جستجوی مقالات مرتبط با کلیدواژه « واکسن ژنی » در نشریات گروه « پزشکی »

Helicobacter pylori (H. pylori) causes successive changes in the stomach wall, which starts with inflammation of the stomach mucosa and in some cases leads to stomach cancer. The leoA gene, by encoding GTPase, plays a vital role in the pathogenicity of this bacterium in the gastric mucosa. The secretory vesicles produced by the leoA gene release poison and stimulate the immune system in the host's body. The aim of the present study was to evaluate the gene vaccine pEGFP-C2-leoA on the expression changes of cytokines such as IL6, IL4, and interferon-gamma in inflammation caused by Helicobacter pylori infection in a mouse model.

In this interventional experimental study, recombinant plasmid (pEGFP-C2-leoA) was produced, propagated, and extracted through transformation into susceptible bacterial cells. Then, suitable concentrations of 1% chitosan nanoparticles solution were prepared for injection into the quadriceps muscle of BALB/c mice. Finally, the gene expression and changes of the mentioned cytokines were measured by Real-Time RT-PCR method, the obtained results were statistically analyzed by SPSS version 16 software; One way ANOVA test and subsequent LSD test, as well as independent t-test, were used to check the existence of correlation and the significance level of the data.

After the injection of the vaccine into the quadriceps muscle of mice during the treatment period, cytokines IFNᵧ (<0.038) and IL6 (<0.049) showed a significant increase in expression. On the other hand, cytokine IL4 and the leoA gene also showed a significant decrease in expression (>0.042).

Based on the results, the leoA gene cloned in the expression vector pEGFP-C2 has the ability to express and produce the specific protein product of this gene in eukaryotic cells, and according to the results obtained in the animal model and the immune characteristic obtained in this research it is shown that the final construct pEGFP-C2-leoA has the necessary potential to investigate immunogenicity in a human model as a gene vaccine.

Vaccines have played a special role in controlling and reducing mortality from infectious diseases. In this regard, DNA vaccines were developed to ease the production and reduce the risks of traditional vaccines. Human papillomavirus (HPV) has been introduced as the causing agent of cervical cancer. The capsid protein (L1) of HPV has been used to produce subunit and DNA vaccines. The aim of this experimental research is to design and construct the L1 expression system of HPV 18 and to investigate its expression in eukaryotic cells.

Method and Materials:

 In this experimental study, the L1 gene of HPV 18 was subcloned in the expression vector pcDNA 3.1 Hygro after optimization and synthesis. Cloning was confirmed through colony PCR test and enzyme digestion reaction. The expression vector was transfected into HEK293 cells using the Turbofect reagent. After 72 hours, total RNA was extracted from transfected cells and control cells and cDNA was synthesized. Gene expression was examined at the mRNA level in cells by performing PCR on cDNA.

The results showed that following the optimization of the L1 gene sequence, the CAI and Fop indices increased to an ideal level. The cloning of the optimized HPV 18-L1 gene in the pcDNA3 expression vector was successfully confirmed by colony PCR test and enzyme digestion reaction, and the results indicate the production of recombinant plasmid pCDNA3.1-L1. Finally, the evaluation of the L1 gene at the mRNA expression level showed the successful expression of the L1 gene in the eukaryotic system.

The results of this research show the effectiveness of the constructed expression vector in the effective expression of the L1 gene in vitro. This expression vector can be used as a DNA vaccine in future studies.

The most important cause of urinary tract infection is Uropathogenic Escherichia coli (UPEC) which produces type I pili. UPEC has intracellular duplication after invasion to bladder epithelial cells; therefore, cellular immunity is important in this case. This study was performed in order to design a gene cassette inducing cellular immune system against Uropathogenic Escherichia coli.

At first, fimH gene was amplified by PCR. PCR product was inserted to pcDNA.1 eukaryotic expression vector and the recombinant vector was confirmed by sequencing. The clone was inserted into COS7 cell and then assessed by RT-PCR in order to evaluate gene expression and the correct function of the gene cassette. Gene expression at mRNA level was evaluated by florescence microscope.

fimH gene was well amplified by PCR. PCR product was inserted to pcDNA.1 eukaryotic expression vector and pcDNA/fimH gene cassette was constructed. COS7 cells were transfected in order to evaluate the correct function of this cassette. Expression of fimH gene in COS7 was confirmed by RT-PCR.

pcDNA/fimH cassette could express inserted fimH gene in eukaryotic cells and is a valuable DNA cassette for urinary tract infection vaccination.