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OBJECTIVE@#To conduct eukaryotic expression of the leucine-rich repeat containing 15 (LRRC15), a differentially expressed protein in excretory secretory antigens of Taenia solium cysticercus, and predict its antigen epitope.@*METHODS@#The molecular weight, stability, amino acid sequence composition, isoelectric point and T lymphocyte epitope of the LRRC15 protein were predicted using the bioinformatics online softwares ExPASy-PortParam and Protean. The full-length splicing primers were designed using PCR-based accurate synthesis, and the LRRC15 gene was synthesized. The recombinant pcDNA3.4-LRRC15 plasmid was constructed and transfected into HEK293 cells to express the LRRC15 protein. In addition, the LRRC15 protein was characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting.@*RESULTS@#The recombinant pcDNA3.4-LRRC15 plasmid was successfully constructed, which expressed the target LRRC15 protein with an approximately molecular weight of 70 kDa. Bioinformatics prediction with the ExPASy-PortParam software showed that LRRC15 was a hydrophilic protein, which was consisted of 644 amino acids and had a molecular weight of 69.89 kDa and an isoelectric point of 5.6. The molecular formula of the LRRC15 protein was C3073H4942N846O953S28 and had an instability coefficient is 50.3, indicating that LRRC15 was an instable protein. Bioinformatics prediction with the Protean software showed that the dominant T-cell antigen epitopes were located in 292 to 295, 353 to 361, 521 to 526 and 555 to 564 amino acids of the LRRC15 protein, and the T-cell antigen epitopes with a high hydrophilicity, good flexibility, high surface accessibility and high antigenicity index were found in 122 to 131, 216 to 233, 249 to 254, 333 to 343, 358 to 361, 368 to 372, 384 to 386, 407 to 412, 445 to 450, 469 to 481, 553 to 564, 588 to 594, 607 to 617 and 624 to 639 amino acids. Following transfection of the recombinant pcDNA3.4-LRRC15 plasmid into HEK293 cells, SDS-PAGE and Western blotting identified LRRC15 proteins in cell secretory culture media, cell lysis supernatants and sediments. The LRRC15-His fusion protein was purified from the cell culture medium, and SDS-PAGE identified a remarkable band at approximately 70 kDa, while Western blotting successfully recognized the band of the recombinant LRRC15 protein.@*CONCLUSIONS@#The eukaryotic expression and antigen epitope prediction of the LRRC15 protein in the excretory secretory antigens of T. solium cysticercus have been successfully performed, which provides insights into further understandings of its biological functions.
Subject(s)
Animals , Humans , Amino Acids , Antigens, Helminth/genetics , Cysticercus/genetics , Epitopes/genetics , Eukaryota , HEK293 Cells , Leucine-Rich Repeat Proteins , Membrane Proteins , Taenia solium/geneticsABSTRACT
The mixed teaching model combines the advantages of traditional teaching and network teaching in the “Internet +” era, which has become one of the important trends in the higher education teaching development. In order to follow this development trend, the human parasitology teaching team makes a reasonable use of modern information techniques, actively promotes the construction and application of online resources, and conducts mixed online and offline teaching based on MOOC resources and the experimental teaching digital platform. This mixed teaching model has shown a positive impact on both teaching and learning among teachers and students; however, students’ personalized independent and deep learning remains unsatisfactory. It is suggested that the online course resources construction, teaching design and digital literacy remain to be increased, so as to create a high-level, innovative and challenging online-offline mixed “golden course”
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Objective To construct a recombinant plasmid pGEX-TSO45W-4B-TSOL18 of Taenia solium,to obtain purified recombinant protein TSO45W-4B-TSOL18 and to prepare rabbit antiserum against the recombinant fusion protein.Methods TSO45W-4B and TSOL18 encoding genes were connected with hydrophobic (Gly4Ser)3 linker.TSO45W-4B-TSOL18 fusion gene was synthesized and cloned into an expression vector pGEX-1λT to construct a recombinant plasmid pGEX-TSO45W-4B-TSOL18.The positive recombinants were transformed into Escherichia(E.) coli ArcticExpress (DE3),and the expression of recombinant protein was induced with isopropylβ-D-thiogalactopyranoside (IPTG) and analyzed by sodium dodecyl sulfate polyacrylamide gelelectrophoresis (SDS-PAGE).The expressed recombinant fusion protein was purified through affinity chromatography.The purified recombinant protein was mixed with complete Freunds adjuvant at a dosage of 0.5 mg.Rabbit was intramuscularly and subcutaneously immunized in the hind leg and the back,respectively.After 2 weeks the rabbit was boosted with purified recombinant protein which was mixed with incomplete Freunds adjuvant at the same dosage.Rabbit can be boosted every 10 days until an adequate response was achieved.At the 6th day after the last immunization,blood was collected from the rabbit heart.Serum was separated to purify and prepare the antiserum.ELISA was applied to determine the titer of the antiserum and Western blot assay was used to determine the specificity of the antiserum.Results The size of the synthesized fusion gene TSO45W-4B-TSOL18 was 789 bp.The results of restriction enzyme digestion showed that the recombinant plasmid pGEX-TSO45W-4B-TSOL18 was successfully constructed.DNA sequencing showed that the size of the fusion gene TSO45W-4B-TSOL18 was 789 bp,which was consistent with expected result.As demonstrated by SDS-PAGE,relative molecular mass of the expressed recombinant fusion protein was approximately 55 × 103,and its purity was 85％ after purification with affinity chromatography.Titer of the antiserum against the recombinant protein was 1 ∶ 512 000 in ELISA assay and the specific rabbit antiserum against the purified recombinant protein TSO45W-4B-TSOL18 could specifically bind to the recombinant fusion protein in Western blot assay.The relative molecular mass of the specific band was about 55 × 103,which was consistent with expected size.Conclusions The recombinant plasmid pGEX-TSO45W-4BTSOL18 of Taenia solium is successfully constructed.High quality recombinant fusion protein TSO45W-4B-TSOL18 and high titer rabbit antiserum are successfully prepared.
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Objective To investigate the protective immunity in mice immunized with recombinantBifidobacteria bifidum(Bb)-Eg95 vaccine of Echinococcus granulosus (Eg) and challenged with Eg protoscoleces.Methods Fifty-six female BALB/c mice 12-14 weeks old and weighed 20-25 g were vaccinated with the recombinant Bb-Eg95 vaccine subcutaneously,intramuscularly,intranasally and orally,respectively,with blank vector,Bb and medium of solution(MRS) as control,8 mice in each group.Mice were challenged with Eg protoscoleces on week 8 after immunization and killed on week 25 after infection.The weight of hydatid cyst was measured and the decreased larva rate was calculated.Sera were collected to determine the levels of IgE,IgG and its subclasses by enzyme linked immunosorbent assay(ELISA).Splenocytes were collected and cultivated to test the proliferation of splenocytes using methyltetrazolium (MTT) assay under EgAg and concanavalin A (ConA) stimulation.The results were compared with analysis of variance and the comparison between two groups was performed with LSD-t test.Results There was significant difference in the weight of hydatid cyst between groups (F =11.062,P ＜ 0.05).Compared with MRS control group[(0.075 ± 0.019)g],the hydatid cyst weight decreased in subcutaneous group [(0.050 ± 0.013)g],intramuscular group[(0.050 ± 0.019)g],intranasal group[(0.028 ± 0.016)g] and oral group [(0.031 ± 0.018)g,all P ＜ 0.01).Compared with subcutaneous and intramuscular groups,the hydatid cyst weight decreased in intranasal and oral groups(all P ＜ 0.05).The decreased larva rate was inversely proportional to the weight of hydatid cyst.There was significant difference in the levels(obsorbancy,A) of IgG,IgG2a,IgG2b,IgG1,IgG3 and IgE between these groups(F =21.774,36.977,27.071,14.746,10.131,9.444,P ＜ 0.05 or P ＜ 0.01).Compared with MRS control group (0.015 ± 0.002,0.002 ± 0.001,0.003 ± 0.001),the levels of IgG,IgG2a and IgG2b increased in subcutaneous group(0.022 ± 0.004,0.007 ± 0.002,0.008 ± 0.002),intramuscular group (0.023 ± 0.003,0.008 ± 0.002,0.007 ± 0.002),intranasal group(0.032 ± 0.007,0.012 ± 0.002,0.013 ± 0.004)and oral group(0.028 ± 0.006,0.010 ± 0.003,0.010 ± 0.002,P ＜ 0.05 or P ＜ 0.01).Compared with subcutaneous and intramuscular groups,the levels of IgG,IgG2a and IgG2b increased in intranasal and oral groups(P ＜ 0.05 or P ＜ 0.01).Compared with MRS control group(0.009 ± 0.001,0.009 ± 0.002,0.009 ± 0.001),the levels of IgG1,IgG3 and IgE decreased in subcutaneous group(0.022 ± 0.004,0.007 ± 0.002,0.008 0.002),intramuscular group(0.004 ± 0.001,0.004 ± 0.001,0.004 ± 0.002),intranasal group(0.005 ± 0.002,0.005 ± 0.003,0.005 ± 0.002)and oral group(0.005 ± 0.001,0.004 ± 0.002,0.004 ± 0.003,all P ＜ 0.01).There was significant difference in the proliferation of splenocytes in the supernatant of cultured splenocyte,of cultured splenocyte + EgAg and of cultured splenocyte + ConA(F =63.975,359.833,167.399,P ＜ 0.01).There was significant difference in the proliferation of splenocytes inside groups(F =6741.955,4953.667,869.320,201.235,175.413,139.653,169.994,all P ＜0.01).Compared with the cultured splenocyte the proliferation of splenocytes increased in the cultured splenocyte +EgAg and splenocyte + ConA (all P ＜ 0.01).Compared with the cultured splenocyte + EgAg,the proliferation of splenocytes increased in the cultured splenocyte + ConA(P ＜ 0.01).Conclusion An effective and protective immunity is induced by the recombinant Bb-Eg95 vaccine of Eg in mice.
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Objective To dynamically observe the changes of cytokines of splenocytes in mice immunized with recombinant bifidobacteria bifidum (Bb)- Eg95-EgA31 vaccine of Echinococcus grauulosus (Eg). Methods Balb/c mice were vaccinated by 5× 108 colony forming unit(CFU) orally and 5 × 105 CFU intranasally, respectively.Mice were killed on week 0,2,4,6,8,10, 12,14,16, 18 and 20 after immunization, respectively, and spleens were separated for cell culture with the stimulation of EgAg, concanavalin A (ConA) or lipopolysaccharide (LPS). The splenocyte supernatants were collected to determine the levels of interferonγ(IFN-γ), interleukin(IL)-12, tumor necrosis factor α(TNF-o) and IL-l0 using enzyme linked immunosorbent assay(ELISA) with MRS as control. Results In the oral immunization group, the levels of IFN-γ, IL-12, TNF-α and IL-10 showed a significant increase from week 2 to week 8, week 2 to week 8, week 4 and week 6 to week 10 after vaccination, respectively, and reached the highest level on week 4, week 2, week 4 and week 6 after vaccination, respectively;in EgAg stimulation group, the levels of IFN-γ, IL-12, TNF-α and IL-10 were (700.0 ± 115.5), (45.0 ± 5.8), (350.0 ± 57.7), (112.5 ± 14.4)ng/L, respectively, compared with week 0[(35.0 ± 5.8), (12.5 ± 2.9), (190.0 ± 11.6), (25.0 ± 5.8)ng/L, P ＜0.05 or ＜ 0.01] and MRS control group[(37.5 ± 5.0),(13.8 ± 2.5), (195.0 ± 5.8), (27.5 ± 2.9)ng/L, P＜ 0.05or ＜ 0.01]. In the intranasal immunization group, the levels of IFN-γ, IL-12, TNF-α and IL-10 showed an obvious increase from week 2 to week 8, week 2 to week 8, week 2 to week 6 and week 6 to week 16 after vaccination,respectively, and reached the highest level on week 2, week 2, week 4 and week 8 after vaccination, respectively;in EgAg stimulation group, the levels of IFN-γ, IL-12, TNF-α and IL-10 were (700.0 ± 115.5), (55.0 ± 5.8),(275.0 ± 28.9), (140.0 ± 11.6)ng/L, compared with week 0[(35.0 ± 5.8), (12.5 ± 2.9), (190.0 ± 11.6), (25.0 ±5.8)ng/L, P ＜ 0.05 or ＜ 0.01] and MRS control group[(37.5 ± 5.0), (13.8 ± 2.5), (195.0 ± 5.8), (27.5 ± 2.9)ng/L, P ＜ 0.05 or ＜ 0.01]. The cytokine levels in the groups with EgAg, ConA or LPS stimulus were significantly higher than those in the corresponding splenocytes suspension groups(P ＜ 0.05 or ＜ 0.01) , and the cytokine levels in the groups with ConA or LPS stimulus were obviously higher than those in the corresponding groups with EgAg stimulation(P ＜ 0.05 or ＜ 0.01). Conclusion The mixed Th1 and Th2 type response can be induced in mice immunized with the recombinant Bb-Eg95-EgA31 vaccine of Echinococcus granulosus in the early stage of immunization(2 to 6weeks).
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Objective To construct and identify recombinant Bifutobacteria (rBb)-Eg95 vaccine of Echinococcus granulosus (Eg). Methods The total RNA was extracted from hydatid cyst protoscoleces shattered by ultrasound, Eg95 antigen encoding gene was obtained by reverse transcription-polymerase chain reaction(RT-PCR) from the template of total RNA using the primer designed according to the DNA sequence of Eg95, the gene was cloned into Escherichia coli-Bifutobacteria(E.coli-Bb) shuttle plasmid pGEX-1λT and transformed into E.coli BL2 (DE3) competent cell to construct recombinant plasmid pGEX-Eg95 using BamH Ⅰ and EcoR Ⅰ, the recombinant plasmid was identified by restriction endonuclease digestion, then was electroporated into Bb to construct rBb-Eg95 vaccine, the vaccine was identified by PCR. Results Four hundred and seventy-one bp Eg95 gene was amplified by RT-PCR, the products of restriction endonuclease digestion were the same as expected(471 bp Eg95 gene and 4947 bp pGEX-1λT), 471 bp Eg95 gene fragment was amplified by PCR from the template of pGEX-Eg95 extracted from rBb vaccine. Conclusion rBb-Eg95 vaccine of Eg is successfully constructed, which lays the theoretical foundation for exploitation and utilization of this vaccine.
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<p><b>OBJECTIVE</b>To investigate the effect of therapeutic ultrasound-induced microbubble destruction on the microcirculation of rat skeletal muscle.</p><p><b>METHODS</b>Thirty SD rats were randomized into 5 groups (n=6), namely normal saline, microbubble, ultrasound, high-energy ultrasound microbubble and low-energy ultrasound microbubble groups. Before and after the treatments, the diameter and blood flow velocity in the microvessels in the skeletal muscle were measured, and the structural changes of the injured microvessels observed by electron microscopy.</p><p><b>RESULTS</b>Microbubble cavitation did not produce significant effect on the mean arterial pressure and diameter of microvessels in rat skeletal muscle (P>0.05), but the blood flow velocity was obviously lowered and blood flow volume reduced in the microvessels. The reduction of the flow velocity and blood flow volume and their subsequent recovery were associated with ultrasound energy, and in the low ultrasound energy group, the flow velocity and blood flow volume in the of venules recovered obviously after about 15 min, which, however, took approximately 1 h for the arterioles. In contrast, recovery of the flow velocity and blood flow volume in the microvessels took more than 2 h in the high ultrasound energy group. Cavitation resulted in endothelium cell rupture, widening of the endothelial interspace and entry of the red blood cells into the extravascular tissues as revealed by electron microscopy, but no rupture of the lining endothelium was observed 2 h after the treatment.</p><p><b>CONCLUSIONS</b>Endothelium cell rupture induced by microbubble cavitation may affect the local microcirculation, and lower ultrasound energy exposure is associated with milder endothelial injury and more rapid recovery.</p>