Designing and Construction Pcdna3.1 Vector Encoding Cfp10 Gene of Mycobacterium tuberculosis

Design and Construction of a Eukaryotic Cloning Vector Encoding the mpt51 Gene of Mycobacterium tuberculosis

BACKGROUND

Tuberculosis (TB) is the leading cause of death by infectious diseases worldwide, and especially prevalent in developing countries. Several vaccines against TB have been developed, recently. The aim of the present study was to design and construct a cloning vector encoding Mycobacterium tuberculosis (MTB) mpt51 gene.

METHODS

DNA was extracted from MTB H37Rv strain. Gene-specific primers were designed using Gene Runner software and the mpt51 gene was amplified by PCR. The amplified fragment and pcDNA3.1(+) cloning vector were both digested with restriction enzymes, the mpt51 fragment was ligated into the vector, and the Escherichia coli (E. coli) TOP10 strain were transformed by the recombinant plasmid. Positive clones were identified by colony PCR, restriction enzyme digestion, and DNA sequencing.

RESULTS

The mpt51 gene was successfully cloned into pcDNA3.1(+). A 6400 bp band for the pcDNA3.1(+)/mpt51 recombinant plasmid and a 926 bp band for mpt51 were observed by colony PCR, and restriction enzyme digestion on agarose gels. The DNA sequence was 100% homologous with the mpt51 fragment of H37Rv in GenBank.

CONCLUSION

In the current study, the mpt51 gene of MTB was correctly cloned into pcDNA3.1(+). The expression of this recombinant vector can be studied in eukaryotic cells. Moreover, it is possible to determine the efficacy of this vector as a DNA vaccine candidate, and to test its protective function compared to BCG in animal models in future.

Designing and Construction of a Cloning Vector Containing mpt64 Gene of Mycobacterium tuberculosis

BACKGROUND

Tuberculosis caused by Mycobacterium tuberculosis (M. tuberculosis), remains as one of the leading causes of deaths worldwide, with nearly two million death cases annually. BCG (Bacille Calmette-Guerin) continues to be the most widely used vaccine in the world, but the protective immunity differs in different parts of the world. Accordingly, new strategies including DNA vaccines are essentially needed. This study was aimed to design and construct a cloning vector containing mpt64 gene of M. tuberculosis.

MATERIALS AND METHODS

M. tuberculosis H37Rv was cultured on Lowenstein Jensen medium, and genomic DNA was extracted. The mpt64 gene was amplified by PCR using designed specific primers. After the digestion of mpt64 and pcDNA3.1 (+) by BamHI and EcoRI restriction enzymes, the mpt64 fragment was ligated into the digested vector using T4 DNA ligase enzyme. Then, the recombinant vector was transformed into competent Escherichia coli (E. coli) TOP10 strain. To confirm the colonies of transformed bacteria, antibiotic resistance, colony-PCR, restriction enzyme digestion and DNA sequencing were used.

RESULTS

To confirm the clones, colony-PCR using mpt64 specific primers was performed and the fragment of 718 bp was observed by gel electrophoresis. Clones were also verified by restriction enzyme digestion using BamHI and EcoRI restriction enzymes and the 718 bp fragment was observed. Furthermore, results of DNA sequencing showed 100% homology with the mpt64 fragment of H37Rv in GenBank.

CONCLUSION

In this study, the mpt64 fragment was successfully cloned in pcDNA3.1 (+) vector. This construct can be used in future studies as a DNA vaccine in animal models to induce immune system responses.

Designing and Construction of a Cloning Vector Encoding mtb32C and mpt51 Fragments of Mycobacterium tuberculosis as a DNA Vaccine Candidate

BACKGROUND & OBJECTIVE

Tuberculosis (TB) remains a major cause of death around the world. Bacillus Calmette Guérin (BCG) is the only vaccine used in TB prevention that has a protective effect in children, but its effectiveness declines in adults. Design and development of new vaccines is the most effective way against TB.The aim of this study was to design and construct a DNA vaccine encoding mtb32C and mpt51 fusion genes of Mycobacterium tuberculosis.

METHODS

First, mpt51 fragment was amplified by PCR method. The pcDNA3.1+/mtb32C plasmid was transformed into E. coli JM109 and then extracted. The mpt51 gene and pcDNA3.1+/mtb32C plasmid were both digested with EcoRI and BamHI restriction enzymes followed by ligation of mpt51 fragment into the digested vector. The recombinant plasmid containing mtb32C and mpt51 was subsequently transformed into competent E. coli TOP10 strain. The clones were confirmed by colony-PCR, restriction enzyme digestion and sequencing.

RESULTS

Using agarose gel electrophoresis, a 926 bp fragment corresponded to mpt51 was observed. Digestion of the vector pcDNa3.1+/mtb32C and mpt51 gene was confirmed by electrophoresis. Then, the pcDNA3.1+/mtb32C plasmid was extracted. Sequencing results confirmed the accuracy of the desired plasmid.

CONCLUSION

In this study, we constructed a cloning vector encoding mtb32C/mpt51 gene of M. tuberculosis. The eukaryotic expression of this vector can be confirmed in future studies. It can be considered as a DNA vaccine in animal models later. Successful cloning provides a basis for the development of new DNA vaccines against TB.

Design and Construction of a Cloning Vector Containing the hspX Gene of Mycobacterium tuberculosis

BACKGROUND

Tuberculosis (TB) is a major cause of death worldwide. Finding an effective vaccine against TB is the best way to control it. Several vaccines against this disease have been developed but none are completely protective. The aim of this study was to design and construct a cloning vector containing the Mycobacterium tuberculosis (M. tuberculosis) heat shock protein X (hspX).

METHODS

First, an hspX fragment was amplified by PCR and cloned into plasmid pcDNA3.1(+) and recombinant vector was confirmed.

RESULTS

A 435 bp hspX fragment was isolated. The fragment was 100% homologous with hspX of M. tuberculosis strain H37Rv in GenBank.

CONCLUSION

In this study, the cloning vector pcDNA3.1(+), containing a 435-bp hspX fragment of M. tuberculosis, was constructed. This could be used as a DNA vaccine to induce immune responses in animal models in future studies.

Evaluation of the eukaryotic expression of mtb32C-hbha fusion gene of Mycobacterium tuberculosis in Hepatocarcinoma cell line

BACKGROUND AND OBJECTIVES

HBHA and Mtb32C have been isolated from culture supernatants of Mycobacterium tuberculosis (M. tuberculosis) and Mycobacterium bovis (M. bovis) and their immunogenicity previously studies have been confirmed. In this study, capability of constructed vector containing two mycobacterial immunodaminant antigens (Mtb32C-HBHA), in producing new chimeric protein under the in-vitro condition was examined.

MATERIALS AND METHODS

In present study Huh7.5 cells was transfected with Mtb32C-HBHA -pCDNA3.1+ recombinant vector using the calcium phosphate method and expression of chimeric protein was assessed by RT-PCR and Western blot methods.

RESULTS

Results of RT-PCR and Western blot showed expression of 35.5 KD recombinant protein (Mtb32C-HBHA) in this cell line.

CONCLUSION

The constructed vector can produce two highly immunogenic antigens that fusion of them to gather makes chimeric antigen with new traits. Other attempts are needed to evaluate specific properties of this new antigen such as molecular conformation modeling and immunologic characteristics in future studies.