SARS-COV-2 RBD (Receptor binding domain) mutations and variants (A sectional-analytical study).

An essential step in SARS-CoV-2 infection is binding the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein to the ACE2 receptor on the surface of host cells. Therefore, variation in this region can have crucial effects on clinical outcomes and the emergence of variants of concern (VOCs) and variants of interest (VOIs). In this cross-sectional descriptive study, 54 patients with SARS-COV-2 infection were enrolled. After collecting samples and identifying the virus using the One-Step Real-Time qRT-PCR technique and confirming the viral infection, the region containing the RBD region for detection of any mutations was amplified using the Nested-PCR method. Finally, to identify probable mutations, the Nested-PCR product was sequenced. Our data show that the most mutant strains in circulation in our population are the delta variant (90.74%), alpha variant (5.56%), and omicron variant (3.70%), respectively. Pangolin Lineages strains were B.1.1.7(Alpha variant), B.1.617.2(Delta variant) and B.1.1.529(Omicron variant). Also, the mutation profile of variants suggests that N501Y, T478K, and D614G amino acid substitutions, are the significant mutations in the alpha and delta variants that are common with the Omicron variant. The highest frequency of clinical signs in the patients were: lung involvement (42.59%); fever, chills (40.74%); body pain (15%), and other signs (1.67%). Our data revealed that SARS-COV-2 RBD region variation results in substituting essential amino acids and the emergence of the new variant. We can consider it as a predictor for monitoring the emergence of variants of concerns and viral outcomes.

Genotyping and sequence characterization of the NSP4 gene of human group A rotavirus strains in Northern Iran.

Rotavirus is known to be responsible for remarkable numbers of severe diarrheal episodes and even death in infants and young children. In this study, we aimed to survey genetic diversity and variation analysis of viroporin, which is encoded by the rotavirus NSP4 segment. Thirty-five rotavirus-positive specimens were obtained, and RNA extraction and polymerase chain reaction amplification were performed. After the sequencing process, four specimens were excluded, and the final 31 samples remained for genetic diversity and variation analysis. The predominant single G/P combination was G1P[8] (~78%), followed by G2P[8] (~13%), and equal percentages (3%) of G2P[4], G3P[8], and G-non-typeable-P[8]. Further analyses revealed that variations could be found in the three regions of NSP4, including VP4 binding site (aa 112-146), double-layered particle binding site (aa 161-175), and finally, in the predicted amphipathic alpha-helix. Phylogenic tree analysis demonstrated that the mentioned samples clustered with genotype E1 and E2 reference sequences. As previously reported in the literature, in this study, it was revealed that no apparent correlation exists in the deduced amino acid sequences corresponding to this region between the rotaviruses collected from patients with and without diarrhea.

Hepatitis C virus DNA vaccines: a systematic review.

BACKGROUND: Vaccination against HCV is an effective measure in reduction of virus-related public health burden and mortality. However, no prophylactic vaccine is available as of yet. DNA-based immunization is a promising modality to generate cellular and humoral immune responses. The objective of this study is to provide a systematic review of HCV DNA vaccines and investigate and discuss the strategies employed to optimize their efficacies. METHODS: MEDLINE (PubMed), Web of Science, Scopus, ScienceDirect, and databases in persian language including the Regional Information Centre for Science & Technology (RICeST), the Scientific Information Database and the Iranian Research Institute for Information Science and Technology (IranDoc) were examined to identify studies pertaining to HCV nucleic acid vaccine development from 2000 to 2020. RESULTS: Twenty-seven articles were included. Studies related to HCV RNA vaccines were yet to be published. A variety of strategies were identified with the potential to optimize HCV DNA vaccines such as incorporating multiple viral proteins and molecular tags such as HBsAg and Immunoglobulin Fc, multi-epitope expression, co-expression plasmid utilization, recombinant subunit immunogens, heterologous prime-boosting, incorporating NS3 mutants in DNA vaccines, utilization of adjuvants, employment of less explored methods such as Gene Electro Transfer, construction of multi- CTL epitopes, utilizing co/post translational modifications and polycistronic genes, among others. The effectiveness of the aforementioned strategies in boosting immune response and improving vaccine potency was assessed. CONCLUSIONS: The recent progress on HCV vaccine development was examined in this systematic review to identify candidates with most promising prophylactic and therapeutic potential.

Antiviral Therapeutic Potential of Curcumin: An Update.

The treatment of viral disease has become a medical challenge because of the increasing incidence and prevalence of human viral pathogens, as well as the lack of viable treatment alternatives, including plant-derived strategies. This review attempts to investigate the trends of research on in vitro antiviral effects of curcumin against different classes of human viral pathogens worldwide. Various electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar were searched for published English articles evaluating the anti-viral activity of curcumin. Data were then extracted and analyzed. The forty-three studies (published from 1993 to 2020) that were identified contain data for 24 different viruses. The 50% cytotoxic concentration (CC50), 50% effective/inhibitory concentration (EC50/IC50), and stimulation index (SI) parameters showed that curcumin had antiviral activity against viruses causing diseases in humans. Data presented in this review highlight the potential antiviral applications of curcumin and open new avenues for further experiments on the clinical applications of curcumin and its derivatives.

Hepatitis C virus alternative reading frame protein (ARFP): Production, features, and pathogenesis.

Earlier observation suggests that hepatitis C virus (HCV) is a single-stranded RNA virus which encodes at least 10 viral proteins. F protein is a novel protein which has been discovered recently. These studies suggest three mechanisms for the production of this protein concerning ribosomal frameshift at codon 10, initial translation at codons 26 and 85 or 87. In this study, the association between protein F and chronicity of hepatocellular carcinoma (HCC) has been reviewed. Evidence suggests that humoral immune system can recognize this protein and produce antibodies against it. By detecting antibodies in infected people, investigators found that F protein might have a role in HCV infection causing chronic cirrhosis and HCC as higher prevalence was found in patients with mentioned complications. The increment of CD4+, CD25+, and FoxP3+ T cells, along with CD8+ T cells with low expression of granzyme B, also leads to weaker responses of the immune system which helps the infection to become chronic. Moreover, it contributes to the survival of the virus in the body through affecting the production of interferon. F protein also might play roles in the disease development, resulting in HCC. The existence of F protein affects cellular pathways through upregulating p53, c-myc, cyclin D1, and phosphorylating Rb. This review will summarize these effects on immune system and related mechanisms in cellular pathways.

Immunization of mice by the co-administration of codon-optimized HPV16 E7 and lL12 genes against HPV16-associated cervical cancer.

BACKGROUND: Various promising procedures have been used to improve the potency of DNA vaccines for the treatment of human papillomavirus type 16 (HPV16) infections. Interleukin-12 (IL12) is a powerful adjuvant that can contribute to T cell-mediated protection against many pathogens, specifically viruses. Considering the important role of T cell-mediated immunity in tumor clearance, the induction of these responses can help control the progression of tumors in animal models. We have demonstrated that the co-administration of codon-optimized E7 (uE7) gene of HPV16 with interleukin-12 is effective in the development of antitumor responses. OBJECTIVES: The present study examined the co-administration of codon-optimized HPV16 E7 gene with murine interleukin-12 gene (mIL-12) as a vaccine adjuvant in tumor mice model. MATERIALS AND METHODS: C57BL/6 mice were studied for tumor progression after injection of recombinant DNA vaccines. Lactate dehydrogenase (LDH) and IFN-γ were measured to evaluate the activity of cytotoxic T lymphocytes (CTLs). Measurements of tumor volume and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay were used for assessment of therapeutic antitumor effects of the vaccines. RESULTS: Results showed that DNA vaccines, specifically codon-optimized E7/murine interleukin-12 (mIL-12), elicited significant differences in levels of IFN-γ and cytotoxic T lymphocyte (CTLs) responses compared to control groups. Furthermore, higher antitumor response and lower tumor size in the vaccine group was significantly evident compared to control group. CONCLUSION: The co-administration of codon-optimized HPV16 E7 gene with IL12 significantly enhances the DNA vaccine potency against HPV16-associated cervical cancer.

Molecular characterization of the neuraminidase gene of influenza B virus in Northern Iran.

Neuraminidase inhibitors are the only FDA-approved class of antiviral agents against influenza B viruses. Resistance to these drugs has been reported from different parts of the world; however, there seems to be not enough information about this issue in Iran. We aimed to study the genetic evolution of these viruses as well as the presence of possible mutations concerning drug resistance in northern Iran. RNA was extracted from naso- and oropharyngeal swabs and amplified by one-step RT-PCR for detection and sequencing of the neuraminidase gene. All the data were edited and assembled utilizing BioEdit DNASequence Alignment Editor Software, and the phylogenetic tree was constructed via MEGA software version 10. Finally, resistance-associated mutations and B-cell epitopes substitutions were assessed by comparing our sequences with the counterparts in the reference strains. Comparing our sequences with reference strains revealed that the analyzed isolates of influenza B pertained to the B-Yamagata lineage, had a few B-cell epitopes alterations, and contained no particular mutations concerning resistance against neuraminidase inhibitors, such as oseltamivir. Our findings suggest that all the strains circulating in northern Iran and hopefully other parts of the country can be considered sensitive to this class of drugs. Although it is promising, we strongly recommend additional investigations to evaluate the impact of such drug-resistant mutations in other regions, which in turn will assist the public health agencies in taking immediate and effective therapeutic measures into account when needed.

Multicenter study of some liver and heart function tests in SARS-Cov-2 patients from three ethnic groups in Iran.

The liver and cardiovascular system disorders are not common in COVID-19 patients, but the patients suffering from these complications are exposed to a higher rate of mortality and disease progression. Hepatic injuries can drive to increased levels of liver enzymes, including ALT, AST, and LDH. Abundant levels of AST, LDH, and CPK can be indicators of cardiac injuries. The current study comparise 366 individuals who are divided into COVID-19 patients and healthy individuals groups, in which we have examined hepatic and cardiac function parameters. Moreover, the clinical characteristics of the participants, ethnicities, and their difference with studied parameters were assessed. The results showed Fars individuals are more susceptible to the disease progression, including liver and heart damage. COVID-19 infection is associated with aging, which indicates that the mean age of the case group is ten years older than the control group (P < 0.001). The blood sugar in the case group (140.50) was higher than in the control group (131.66), although there was no difference between the infection and BS (P = 0.505). Similarly, the increased- mean of the ALT level in the case group (102.369) compared with the control group (68.324) resulted in no significant difference (P = 0.318). Other parameters, including CPK, LDH, and AST showed an increase in the control group values compared to the case group; however, the differences were not significant (P = 0.264, P = 0.795, P = 0.417). Considering the involvement of cardiac and hepatic organs by SARS-CoV-2, paying particular attention to the disorders of these organs through assessing the hepatic and cardiac function parameters can enhance the patient's recovery and survival. However, in this study, we not observed significant differences, except for the Fars people. There is need for further assessment of this issue.

Relative Frequency of Blood-Borne Viruses in Hemodialysis-Dependent and Kidney Transplant Recipients in Iran.

BACKGROUND: Hemodialysis (HD) patients and kidney transplant (KT) recipients are exposed to be infected by blood-borne viruses (BBVs). Current study was conducted to evaluate the prevalence of BBVs in HD and KT patients in the whole Iranian population. METHODS: From Jan 2016 to Dec 2017, 174 hemodialysis and 139 kidney transplant recipients enrolled in this survey. After blood sampling, serum samples were detected for HBV, HCV, HCMV, HIV and HTLV antibodies. Seropositive samples confirmed by Polymerase chain reaction (PCR) method. RESULTS: Overall, 6 (3.44%) and 3 (2.15%) of hemodialysis-dependent and transplantation patients had evidence of HCV infection, whereas no patients were HIV and HBV positive, two cases (1.14%) of hemodialysis and one case (0.71%) of transplantation patients demonstrated the HTLV-1 infection. 52 (37.4%) of patients received graft were positive for HCMV antibody. In addition, our study showed a co-infection of HCMV with HCV (3 patients, 2.15%) in transplantation patients. CONCLUSION: Prevalence of BBVs infection was lower in comparison to the previous studies. The current strict infection control practices in Iran appear to be effective in limiting dialysis and related infections after transplantation. Because BBVs infections constantly occur especially in dialysis and after transplantation units, our data will be useful to build a new strategic plan for the elimination of BBVs infection in kidney therapycenters.

Evaluation and Phylogenetic Analysis of Regular Rabies Virus Vaccine Strains.

BACKGROUND: This study aimed to evaluate Rabies virus vaccine strains. The obtained results may be helpful for vaccine producers and researchers to compare the strains with wild type and other vaccine strains and select the correct strain to challenge their products. METHODS: Fourteen rabies virus vaccine strains were compared with each other. The full genomes of the selected strains were taken from the GenBank and the N, P and G genes were labeled. The major and minor antigenic sites of these sequences were identified and contrasted with each other. The identity matrix was designed for rabies virus full genome, N and G genes. In addition, the phylogenetic tree was drawn based on rabies virus N gene for deep analysis. RESULTS: Although there were no significant differences between antigenic sites in N, P, and G genes, there were noticeable differences for full genome identity matrix and this significant difference can also be observed in N and G identity matrix. In the phylogenetic tree, the Iranian sequences were distant from currently applied vaccine strains. CONCLUSION: It is necessary to pay attention to the results shown in phylogenetic tree because they warn us about distance between the Iranian sequences and current strains used in applied vaccines. In addition, the obtained results help vaccine producers to choose a correct strain to challenge their product and evaluate their vaccine potency.

E6-Specific Detection and Typing of Human Papillomaviruses in Oral Cavity Specimens from Iranian Patients

Background: Detection and quantification of human Papillomavirus (HPV) genome in oral carcinoma play an important role in diagnosis, as well as implications for progression of disease. Methods: We evaluated tissues from 50 esopharyngeal cancers collected from different regions of Iran for HPV E6 using the two type-specific primers sets. E6 gene of HPV genotypes was amplified by specific primers. The sensitivity of PCR assay was analyzed and determined using HPV-DNA-containing plasmids. Real-time PCR was utilized to determine the prevalence and HPV viral load in patients with oral cavity squamous cell carcinoma. Results: Eighteen (36%) specimens were positive for HPV. Among the 18 positive specimens, 10 showed HPV-18 (55.55%), and 8 specimens were positive for HPV-11 (44.44%). Of the 18 infected specimens, 6 (33.32%) and 12 (66.65%) were identified as high-titer and low-titer viral load, respectively. Conclusion: The PCR-based assay, developed in the current study, could be used for HPV detection, quantification, and genotyping in epidemiological and clinical studies.

Assessment the Efficiency of the Constructed Minigenome of Rabies Virus using PV Strain as Helper Virus.

INTRODUCTION: Rabies is an acute viral disease that causes encephalomyelitis in mammals and human. The only way to prevent this disease is through vaccination before or after exposure. The aim of this study is to evaluate the efficiency of the Pasteur virus (PV) minigenome, using PV strain. MATERIALS AND METHODS: Enhanced Green Fluorescent Protein (EGFP) sequence was placed between the designed necessary elements (Hammerhead, HDV ribozyme, 3' Leader, and 5' Trailer sequences), which resemble the rabies virus PV strain (PV2061) genome and anti-genome. These constructs were placed between T7 polymerase promoter and T7 polymerase terminator sequences. The accuracy of the minigenome was confirmed by the expression of EGFP using the helper virus in T7-BHK cell line. RESULTS: The viral necessary elements of positive and negative sense strands were evaluated for the ability of EGFP expression in the presence of the helper virus. While the positive strand showed background results, no EGFP background was observed in the negative strand application. CONCLUSION: Establishment of minigenome system does not require advanced biosafety levels. Furthermore, using minigenome system eliminates many potential confounding factors that may be present in coding regions of the genome. Use of the minigenome system is easier and more feasible than the full genome rescue of the virus. This study successfully shows the efficiency of the constructed rabies virus minigenome in expression of inserted gene.

A comparative approach between heterologous prime-boost vaccination strategy and DNA vaccinations for rabies.

BACKGROUND AND AIM: Rabies is a widespread neurological zoonotic disease causing significant mortality rates, especially in developing countries. Although a vaccine for rabies is available, its production and scheduling are costly in such countries. Advances in recombinant DNA technology have made it a good candidate for an affordable vaccine. Among the proteins of rabies virus, the Glycoprotein (RVG) has been the major target for new vaccine development which plays the principal role in providing complete protection against RV challenge. The aim of this study is to produce recombinant RVG which could be a DNA vaccine candidate and to evaluate the efficiency of this construct in a prime-boost vaccination regimen, compared to commercial vaccine. METHODS: Cloning to pcDNA3.1(+) and expression of rabies virus glycoprotein gene in BSR cell  line were performed followed by SDS-PAGE and Western blot analysis of the expressed glycoprotein. The resulting genetic construct was used as a DNA vaccine by injecting 80 µg of the plasmid to MNRI mice twice. Prime-Boost vaccination strategy was performed using 80 µg plasmid construct as prime dose and the second dose of an inactivated rabies virus vaccine. Production of rabies virus neutralizing antibody (RVNA) titers of the serum samples were determined by RFFIT. RESULTS: In comparisons between heterologous prime-boost vaccination strategy and DNA vaccinations, the potency of group D that received Prime-Boost vaccine with the second dose of pcDNA3.1(+)-Gp was enhanced significantly compared to the group C which had received pcDNA3.1(+)-Gp as first injection. CONCLUSION: In this study, RVGP expressing construct was used in a comparative approach between Prime-Boost vaccination strategy and DNA vaccination and compared with the standard method of rabies vaccination. It was concluded that this strategy could lead to induction of acceptable humoral immunity.

Detection of Specific Antibodies to HCV-ARF/CORE+1 Protein in Cirrhotic and Non-Cirrhotic Patients with Hepatitis C: A Possible Association with Progressive Fibrosis.

BACKGROUND: The role of different viral proteins in the progression of the disease to cirrhosis is not completely understood. The ARFP/F protein is a newly described protein synthesized from the +1 or -2 reading frames of the core protein gene, which its function remains unknown. The purpose of this study is to detect specific antibodies to HCV-ARF/Core+1 protein in cirrhotic and non-cirrhotic patients with HCV and investigate any possible association. METHODS: ARF/Core+1 recombinant proteins from HCV genotype 1a were expressed in Escherichia coli, and purified. Using an enzyme-linked immunosorbent assay, we assessed the prevalence of anti-ARF/Core+1 antibodies in 50 cirrhotic and 50 non-cirrhotic hepatitis C patients. RESULTS: All 50 cirrhotic patients were positive for anti-ARF/Core+1 antibody, while only 80% positive samples among non-cirrhotic patients were detected. The titer of anti-ARF/Core+1 antibody was also significantly higher in patients with cirrhosis than in non-cirrhotic patients. CONCLUSION: Compared to 80% positive samples among non-cirrhotic patients all 50 cirrhotic patients were positive for anti-ARF/Core+1 antibody and titer of anti-ARF/Core+1 antibody was significantly higher in patients with cirrhosis than in non-cirrhotic. These results suggest that ARF/Core+1 protein is associated with cirrhosis. A possible causative association between ARF/Core+1 and cirrhosis as well as the mechanism of this association needs to be further investigated.

F protein increases CD4+CD25+ T cell population in patients with chronic hepatitis C.

HCV is a global health problem with an estimated 230 million chronically infected people worldwide. It has been reported that a 17-kd protein translated from core-encoding genomic region can contribute to immune-mediated mechanisms associated with the development of the chronic disease. Also, Treg cells can be contributed to an inadequate response against the viruses, leading to chronic infection. Here we evaluated the ability of protein F to modulate the frequency of CD4+CD25+FoxP3+T and IL-10+T cells in patients with chronic HCV infection. F gene was amplified and cloned in the expression vector. The protein was purified and used for stimulation of PBMCs in the HCV chronic patients and the control groups. The frequency of CD4+CD25+FoxP3+ T cell-like populations and IL-10-producing CD4+CD25+ T cells was assessed in the HCV-infected patients and in the healthy controls by flow cytometry, which showed an increase of both CD4+CD25+FoxP3+ T cell-like population and IL-10-producing CD4+CD25+ T cells in the HCV-infected patients positive for anti-F antibody. Our results suggest the potential involvement of F and core antigens in increasing the frequency of CD4+CD25+FoxP3+ T cell-like population and IL-10-producing CD4+CD25+ T cells which may be associated with HCV-persistent infection.

A novel combined method for cost-benefit production of DNA ladders.

BACKGROUND: Molecular deoxyribonucleic acid markers are one of the most important tools in molecular biology labs. The size of DNA molecule is determined by comparing them with known bands of markers during gel electrophoresis. In this study, we have suggested an efficient strategy to produce molecular weight markers in an industrial scale. MATERIALS AND METHODS: A combination of two previously known methods, restriction enzyme digestion and polymerase chain reaction (PCR), was used. The enzymatic digestion process was based on designing and constructing plasmids which equaled in size with the bands of ladder and produce the DNA fragment by plasmid linearization through digestion. In the PCR method, the DNA fragments with length 102 bp lesser than the related bands in DNA ladder are amplified by PCR and cloned in pTZ57T/A cloning vector. Then, PCRs with forward and reverse 100-bp primers on the resulting plasmids amplify the ladder fragments. F100 and R100 primers bind to the backbone of pTZ57R (without insert) and amplify a 100-bp PCR product. PCR on the plasmid with insert amplifies DNA fragment with 102+ insert length bp size. RESULTS: Upon application of this strategy, 2000-10,000 bp DNA fragments were produced by enzymatic digestion of plasmids of the same size. Moreover, 100-1500 bp fragments were produced during PCR using only a set of forward and reverse (100 bp) primers. CONCLUSION: The highest advantage of this cost-benefit approach is to produce different types of molecular weight markers by using an effective and short protocol.

Construction of an eGFP Expression Plasmid under Control of T7 Promoter and IRES Sequence for Assay of T7 RNA Polymerase Activity in Mammalian Cell Lines.

BACKGROUND: Recently, the use of T7 RNA polymerase instead of other viral and cellular promoters is increasing due to high efficacy of transcription in the cell cytoplasm by this polymerase. In order to translate the transcripts produced by T7 RNA polymerase in mammalian cell lines, it is necessary to include Internal Ribosome Entry Site (IRES) sequences. In addition, if sequence of poly A signal would be included after interested gene, the rate of expression could be increased in the cells. METHODS: For expression of eGFP in HEK-293 and T7-BHK cells by T7 RNA polymerase, the sequence of eGFP as well as IRES sequences upstream of eGFP gene and poly A signal were inserted into a pUC57 plasmid. On the other hand, gene of T7 RNA polymerase was cloned into modified pIRES2-EGFP plasmid. Then, the constructed plasmids were transfected into HEK-293 cells. T7-BHK cell was used for control of T7 RNA polymerase activity. RESULTS: Our results showed that using T7 RNA polymerase for expression of foreign genes in mammalian cell lines is highly efficient. CONCLUSION: Highly efficient eGFP expression in HEK-293 cells showed that T7 RNA polymerase could be used for cytoplasmic RNA transcription such as production of anti-cancer proteins and oncolytic viral genomic RNA by reverse genetics.