جستجوی مقالات مرتبط با کلیدواژه « dna vaccine » در نشریات گروه « زیست شناسی »

Aeromonas hydrophila is one of the most important pathogenic bacteria in fish that causes hemorrhagic septicemia, ascites and mortality in different ages and in different fish species including carp. Immunization is one of the best ways to prevent this disease. The use of gene constructs containing bacterial-specific antigens has been developed in recent years to develop high-performance vaccines and to use them in easier methods such as oral administration in aquaculture. In this study, aopB protein of type III secretory system of A. hydrophila isolated from carp in Khuzestan province was used to design a gene construct for DNA vaccine which cloned into the expression eukaryotic plasmid pCDNA3.1. In this study, A. hydrophila isolated from carp with Aeromonas septicemia in carp farms of Khuzestan province which species confirmed by molecular and phenotypic methods. The aopB gene sequence was extracted from the NCBI gene bank and the gene encoding region was amplified using primers containing EcoRI and NheI enzyme cleavage regions. The PCR product was then inserted into the eukaryotic expression plasmid pCDNA3.1-HisA and was transfected to TOP10-F 'bacteria using heat shock. After screening for positive clones using colony PCR and sequencing, the pCDNA3.1-AopB gene construct was transferred to CHO cells using electroporation method and recombinant protein expression was assessed by Western blotting on cell lysis. PCR results and sequencing of gene constructs indicated the cloning of the aopB gene approximately 1000bp in plasmid pCDNA3.1-HisA. Western blot using anti-HisTag antibody showed the presence of a protein with a molecular weight of about 36kD. Conclusively, the pCDNA3.1-AopB gene construct containing the aopB gene was designed and validated. This gene construct can be used in clinical studies to evaluate the immunogenicity of carp in experimental pathogenicity with A. hydrophila.

Diarrhea is the second most common cause of under-5 mortality. The most important strains of Entrotoxigenic Escherichia coli causing Lt and St toxin cause diarrhea and Entrohemoragic E.coli causing Shiga-like toxin secretion. Chlorine enterotoxin B subunit (Ctx) plays a key role in the development of diarrhea in Vibrio cholerae. More specific antibodies could be developed to counter these toxins by combining the CtxB, LtB and StB (LSC) epitopes and the production of trivalent vaccine. The aim of this study was to cloning lsc gene into pcDNA3.1 to design a vaccine DNA.

The lsc gene sequence was transferred to pcDNA3.1(+) vector after primer design and amplification by PCR. The pcDNA3.1(+) vector and the PCR product were digested using HindIII and EcoRI enzymes. Cloning of lsc gene was performed in pcDNA3.1(+) vector and PCR. The clones were digested enzymatically. To ensure expression of lsc gene, it was transferred to HEK-293T cell and confirmed by Western blotting.

The lsc gene was confirmed by PCR and cloning in pcDNA3.1(+) vector using enzymatic digestion and a fragment length of 933 bp was detected and confirmed. Transfection kit was then transferred to HEK-293T cell and expression of the recombinant protein was confirmed by Western blotting and the protein was 39 kDa.

The results of the chimeric gene are well expressed in the cell line and confirmed by Western blotting that can be a good candidate for the fight against bacterial infection.

One of the challenges of today's world and also global health priorities is pandemicity of AIDS. Studies have shown that the scope and breadth of the immune responses induction are very effective to protect against HIV. Moreover, simultaneous induction of humoral and cellular immunity responses increases the effectiveness of candidate HIV vaccines. Hence, new approaches such as polyepitopic vaccine strategy and addition of different adjuvants in HIV vaccines’ formulations have been recently considered. In the present study, eukaryotic expression vector (pcDNA3.1-tat/pol/gag/env) was transformed and amplified in the prokaryotic host cells E. coli (DH5α). After vector extraction, it was concentrated and formulated alone and in combination with Alum adjuvant and used as DNA candidate vaccines. DNA candidate vaccines were, then, subcutaneously injected to the BALB/c mice on 0, 14, and 28 days and elicited humoral and cellular immunity responses were finally evaluated. The results showed that the candidate DNA vaccine could not efficiently induce immunity responses (both humoral and cellular responses) by subcutaneous route injection. This observation can be due to a defect in each of the steps of vector harvesting by the target cell to express the surface presentation of the epitopes on the one hand, or the inefficiency of the subcutaneous injection method on the other. Therefore, other vaccines’ injection and deliveries routes along with addition of other adjuvants in vaccine’s formulations could induce immunity responses efficiently and increase vaccine efficacy.

DNA vaccines may be safer than of some live virus vaccines. Largely Immune response to the vaccine antigen correlates with expression level Which is directly based on transient transfection of cells in vitro measured DNA vaccines into muscle or skin inoculated with a syringe or a device such as a gene gun. DNA uptake by cells Followed by a pathogenic gene transcription and translation and subsequent immune response of antibodies (Ab), helper T cells (Th) and cytotoxic T lymphocytes (CTL) to follow The DNA vaccine are used for immunization against a variety of diseases, including viral infections, bacterial, parasitic, allergic, autoimmune and cancer. In some studies, DNA vaccines express multiple antigens. Even with this, the immune system is induced. Combinational vaccines increase protection against a single pathogen or protection against a range of infectious agents is induced by DNA vaccine. The aim of DNA vaccination development and improvement of effective strategies against effective infectious agents and tumors of the previous unifie.