1.Method for Japanese encephalitis virus NS3 protease activity analysis and high-throughput screening assay for inhibitors.
Jingyun ZHOU ; Xue WANG ; Chao PEI ; Yunfeng SONG ; Huanchun CHEN
Chinese Journal of Biotechnology 2014;30(2):194-202
Japanese encephalitis virus (JEV) is a single-stranded and positive-sense RNA, which has a single ORF (open reading frame), encoding a polyprotein precursor. Non-structural protein 3 (NS3) plays an important role in processing the polyprotein precursor and has become an important drug target of flavivirus. In this study, NS2BH-NS3 gene was amplified by PCR and subcloned to the prokaryotic expression plasmid, resulting pET30a-NS2BH-NS3. The fusion protein was expressed in Escherichia coli BL21 (DE3) in soluble form after induction by Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). The recombinant protein was purified by Ni-NTA affinity column. Then a fluorescence resonance energy transfer (FRET) method was used to determine enzymatic activity and the assay conditions were optimized. After screening 113 compounds, we found two compounds inhibiting the activity of NS2BH-NS3. This study provides a convenient and cost-effective method for screening of JEV NS3 protease inhibitor.
Encephalitis Virus, Japanese
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enzymology
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Escherichia coli
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metabolism
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High-Throughput Screening Assays
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Protease Inhibitors
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chemistry
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RNA Helicases
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metabolism
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Recombinant Fusion Proteins
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metabolism
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Serine Endopeptidases
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metabolism
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Viral Nonstructural Proteins
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metabolism
2.A clinical study on ten-day sequential therapy for H.pylori eradication
Hanbo YU ; Wenjing CHEN ; Huanchun WU ; Qisheng ZHOU
Chinese Journal of Primary Medicine and Pharmacy 2014;21(13):1951-1953
Objective To observe the clinical curative effect of ten-day sequential therapy composed of omeprazole,amoxicillin,clarithromycin,levofloxacin in Helicobacter pylori (Hp) eradication.Methods 120 adult patients with positive rapid urease test of gastric mucosa were selected,they were randomly divided into the sequential group (60 cases) and control group (60 cases).The sequential group was treated with 10 d sequential therapy and control group was given 10 d standard therapy for eradication of Hp.In the two groups,patients with active ulcerative continued taking omeprazole for 4 weeks,the 14C urea breath test was taken after stopping drug,negative for Hp eradication.The clinical efficacy of two groups was observed.Results Hp eradication rate of sequential group was 94.8 %,which was significantly higher than 79.3 % of the control group (x2 =6.20,P < 0.05).The incidence rate of adverse reactions in the sequential group was 17.5%,which in control group was 15.0%,the difference was not significant (x2 =0.06,P > 0.05).Conclusion Ten-day sequential therapy composed of omeprazole,amoxicillin,clarithromycin,levofloxacin for eradication of Hp is safe,the cure rate is high,and the adverse reaction is similar with standard therapy,it is worth the clinical promotion.
3.Construction and characterization of Actinobacillus pleuropneumoniae serovar 7 live attenuated vaccine strain co-expressing ApxIA.
Jinlin LIU ; Yan CHEN ; Linlin HU ; Weicheng BEI ; Huanchun CHEN
Chinese Journal of Biotechnology 2010;26(3):305-310
Actinobacillus pleuropneumoniae (A. pleuropneumoniae), the causative agent of porcine contagious pleuropneumonia (PCP), is a significant pathogen of the world pig industry, vaccination is potentially an effective tool for the prevention of PCP. The purpose of present study was to enhance the immunogenicity of A. pleuropneumoniae live vaccine strain HB04C- (serovar 7), which was unable to express ApxIA, and to develop effective multivalent vaccines for the respiratory pathogens based on the attenuated A. pleuropneumoniae. We introduced a shuttle vector containing intact apxIA gene into HB04C-, generating HB04C2, an A. pleuropneumoniae serovar 7 live attenuated vaccine strain co-expressing ApxIA. Then we investigated the biological characteristics of HB04C2. We found that the shuttle vector expressing ApxIA was stable in HB04C2, and the growth ability of HB04C2 was not affected by the shuttle vector. We observed that HB04C2 elicited detectable antibodies against ApxIA and ApxIIA when it was administrated intratracheally as a live vaccine in pigs, and all immunized pigs were protected from heterologous virulent A. pleuropneumoniae (serovar 1) challenge. In conclusion, we demonstrated that A. pleuropneumoniae live vaccine could be used as a vector for expression of heterologous antigens.
Actinobacillus Infections
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prevention & control
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veterinary
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Actinobacillus pleuropneumoniae
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classification
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immunology
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Animals
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Bacterial Proteins
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biosynthesis
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genetics
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Bacterial Vaccines
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biosynthesis
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immunology
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Hemolysin Proteins
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biosynthesis
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genetics
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Pleuropneumonia
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microbiology
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prevention & control
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Swine
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Swine Diseases
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microbiology
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prevention & control
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Vaccines, Attenuated
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biosynthesis
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immunology
4.Construction and eukaryotic expression of recombinant plasmid encoding fusion protein of goat complement C3d and foot-and-mouth disease virus VP1.
Jieyu LING ; Zhao LIU ; Tiezhu TONG ; Huiying FAN ; Dekun ZHANG ; Huanchun CHEN ; Aizhen GUO
Chinese Journal of Biotechnology 2008;24(2):209-213
We constructed a recombinant plasmid encoding VP1 gene of O type foot-and-mouth disease virus fused to a molecular adjuvant, goat complement C3d gene. The goat C3d gene was cloned and three copies were tandem-linked with the linker (G4S)2 sequence. VP1 gene of O type foot-and-mouth disease virus was linked to three tandem repeats of C3d through the linker sequence and cloned into pUC19 to obtain the recombinant plasmid pUC19-VP1-C3d3. The VP1-C3d3 fusion gene was then subcloned into the eukaryotic vector pcDNA3.1(+) that had been modified to contain the tissue plasminogen activator (tPA) leader sequence to obtain pcDNA3.1-tPA-VP1-C3d3. HeLa cells were transfected with pcDNA3.1-tPA-VP1-C3d3 by Lipofectamine 2000. Indirect immunofluorescent assay and Western blot assay showed that VP1-C3d3 fusion gene was successfully expressed in HeLa cells. The fusion protein with the expected size 133 kD could be secreted outside the cells. This study laid a good foundation to further research on the novel vaccine against foot-and-mouth disease virus by using goat C3d as a molecular adjuvant to enhance the immunogenicity of VP1.
Animals
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Capsid Proteins
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biosynthesis
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genetics
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Cloning, Molecular
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Complement C3d
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biosynthesis
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genetics
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immunology
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Female
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Foot-and-Mouth Disease Virus
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genetics
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Goats
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HeLa Cells
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Humans
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Immunologic Factors
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biosynthesis
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genetics
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immunology
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Plasmids
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genetics
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Recombinant Fusion Proteins
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biosynthesis
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genetics
;
immunology
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Transfection
5.Comparison of clinical effect between small incision surgery and traditional resection for thyroid adenoma
Nannan CUI ; Huanchun LIANG ; Jiakai CHEN ; Yu LIU
China Modern Doctor 2019;57(10):50-52
Objective To compare the clinical effect between small incision surgery and traditional resection for thyroid adenoma. Methods 60 patients with thyroid adenoma were divided into two groups according to different surgical methods. 30 patients in the observation group underwent small incision resection, and 30 patients in the control group underwent conventional thyroid tumor resection. The postoperative surgical results, the intraoperative blood loss, operation time, hospital stay and postoperative complications were compared between the two groups. Results The intraoperative blood loss of the observation group was (19.15±8.30) mL, which was significantly than that of the control group. The operation time of the observation group was (78.73±12.61) min, which was significantly than that of the control group.The hospitalization time of the observation group was (3.74±1.05) d, which was significantly shorter than that in the con trol group, and the difference was significant (P<0.05). After operation, the total effective rate of the observation group was significantly higher than that of the control group, and the difference was significant (P<0.05). The postoperative complication rate of the observation group was significantly lower than that of the control group. There was significant difference between the two groups (3.3% vs 16.7%, P<0.05). Conclusion Small incision surgery is more effective than traditional resection for thyroid adenoma. It has the advantages of small incision, less bleeding, less complications, and quick recovery after surgery.It is worthy of widespread application and application.
6.Establishment of human IFN-gamma in vitro release assay and its application in tuberculosis diagnosis.
Yingyu CHEN ; Quantao DENG ; Zhihua ZHAN ; Aizhen GUO ; Jie XIANG ; Jun CHEN ; Jinhai ZHOU ; Qinzhi ZENG ; Wu WEI ; Qingwei TONG ; Yanjie CHAO ; Youji KUANG ; Huanchun CHEN
Chinese Journal of Biotechnology 2008;24(9):1653-1657
This study aimed to establish human IFN-gamma (hIFN-gamma) in vitro release assay and to apply it in diagnosis of human tuberculosis. Human IFN-gamma gene was cloned and expressed in Escherichia coli. The recombinant hIFN-gamma was purified and used as immunogen to immunize mice and rabbits respectively. Monoclonal and polyclonal antibodies were respectively developed and a sandwich ELISA was established. The heparized whole blood from 111 active tuberculosis patients and 292 clinical healthy controls were collected. The blood was stimulated with tuberculosis specific fused antigen ESAT-6/CFP-10 and the plasma was collected for IFN-gamma detection. The sensitivity for tuberculosis diagnosis was 95.5%, whereas the positive detection rate for the healthy controls was 16.7%. There was a significant difference between the patients and healthy controls (P<0.01) indicating that this assay had a high sensitivity and specificity, and thus could be promising in tuberculosis diagnosis.
Animals
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Antibodies, Monoclonal
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Enzyme-Linked Immunosorbent Assay
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Female
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Humans
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Interferon-gamma
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immunology
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secretion
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Mice
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Mice, Inbred BALB C
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Mycobacterium tuberculosis
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immunology
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Rabbits
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T-Lymphocytes
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immunology
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Tuberculosis
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diagnosis
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immunology
7.Characterization of attenuated Salmonella C500 strain with a delta asd mutant and use as an Asd+ balanced-lethal host-vector system.
Zhanqin ZHAO ; Yindi XU ; Bin WU ; Xiangchao CHENG ; Yinju LI ; Xibiao TANG ; Chunjie ZHANG ; Huanchun CHEN
Chinese Journal of Biotechnology 2009;25(1):29-36
Salmonella enterica serovar Choleraesuis strain C500 is a live, attenuated vaccine that has been used in China for over 40 years to prevent piglet paratyphoid. The objective of this study was to evaluate the potential of attenuated Salmonella enterica serovar Choleraesuis C500 strain with a delta asd mutant as an effective live vaccine vector by the Asd+ balanced-lethal host-vector system. Here, we compared the characteristics of S. enterica serovar Choleraesuis delta asdC500 strain with the parent C500 strain, including phenotype, growth rate, virulence, safety, and expression for heterologous antigen. The mean generation times of delta asdC500 mutant, the vector control delta asdC500 (pYA3493), and the parent avirulent C500 vaccine strain in Luria broth were 30.7, 28.1, and 27.9 min, respectively. The fermentation patterns of theses three strains on different carbohydrates, and the levels of production of H2S, were similar. The O and H antigens of delta asdC500 mutant, delta asdC500 (pYA3493) and delta asdC500 (pYA-F1P2) were 6,7:C:1,5, identical to the parent strain C500. By the method of Reed and Muench, groups of mice were challenged by the intraperitoneal route with different amounts of delta asdC500 (pYA3493) or the parent C500 strain, and the virulence of delta asdC500 (pYA3493) with LD50 of 1.1 x 10(7) CFU was a little lower than C500 with LD50 of 4.4 x 10(6) CFU. All piglets inoculated with delta asdC500 (pYA3493) or C500 survived, and no signs of disease were observed during the entire experimental period. No major differences were found in these two groups. In addition, the recombinant pYA-F1P2 plasmid was very stable in the recombinant delta asdC500 (pYA-F1P2) strain, which expressed secretorily a large amount of the recombinant filamentous hemagglutinin type I domain and pertactin region 2 domain antigen (rF1P2) of Bordetella bronchiseptica. In this study, we have shown that the delta asdC500 mutant had a series of biological characteristics similar to the parent vaccine strain C500. Furthermore, the strain could express secretorily a large amount of heterologous antigen. It is likely that this Salmonella expression and delivery system could be easily adapted to develop multivalent recombinant Salmonella vaccines against infectious agents using the Asd+ balanced-lethal host-vector system.
Amino Acid Oxidoreductases
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genetics
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Animals
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Bacterial Proteins
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genetics
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Gene Deletion
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Genetic Vectors
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Mice
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Mutation
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Salmonella Vaccines
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genetics
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immunology
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Salmonella enterica
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genetics
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immunology
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pathogenicity
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Swine
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Transduction, Genetic
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Vaccines, Attenuated
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genetics
;
immunology
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Vaccines, Synthetic
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genetics
;
immunology
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Virulence
8.Construction and identification of a recombinant PRRSV expressing protective antigens of type O foot-and-mouth disease virus.
Wu TONG ; Yanzhao XU ; Yanjun ZHOU ; Yifeng JIANG ; Shanrui ZHANG ; Yaxin WANG ; Jianping ZHU ; Lingxue YU ; Jing SUN ; Huanchun CHEN ; Guangzhi TONG
Chinese Journal of Biotechnology 2012;28(12):1431-1440
Using mutation PCR, we cloned the target gene containing 421-480nt (141-160aa) and 598-639nt (200-213aa) of VP1 gene of foot and mouth disease virus (FMDV) into the deleted region (508-532aa) of Nsp2 gene of a highly pathogenic porcine reproductive and respiratory syndrome virus derived vaccine strain (HuN4-F112) that was used as vector. The recombinant cDNA was in vitro transcribed followed by transfection of BHK-21 cells for 36 h. Then, the supernatant of the cell culture was continuously seeded to monolayer of MARC-145 cells for recovery of the recombinant virus. CPE was obviously visible after a couple of passages in the seeded MARC-145, and the rescued virus (designated as rPRRSV-F112-O/VP1ep) was identified by Mlu I digestion, sequencing and immunofluorescence assay. Meanwhile, expression of inserted FMDV epitopes was also detected by indirect immunofluorescence assay with polyclonal antibodies against VP1 protein of FMDV. The analysis of biological characteristics shows that the titer of the rescued recombinant PRRSV (TCID50 = -log10(-6.75)/0.1 mL) was similar to its direct parental virus rHuN4-F112-delta508-532, but higher than rHuN4-F112.
Animals
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Antigens, Viral
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immunology
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Base Sequence
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Capsid Proteins
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immunology
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Cell Line
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Cysteine Endopeptidases
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genetics
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Epitopes
;
genetics
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Foot-and-Mouth Disease
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immunology
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prevention & control
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Foot-and-Mouth Disease Virus
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genetics
;
immunology
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Molecular Sequence Data
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Mutation
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Porcine respiratory and reproductive syndrome virus
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genetics
;
immunology
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Recombination, Genetic
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Swine
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Transfection
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Vaccines, Attenuated
;
genetics
;
immunology
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Viral Envelope Proteins
;
genetics
;
immunology
;
Viral Vaccines
;
genetics
;
immunology