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Objective:To evaluate the immunogenicity of a quadrivalent subunit vaccine combined with RFH01 adjuvant in a mouse model.Methods:Identification tests were performed on four monovalent influenza virus subunit vaccine stock solutions according to the methods described in Part 3 of the Chinese Pharmacopoeia 2020 Edition. In the study of the quadrivalent subunit vaccine combined with RFH01 adjuvant, 460 female BALB/c mice (6-8 weeks old) were randomly divided into 46 groups including experimental groups, vaccine control group, negative control group and blank group with 10 mice in each group. In the study of the quadrivalent subunit vaccine in old and young mice, 80 female 10-month-old and 80 female 10-week-old BALB/c mice were randomly divided into 16 groups ( n=10) including monovalent influenza virus vaccine group, quadrivalent subunit vaccine group, quadrivalent subunit vaccine+ RFH01 adjuvant group, chicken embryo quadrivalent split vaccine control group and PBS group. All mice were immunized by intramuscular injection. At 21 d after the primary immunization, a booster immunization was conducted using the same strategy. Blood samples were collected at 21 d and 42 d after the primary immunization for serum separation. Haemagglutination inhibition (HI) test was performed to detect the antibody levels in mouse serum samples. Results:After the booster immunization, the positive conversion rates in all vaccine+ RFH01 adjuvant groups reached 100%, and the geometric mean titers (GMTs) of serum antibodies were significantly higher than those of the vaccine groups without RFH01 adjuvant. There were significant differences in serum antibody titers between the monovalent/quadrivalent subunit vaccine groups with and without RFH01 adjuvant. After the booster immunization, the titers of serum antibodies against H1N1, H3N2, B/Victoria and B/Yamagata in the 10-week-old mice were significantly higher than those in the 10-month-old mice.Conclusions:The monovalent and quadrivalent influenza virus vaccines in combination with RFH01 adjuvant could elicit higher antibody titers in young (6-10 weeks old) and old (10 months old) mice, showing good immunogenicity.
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Objective:To purify H5N1 influenza virus concentrate prepared by MDCK cells with a new mixed-mode chromatography medium Capto Core700 and the traditional medium Sepharose 4FF, and to compare the separation and purification efficacy of the two media.Methods:Capto Core700 and Sepharose 4FF were used to purify inactivated H5N1 influenza virus concentrate. The morphology of virus particles in different samples was then observed under a transmission electron microscope. Single radial immunodiffusion (SRID), Folin-Phenol (Lowry) method, double-antibody sandwich ELISA and qPCR were used to detect hemagglutinin, total protein, host cell protein (HCP) and host cell DNA (HCD) before and after purification. The recovery rate of virus antigen and the removal rate of impurities were calculated. The immunogenicity of the viruses purified with different media was analyzed using animal experiments. Difference in the purification efficacy of the two chromatography media was analyzed by t-test. Results:H5N1 influenza viruses purified by Capto Core700 or Sepharose 4FF showed the typical influenza virus morphology under transmission electron microscope. There was no significant difference in the recovery rate of hemagglutinin between the two chromatography media ( P>0.05), but compared with Sepharose 4FF, Capto Core700 had a higher removal rate of impurities (total protein, HCP, HCD) and the difference was statistically significant ( P<0.05). Animal experiments showed that the viruses purified by the two chromatography media had good immunogenicity. Conclusions:Compared with Sepharose 4FF chromatography medium, Capto Core700 could more effectively remove process-related impurities such as HCP, HCD and total protein without affecting the recovery rate of viral antigen. This study provided reference for the development of purification technology in the production of H5N1 influenza virus vaccine in MDCK cells.
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Objective:To prepare a recombinant hemagglutinin trimer (HA-Tri) vaccine against influenza viruses and to study its immunogenicity in a mouse model.Methods:A stable CHO cell line that could express HA-Tri was constructed. Western blot, single radial immunodiffusion, protein particle size detection and N-glycosylation site analysis were performed for qualitative and quantitative analysis of the recombinant protein. According to the different treatment conditions such as dosage and adjuvant, BALB/c mice were divided into 11 groups and subjected to consistent immunization procedures. Serum neutralizing antibody titers were measured on 56 d after the first immunization to evaluate the immunogenicity of HA-Tri.Results:The constructed CHO cells could secret and express HA-Tri proteins. The HA-Tri proteins were biologically active and capable of forming precipitation rings in the single radial immunodiffusion. The particle size of HA-Tri was approximately 18.79 nm and 10 N-glycosylation sites were detected, including high mannose, complex glycoforms and heterozygous glycoforms. After prime-boost immunization, there was no statistically significant difference in the titers of neutralizing antibodies induced in mice by 3.75 μg of HA-Tri in combination with RFH01 adjuvant and 15 μg of monovalent vaccine stock solution ( P=0.431 2, U=36). Serum antibody titers in the HA-Tri+ RFH01 groups were higher than those in the corresponding HA-Tri groups without RFH01 adjuvant, and the highest titer was induced in the 15 μg HA-Tri+ RFH01 group, which was 1 280. Conclusions:The recombinant HA-Tri protein was successfully prepared. HA-Tri in combination with RFH01 adjuvant could induce humoral immune responses against influenza viruses in BALB/c mice, which would provide reference for the development of influenza virus recombinant subunit vaccines.
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Objective:To investigate the effects of poly(A) tails with different lengths on mRNA expression in vitro and the passage stability of transcription template with poly (A) tail in Escherichia coli ( E. coli). Methods:Plasmids with poly(A) tails of 38, 60, 103, 125 and 126 (60 nt+ 6 nt spacer+ 60 nt) nt were designed and constructed. Then the plasmids were linearized by single enzyme digestion and used as transcription template for preparing enhanced green fluorescent protein (EGFP)-mRNA. EGFP-mRNA containing poly(A) tails of different lengths were transfected into 293T cells and the expression of EGFP was detected by flow cytometry. As to stability test, the template plasmids with poly (A) tail of 125 and 126 nt were transformed into E. coli TransStbl3 and Top10 competent cells. Seven clones were selected for culture and plasmid extraction, and then the plasmids were digested by restriction enzyme and detected by capillary electrophoresis. For passage stability, three correctly sequenced clones of each group were selected for continuous passage at 37℃, and the plasmids were extracted and digested every two generations for capillary electrophoresis. At the same time, the correctly sequenced clones of 125 nt group were also passaged at 30℃, and the plasmids were also extracted and digested every two generations for capillary electrophoresis. Results:The transcription templates with poly(A) tail of different lengths were successfully constructed. Flow cytometry showed that the fluorescence expression of the template plasmids with poly (A) tail of 103 and 125 nt were significantly higher than that of 38 and 60 nt. The fluorescence expression of the plasmid with poly (A) tail of 126 nt was significantly higher than that of all other groups. The percentages of stable sequences of the template plasmid with poly(A) tail of 125 nt in TransStbl3 and Top10 competent cells were 76% and 91%, respectively. The results of continuous passage showed that poly(A) tail of 125 nt could be stable to the 4th generation at 37℃ in both TransStbl3 and Top10 competent cells, and stable to the 16th and 10th generations at 30℃. The percentages of stable sequences of the template plasmid with poly(A) tail of 126 nt in TransStbl3 and Top10 competent cells were 95% and 48%, respectively. The results of continuous passage showed that poly(A) tail of 126 nt could be stable to the 12th generation at 37℃ in both TransStbl3 and Top10 competent cells.Conclusions:The length and composition of poly(A) tail in mRNA affected the expression of target protein. Adding a spacer with a length of 6 nt to poly(A) tail and low temperature culture were both helpful to improve the stability of the template plasmid, which provided a reference for the design and preparation of in vitro transcription template of mRNA vaccine.
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Transglutaminase 2 (TGM2) is a ubiquitous multifunctional protein, which is related to the adhesion of different cells and tumor formation. Previous studies found that TGM2 is involved in the interaction between host cells and viruses, but the effect of TGM2 on the proliferation of influenza virus in cells has not been reported. To explore the effect of TGM2 during H1N1 subtype influenza virus infection, a stable MDCK cell line with TGM2 overexpression and a knockout cell line were constructed. The mRNA and protein expression levels of NP and NS1 as well as the virus titer were measured at 48 hours after pot-infection with H1N1 subtype influenza virus. The results showed that overexpression of TGM2 effectively inhibited the expression of NP and NS1 genes of H1N1 subtype influenza virus, while knockout of TGM2 up-regulated the expression of the NP and NS1 genes, and the expression of the NP at protein level was consistent with that at mRNA level. Virus proliferation curve showed that the titer of H1N1 subtype influenza virus decreased significantly upon TGM2 overexpression. On the contrary, the virus titer in TGM2 knockout cells reached the peak at 48 h, which further proved that TGM2 was involved in the inhibition of H1N1 subtype influenza virus proliferation in MDCK cells. By analyzing the expression of genes downstream of influenza virus response signaling pathway, we found that TGM2 may inhibit the proliferation of H1N1 subtype influenza virus by promoting the activation of JAK-STAT molecular pathway and inhibiting RIG-1 signaling pathway. The above findings are of great significance for revealing the mechanism underlying the interactions between host cells and virus and establishing a genetically engineering cell line for high-yield influenza vaccine production of influenza virus.
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Animals , Dogs , Humans , Cell Proliferation , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human , Madin Darby Canine Kidney Cells , Protein Glutamine gamma Glutamyltransferase 2ABSTRACT
Objective:To express the head domain of influenza A virus hemagglutinin (HA) in a prokaryotic expression system and to evaluate its immunogenicity.Methods:The genes encoding the HA head domains of H1N1 and H3N2 influenza viruses were cloned into pET-22b(+ ) prokaryotic expression plasmid. After the induction with IPTG, the fusion proteins rH1N1-HA and rH3N2-HA containing HA head domain and His-tag were expressed and obtained from E. coli BL21. SDS-PAGE and Western blot was used to verify the expression of the recombinant proteins. Rabbits were immunized with multiple doses of the purified recombinant proteins to obtain polyclonal antibodies against the HA head domains of H1N1 and H3N2. The immunogenicity of the recombinant proteins was evaluated in BALB/c mice. Results:rH1N1-HA and rH3N2-HA induced protective antibodies (geometric mean titer ≥40) in mice and could be used as protective antigens. Polyclonal antibodies against rH1N1-HA and rH3N2-HA could be used as important materials for Western blot, ELISA and other immunological assays.Conclusions:The HA head domains prepared in this study could be used as protective antigens to induce protective antibodies in mice. Polyclonal antibodies against the HA head domains could be used for immunological and serological studies of influenza A viruses.
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Objective:To establish a method for isolation and purification of neuraminidase from influenza vaccine and to prepare reference substance for quantitative detection of neuraminidase.Methods:Functional magnetic particles with specific affinity for neuraminidase were prepared. The method for separation and purification of neuraminidase was established based on the magnetic particles. The separation and purification conditions were optimized. The purity of neuraminidase was analyzed and the specificity was verified. The enzyme activity was determined and the protein was quantified.Results:The functional magnetic particles modified with 4-aminophenanthroline were successfully prepared and the method for isolation and purification of neuraminidase based on the magnetic particles was established. The purity of neuraminidase was 98.7%. The concentrations of neuraminidase isolated and purified from the monovalent stock solution of H1N1, H3N2, B/Victoria and B/Yamagate vaccines were 71.50, 100.58, 64.11 and 37.68 μg/ml, respectively, and the enzyme activity remained.Conclusions:The method for isolation and purification of influenza virus neuraminidase was established and the corresponding reference substance was prepared.
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Objective:To evaluate the immunogenicity of Madin-Darby canine kidney (MDCK) cell-based quadrivalent influenza split vaccine (MDCK-Va) combined with different adjuvants.Methods:Different doses of MDCK-Va and chicken embryo-based quadrivalent influenza split vaccine (egg-Va) were intramuscularly immunized BALB/c mice twice with an interval of three weeks. Serum samples were collected to detect antibody titers using hemagglutination inhibition (HI) assay. BALB/c mice were immunized with different doses of MDCK-Va combined with QS21, AddVax, PolyI∶C, CpG ODN 1826 and AddVax/PolyI∶C (Add/Poly), respectively. HI and microneutralization assays were used to detect antibody titers 21 d after the first and booster immunization. Spleen tissues were collected from the mice immunized with 10 μg MDCK-Va combined with the above adjuvants 5 d after the booster immunization to analyze spleen index and the types of spleen cells.Results:The immunoprotective effect of MDCK-Va was not inferior to that of egg-Va. MDCK-Va combined with each of the above adjuvants could induce higher HI antibody titer than MDCK-Va alone, especially the QS21/Va and Add/Poly/Va groups, and the differences were statistically significant. For H1N1 vaccine, the Pearson′s correlation coefficient ( r) between HI antibody and neutralizing antibody was 0.737-0.910, and for H3N2 subtype vaccine, the value of r was 0.839-0.947. Compared with the MDCK-Va group, the QS21/Va group showed significantly increased spleen index and decreased proportion of single lymphocytes. QS21 and Add/Poly were much better than other adjuvants in stimulating mouse splenic neutrophils and CD4/CD8 cells. Conclusions:Add/Poly had a stronger immune enhancement effect on MDCK-Va, suggesting that it was a potential adjuvant for MDCK-Va. The antibody titer detected by HI and MN assays had a strong positive correlation.
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Objective:To compare the optimal conditions, virus yield, viral titer and cell metabolism between culturing influenza virus H1N1 vaccine strain in MDCK and MDCK-G1 cells.Methods:The optimal culture conditions were investigated using chessboard method. The hemagglutination titer, half of the tissue infection dose (TCID 50) and the metabolism of glucose and lactic acid were monitored and compared between the two cell lines. Results:After MDCK-G1 cells were inoculated with H1N1 at the multiplicity of infection (MOI) of 0.001 with the presence of 1 μg/ml of trypsin, the hemagglutination titer reached the peak of 1∶512 at 72 h and the viral titer was 10 7.4TCID 50/ml. In the MDCK cell line group, the hemagglutination titer reached the peak of 1∶256 at 72 h and the viral titer was 10 6.6TCID 50/ml when using H1N1 at MOI=0.0001 and 1 μg/ml of trypsin. Conclusions:MDCK-G1 cells were more suitable than MDCK cells for the proliferation of influenza virus. This study provided reference data for further research on cell-derived influenza vaccine.
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Currently, influenza vaccination is the most effective measure to control the epidemic of influenza. The addition of adjuvant in a vaccine can reduce the dose of antigen required, enhance the immunogenicity, and produce cross-protection. This review summarized the literature on influenza-related adjuvants and outlined the mechanism and safety of vaccine adjuvants approved and under development in order to provide reference for the development of new influenza vaccines.
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Objective@#To investigate the best amount of TPCK trypsin in Madin Darby canine kidney (MDCK) cell suspension for the culture of H7N9 avian influenza virus.@*Methods@#Different concentrations of TPCK trypsin were added during the periods of cell growth and virus production. Their effects on cell growth, viability, glucose and lactate metabolism, and hemagglutination titer were monitored every 12 h. Inter-batch differences were analyzed. The amount of trypsin added in the cell growth phase was 0, 1 μg/ml, 2 μg/ml, 4 μg/ml, 6 μg/ml, 8 μg/ml, 10 μg/ml and 15 μg/ml. The amount of trypsin added during the virus production period was 0, 0.5 μg/ml, 1 μg/ml, 1.5 μg/ml, 2 μg/ml and 2.5 μg/ml. When the hemagglutination titers were same, the adding amount was further optimized at different multiplicity of infection (MOI) of 0.001, 0.005, 0.025 and 0.05.@*Results@#No significant linear effects of TPCK trypsin concentration on cell number, viability, and glucose and lactate metabolism were observed. No toxicity to cell growth was observed when TPCK trypsin concentration reached 15 μg/ml. After the inoculation of H7N9 avian influenza virus, the hemagglutination titers in the 1 μg/ml, 1.5 μg/ml, 2 μg/ml and 2.5 μg/ml TPCK trypsin groups reached the peaks at 48 h, which were 1∶26.5. At 60 h, the hemagglutination titers of the latter two groups decreased faster than those of the former two groups. When the MOI was 0.005, the hemagglutination titer of the 1.5 μg/ml group at 48 h was 26.5 higher than 26 in the 1 μg/ml group under the same condition. There were differences between different batches of TPCK trypsin.@*Conclusions@#Adding 1 μg/ml and 1.5 μg/ml of trypsin could better promote the proliferation of H7N9 avian influenza virus, and 1.5 μg/ml of trypsin had a wider range of MOI applicability.
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Objective@#To reduce the residual proteins and DNA of host cells in the preparation of H5N1 influenza A virus.@*Methods@#Core 700 was firstly used to remove residual host cell proteins, and then Capto Q was used to remove host cell DNA. Several batches of H5N1 influenza A virus cultured in Madin-Darby canine kidney (MDCK) cells were purified using this method. The efficiency of purification was evaluated using many methods including quantitative real-time PCR, hemagglutination (HA) test and single radial immunodiffusion assay. Moreover, Benzonase nuclease was used for comparison.@*Results@#Without the use of Benzonase nuclease, the overall removal rates of host cell DNA and residual proteins were 99.62% and 98.1%, and the HA antigen recovery rate was 66.96%.@*Conclusions@#This study established a purification strategy with good effect for cell-based influenza vaccines. It can efficiently remove host cell DNA and proteins and achieve a high HA recovery rate. The purification result is no worse than that of adding Benzonase nuclease, suggesting the potential of its application in actual vaccine production.
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Objective To reduce the residual proteins and DNA of host cells in the preparation of H5N1 influenza A virus. Methods Core 700 was firstly used to remove residual host cell proteins, and then Capto Q was used to remove host cell DNA. Several batches of H5N1 influenza A virus cultured in Ma-din-Darby canine kidney ( MDCK) cells were purified using this method. The efficiency of purification was evaluated using many methods including quantitative real-time PCR, hemagglutination ( HA) test and single radial immunodiffusion assay. Moreover, Benzonase nuclease was used for comparison. Results Without the use of Benzonase nuclease, the overall removal rates of host cell DNA and residual proteins were 99. 62％ and 98. 1％, and the HA antigen recovery rate was 66. 96％. Conclusions This study established a purification strategy with good effect for cell-based influenza vaccines. It can efficiently remove host cell DNA and proteins and achieve a high HA recovery rate. The purification result is no worse than that of adding Benzonase nuclease, suggesting the potential of its application in actual vaccine production.
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Objective To screen a Madin-Darby canine kidney (MDCK) cell line for H5N1 influ-enza virus isolation and to evaluate its safety in vaccine production. Methods MDCK cells were cloned by the method of limiting dilution. Hemagglutination test was used to screen MDCK cells that were suitable for H5N1 influenza virus production. Tests for analyzing the characteristics, extraneous agents, endogenous agents and tumorigenicity of MDCK cells were performed according to Chinese Pharmacopeia Volume Ⅲ. Results A total of 108 MDCK cell lines were obtained and three of them were selected after hemagglutina-tion test. G1 cells were chosen following further screening with tumorigenicity test and receptor abundance analysis. The average number of chromosomes of the MDCK-G1 cells was 78±4. No bacteria, fungi or myco-plasma contamination was detected. In experimental group, each nude mouse was injected with 1×107/ml viable cells to observe their tumorigenicity. Twelve weeks after cell injection, no node was found at injection sites or in gross anatomy. There was no significant difference between the experimental and negative control groups. The result of the tumorigenicity test was negative. No node formation was found after injecting nude mice with cell lysate or cellular DNA collected from equivalent amount of cells. It was indicated that the MDCK-G1 cells were of low-oncogenic potential. Conclusions The MDCK-G1 cell line could be used as a substrate to produce H5N1 influenza virus vaccine.
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Objective To evaluate the immunogenicity of inactivated quadrivalent influenza vaccine (QIV) in adults aged 18-64 years,through a Meta-analysis.Methods Literature was retrieved by searching the Medline,Cochrane Library,Science Direct in the past decade.All the studies were under random control trial (RCT) and including data related to immunogenicity which involving sero-protection rate (SPR) and sero-conversion rate (SCR) of the QIV,versus inactivated trivalent influenza vaccine (TIV) in the population aged 18 to 64.Revman 5.3 software was employed to manipulate the pooled date of the included literature.Result A total of 8 studies for the SPR and SCR of the shared strains (two A lineage and one B lineage) were included.There appeared no significant differences in the response rates between the two vaccines.As for QIV versus TIV (B/Yamagata),the pooled RR of the SPR for B/Victoria was 1.28 (95％CI:1.08-1.51,P＜0.05),with the pooled RR of the SCR for B/Victoria as 1.94 (95％CI:1.50-2.50,P＜0.05).For QIV versus TIV (B/Victoria),the pooled RR of the SPR for B/Yamagata as 1.10 (95％CI:1.02-1.18,P＜0.05),and the pooled RR of SCR for B/Yamagata as 1.99 (95％CI:1.34-2.97,P＜0.05).Conclusion In the population aged 18-64 years,inactivated QIV was equivalently immunogenic against the shared three strains included in the activated TIV while a superior immunogenic effect was noticed in the vaccine strain which did not include the inactivated QIV.
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Objective To evaluate the immunogenicity of inactivated quadrivalent influenza vaccine (QIV) in adults aged 18-64 years,through a Meta-analysis.Methods Literature was retrieved by searching the Medline,Cochrane Library,Science Direct in the past decade.All the studies were under random control trial (RCT) and including data related to immunogenicity which involving sero-protection rate (SPR) and sero-conversion rate (SCR) of the QIV,versus inactivated trivalent influenza vaccine (TIV) in the population aged 18 to 64.Revman 5.3 software was employed to manipulate the pooled date of the included literature.Result A total of 8 studies for the SPR and SCR of the shared strains (two A lineage and one B lineage) were included.There appeared no significant differences in the response rates between the two vaccines.As for QIV versus TIV (B/Yamagata),the pooled RR of the SPR for B/Victoria was 1.28 (95％CI:1.08-1.51,P＜0.05),with the pooled RR of the SCR for B/Victoria as 1.94 (95％CI:1.50-2.50,P＜0.05).For QIV versus TIV (B/Victoria),the pooled RR of the SPR for B/Yamagata as 1.10 (95％CI:1.02-1.18,P＜0.05),and the pooled RR of SCR for B/Yamagata as 1.99 (95％CI:1.34-2.97,P＜0.05).Conclusion In the population aged 18-64 years,inactivated QIV was equivalently immunogenic against the shared three strains included in the activated TIV while a superior immunogenic effect was noticed in the vaccine strain which did not include the inactivated QIV.
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Objective To study the clinical effectiveness of low cut and five dissector thyroidectomy to treat hyperthyroidism.Methods 337 cases of hyperthyroidism were randomly divided into study group(low cut and five dissector technique,223 cases) and control group(traditional technique,114 cases) according to the ratio of two:operating time,bleeding,complications,recur were compared between these two groups.Results The operating time of the study group and control group were(66.33?25.11)min and(121.27?42.35)min(t=12.75,P0.05).The rate of recurrence was marked(P
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0.05). The marks of the group of CBL in case analysis test and clinical skills test are significantly higher than that of the group of stepwise learning (P
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Objective: To observe the influence of sot alol on the QT dispersion in patients with atrioventricular accessory pathways u nderwent radiofrequency catheter ablation (RFCA). Methods: Thirt y-six patients were divided into 2 groups by random. One was the drug group(18 cases) treated by RFCA， and sotalol 160 mg was orally administered and intracar diac electrophysiological study was performed every 30 min for 5 times. Th e other group(control group, 18 cases) only treated by RFCA.QTd,QTcd and QTLcd w ere measured before and after RFCA. Results: There was no signif icant difference with QT dispersion before and after RFCA in control group. When compared with before RFCA, QTd in patients administered sotalol was (30.9 ±14.3) ms vs (24.7±9.6) ms; QTcd(33.7±17.1) ms vs (25.2±10.1) ms; QT Lcd(30.8±14.1)ms vs (25.6±19.4) ms (P<0.05). Conclusion: Sotalol can slightly lower QT dispersion, which is beneficial for preventing malignant ventricular arrthythmia. It is safe in RFCA in pateints with accessory pathway.
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Objective: To investigate the effects of pravastatin o n atherosclerotic plaque and cardiovascular events. Methods: Fifty- seven patients with coronary artery disease (44 male and 13 female, 58.4±11.3 y ears) were randommized into pravastatin and control groups. The patients in prav astatin group were administered 10 mg of pravastatin from the night of coronary angiography day. After 7.3 months (mean) of follow-up, plasma lipid parameters and coronary angiograph were repeated. Results: (1) A favorable effect on plasma lipid parameters was found. After administration, total choles terol(TC), low density lipoprotein cholesterol (LDL-C) and triglyceride(TG) red uced by 15.0% (P<0.01), 18.0% (P<0.01) and 6.0%, respectively. High den s ity lipoprotein cholesterol(HDL-C) increased by 10.6%. However, in control grou p, TC and LDL-C showed a tendency to reduce, but no significant difference was found between those of pre- and post-administration. (2)There was no significa nt difference in luminal diameter between pre- and post-administration in both groups. (3) Cardiovascular events in pravastatin group was significantly lower than those in control (P<0.05). (4) Pravastatin had no significant effect on HR, BP and left ventricular ejection fraction in both groups. Conclusio n: Pravastatin can stabilize coronary atherosclerostic plaque and reduce the incidence of cardiovascular events by improving plasma lipid parameters.