Progress in research on molecular biology and application in dominant antigens ESAT6 and CFP10 of TB vaccine / 生物医学工程学杂志

As the dominant antigens, early secreted antigenic target 6 (ESAT6, E6) and culture filtrate protein 10 (CFP10, C10) had once been the focus of tuberculosis (TB) vaccine due to their capability of inducing strong cell immune response in the host. They are also endowed with promising future of prevention against and diagnosis of TB. In this review, we systematically introduce recent research progress of E6 and C10, especially in structure-function, biological characteristics, protein expression and secretion, host immunity and vaccine development, and the prospects of their application are also discussed.

Cloning, expression and bioinformatic analysis of Rv3871 gene related to Mycobacterium tuberculosis virulent protein secretion / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone and express the Rv3871 gene related to the virulent protein secretion of Mycobacterium tuberculosis and analyze its molecular structure, function and homology using bioinformatic approach.</p><p><b>METHODS</b>A pair of primers was designed to amplify the Rv3871 gene, which was subcloned into the prokaryotic plasmid pET32a(+). The recombinant plasmid was identified by sequence analysis and the expressed recombinant protein by SDS-PAGE. The structure, function and homology alignment of Rv3871 were analyzed comparatively against other mycobacteria.</p><p><b>RESULTS</b>The restriction fragments through molecular cloning matched perfectly in size with our prediction. The gene sequence was consistent with the corresponding sequence in GenBank. The expression protein was detected by SDS-PAGE with a molecular weight of 84 kD. Two FtsK/SpoE III domains were found by bioinformatic analysis. The homology results showed distinct differences between Rv3871 of the pathogenic M. tuberculosis and its counterparts in non-pathogenic mycobacteria.</p><p><b>CONCLUSION</b>Molecular cloning, expression and sequencing identify the structural and functional characteristics of Rv3871. The structural and functional differences of the gene between pathogenic and non-pathogenic mycobacteria identified by bioinformatics provide some evidence for the pathogenesis and drug targets of tuberculosis.</p>

Construction of eukaryotic recombinant vector and expression in COS7 cell of LipL32-HlyX fusion gene from Leptospira serovar Lai / 生物医学工程学杂志

This study was conducted to construct eukaryotic recombinant vector of LipL32-HlyX fusion gene from Leptospira serovar Lai and express it in mammalian cell. Both of LipL32 gene and HlyX gene were amplified from Leptospira strain O17 genomic DNA by PCR. Then with the two genes as template, LipL32-HlyX fusion gene was obtained by SOE PCR (gene splicing by overlap extension PCR). The fusion gene was then cloned into pcDNA3.1 by restriction nuclease digestion. Having been transformed into E. coli DH5alpha, the recombiant plasmid was identified by restriction nuclease digestion, PCR analysis and sequencing. The recombinant plasmid was then transfected into COS7 cell whose expression was detected by RT-PCR and Western blotting analysis. RT-PCR amplified a fragment about 2000 bp and Western blotting analysis found a specific band about 75 KD which was consistent with the expected fusion protein size. In conclusion, the successful construction of eukaryotic recombinant vector containing LipL32-HlyX fusion gene and the effective expression in mammalian have laid a foundation for the application of Leptospira DNA vaccine.

Eukaryotic expression and DNA immunization of hemolysin HlyX gene from Leptospira serovar Lai / 中华微生物学和免疫学杂志

Objective To study on the expression of the eukaryotic recombinant vector carrying HlyX gene of Leptospira serovar Lai in mammalian cell and explore the humoral immune response in BALB/c mice immunized with the recombinant plasmid. Methods The HlyX gene was amplified from Leptospira serovar Lai genomic DNA by PCR and inserted into pcDNA3.1 vector. After transformed into E. coli DH5α,the recombinant plasmid was assayed for identification by PCR analysis,restriction nuclease enzyme digestion and sequencing. The recombinant plasmid was transfected into COS-7 cells,then RT-PCR and Western blot were performed to test the expression of the target gene. The recombinant plasmid was injected intramuscularly into BALB/c mice for three times at intervals of two weeks,and the antibody titer was measured by ELISA. Results PCR showed the full length HlyX gene was about 1100 bp. PCR analysis,restriction nuclease enzyme digestion and sequencing indicated the recombinant vector was constructed successfully. After the plasmid Was transfected into COS-7 cells,a fragment about 1100 bp was found by RT-PCR and a specific band relative molecular mass(Mr)about 40×103,which was consistent with the expected size of the target proteins was showed by Western blot. ELISA showed the antibody titer in BALB/c mice immunized by the HlyX gene of Leptospira serovar Lai can elicit high-titer antibody in BALB/c mice,which has laid the foundation for the application of the DNA vaccine.

Molecular cloning and expression of hypothetical proteins Rv1494 and Rv1495 of M.tuberculosis H37Rv strain / 南方医科大学学报

<p><b>OBJECTIVE</b>The mechanism by which M.tuberculosis persists and survives in host macrophage is not fully understood, however, the M. tuberculosis chromosome-encoded TA loci perform functions possibly of signaling to these processes. To explore the biological functions of M. tuberculosis chromosome-encoded TA loci, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and expressed.</p><p><b>METHODS</b>The hypothetical proteins Rv1494 and Rv1495 were bioinformatically analyzed by means of Bioedit software, Dnaman software and Pfam database. The complete open-reading frame sequences of Rv1494 and Rv1495 genes were amplified by PCR using M.tuberculosis H37Rv genomic DNA as the template, and the PCR products were cloned into prokaryotic expression vector pET32a(+), respectively. After induction of expressions in E.coli host strain BL21 (DE3), the recombinant proteins were purified and detected by Western blotting.</p><p><b>RESULTS</b>According to bioinformatic analysis, the hypothetical proteins of Rv1494 and Rv1495 genes shared some homologies with mazEF family, one of E. coli chromosomal TA loci (homology at 26% and 29.5%). Sequence analysis showed that the inserted target genes and its reading frames were completely correct. The recombinant plasmids were induced with IPTG to effectively express the fusion proteins with relative molecular mass coincident with prediction. The specific positive signals were identified from the immunoblots.</p><p><b>CONCLUSION</b>For the first time, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and its prokaryotic expression vectors were constructed successfully in this experiment, which may facilitate further functional study of this mazEF-like gene pair.</p>

Construction of recombinant Mycobacterium smegmatis expressing ESAT-6 and its effects on macrophages / 南方医科大学学报

<p><b>OBJECTIVE</b>Objective To construct recombinant Mycobacterium smegmatis expressing ESAT-6 of the human pathogen Mycobacterium tuberculosis.</p><p><b>METHODS</b>ESAT-6 gene was amplified from M. tuberculosis genomic DNA and inserted into an E.coli-mycobacterium shuttle vector under the control of HSP60 promoter. The recombinant vector was transformed into M. smegmatis by electroporation. To assess the ability of recombinant M. smegmatis to activate macrophage, mouse macrophage ANA-1 was cocultured with recombinant M. smegmatis. The apoptosis of ANA-1 cells was detected by flow cytometry and iNOS mRNA expression of the cells was detected by reverse transcription-polymerase chain reaction (RT-PCR). The survival of M. smegmatis strains in ANA-1 cells was evaluated.</p><p><b>RESULTS</b>The recombinant vector was verified by restriction endonuclease digestion and DNA sequencing. ESAT-6 protein was expressed in M. smegmatis in response to heat shock and the molecular weight of the expression product was identical to the expected value. The growth curve of the new recombinant M. smegmatis was consistent with that of the wild-type strain, suggesting the absence of ESAT-6 protein toxicity against M. smegmatis. The recombinant M. smegmatis did not induce significant changes in mouse macrophage ANA-1 apoptosis. Coculture of the macrophages with recombinant M. smegmatis for 4 to 24 h could induce iNOS expression in the former, and the CFU of recombination M. smegmatis grown in ANA-1 cells was much less than that of the control bacteria.</p><p><b>CONCLUSION</b>The recombinant M. smegmatis expressing M. tuberculosis ESAT-6 gene possess immunogenicity, which provides experimental evidence for the development of novel M. smegmatis-based vaccine against tuberculosis.</p>

Construction of the recombinant integrating shuttle plasmid with cfpl0-esat6 fusion gene of Mycobacterium tuberculosis and its expression in BCG / 生物医学工程学杂志

This study was conducted to amplify the cfpl0-esat6 fusion gene by SOE and insert into the integrating shuttle plasmid pMV361 to form the recombinant plasmid. Then another recombinant plasmid was constructed by insertinga-A g signal sequence of BCG. The two recombinant plasmids were introduced into BCG and the induced products from recombinant BCG were analyzed. In conclusion,the successful construction of rBCG expressing the fusion protein CFP10-ESAT6 will be the base of the development of novel Mycobacterium tuberclosis vaccines.

E. coli-based production of recombinant HMG-17 and its antibacterial domain / 生物医学工程学杂志

Total RNA was extracted from human LAK cell, and a cDNA encoding mature peptide HMG-17 and its alpha helix domain was amplified by RT-PCR. The recombinant prokaryotic expression vector pGEX-1lambdaT-HMG-17 and pGEX-1lambdaT HMG-17alpha helix was constructed. Using affinity chromatography, thrombin cleaving and AU-PAGE elution, we obtained the purified HMG-17. Analyses of MIC, MEC and MBC indicated that HMG-17 and HMG-17alpha had strong antibacterial activity. MIC of the alpha-helic domain was almost the same as that of HMG17, suggesting that the alpha-helic structure would be essential for the antibacterial activity of HMG-17.

Novel mutations of PAX9 gene in Chinese patients with oligodontia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the mutational characteristics of PAX9 gene in Chinese patients with congenital oligodontia and thus to provide a molecular basis for studying the pathogenesis of oligodontia.</p><p><b>METHODS</b>Thirteen individuals with oligodontia and 9 healthy individuals, from 4 unrelated autosomal dominant families, and 16 sporadic patients with hypodontia in China, as well as 196 healthy control individuals (without oligodontia or hypodontia) were screened. Congenital absence of teeth was confirmed by panoramic X-ray analysis. Mutations of PAX9 gene were detected using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. After the finding of abnormal SSCP bands, analysis was carried out with DNA sequencing.</p><p><b>RESULTS</b>PCR-SSCP detected SSCP bands alteration in exon2 of PAX9 gene in two unrelated families. Sequencing of PAX9 gene revealed a novel frameshift mutation (109InsG) and a novel missense mutation (C139T). All the affected members of each family were heterozygous for the mutations. In sporadic patients and the other two families, no similar sequence changes in PAX9 gene were found.</p><p><b>CONCLUSIONS</b>The results extend the spectrum of mutations in PAX9 gene associated with oligodontia. The novel mutations will play an important role in gene diagnosis of oligodontia.</p>

Functional analysis of novel mutations in PAX9 associated with familial oligodontia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To gain new insights into the molecular pathogenesis of the 109(InsG) and 139(C--> T) mutations and their roles in familial oligodontia.</p><p><b>METHODS</b>The region of PAX9 paired domain (PAX9PD) was amplified and the expression plasmids were constructed in pGEXlambda -1T by PCR-based cloning. PAX9PD proteins were prepared on the basis of GST instruction. The binding of wild type and two novely mutant PAX9 paired domain to double-stranded DNA targets were analyzed by gel mobility shift assay.</p><p><b>RESULTS</b>Wild type PAX9PD protein bind to the high affinity paired domain recognition sequences, CD19-2(A-ins) and Pax6CON, the 109(InsG) and 139(C--> T) mutant PAX9PD protein were unable to bind to these cognate DNA-binding sites.</p><p><b>CONCLUSION</b>The functional defects in DNA binding of mutant 109(InsG) PAX9 and 139(C--> T) PAX9, as well as loss-of-function of PAX9 most likely result in its haploinsufficiency during the patterning of dentition and the subsequent loss of posterior teeth.</p>

Expression and immunity reaction of a novel gene OmpL17 of the strong virulent L. interrogans serovar Lai in China / 生物医学工程学杂志

This study was conducted to potentiate the expression of outer membrane protein OmpL17 of the strong virulent L. interrogans serovar Lai and investigate its immunogenicity in rabbits. The OmpL17 was cloned into prokaryotic expression vector pGEX-1lambdaT. The recombination expression plasmid pGEX-OmpL17 was transformed into E. Coli JM109. The GST fused protein GST-OmpL17 was expressed after induction by IPTG, then GST-tag was by thrombin and purified using Bulk GST purification Modules. SDS-PAGE and Western blotting analysis indicated that the molecular weight of GST-OmpL17 and OmpL17 was about 54 KDa and 28 KDa respectively. The outer membrane protein OmpL17 was subcutaneously injected into rabbits and high titre anti-OmpL17 antibody was obtained (1:4896) which could conjugate specifical with OmpL17. In conclusion, OmpL17 and specifical anti-OmpL17 antibody were obtained, which provided an experimental basis for researching pathogenic effect and immunity functions of OmpL17.

The construction and expression of recombinant shuttle plasmid with OmpL1 gene from leptospira interrogans serovar Lai strain 017 in Bacille Calmette-Guerin / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To construct recombinant BCG against leptospirosis.</p><p><b>METHODS</b>We amplified the entire open reading frame of the OmpL1 gene from the genome of the leptospire serovar Lai strain 017. Two recombinant plasmids pBQ1 and pBQ2 were constructed by oriented ligation based on the E. coli-BCG shuttle plasmids pMV261 and pMV361 respectively. The recombinant plasmids were transformed into BCG by electroporation. The rBCGs bearing pBQ1 and pBQ2 were induced by high temperature of 45 degrees C.</p><p><b>RESULTS</b>The expressed product, a 35kD protein was detected by SDS-PAGE. The result indicates that pBQ1 and pBQ2 can express OmpL1 in rBCG.</p><p><b>CONCLUSION</b>The technical methods in this study may help detect the immunogenicity and immunoprotection of OmpL1 and develop more safe, highly effective rBCG bearing leptospiral antigen with long-lasting protection.</p>

Comparative study on two DNA vaccines of tuberculosis Ag85A antigen / 中华传染病杂志

Objective To explore new method for enhancing the efficacy of tuberculosis DNA vaccine. Methods Two recombinant plasmids were constructed, one named as pBK GM/85A encoding mouse granulocyte macrophage colony stimulating factor(GM CSF) fused to Mycobacterium tuberculosis Ag85A antigen, the other named as pBK 85A encoding Mycobacterium tuberculosis Ag85A antigen alone. Subsequently, the two plasmids were transferred into cultured COS7 cells by using cationic liposomes. The expression products were identified by Western blotting. Then, in a murine model, we compared the immunogenicity and protective immunity of the two recombinant plasmids following genetic immunization. Results All pBK GM/85A injected mice elicited higher antibody titres than that for pBK 85A injected mice. Lymphocytes obtained from the spleen of pBK GM/85A immunized mice exhibited higher lymphocyte proliferative response、IFN ? production and CTL activity than that for pBK 85A immunized mice. The protective efficacy was also higher for pBK GM/85A immunized mice than that for pBK 85A immunized mice. However, The protective efficacy for pBK GM/85A immunized mice was lower than that for BCG immunized mice. Conclusion These results showed that DNA vaccines with GM CSF/antigen fusion constructs could greatly improve the immunogenicity of DNA vaccine against Mycobacterium tuberculosis.

Molecular genetic study on 17?-hydroxylase deficiency / 中华内分泌代谢杂志

Objective To study the molecular genetic mechanism of a patient with 17? hydroxylase (CYP17) deficiency. Methods Genomic DNA were abstracted from the blood of the patient, her parents and healthy control. The 8 exons of CYP17 gene were amplified, using 5 pairs of designed primers, with polymerase chain reaction (PCR), and the 8 exons were sequenced by the dideoxy terminator method to determined the mutation sites. The corresponding exons of the parents of the patients were also amplified and sequenced to determine the zygosity of the patient and the source of the gene variances. Results The analysis revealed that the patient (46, XY) was a compound heterozygote carrying two different inherited mutations on CYP17 gene, one from mother containing a point mutation Arg 96 (C G G)→ Gln(C A G) and the other from father containing a nine base deletion (CACTCTTTC) at amino acid position 487～489 (Asp Ser Phe) near the carboxyl terminus of P450c17. Conclusion The CYP17 gene of the patient with 17? hydroxylase deficiency is a compound heterozygous mutation. The mutation changes the amino acid sequence of P450c17 enzyme, which in turn affected the enzymatic activity. Arg 96 is essential in P450c17 enzyme activity. Deletion of Asp 487 Ser 488 Phe 489 in exon 8 may be a prevalent mutation causing P450c17 deficiency in Southeast Asia.

Cloning expression and toxic effect on the host bacterial viability of an outer envelope protein from the strong virulent leptospira lai in China / 中国病理生理杂志

AIM: Construction of an eukaryote- E. coli shuttle expressing recombinant plasmid which expresses OmpL1 envelope protein of pathogenic Leptospira, serovar Lai strain 017. METHODS: The OmpL 1 gene was amplified by PCR from the leptospiral genome. Then it was cut with restriction enzymes and ligated to the plasmid pBK-CMV. The correct recombinant plasmid was screened out with analysis of restriction enzymes and PCR. After inducing the E. coli baring recombinant plasmid with IPTG,the complete protein of the bacteria was extracted for SDS-PAGE. At the same time, OD600 of the host bacteria was examined at different time after inducing or uninducing with IPTG. RESULTS: Five strains E. coli containing proper recombinant plasmids were screened out. Four strains E. coli expressed a new protein with a weight of 37 kD among them. With the expression of the heterogenous protein,the OD600 of the host bacteria decreased. CONCLUSION: The shuttle expressing plasmid of the OmpL 1 gene of strong virulent Leptospira strain 017 was successfully constructed. Furthermore,the recombinant plasmid expressed the expected OmpL 1 fusion protein in E. coli and the expression of the heterogenous protein had toxic effect on the host bacteria. This work was important for the future research of OmpL1 protein which relates to the diagnosis,new vaccine preparing and the pathogenic mechanism of leptospirosis.

Impact of Amoxicillin on Dysmenorrhea Model Mice Treated with Peoniflorin / 中国药房

OBJECTIVE:To study the impact of amoxicillin on dysmenorrhea model mice treated with paeoniflorin.METHODS:The enrolled mice were randomized to different groups and all were given diethylstilbestrol i.g.for 12 consecutive days.From day 5 to day 12,the model control(MC)group,positive control(PC)group and 3 PA groups(different dosage of paeoniflorin plus amoxicillin)were given amoxicillin i.g.On day 12,3 P(paeoniflorin)groups and 3 PA groups were respectively given different dosage of paeoniflorin i.g.All groups were respectively given oxytocin i.p 1 hour after medication.The incubation period(TIP,seconds)between oxytocin i.p.and the first time of body twisting and the number of the body twisting(NBT)in 15 minutes of the mice were recorded.RESULTS:Compare to NC(negative control)and MC groups,the TIP was significantly prolonged and the NBT in 15min were significantly decreased in 3 P groups(P0.05).CONCLUSION:The curative effect of paeoniflorin in treating dysmenorrheal model mouse was decreased by amoxicillin suggests that the 2 drugs were unsuitable to be used concomitantly.

Preliminary study on detecting drug-resistance mycobacterium tuberculosis by using DNA microarray hybridization / 中国病理生理杂志

AIM:To detect the drug-resistance mycobacterium tuberculosis by using DNA microarray hybridization.METHODS: DNA microarray for detecting drug-resistance of mycobacterium tuberculosis was prepared; Clinical isolated strains were cultivated and their drug-resistance sensitivity was detected. The genome DNA of mycobacterium tuberculosis was prepared and the drug-resistance genes of the mycobacterium tuberculosis were amplified by PCR. Then the gene chip was hybridized, washed, detected and analyzed. RESULTS: Results of cultivating mycobacterium tuberculosis and detecting the drug-resistance sensitivity: one strain was drug-sensitive; four strains were multi-drug-resistant; The detecting results of the drug-resistance was consistent with the results of diagnosis therapy of the 5 clinical patients. The detecting results of gene chip confirmed the above facts. CONCLUSION: Detecting drug-resistance mycobacterium tuberculosis by the gene chip is precise, fast and highly-efficient.

Screening and sequencing of the novel differential gene in leptospira serovar lai / 中国病理生理杂志

AIM: To amplify and analyze the differential DNA fragment between pathogenic leptospira serovar lai and nonpathagenic leptospira serovar patoc I. METHODS: The previously subtractive DNA fragment only existing in leptospira serovar Lai was amplified by cassette ligation and semi-nested PCR.The obtained gene was sequenced and searched homologically. In addition, the deduced amino acid was analyzed and the secondary stracture of protein was predicted. RESULTS: The 580 bp DNA fragment, which deposited in GenBank (AF495587), was cloned, and four overlapping open reading frames (ORF) was contained. The high homology with conserved hypothetical protein streptococcus pyogenes was found. CONCLUSION: This study lays foundation for deeply exploring biological actions of new gene and pathogenic mechanism of leptospira serovar lai.