi
Bing LIU ; Guangyuan LIU ; Nannan GAO ; Zhaoliang DING ; Jie YU ; Chuanlu WEI ; Haijing LI ; Hua WANG ; Shishan DONG ; Jianbao DONG
Chinese Journal of Veterinary Science 2025;45(11):2365-2371
Strangles,caused by Streptococcus equi subsp.equi,remains one of the most prevalent and high-incidence infectious diseases in intensive donkey farms,posing a significant threat to the healthy development of the donkey industry.Vaccination serves as an effective measure for the pre-vention and control of the disease,however,there is currently no attenuated vaccine against this disease in China.To provide a candidate strain for the development of a live attenuated strangles vaccine,this study focused on a wild-type S.equi subsp.equi strain isolated from donkeys.Using homologous recombination gene knockout technology,the aroA gene(encoding 5-enolpyru-vylshikimate-3-phosphate synthase)and the sag A gene(encoding the precursor of streptolysin S toxin)were sequentially deleted to construct a double-gene-deletion strain(ΔsagA/aroA).The virulence and key biological characteristics of the mutant strain were systematically evaluated.TheΔsagA/aroA strain was successfully generated,exhibiting complete loss of hemolytic activity and maintaining stable genetic inheritance over 60 consecutive passages.Electron microscopy revealed that the mutant retained morphological characteristics compared to the wild-type strain,and its growth rate was significantly slower(P<0.000 1).Virulence assessment using a challenge dose of 1× 105 CFU/0.2 mL(the minimum fully lethal dose of the wild-type strain)demonstrated markedly attenuated virulence in the mutant.Immunization trials with 1 ×104 CFU/0.2 mL of theΔsagA/aroA strain revealed a increase in ELISA antibody titers by day 7 post-vaccination,and higher levels at days 14 and 21.Notably,antibody levels in the experimental group were significant-ly higher than those in the control group(P<0.000 1).These findings confirm that the double-gene-deletion strain S.equi subsp.equi ΔsagA/aroA exhibits reduced virulence while retaining im-munogenicity,which suggested it can be used as a promising candidate strain for further develop-ment of a live attenuated strangles vaccine.
3.Association between temperature and mortality: a multi-city time series study in Sichuan Basin, southwest China.
Yizhang XIA ; Chunli SHI ; Yang LI ; Shijuan RUAN ; Xianyan JIANG ; Wei HUANG ; Yu CHEN ; Xufang GAO ; Rong XUE ; Mingjiang LI ; Hongying SUN ; Xiaojuan PENG ; Renqiang XIANG ; Jianyu CHEN ; Li ZHANG
Environmental Health and Preventive Medicine 2024;29():1-1
BACKGROUND:
There are few multi-city studies on the association between temperature and mortality in basin climates. This study was based on the Sichuan Basin in southwest China to assess the association of basin temperature with non-accidental mortality in the population and with the temperature-related mortality burden.
METHODS:
Daily mortality data, meteorological and air pollution data were collected for four cities in the Sichuan Basin of southwest China. We used a two-stage time-series analysis to quantify the association between temperature and non-accidental mortality in each city, and a multivariate meta-analysis was performed to obtain the overall cumulative risk. The attributable fractions (AFs) were calculated to access the mortality burden attributable to non-optimal temperature. Additionally, we performed a stratified analyses by gender, age group, education level, and marital status.
RESULTS:
A total of 751,930 non-accidental deaths were collected in our study. Overall, 10.16% of non-accidental deaths could be attributed to non-optimal temperatures. A majority of temperature-related non-accidental deaths were caused by low temperature, accounting for 9.10% (95% eCI: 5.50%, 12.19%), and heat effects accounted for only 1.06% (95% eCI: 0.76%, 1.33%). The mortality burden attributable to non-optimal temperatures was higher among those under 65 years old, females, those with a low education level, and those with an alternative marriage status.
CONCLUSIONS
Our study suggested that a significant association between non-optimal temperature and non-accidental mortality. Those under 65 years old, females, and those with a low educational level or alternative marriage status had the highest attributable burden.
Female
;
Humans
;
China/epidemiology*
;
Cities
;
Cold Temperature
;
Hot Temperature
;
Mortality
;
Temperature
;
Time Factors
;
Middle Aged
;
Male
4.Research progress on the role of SHP-2 in tumor-associated macrophages
Xueliang WU ; Jianchun FAN ; Fei GUO ; Qi ZHANG ; Jun XUE ; Ximo WANG ; Guangyuan SUN ; Jianling LIU ; Lei HAN ; Shuquan GAO
Chinese Journal of Comparative Medicine 2024;34(1):171-176
Tumor-associated macrophages(TAMs)are the predominant cell group in the tumor microenvironment(TME)and are the most important regulatory cells of immune system suppression and tumor cell proliferation in TIME.Src homology-2 domain-containing protein tyrosine phosphatase 2(SHP-2)is a non-receptor protein tyrosine phosphatase that plays an important role in the transmission of signals from the cell surface to the nucleus.SHP-2 is a key intracellular regulatory factor mediating cell proliferation and differentiation and is involved in a variety of growth factor and cytokine signaling pathways linking the cell surface to the nucleus.Recent studies have shown that SHP-2 is a key enzyme in determining the function of TAMs,but because of its variable function,it plays different or even opposite roles in different solid TMEs.This paper reviews the function of SHP-2 in TAMs and related solid tumors to provide a comprehensive reference for tumor immunity and targeted therapy research.
5.The protective effect and mechanism of Ophiopogonin D on LPS-induced mouse macrophages
Xinyi SHAO ; Guangyuan HAN ; Ruheng WEI ; Jianzhong GAO
International Journal of Traditional Chinese Medicine 2023;45(2):169-173
Objective:To study the protective effect of Ophiopogonin D on lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7 and its related mechanism.Methods:Mouse macrophage RAW264.7 cells were cultured and divided into normal control group, model group and Ophiopogonin D pretreatment group according to random number table method. The activity of Ophiopogonin D on RAW264.7 cells was detected by CCK-8 method; the protein levels of TNF-α, IL-1β, IL-6, reactive oxygen species (ROS), MDA and SOD were detected by ELISA; the protein expression of NF-κB, TLR4, NF-E2-related factor2 (Nrf2) and heme oxygenase-1 (HO-1) were detected by Western Blot.Results:Compared with model group, the levels of TNF-α, IL-1β, IL-6, ROS and MDA in cell supernatant of Ophiopogonin D group were decreased ( P<0.05), and the level of SOD was increased ( P<0.05). The protein expressions of NF-κB (0.76±0.10 vs. 2.26±0.17) and TLR4 (0.98±0.09 vs. 1.74±0.19) significantly decreased ( P<0.05). The protein expressions of Nrf2 (0.85±0.03 vs. 0.54±0.03) and HO-1 (0.97±0.11 vs. 0.37±0.04) significantly increased ( P<0.05). Conclusion:Ophiopogonin D may reduce inflammatory response by reducing TLR4/NF-κB pathway, and activate Nrf2/HO-1 pathway to reduce oxidative damage and play a protective role.
6.Effects of TRIM59 gene silencing on proliferation and cell cycle of colorectal cancer cells
Xiaobin Gao ; Xueliang Wu ; Shengjie Wang ; Guangyuan Sun ; Wenjing Wang ; Feng Liang ; Yifeng Zhao ; Zhenxian Liu
Acta Universitatis Medicinalis Anhui 2022;57(5):796-801
Objective:
To investigate the effect of tripartite motif containing 59(TRIM59) on the biological function of human colorectal cancer HCT116 cells and its possible mechanism.
Methods:
The recombinant TRIM59 interference plasmid(si-TRIM59) was constructed and transfected into colorectal cancer cell line HCT116 by liposome transfection. The transfection efficiency was verified by RT-qPCR and Western blot. The effects of TRIM59 gene silencing on the proliferation, colony-formation ability and cell cycle of colorectal cancer cells were detected by CCK-8 method, colony formation assays and flow cytometry respectively. Western blot was used to detect the expression level of CDK4 and cyclinD1.
Results:
The expression levels ofTRIM59mRNA and protein in colorectal cancer cells were significantly higher than those in normal colorectal mucosa cells(P<0. 05). After knockdown of TRIM59expression, the proliferation activity and colony forming ability of HCT116 cells were significantly inhibited(P<0. 05), and the cell cycle was arrested in G0/G1 phase. At the same time, the expression levels of CDK4and CyclinD1 significantly decreased(P<0. 05).
Conclusion
TRIM59was highly expressed in colorectal cancer cells. Down regulation ofTRIM59expression can inhibit the proliferation and clone formation of colorectal cancer cells, suggesting thatTRIM59may become a new target for gene therapy of colorectal cancer.
7.Comparison of the antigenicity of African swine fever virus p35 protein as diagnostic antigen.
Lei SHI ; Zhancheng TIAN ; Jifei YANG ; Shandian GAO ; Junzheng DU ; Yaru ZHAO ; Zhijie LIU ; Guiquan GUAN ; Guangyuan LIU ; Jianxun LUO ; Hong YIN
Chinese Journal of Biotechnology 2021;37(1):187-195
In order to screen African swine fever virus (ASFV) diagnostic antigen with the best enzyme linked immunosorbent assay (ELISA) reactivity. By establishing the ELISA method, the diagnostic antigen of ASFV p30 protein expressed by baculovirus-insect cell expression system as reference, we explored the antigenic properties and diagnostic potential of ASFV p35 protein expressed by prokaryotic expression system as a diagnostic antigen. The results of Western blotting and immunofluorescence show that the molecular weight of the recombinant p35 protein and p30 protein obtained was 40 kDa and 30 kDa, respectively, and these two proteins had good immuno-reactivity with ASFV positive serum. Recombinant p30 and p35 proteins were used as diagnostic antigens to establish ELISA, and the sensitivity and repeatability of these methods were tested. The results show that although the detection sensitivity of the p30-ELISA established in this study was higher than that of the p35-ELISA, the sensitivity of p35-ELISA was 95.8%, and variations in intra- and inter-assay repeatability of the two methods were less than 10%. The coincidence rate between the p35-ELISA and the imported kit was 97.2%. Results show that p35-ELISA was sensitive and stable, and could detect specific antibodies against ASFV.
African Swine Fever/diagnosis*
;
African Swine Fever Virus/genetics*
;
Animals
;
Antibodies, Viral
;
Enzyme-Linked Immunosorbent Assay
;
Recombinant Proteins/genetics*
;
Swine
8.Comparson of the immunogenicity of genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens.
Ruiming YU ; Zhancheng TIAN ; Shandian GAO ; Junzheng DU ; Guangyuan LIU ; Jianxun LUO ; Hong YIN
Chinese Journal of Biotechnology 2020;36(7):1314-1322
To screen the best genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens, the prMEIII gene, the polytope gene and the prMEIII-polytope fusion gene of the GenotypeⅠJapanese encephalitis virus GS strain were cloned into prokaryotic expression vector pET-30a. The recombinant proteins were obtained after the induction and purification. The prepared recombinant proteins were immunized to mice, and the immunogenicity of the subunit vaccine candidate antigens was evaluated through monitoring the humoral immune response by ELISA, detecting the neutralizing antibody titer by plaque reduction neutralization test, and testing the cell-mediated immune response by lymphocyte proliferation assay and cytokine profiling. The recombinant proteins with the molecular weights of 35 (prMEIII), 28 (polytope antigen) and 57 kDa (prMEIII-polytope) induced strong humoral and cellular immune responses in mice. Compared with prMEIII-polytope and polytope proteins, the prMEIII protein induced a significant expression of IL-2 and IFN-γ (P<0.05) and the significant lymphoproliferation of splenocytes (P<0.05). The neutralizing antibody titer induced by the prMEIII protein was close to that induced by the commercial attenuated vaccine SA14-14-2 (P>0.05). The study suggests that the prMEIII protein can be used for the development of the Japanese encephalitis virus subunit vaccine.
Animals
;
Antibodies, Viral
;
blood
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Antigens, Viral
;
immunology
;
Encephalitis Virus, Japanese
;
immunology
;
Encephalitis, Japanese
;
immunology
;
prevention & control
;
Immunogenicity, Vaccine
;
Mice
;
Mice, Inbred BALB C
;
Vaccines, Subunit
;
immunology
;
Viral Vaccines
;
immunology
9.Biosafety of medical injectable carboxymethyl glycosaminoglycan anti-adhesion gel
Ping GAO ; Lin CHENG ; Bin CHEN ; Ruizhi LI ; Xin LI ; Mengrou SHI ; Guangyuan LI ; Peng CHENG ; Dongfeng LI ; Huan YU ; Xiaohui WANG
Chinese Journal of Tissue Engineering Research 2019;23(10):1570-1574
BACKGROUND: The injectable carboxymethyl glycosaminoglycan anti-adhesion gel prepared in the previous study combines the advantages of anti-adhesion membrane and anti-adhesion liquid. It can form soft gel in situ in a relatively short time, which is not affected by body position, bear the pressure of surrounding tissues and can be used without compression. OBJECTIVE: To evaluate the biocompatibility of medical injectable carboxymethyl glycosaminoglycan anti-adhesion gel. METHODS: Logarithmic growing L929 cells were used as test cells, and the cytotoxicity of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract was detected by MTT method. The intradermal stimulation test of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract was carried out in Japanese big ear rabbits. Guinea pigs were used as experimental animals to carry out intradermal induction and local induced delayed hypersensitivity test of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract. Wistar rats were used as experimental animals to carry out the subchronic toxicity test of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract. RESULTS AND CONCLUSION: The cytotoxicity of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract was grade 1, meeting the standard requirements. Injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract had no potential intradermal stimulation and no potential skin sensitization. In the subchronic toxicity test, the rats were subjected to the tail vein injection of injectable carboxymethyl glycosaminoglycan anti-adhesion gel extract for 28 continuous days, and there was no obvious subchronic systemic toxicity in body mass, hematology, coagulation function, blood biochemistry and visceral pathology. These results indicate that the injectable carboxymethyl glycosaminoglycan anti-adhesion gel has good biosafety.
10.Comparison of the three preparation methods in technology of salinomycin micelle
Chinese Journal of Biochemical Pharmaceutics 2017;37(2):37-39
Objective To research the optimal preparation technology of salinomycin micelle.Methods DSPE-PEG2000 was selected as the carrier.Salinomycin was selected as the model drug.The film dispersion method, the ethanol injection method and the dialysis method were used to prepare salinomycin micelles respectively.The comprehensive evaluation indexes included entrapment rate and drug-loading rate, release capacity and vitro cytotoxicity test in order to select the most suitable preparation technology of salinomycin micelle .Results The film dispersion method is the most suitable preparation technology of salinomycin micelle in the three methods.Its average grain diameter was (14 ±2.3) nm, entrapment rate was (82 ± 2.6)%, drug-loading rate was (6.3 ±2.1)%, IC50 to HepG2 tumor cells was 16.10 ±3.71.Conclusion The film dispersion method of salinomycin micelles has the advantages with the smallest size, the highest entrapment rate and the largest drug-loading rate, which has the function to kill tunmor cells and release slowly.


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