Construction of pLLO vector encoding truncated form of Listeriolysin O as molecular adjuvant for DNA vaccine studies

Background: The major problem of DNA vaccine is less immunogenicity of them verses other killed or live whole organism vaccines therefore adjuvants for use in this kind vaccines is very necessary. Genetic adjuvants with bacterial sources are an appropriate approach to modulate immune responses to DNA vaccines. Listeria Monocytogenes proteins such as Listeriolysin O (LLO) with CD4 and CD8 epitopes can be as an adjuvant to initiate both innate and adaptive immune responses if the protein cytotoxicity can be eliminated. Herein we constructed a truncated LLO plasmid as genetic adjuvant and tested it in combination with a DNA construct as a model vaccine.Materials and Methods: About 1340bp of the 5' end of whole LLO gene was amplified by PCR on DNA purified from Listeria Monocytogenes. Sequential sub cloning of truncated LLO into the Xho I/EcoRV sites of pcDNA3.1 plasmid, downstream of CMV promoter was done. pLLO plasmid was transfected to HEK293T cell line by lipofection method. LLO protein expression from transiently transfected 293T cell lysates was confirmed by western blotting. Then the adjuvant activity of LLO in BALB/c mice model was analyzed using proliferation test.Results: Double digestion of pLLO plasmid with the enzymes that were applied for cloning led to the isolation of two fragments with expected sizes. The final plasmid was also confirmed following sequencing reactions. Moreover, expression of LLO was evidenced in transfected 293T cells, compared to non-transfected controls. In vivo study was shown, high significant proliferative responses in LLO co-immunization pattern.Conclusion: In the DNA vaccine study, LLO co-administration plasmid could be a suitable genetic adjuvant to enhance cellular immune response of vaccine

Solvent effects on structural and thermochemical properties of p53 tumor-suppressor gene: a molecular modeling approach in drug design

The p53 tumor-suppressor protein is a cellular phosphoprotein and a negative regulator of cell growth. Most p53 mutations occur in exons 5–8 within the DNA-binding domain. Therefore, p53 can potentially be targeted with novel drugs designed to bind to a mutation and restore its stability or wild-type conformation. For the current study, Hartree–Fock calculations were used to investigate the solvent-induced effects of five different solvent media (acetone, ethanol, methanol, dimethyl sulfoxide, and water) on the thermochemical parameters and relative energies, and on the multinuclear nuclear magnetic resonance shielding tensors of oxygen, nitrogen, and phosphorus nuclei, of GAT. To understand how the solvent affects the mutation region (the “hot spot”) of p53, the relative energies of GAT in selected solvent media were determined. Some biological evidence suggested the structural stabilities of hot spots of GAT have the optimum temperature and solvent type for mutation. All the authors’ findings are in accordance with common biological phenomena. Another important objective of this study was to compare the hydration Gibbs free energies of CUA and GAT in water using two different approaches where the solvent was treated as a continuum of the constant at different levels of Hartree–Fock theory. The Gibbs hydration energy values obtained in water with the polarized continuum model directly applied on the isolated CUA and GAT sequences were compared with those determined from the hydrated models with four, six, and eight water molecule clusters around the hot spots uracil and adenine. The clustered structures of water molecules around the hot spots of GAT (in DNA level) and CUA (in transcriptional level) were found to be energetically favored. The results of this study provide a reliable insight into the nature of mutation processes, which is of utmost importance for the study of biochemical structures, and provide a basis for drug design

Design, construction and evaluation of 1a/JFH1 HCV chimera by replacing the intergenotypic variable region

Peer reviewedPublisher PD

Effect of Dexamethasone on Striatal Neurotransmissions in the Rats Subjected to Parkinson’s Disease Animal Model

Objective(s)The aim of this study was to evaluate the effects of dexamethasone on striatal dopaminergic, glutamatergic and gamma amino butyric acid (GABA) ergic neurotransmission in normal and parkinsonian rats.Materials and MethodsDexamethasone (0.15, 0.30, 0.60 and 0.8 mg/kg) was administered to normal or parkinsonian rats (i.p.) followed by the analysis of the striatal neurotransmitters concentrations. Additionally, the effect of dexamethasone on the damaged Substantia nigra pars compata (SNc) neurons has been investigated. ResultsDexamethasone resulted in decreased level of striatum glutamatergic-GABAergic and enhanced dopaminergic neurotransmission in normal and parkinsonian rats. In addition, acute treatment with dexamethasone did not improve the lesion at all. ConclusionThese findings suggest the new therapeutic mechanism of action for dexamethasone in Parkinson’s disease animal model

High Resolution Melting Curve Assay for Detecting rs12979860 IL28B Polymorphisms Involved in Response of Iranian Patients to Chronic Hepatitis C Treatment

Background: A recent genome-wide association study (GWAS) on patients with chronic hepatitis C (CHC) treated with peginterferon and ribavirin (pegIFN-α/RBV) identified a single nucleotide polymorphism (SNP) on chromosome 19 (rs12979860) which was strongly associated with a sustained virological response (SVR). The aim of this study was twofold: to study the relationship between IL28B rs12979860 and sustained virological response (SVR) to pegIFN-α/RVB therapy among CHC patients and to detect the rs12979860 polymorphism by high resolution melting curve (HRM) assay as a simple, fast, sensitive, and inexpensive method. Materials and Methods: The study examined outcomes in 100 patients with chronic hepatitis C in 2 provinces of Iran from December 2011 to June 2013. Two methods were applied to detect IL28B polymorphisms: PCR-sequencing as a gold standard method and HRM as a simple, fast, sensitive, and inexpensive method. Results: The frequencies of IL28B rs12979860 CC, CT, and TT alleles in chronic hepatitis C genotype 1a patients were 10% (10/100), 35% (35/100), and 6% (6/100) and in genotype 3a were 13% (13/100), 31% (31/100), and 5% (5/100), respectively. In genotype 3a infected patients, rs12979860 (CC and CT alleles) and in genotype 1a infected patients (CC allele) were significantly associated with a sustained virological response (SVR). The SVR rates for CC, CT and TT (IL28B rs12979860) were 18%, 34% and 4%, respectively. Multiple logistic regression analysis identified two independent factors that were significantly associated with SVR: IL-28B genotype (rs 12979860 CC vs TT and CT; odds ratio [ORs], 7.86 and 4.084, respectively), and HCV subtype 1a (OR, 7.46). In the present study, an association between SVR rates and IL28B polymorphisms was observed. Conclusions: The HRM assay described herein is rapid, inexpensive, sensitive and accurate for detecting rs12979860 alleles in CHC patients. This method can be readily adopted by any molecular diagnostic laboratory with HRM capability and will be clinically beneficial in predicting treatment response in HCV genotype 1 and 3 infected patients. In addition, it was demonstrated that CC and CT alleles in HCV-3a and the CC allele in HCV-1a were significantly associated with response to pegIFN-α/RBV treatment. The present results may help identify subjects for whom the therapy might be successful

Design of novel multiepitope constructs-based peptide vaccine against the structural S, N and M proteins of human COVID-19 using immunoinformatics analysis.

The causative agent of severe acute respiratory syndrome (SARS) reported by the Chinese Center for Disease Control (China CDC) has been identified as a novel Betacoronavirus (SARS-CoV-2). A computational approach was adopted to identify multiepitope vaccine candidates against SARS-CoV-2 based on S, N and M proteins being able to elicit both humoral and cellular immune responses. In this study, the sequence of the virus was obtained from NCBI database and analyzed with in silico tools such as NetMHCpan, IEDB, BepiPred, NetCTL, Tap transport/proteasomal cleavage, Pa3P, GalexyPepDock, I-TASSER, Ellipro and ClusPro. To identify the most immunodominant regions, after analysis of population coverage and epitope conservancy, we proposed three different constructs based on linear B-cell, CTL and HTL epitopes. The 3D structure of constructs was assessed to find discontinuous B-cell epitopes. Among CTL predicted epitopes, S257-265, S603-611 and S360-368, and among HTL predicted epitopes, N167-181, S313-330 and S1110-1126 had better MHC binding rank. We found one putative CTL epitope, S360-368 related to receptor-binding domain (RBD) region for S protein. The predicted epitopes were non-allergen and showed a high quality of proteasomal cleavage and Tap transport efficiency and 100% conservancy within four different clades of SARS-CoV-2. For CTL and HTL epitopes, the highest population coverage of the world's population was calculated for S27-37 with 86.27% and for S196-231, S303-323, S313-330, S1009-1030 and N328-349 with 90.33%, respectively. We identified overall 10 discontinuous B-cell epitopes for three multiepitope constructs. All three constructs showed strong interactions with TLRs 2, 3 and 4 supporting the hypothesis of SARS-CoV-2 susceptibility to TLRs 2, 3 and 4 like other Coronaviridae families. These data demonstrated that the novel designed multiepitope constructs can contribute to develop SARS-CoV-2 peptide vaccine candidates. The in vivo studies are underway using several vaccination strategies

Designing, Constructing and Immunogenic Evaluation of Polytope DNA Constructs by the Application of Hepatitis C Virus Immunodominant Epitopes in BALB/c Mouse

Objective: Polytope DNA vaccines, capable of focusing the cytotoxic T lymphocyte (CTL)response on critical epitopes, represent a promising approach in HCV immunotherapy. Nevertheless,due to controversial rules governing epitope processing and the low level expression/immunogenicity of recombinant polytope peptides, designing and primary expression/immunogenicity analysis of these vaccine types should be the first consideration prior tocostly transgenic animal studies.Materials and Methods: Four HLA-A2 and H-2d restricted CTL epitopes were selected anddesigned in three appropriate sequential tandems based on epitope and proteasomal cleavagepredictions. The related nucleotide sequences were synthesized using SOEing PCRmethod and cloned into a pcDNA3.1 vector, either alone or fused to the small hepatitis B surfaceantigen (HBsAg-S) gene. Following the preparation of polyclonal anti-sera, expression/secretion of polytopes was evaluated in Cos-7 cells by using immunofluorescence, Westernblot,dot blot, ELISA and RT-PCR techniques. The immunogenicity of the plasmids was alsoassessed through the delayed-type hypersensitivity (DTH) assay in BALB/c mice.Results: Due to in silico designs and optimizations, the polytope products of constructedplasmids were efficiently detected in vitro through common techniques and HBsAg-S-basedparticles were shown to be secreted into the culture media (up to 30%). Moreover, all plasmidswere able to efficiently induce a positive DTH response while HBsAg-S fusion constructsindicated a significant immunopotential effect towards the incorporated mouse epitopes.Conclusion: Designed polytope constructs of this study are efficiently expressed and processed.They have the required initial potency for further immunogenicity analysis in transgenicmice

Design, cloning and expression assay of oipA gene in a bicistronic vector harboring mice IL-18 gene: potential implications for Helicobacter pylori vaccine investigations

Introduction: Helicobacter pylori (H. pylori) infection has remained as a global health problem. Animal studies demonstrated the role of H. pylori oipA gene in the development of gastric cancer. The aim of this study was the cloning and expression of Helicobacter pylori oipA gene in a bicistronic vector harboring mice IL-18 gene. Materials and methods: The target gene encoding oipA was amplified from a codon-optimized clone by PCR, and then double-digested by restriction enzymes. The pIRES-Igk/mIL18/Fc plasmid was simultaneously digested by BstXI/NotI enzymes to elicit the eGFP segment. PCR product of oipA was inserted into pIRES-Igk/mIL18/Fc plasmid using T4 ligase. Transformation into DH5α strain was done. Cloning was confirmed by PCR, enzymatic digestion and sequencing. Expression of the oipA and IL-18 mRNA was assessed by means of TaqMan Real-time PCR. Results: Electrophoresis of PCR product, enzymatic digestion and sequencing showed that the H. pylori oipA gene was successfully cloned into pIRES-Igk/mIL18/Fc to generate mIL-18-pIRES2-oipA plasmid. The results of Real-time PCR confirmed the successful expression of both oipA and IL-18 in mouse macrophage cell line. Conclusion: Considering the role of oipA in pathogenesis of H. pylori and potent activity of IL-18 as a molecular adjuvant, the results of the present study showed that the expression of codon-optimized oipA gene in bicistronic vector including mouse IL-18 is successful. So, it could be considered as an appropriate genetic vaccine candidate for H. pylori in future investigations

Association of GSTP1 Ile105Val gene polymorphism and uterine leiomyoma in Iranian population

Background: Uterine leiomyoma is one of the most common benign smooth muscle tumors occurring in 20-40% of women worldwide in their reproductive years. Recent studies revealed that estrogen plays an important role in the pathogenesis of uterine leiomyoma. Since, Glutathione s-transferase (GST) gene families are involved in the biosynthesis of estrogen, the prior probability that variants at this locus are associated with uterine leiomyoma is likely to be above the null. Therefore, this study was carried out to examine whether GSTP1 Ile105Val polymorphism is associated with uterine leiomyoma in Iranian population. Methods: In this case-control study, 50 women affected with uterine leiomyoma and 50 healthy controls were recruited among participants at the Pasteur Institute of Iran from November 2012 to September 2013. The genomic DNA was extracted from peripheral blood leucocytes using the standard phenol-chloroform method and subsequently the GSTP1 polymorphism was genotyped using Amplification Refractory Mutation System (ARMS-PCR). Association of Ile105Val polymorphism with uterine leiomyoma was examined using the SPSS statistical software package, version 18.0 after age adjustment. Results: The results showed significant differences between case and control groups in terms of genotype frequency (P<0.0001). In addition, the results indicated that the presence of the valine allele significantly increased risk of uterine leiomyoma approximately 3 times more in individuals carrying the mutant allele compared to control group (Odds Ratio: 3.34; 95%CI: 1.82-6.15; P<0.0001). Conclusion: To our knowledge, this is the first study performed in Iranian population assessing the association between GSTP1 Ile105Val polymorphism and risk of uterine leiomyoma. However, further extensive researches with a large number of samples from different populations and ethnicities are required to validate the results obtained in this study