Comparative evaluation of cervical pulpotomy and pulpectomy for primary molars with irreversible pulpitis: a multicentre randomised controlled trial

PURPOSE

The objective of this multicentre randomised controlled trial was to compare the clinical/radiographic outcomes of cervical pulpotomy using calcium-enriched mixture cement (PCEM) and pulpectomy using Metapex (PM) in primary molars with irreversible pulpitis (IP).

METHODS

A total of 134 primary molars from 94 children were randomly assigned to two intervention groups: the PCEM group (n = 74) and the PM group (n = 60). Baseline characteristics including age/gender/molar type/tooth type/jaw were recorded. The primary outcome measures were clinical/radiographic success rates assessed at the first and second follow-up appointments. Secondary outcomes included reasons for clinical/radiographic failures. Multiple logistic regression analysis was performed to determine the impact of various factors on the success rates.

RESULTS

The mean age of the participants in both groups was similar (PCEM group: 5.4 years, PM group: 5.5 years). Gender distribution, molar type, tooth type, jaw, and number of practitioners were comparable between the groups. The clinical success rate at the first follow-up was 98.6% in the PCEM group and 96.4% in the PM group. At the second follow-up, the clinical success rate was 97.1% in the PCEM group and 91.1% in the PM group. The radiographic success rates at the first and second follow-up were 98.6% and 96.4% in the PCEM group and 96.4% and 91.1% in the PM group, respectively. Multiple logistic regression analysis did not reveal any significant association between the success rates and age/gender/molar type/jaw, or treatment groups (P > 0.05).

CONCLUSION

In primary molars with IP, both simple/conservative cervical pulpotomy using calcium-enriched mixture cement and pulpectomy using Metapex demonstrated high clinical/radiographic success rates. No significant differences were observed between the two treatment modalities. These findings suggest that both techniques can be considered effective treatment options for managing primary molars with IP.

TRIAL REGISTRATION NUMBER

Trial registration number: IRCT20201226049838N1, retrospectively registered on 12 January 2021.

Development of novel HPV therapeutic vaccine constructs based on engineered exosomes and tumor cell lysates

AIMS

Human papillomavirus (HPV) infections are highly prevalent globally. While preventive HPV vaccines exist, therapeutic vaccines are needed to treat existing HPV lesions and malignancies. This study evaluated the immunostimulatory and anti-tumor effects of three therapeutic vaccine candidates based on the recombinant protein, tumor cell lysate (TCL), and engineered exosome (Exo) harboring the heat shock protein 27 (Hsp27)-E7 fusion construct in mouse model.

MAIN METHODS

At first, the recombinant Hsp27-E7 protein was generated in E. coli expression system. Then, tumor cell lysates-based and engineered exosomes-based vaccine constructs harboring green fluorescent protein (GFP) and Hsp27-E7 were produced using lentiviral system. Finally, their immunological and antitumor effects were investigated in both prophylactic and therapeutic experiments.

KEY FINDINGS

Our data showed that the recombinant Hsp27-E7 protein, TCL-Hsp27-E7 and Exo-Hsp27-E7 regimens can induce the highest level of IFN-γ, TNF-α and Granzyme B, respectively. The percentage of tumor-free mice was identical for three vaccine strategies (survival rate: 75 %) in both prophylactic and therapeutic experiments. Generally, the TCL-Hsp27-E7, Exo-Hsp27-E7 and recombinant Hsp27-E7 protein regimens induced effective immune responses toward Th1 and CTL activity, and subsequently antitumor effects in mouse model.

SIGNIFICANCE

Regarding to higher Granzyme B secretion, lower tumor growth and more safety, the Exo-Hsp27-E7 regimen can be considered as the most promising HPV vaccination strategy.

In-vitro antimicrobial activity of AF-DP protein and in-silico approach of cell membrane disruption

Microbial resistance against common antibiotics has become one of the most serious threats to human health. The increasing statistics on this problem show the necessity of finding a way to deal with it. In recent years, antimicrobial peptides with unique properties and the capability of targeting a wide range of pathogens, have been considered as a potential for replacing common antibiotics. A small chitin-binding protein with anticandidal activity was isolated from Moringa oleifera seeds by Neto and colleagues in 2017, which very much resembled antimicrobial peptides. In this study, the antimicrobial protein 'AF-DP' was identified and characterized. AF-DP was heterologously expressed, purified, and characterized, and its 3D structure was predicted. Six molecular dynamic simulations were performed to investigate how the protein interacts with Gram-negative inner and outer, Gram-positive, fungal, cancerous, and normal mammalian membranes. Also, its antimicrobial and anticancer activity was assessed in vitro via minimum inhibition concentration (MIC) and MTT assays, respectively. This protein with 111 amino acids and a total net charge (of 10.5) has been predicted to be mainly composed of alpha helix and random coils. Its MIC affecting the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans was 30 µg/ml, 100 µg/ml, and 100 µg/ml, respectively; AF-DP showed anticancer activity against MCF-7 breast cancer cell line. Scanning electron microscopic analysis confirmed the creation of pores and scratches on the surface of the bacterial membrane. The results of this research show that AF-DP can be a candidate for the production of new drugs as an AMP with antimicrobial activity.Communicated by Ramaswamy H. Sarma.

Lessons from COVID-19 Pandemic: A Successful Policy and Practice by Pasteur Institute of Iran

The present study aims to provide an insight to the comprehensive efforts of Pasteur Institute of Iran (PII) regarding COVID-19 management, research, achievements, and vaccine production, though there are many challenges. The relevant literature review was investigated through national and international database and also reports from the related research departments. Six strategies were taken by PII to manage the pandemic of COVID-19. While this pandemic has been hopefully controlled, SARS-CoV-2 could still be a potential threat. Therefore, COVID-19 data management and updated studies, as well as long-term safety and efficacy of the SARS-CoV-2 vaccines are still on the agenda.

Rapid and sensitive detection of SARS-CoV-2 virus in human saliva samples using glycan based nanozyme: a clinical study

A highly sensitive colorimetric method (glycan-based nano(e)zyme) was developed for sensitive and rapid detection of the SARS-CoV-2 virus based on N-acetyl neuraminic acid (sialic acid)-functionalized gold nanoparticles (SA-Au NZs). A number of techniques were used to characterize the prepared nanomaterials including XRD, FT-IR, UV-vis, DLS, and TEM. DLS analysis indicates an average hydrodynamic size of 34 nm, whereas TEM analysis indicates an average particle size of 15.78 nm. This observation confirms that water interacts with nanoparticle surfaces, resulting in a large hydrodynamic diameter. The peroxidase-like activity of SA-Au NZs was examined with SARS-CoV-2 and influenza viruses (influenza A (H1N1), influenza A (H3N2), and influenza B). UV-visible spectroscopy was used to monitor and record the results, as well as naked eye detection (photographs). SA-Au NZs exhibit a change in color from light red to purple when SARS-CoV-2 is present, and they exhibit a redshift in their spectrum. N-acetyl neuraminic acid interacts with SARS-CoV-2 spike glycoprotein, confirming its ability to bind glycans. As a result, SA-Au NZs can detect COVID-19 with sensitivity and specificity of over 95% and 98%, respectively. This method was approved by testing saliva samples from 533 suspected individuals at Ghaem Hospital of Mashhad, Mashhad, Iran. Sensitivity and specificity were calculated by comparing the results with the definitive results. The positive results were accompanied by a color change from bright red to purple within five minutes. Statistical analysis was performed based on variables such as age, gender, smoking, diabetes, hypertension, and lung involvement. In clinical trials, it was demonstrated that this method can be used to diagnose SARS-CoV-2 in a variety of places, such as medical centers, hospitals, airports, universities, and schools.

Epidemiological surveillance of respiratory viral infections in SARS-CoV-2-negative samples during COVID-19 pandemic in Iran

BACKGROUND

To improve the patient care, public health surveillance, and infection control, it is crucial to identify the presence and frequency of the common respiratory infections in individuals with COVID-19 symptoms but tested negative for SARS-CoV-2. This study aimed to shed light on this during the COVID-19 pandemic in Iran.

METHODS

In this cross-sectional study, a total of 1,002 patients with acute respiratory infection who had negative SARS-CoV-2 test results and referred to Valfajr Health Center, the National Collaborating Laboratory of Influenza and COVID-19 National Reference Laboratory at Pasteur Institute of Iran were recruited between January 2020 and January 2022. Nasopharyngeal and oropharyngeal swab samples were collected to detect 17 common respiratory viruses via TaqMan one-step real-time multiplex PCR. Demographic and clinical data of the participants were obtained from their electronic medical records.

RESULTS

In total, 218 samples (21.8%) were tested positive for at least one respiratory virus infection. Most of the common investigated respiratory viruses belonged to the years 2020 and 2022. The number of investigated patients in 2021 was few, which highlights the impact of health measures following the COVID-19 pandemic in Iran. Influenza A was the most common virus (5.8%), while adenovirus had the lowest prevalence (0.1%). Although the rate of respiratory virus infection was higher in men (24%) compared to women (19.3%), this difference was not statistically significant (P = 0.069). The prevalence of respiratory viruses had an inverse association with increasing age, with the highest rate (55.6%) observed in the age group below 2 years and the lowest rate (12.7%) in those above 65 years.

CONCLUSION

Our findings underscore the significance of adopting a comprehensive approach to respiratory infections detection and management. These results can be employed for the development of syndromic surveillance systems and implementation of the effective infection control measures. Furthermore, the results contribute to better understanding of the dynamics of respiratory viruses, both during pandemic periods and in non-pandemic contexts.

A Comprehensive Comparison of Rapid RNA Extraction Methods for Detection of SARS-CoV-2 as the Infectious Agent of the Upper Respiratory Tract using Direct RT-LAMP Assay

Background

The current COVID-19 pandemic has highlighted the need for faster and more cost-effective diagnostic methods. The RNA extraction step in current diagnostic methods, such as real-time qPCR, increases the cost and time required for testing. Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) is a promising technique for developing diagnostic tests with desired sensitivity and specificity without the need for RNA extraction.

Materials and Methods

An RT-LAMP assay was developed to detect SARS-CoV-2 with a sensitivity of 0.5 copies of positive control plasmid per microliter in 40 min. Several rapid RNA extraction protocols were evaluated using different reagents, including bovine serum albumin, Triton X-100, Tween 20, proteinase K, guanidine hydrochloride, guanidinium isothiocyanate (GITC), and thermal treatment. Finally, the sensitivity and specificity of the developed direct RT-LAMP were determined using 150 upper respiratory tract samples.

Results

Method 10 was selected as the most efficient protocol for the RNA extraction step. The sensitivity and specificity of the developed direct RT-LAMP assay with clinical samples were estimated at 98.4% and 88.8%, respectively.

Conclusion

These results suggest that the combination of GITC and Triton X-100 detergent is a highly efficient method for RNA extraction and direct RT-LAMP detection of SARS-CoV-2 in clinical samples, providing a valuable tool for the rapid and cost-effective diagnosis of COVID-19.

Development of a robust TaqMan probe-based one-step multiplex RT-qPCR for simultaneous detection of SARS-CoV-2 and Influenza A/B viruses

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Influenza A, and Influenza B viruses is essential for rapid differential diagnosis in patients with similar symptoms, especially during "flu season" in the post-pandemic era. So far, several multiplex methods have been approved for the simultaneous detection of SARS-CoV-2, Influenza A, and Influenza B. However, due to the rapid mutation rate of the SARS-CoV-2 genome and the emergence of new variants, existing methods must be improved and updated.

METHODS

To identify a highly conserved region in the SARS-CoV-2 N-gene, a genomic survey was performed to increase the sensitivity and specificity of primer and probe sets targeting the SARS-CoV-2 genome. The 95% LLOD (95% lower limits of detection) were calculated by probit analysis. A total of 70 predetermined clinical samples using singleplex RT-qPCR assays, were included. The clinical performance of the multiplex RT-qPCR assay was determined and compared with a commercial multiplex kit. The Cohen's kappa coefficient, P-value (McNemar's test), Passing-Bablok regression, and Bland Altman agreement analysis were determined to monitor the agreement of the assays.

RESULTS

The novel SARS-CoV-2 primer and probe set designed in this assay was able to detect all variants of concern (VOCs) and variants of interest (VOIs) with high analytical and clinical performance. The 95% LLOD for the multiplex RT-qPCR was 20 copies per reaction for the N gene of SARS-CoV-2, 2 copies per reaction for M1 gene of Influenza A and NS1 gene of Influenza B. The diagnostic sensitivity of the multiplex RT-qPCR was 94.4%, 93.7%, and 100% for the detection of SARS-CoV-2, Influenza A, and Influenza B genomes, respectively. Moreover, the specificity was identical (100%) in both assays. According to the agreement analysis results, there was no statistical difference between our multiplex assay and the commercial kit.

CONCLUSIONS

In this study, we developed a novel in-house made multiplex RT-qPCR assay, with high sensitivity, specificity, and reliability for the diagnosis of SARS-CoV-2 infection in clinical samples. This is valuable during Influenza seasons when influenza co-circulates with SARS-CoV-2, as it saves costs, time, and thus specific and timely treatment of patients.

Evaluation of PastoCovac plus vaccine as a booster dose on vaccinated individuals with inactivated COVID-19 vaccine

COVID-19 pandemic has been managed through global vaccination programs. However, the antibody waning in various types of vaccines came to notice. Hereby, PastoCovac Plus as a protein subunit vaccine was investigated in immunized health care workers by COVAXIN (BBV152). The booster vaccine was recommended at least three months post the second dose of COVAXIN. Sera collection was done before and after each injection. SARS-CoV-2 PCR test was done monthly to detect any asymptomatic and symptomatic vaccine breakthrough. 47.9 and 24.3% of the participants were seronegative for anti-N and anti-S antibodies three months after the second dose of COVAXIN, respectively. On average, fold-rises of 70, 93, 8 and mean-rises of 23.32, 892.4, 5.59 were recorded regarding neutralizing antibody, quantitative and semi-quantitative anti-Spike antibody, respectively. Anti-Spike and neutralizing antibodies seroconversion was seen 59.3% and 45.7%, respectively. The vaccine breakthrough assessment showed that all the isolated samples belonged to SARS-CoV-2 Delta variant. PastoCovac Plus boosting is strongly recommended in combination with inactivated vaccine platforms against SARS-CoV-2.

Phylogenetic analysis and docking study of neuraminidase gene of influenza A/H1N1 viruses circulating in Iran from 2010 to 2019

Influenza A viruses (H1N1) have been consistently one of the most evolving viruses that escape from vaccine-induced immunity. Although there has been a rapid rise in human influenza virus knowledge since the 2009 pandemic, the molecular information about Iranian strains is still inadequate. The aim of this study was to analyze the neuraminidase (NA) segment of the Iranian isolates in terms of phylogenetic, antiviral resistance, and vaccine efficiency. Ninety-three NA sequences collected among 1758 nasopharyngeal swab samples during the 2015-2016 influenza season were sequenced and submitted to NCBI. Moreover, all the submitted Iranian influenza H1N1 NA sequences since 2010 till 2019 were included in the study. Software including MEGA-X, MODELLER, UCSF ChimeraX, Auto-Dock 4.2, and other online tools were used to analyze the phylogenetic relationship, vaccine efficiency, and binding affinity to sialic acid of the selected NA proteins. Moreover, the information about antiviral drug resistance mutations of NA were gathered and compared to the Iranian NA segments to check the presence of antiviral drug-resistant strains. The phylogenetic study showed that most Iranian NA sequences (between 2015 and 2016) were located in a single clade and following years were located in its subclade by 3 major mutations (G77R/K, V81A, and J188T). Resistant mutations in drug targets of NA including I117M, D151E, I223V, and S247N were ascertained in 10 isolates during the 2015-2016 flu seasons. Investigation of vaccination effect revealed that Iranian isolates in 2017 and 2018 were best matched to A/Brisbane/02/2018 (H1N1), and in 2019 to A/Guangdong-Maonan/SWL1536/2019 (H1N1). Furthermore, we performed an in-silico analysis of NA enzymatic activity of all Iranian sequences by assessment of enzyme stability, ligand affinity, and active site availability. Overall, the enzyme activity of four Iranian strains (AUG84119, AUG84157, AUG84095, and AUG84100) was assumed as the maximum enzyme activity. This study highlighted the evolutionary trend of influenza A virus/H1N1 circulating in Iran, which provides a preliminary viewpoint for a better comprehension of new emerging strains' virulence and thus, more appropriate monitoring of influenza virus A/H1N1 during each outbreak season.

Computational peptide engineering approach for selection of the new C05 antibody-driven peptide with potency to blocking influenza a virus attachment; from in silico to in vivo

Antiviral drugs are currently used to prevent or treat viral infections like influenza A Virus (IAV). Nonetheless, annual genetic mutations of influenza viruses make them resistant to efficient treatment by current medications. Antiviral peptides have recently attracted researchers' attention and can potentially supplant the current medications. This study aimed to design peptides against IAV propagation. For this purpose, P2 and P3 peptides were computationally designed based on the HCDR3 region of the C05 antibody (a monoclonal antibody that neutralizes influenza HA protein and inhibits the virus attachment). The synthesized peptides were tested against the influenza A virus (A/Puerto Rico/8/34 (H1N1)) in vitro, and the most efficient peptide was selected for in vivo experiments. It was shown that the designed peptide shows much more prophylactic and therapeutic effects against the virus. These findings demonstrated that the designed peptide can control the virus infection without any cytotoxicity effect. Antiviral peptide design is acknowledged as a critical tactic to manage viral infections by preventing viral binding to the host cells.Communicated by Ramaswamy H. Sarma.

Induction of Homosubtypic and Heterosubtypic Immunity to Influenza Viruses Using a Conserved Internal and External Proteins

The immunogenicity and protective properties of the designed recombinant fusion peptide of 3M2e and truncated nucleoprotein (trNP), originating from Influenza A virus, were investigated in the BALB/c mice model in comparison with the Mix protein (3M2e + trNP). The results were evaluated by antibody response, cytokine production, lymphocyte proliferation assay, and mortality rate after challenge with homologous (H1N1) and heterologous (H3N2) influenza viruses in BALB/c mice. The animals that received the chimer protein with or without adjuvant had more specific antibody responses and elicited memory CD4 T cells, and cytokines of Th1 and Th2 cells compared to the Mix protein. Moreover, the Mix protein, like the recombinant chimer protein, provided equal and effective protection against both homologous and heterologous challenges in mice. Nevertheless, the chimer protein demonstrated superior immune protection compared to the Mix protein. The percentage of survived animals in the adjuvanted protein group (78.4%) was less than the non-adjuvanted one (85.7%). However, the Mix protein plus Alum could induce protective immunity in only 57.1% and 42.8% of homologous and heterologous virus-challenged mice, respectively. Regarding the sufficient immunogenicity and protectivity of the chimer protein construct against influenza viruses, the findings of the study suggest that the chimer protein without a requirement of adjuvant can be used as an adequate vaccine formulation to protect against a broad spectrum of influenza viruses.

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.

Rapid, label-free and low-cost diagnostic kit for COVID-19 based on liquid crystals and machine learning

We report a label-free method for detection of the SARS-CoV-2 virus in nasopharyngeal swab samples without purification steps and multiplication of the target which simplifies and expedites the analysis process. The kit consists of a textile grid on which liquid crystals (LC) are deposited and the grid is placed in a crossed polarized microscopy. The swab samples are subsequently placed on the LCs. In the presence of a particular biomolecule, the direction of LCs changes locally based on the properties of the biomolecule and forms a particular pattern. As the swab samples are not perfectly purified, image processing and machine learning techniques are employed to detect the presence of specific molecules or quantify their concentrations in the medium. The method can differentiate negative and positive COVID-19 samples with an accuracy of 96% and also differentiate COVID-19 from influenza types A and B with an accuracy of 93%. The kit is portable, simple to manufacture, convenient to operate, cost effective, rapid and sensitive. The simplicity of the specimen processing, the speed of image acquisition, and fast diagnostic operations enable the deployment of the proposed technique for performing extensive on-spot screening of COVID-19 in public places.

Genomic and serological assessment of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in child labor

Since working children have limited access to testing and monitoring for COVID-19, we decided to measure SARS-CoV-2 prevalence among them and compare it to non-working children. Our objective is to compare the frequency of SARS-CoV-2 genome and anti-SARS-CoV-2 antibody among working and non-working children. Volunteer child labor studying at Defense of Child Labor and Street Children and randomly selected 5-18-year-old (same range as child labor group) unemployed children participated in this study. The groups, respectively, had 65 and 137 members. This is an analytical cross-sectional study that surveys molecular prevalence of SARS-CoV-2 infection by RT-PCR, and seroprevalence of SARS-CoV-2 antibody by ELISA in working and non-working children. The IBM SPSS statistics software version 25 was used for data analysis. The χ2 or Fisher's exact test was used to analyze categorical dependent variables, for calculating odds ratios and 95% confidence intervals. Among the children enrolled in this study, molecular prevalence of SARS-CoV-2 turned out to be 18.5% in working children while it was 5.8% in unemployed children [aOR: 3.00 (CI95%: 1.00-7.00); P value: 0.003] and seroprevalence turned out to be 20% in working children vs 13.9% in non-working children [aOR: 1.000 (CI95%: 0.00-2.00); > P 0.001]. Equal SARS-CoV-2 viral load as adults and no symptoms or mild ones in children, coupled with working children's strong presence in crowded areas and their higher rate of COVID-19 prevalence, make them a probable source for spread of the virus.

In vitro anti-influenza assessment of anionic compounds ascorbate, acetate and citrate

Background

Influenza A virus (IAV) infection remains a serious public health threat. Due to drug resistance and side effects of the conventional antiviral drugs, repurposing the available natural compounds with high tolerability and fewer side effects has attracted researchers’ attention. The aim of this study was to screen in vitro anti-influenza activity of three anionic compounds ascorbate, acetate, and citrate.

Methods

The non-cytotoxic concentration of the compounds was determined by MTT assay and examined for the activity against IAV in simultaneous, pre-, and post-penetration combination treatments over 1 h incubation on Madin-Darby Canine Kidney (MDCK) cell line. The virus titer and viral load were determined using hemagglutination assay (HA) and qPCR, respectively. Few pro-inflammatory and anti-inflammatory cytokines were evaluated at RNA and protein levels by qPCR and ELISA, respectively.

Results

The non-cytotoxic concentrations of the ascorbate (200 mg/ml), acetate and citrate (both 3 mg/ml) reduced the viral titer by 6.5, 4.5, and 1.5 logs in the simultaneous combination treatment. The M protein gene copy number decreased significantly in simultaneous treatment (P < 0.01). The expression of cytokines was also affected by the treatment of these compounds.

Conclusions

These anionic compounds could affect the influenza virus load, thereby reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines levels.

Modulation of Immune Responses Against HA1 Influenza Vaccine Candidate by B-lymphocyte Stimulator Cytokine in Mice

Utilizing subunit vaccines is one of the strategies to address influenza infection. Recent innovations have focused on high doses of vaccine antigens and immune enhancers or adjuvant to induce more robust and long-lasting immune responses. Here, an effect of the B cell-activating factor receptor (BAFF-R) to increase the magnitude and durability of immune responses of the recombinant HA1 (rHA1) protein against the H1N1 influenza virus was studied. The HA1 protein and the effector domain of BAFF-R were expressed in the pET-28a (+) vector. Eight-week-old BALB/c mice were equally grouped into five groups (n=20). The 15 and 25 μg/μL of rHA1 were mixed with 2 μg/μL of rBAFF-R and injected three times for vaccinated groups. Three control groups were received normal saline and two concentrations of rHA1. The ability of rBAFF-R in eliciting HA-specific antibody response and stimulating T lymphocyte proliferation to induce the cell-mediated immunity was assayed. Induction of protection was evaluated following the challenge with PR8 strain. Analysis of immune responses showed that the co-administration of rBAFF-R with rHA1 boosted HI responses to the antigen in mice, whilst it was not able to promote the T cell proliferation responses against influenza. Compared to rHA1alone, the rBAFF-R/rHA1 generated efficient protection for the animals. There were no significant differences in eliciting the immune responses in mice immunized with the lower dose of rHA1 than that with the higher dose. The data indicate the rBAFF-R can enhance the primary and memory immune responses to protect against influenza infection.

SARS-CoV-2 re-infection rate in Iranian COVID-19 cases within one-year follow-up

Since the COVID-19 pandemic initiation, the possibility of re-infection has been unclearly present. Although herd immunity has a potential reliance through natural infection, human corona viruses has the ability to subvert immunity and re-infection happens for seasonal corona viruses. Currently, the frequency of SARS-CoV-2 re-infection incidence is not exactly defined. In this study we aimed at determination of SARS-CoV-2 re-infection rate in Iranian population. In a total of 5696 COVID-19 suspicious individuals, RT-PCR was applied to diagnose the infection. The confirmed patients were followed for 12 months and serology tests were applied to measure the specific antibodies. Among 1492 confirmed COVID-19 cases, five individuals experienced the subsequent infection. The re-infection/reactivation incidence rate was totally 0.33% after one year of follow-up. The interval ranged from 63 to 156 days. All the cases had viral mutations in the second episode of the infection. All of them were symptomatic cases with moderate severity. The estimated rate of SARS-CoV-2 in Persian population is therefore rare and natural infection seems to induce good protection against re-infection which clarifies that mass vaccination can hugely affect the society.

Potential antiviral effects of some native Iranian medicinal plants extracts and fractions against influenza A virus

Background

Influenza A virus (IAV) infection is a continual threat to the health of animals and humans globally. Consumption of the conventional drugs has shown several side effects and drug resistance. This study was aimed to screen some Iranian medicinal plants extracts and their fractions against influenza A virus.

Methods

Glycyrrhiza glabra (rhizome), Myrtus  commonis (leaves), Melissa officinalis (leaves), Hypericum perforatum (aerial parts), Tilia platyphyllos (flower), Salix alba (bark), and Camellia sinensis (green and fermented leaves) were extracted with 80% methanol and fractionated with chloroform and methanol, respectively. The cytotoxicity of the compounds were determined by MTT colorimetric assay on MDCK cells. The effective concentrations (EC₅₀) of the compounds were calculated from the MTT results compared to the negative control with no significant effects on cell viability. The effects of EC₅₀ of the compounds on viral surface glycoproteins and viral titer were tested by HI and HA virological assays, respectively and compared with oseltamivir and amantadine. Preliminary phytochemical analysis were done for promising anti-IAV extracts and fractions.

Results

The most effective samples against IAV titer (P ≤ 0.05) were crude extracts of G. glabra, M. officinalis and S. alba; methanol fractions of M. communis and M. officinalis; and chloroform fractions of M. communis and C. sinensis (fermented) mostly in co- and pre-penetration combined treatments. The potential extracts and fractions were rich in flavonoids, tannins, steroids and triterpenoids.

Conclusion

The outcomes confirmed a scientific basis for anti-influenza A virus capacity of the extracts and fractions from the selected plants for the first time, and correlated their effects with their phytochemical constituents. It is worth focusing on elucidating pure compounds and identifying their mechanism(s) of action.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03423-x.

Antitumor immunity enhancement through Newcastle viral oncolysate in mice model: A promising method to treat tumors

A Newcastle disease virus (NDV) oncolysate has been established as a unique and effective immune-stimulatory root for tumor treatment. Thus, the aim of the current study was to investigate the effects of intratumoral administration of NDV oncolysate on immune response and tumor regression of C57BL/6 mouse model of human papillomavirus (HPV) related transplanted with TC-1 syngeneic cancer cells. To further investigate the mechanism underlying the antitumor response, cytolytic and lymphocyte proliferation responses in splenocytes were measured using lactate dehydrogenase (LDH) release and MTT assays, respectively. In this regard, levels of IL-10, IFN-γ, and IL-4 were measured using ELISA after re-stimulation. The immune responses efficacy was evaluated by in vivo tumor regression assay. The results showed that immunization with the different titers of NDV lysate significantly reduced tumor volume in comparison with a combination of virus lysate and tumor cell lysate. Also, virus lysate could significantly enhance cytotoxic T lymphocyte production and lymphocyte proliferation rates versus tumor cell lysate. Also, our major findings are that the peritumorally injection of NDV oncolysate effectively induces antitumor immune responses through increased levels of IL-4, IFN-γ, and reduction of IL-10. These results indicate that this treatment is a specific, active immune mechanism stimulator, and may prove to be a useful therapeutic for a treatment against cervical cancers and merits further investigation.

Prolonged viral shedding and antibody persistence in patients with COVID-19

SARS-CoV-2 as a new global threat has affected global population for one year. Despite the great effort to eradicate this infection, there are still some challenges including different viral presentation, temporal immunity in infected individuals and variable data of viral shedding. We studied 255 COVID-19 suspected individuals to assess the viral shedding duration and also the antibody development against SARS-CoV-2 among the cases. Real Time RT-PCR assay was applied to determine the virus presence and SARS-CoV-2 antibodies were evaluated using SARS-CoV-2 IgM and IgG kits. 113 patients were confirmed for COVID-19 infection. The patients were followed until negative PCR achieved. The median viral shedding among studied population was obtained 34.16 (±17.65) days which was not significantly associated with age, sex and underlying diseases. Shiver and body pain were found in prolonged form of the infection and also patients who had gastrointestinal problems experienced longer viral shedding. Moreover, IgG was present in 84% of patients after 150 days. According to this data, the median viral shedding prolongation was 34.16 days which indicates that 14 days isolation might not be enough for population. In addition, IgG profiling indicated that it is persistent in a majority of patients for nearly 6 months which has brought some hopes in vaccine efficacy and application.

SARS-CoV-2 presented moderately during two episodes of the infection with lack of antibody responses

The world has gone through the critical phase of SARS-CoV-2 crisis caused by the new variants of the virus. The globally concerted effort to characterize viral genomic mutations across different clades has revealed several changes in the coding and also non-coding regions which might lead to a violent presentation or re-infection occurrence. Here, we studied a COVID-19 subject who represented the symptoms following the full recovery of the first infection. COVID-19 specific IgM and IgG were evaluated in both steps. The viral samples from oropharyngeal/nasopharyngeal were subjected to RT-PCR and full sequencing was done in both incidences. The sequencing data was fully investigated with the reference sequence of SARS-CoV-2 and the changes were detected. The obtained data is in favor of re-infection with 128 days of interval. SARS-CoV-2 presented more severely in the second episode of the disease and the specific antibodies against COVID-19 were not detectable. Both infections were caused by the same clade 20G, however, the mutation rates were higher in the second incidence including 10 nucleotide substitutions which had rarely been reported before. In the present study, the nucleotide mutations in various regions of the viral genome have been presented. The re-infection could have significant effect on clinical implications as well as vaccination.

Association of the host genetic factors, hypercholesterolemia and diabetes with mild influenza in an Iranian population

BACKGROUND

Variation in host genetic factors may result in variation in the host immune response to the infection. Some chronic diseases may also affect individuals' susceptibility to infectious diseases. The aim of this study was to evaluate the association of the host genetic factors mostly involved in inflammation, as well as hypercholesterolemia and diabetes with mild flu in an Iranian population.

METHODS

In this cross-sectional study, nasopharyngeal swab samples were collected from 93 patients referred to primary care centers of Markazi, Semnan, and Zanjan provinces (central Iran) due to flu-like symptoms between March 2015 and December 2018. Of these, PCR test identified 49 influenza A/H1N1 and 44 flu-negative individuals. Twelve single-nucleotide polymorphisms (SNPs) in RPAIN, FCGR2A, MBL-2, CD55, C1QBP, IL-10, TNF-α and an unknown gene were genotyped using iPLEX GOLD SNP genotyping analysis. Hypercholesterolemia and diabetes status was determined based on the physician diagnosis. Association of the host genetic variants, hypercholesterolemia and diabetes with mild A/H1N1 flu was assessed with univariable and multivariable logistic regression analysis as implemented in Stata software (v.14). Statistical tests were considered as significant at 0.05 levels.

RESULTS

Frequency of diabetes and hypercholesterolemia, as well as participants mean age was significantly higher in the flu-negative rather than the flu-positive group. Of 12 SNPs, nine did not show any significant association with mild flu in our study (rs1801274, rs1800451, rs2564978, rs361525, rs1800450, rs1800871, rs1800872, rs1800896, rs1800629). Possessing G vs. A allele in two SNPs (rs3786054 and rs8070740) was associated with a threefold increase in the chance of mild flu when compared to flu-negative patients (95% CI: 1.1, 22.0). Possessing C allele (vs. A) in the rs9856661 locus also increased the chance of mild flu up to 2 folds (95% CI: 1.0, 10.0).

CONCLUSION

The results showed that possessing the G allele in either rs3786054 or rs8070740 loci in C1QBP and RPAIN genes, respectively, increased the risk of H1N1 infection up to 3.3 folds, regardless of the patient's age, BMI, diabetes, and hypercholesterolemia. Complementary functional genomic studies would shed more light on the underlying mechanism of human immunity associated with these genetic markers. The identified genetic factors may have the same role in susceptibility to similar respiratory infections with RNA viruses, like SARS, MERS and COVID-19. Future genetic association studies targeting these RNA viruses, especially COVID-19 is recommended. Studies on other ethnic groups would also shed light on possible ethnic variations in genetic susceptibility to respiratory RNA viruses. Trial registry IR.PII.REC.1399.063.

Clinical characteristics of SARS-CoV-2 by re-infection vs. reactivation: a case series from Iran

COVID-19 immunity in infected individuals may not be persistent. The specific response wanes in patients who have recovered from this infection. Nevertheless, it has not been fully understood whether true re-infection occurs or the viral reactivation. In this study, we investigated three COVID-19 patients who represented the symptoms after recovery. Chest CT scan was applied to assess the patients along with the viral samples from oropharyngeal/nasopharyngeal which were subjected to RT-PCR. The viral genome sequencing was applied where possible to distinguish possible re-infection or latent reactivation. Moreover, COVID-19-specific antibodies available data were evaluated in each incidence. The second episode of SARS-CoV-2 infection was different among the investigated subjects who experienced an interval between positive PCR tests ranged between 63 and 156 days. The disease presentation was less or more severe in the second infection. All cases were found IgG positive in the re-infection phase. The sequencing of SARS-CoV-2 sample obtained from two cases revealed a D614G mutation of S gene from the second isolated sample strengthens the case for the re-infection. The possibility of re-infection and reactivation could have significant effect on clinical implications and also vaccination. Our data supports clear warning of SARS-CoV-2 continuous circulation potency among the populations in spite of herd immunity either with natural infection or vaccination. This issue is critical in term of the patients, clinical investigate, and viral transmission.

Anti-influenza A virus activity of two Newtonia species and the isolated compound myricetin-3-o-rhamnoside

BACKGROUND

Some viruses play a key role in the disturbance of the digestive system. The common viruses which cause infectious diarrhoea (gastroenteritis) include astrovirus, caliciviruses, coronavirus and torovirus which are single-stranded RNA viruses. Influenza A virus (H1N1) also causes diarrhoea in addition to being associated with respiratory symptoms. In preliminary studies, Newtonia hildebrandtii and N. buchananii leaf extracts had good antibacterial activity against some bacteria implicated in causing diarrhoea. The aim of this study was to evaluate the anti-influenza activity of two Newtonia species extracts and the isolated compound (myricitrin).

METHODS

N. hildebrandtii and N. buchananii acetone, and MeOH: DCM (methanol-dichloromethane) leaf and stem extracts, and an antibacterial compound myricetin-3-o-rhamnoside (myricitrin), isolated from N. buchananii, were evaluated for their antiviral efficacy against influenza A virus (IAV) PR8/34/H1N1 as a model organism. The MTT and hemagglutination assays were used to assess the extracts and compound interference with cell viability and viral surface HA glycoprotein. The quantitative real-time PCR was performed to assess the viral load.

RESULTS

Plant extracts of N. hildebrandtii and N. buchananii were effective against IAV. The extracts in combination with H1N1 showed highly significant antiviral activity (P < 0.01) and maintained cell viabilities (P < 0.05). Myricitrin was non-cytotoxic at concentration 104 μg/ml. Myricitrin was most effective against IAV in a co-penetration combined treatment, thereby confirming the inhibitory effect of this compound in the viral attachment and entry stages. Myricitrin treatment also resulted in the highest viability of the cells in co-penetration treatment. The activity of myricitrin indicates the potential of the extracts in controlling viral infection at the attachment stage. The antiviral effect of myricitrin on IAV load in MDCK cell culture was confirmed using quantitative real-time PCR.

CONCLUSION

Data from this study support further research and development on Newtonia hildebrandtii, Newtonia buchananii and myricitrin to address diarrhoea and related conditions caused by viruses in both human and veterinary medicine. Further work needs to be conducted on the activity of the extracts and the purified compound on other viruses of importance which have similar symptoms to influenza virus such as the coronavirus which led to a recent global pandemic.

Oncolytic effects of Hitchner B1 strain of newcastle disease virus against cervical cancer cell proliferation is mediated by the increased expression of cytochrome C, autophagy and apoptotic pathways

Newcastle disease virus (NDV) is a potential oncolytic virus for the cancer treatment due to its ability to replicate in tumor cells. The aim of this study was to evaluate the in vitro anticancer properties of Hitchner B1 (HB1) strain of NDV on TC-1 cell line and underlying molecular mechanisms. The cytolytic effects of oncolytic HB1 strain of NDV was determined by lactate dehydrogenase (LDH) release assay. Apoptosis, intracellular reactive oxygen species (ROS) levels, cleaved caspase-3 and autophagy were evaluated by flow cytometry. Cytochrome-C and survivin protein levels were distinguished by Enzyme-Linked Immunosorbent Assay (ELISA). Our results from LDH method showed that the viability of the TC-1 cell line following HB1 NDV infection was dose-dependent and decreased significantly with increasing the dose of HB1 NDV infection (MOIs: 5, 10, and 15). Other evaluations also revealed that HB1 strain of NDV potentially led to the ROS production, and apoptosis and autophagy induction in TC-1 cell line in a dose-dependent manner. The in vitro experiments also presented that NDV treatment significantly up-regulated the expression of cytochrome-C and down-regulated the expression of survivin, as detected by ELISA assay. Our results confirmed that the HB1 NDV could be introduced as a powerful candidate for the therapy of cervical cancer. However, further examinations are needed to explain the underlying mechanisms of the HB1 NDV against TC-1 cell line and cervical cancer.

Experimental validation and computational modeling of anti-influenza effects of quercetin-3-O-α-L-rhamnopyranoside from indigenous south African medicinal plant Rapanea melanophloeos

BACKGROUND

Influenza A virus (IAV) is still a major health threat. The clinical manifestations of this infection are related to immune dysregulation, which causes morbidity and mortality. The usage of traditional medication with immunomodulatory properties against influenza infection has been increased recently. Our previous study showed antiviral activity of quercetin-3-O-α-L-rhamnopyranoside (Q3R) isolated from Rapanea melanophloeos (RM) (L.) Mez (family Myrsinaceae) against H1N1 (A/PR/8/34) infection. This study aimed to confirm the wider range of immunomodulatory effect of Q3R on selective pro- and anti-inflammatory cytokines against IAV in vitro, to evaluate the effect of Q3R on apoptosis pathway in combination with H1N1, also to assess the physical interaction of Q3R with virus glycoproteins and RhoA protein using computational docking.

METHODS

MDCK cells were exposed to Q3R and 100CCID50/100 μl of H1N1 in combined treatments (co-, pre- and post-penetration treatments). The treatments were tested for the cytokines evaluation at RNA and protein levels by qPCR and ELISA, respectively. In another set of treatment, apoptosis was examined by detecting RhoA GTPase protein and caspase-3 activity. Molecular docking was used as a tool for evaluation of the potential anti-influenza activity of Q3R.

RESULTS

The expressions of cytokines in both genome and protein levels were significantly affected by Q3R treatment. It was shown that Q3R was much more effective against influenza when it was applied in co-penetration treatment. Q3R in combination with H1N1 increased caspase-3 activity while decreasing RhoA activation. The molecular docking results showed strong binding ability of Q3R with M2 transmembrane, Neuraminidase of 2009 pandemic H1N1, N1 and H1 of PR/8/1934 and Human RhoA proteins, with docking energy of - 10.81, - 10.47, - 9.52, - 9.24 and - 8.78 Kcal/mol, respectively.

CONCLUSIONS

Quercetin-3-O-α-L-rhamnopyranoside from RM was significantly effective against influenza infection by immunomodulatory properties, affecting the apoptosis pathway and binding ability to viral receptors M2 transmembrane and Neuraminidase of 2009 pandemic H1N1 and human RhoA cellular protein. Further research will focus on detecting the detailed specific mechanism of Q3R in virus-host interactions.

Physicochemical study of the influenza A virus M2 protein and aluminum salt adjuvant interaction as a vaccine candidate model

Aim: The present study evaluated the structural changes resulting from the interaction between a recombinant influenza A virus M2 protein and aluminum hydroxide adjuvant to investigate the antigen for further immunological studies. Materials & methods: Membrane protein II was produced from the H1N1 subtype of human influenza A virus. The interaction between M2 protein and alum inum hydroxide adjuvant was evaluated by physicochemical techniques including scanning electron microscope, UV-Vis spectra, Fourier-transform infrared spectroscopy and circular dichroism spectroscopy. Results: Physicochemical methods showed high-level protein adsorption and accessibility to the effective parts of the protein. Conclusion: It was concluded that M2 protein secondary structural perturbations, including the α-helix-to-β-sheet transition, enhanced its mechanical properties toward adsorption.

Chimeric protein consisting of 3M2e and HSP as a universal influenza vaccine candidate: from in silico analysis to preliminary evaluation

The 23-amino acid ectodomain of influenza virus M2 protein (M2e) is highly conserved among human influenza virus variants and represents an attractive target for developing a universal vaccine. Although this peptide has limited potency and low immunogenicity, the degree of M2e density has been shown to be a critical factor influencing the magnitude of epitope-specific responses. The aim of this study was to design a chimer protein consisting of three tandem repeats of M2e peptide sequence fused to the Leishmania major HSP70 gene and evaluate its characteristics and immunogenicity. The structure of the deduced protein and its stability, aliphatic index, biocomputed half-life and the anticipated immunogenicity were analyzed by bioinformatics software. The oligonucleotides encoding 3M2e and chimer 3M2e-HSP70 were expressed in Escherichia coli and affinity purified. The immunogenicity of the purified recombinant proteins was preliminary examined in mouse model. It was predicted that fusion of HSP70 to the C-terminal of 3M2e peptide led to increased stability, hydropathicity, continuous B cell epitopes and antigenic propensity score of chimer protein. Also, the predominant 3M2e epitopes were not hidden in the chimer protein. The initial in vivo experiment showed that 3M2e-HSP chimer protein stimulates specific immune responses. In conclusion, the results of the current study suggest that 3M2e-HSP chimer protein would be an effective universal subunit vaccine candidate against influenza infection.

Molecular epidemiology of the hemagglutinin gene of prevalent influenza virus A/H1N1/pdm09 among patient in Iran

In 2015, the influenza virus A/H1N1/pdm09 strain outbreak became prevalent throughout the different provinces of Iran. There are relatively limited complete genetic sequences available for this virus from Asian countries. Diagnosis and virological surveillance of influenza is essential for detecting novel genetic variants causing epidemic potential. This study describes the genetic properties of HA genome of influenza A/H1N1 pdm09 viruses circulating in Iran during the 2015/2016 season. In order to investigate the genetic pattern of influenza A/H1N1 pdm09, a total of 1758 nasopharyngeal swabs were screened by real-time RT-PCR. Of those, 510 cases were found to be positive for A/H1N1/pdm09 virus. Evolution of the approximately 100 positive specimens with high virus load was conducted via genomic phylogeny. Phylogenetic analysis of the HA genes of the A/H1N1pdm09 viruses revealed the circulation of clade 6B1, characterized by amino acid substitutions S84N, S162N and I216T, where position 162 became glycosylated. The N-glycosylation of HA protein is post or co-translational modification that affect the evolution of influenza viruses. For influenza A(H1N1) pdm09 viruses, we found more mutations in the antigenic sites than in the stem region. The results of this study confirmed the necessity of constant regular antigenic and molecular surveillance of circulating seasonal influenza viruses.

Establishment of reverse transcription polymerase chain reaction assay for simultaneous detection of human parainfluenza virus types 1 to 4 in children with influenza like illnesses

OBJECTIVES

The aim of this study was to develop an in-house multiplex reverse transcription polymerase chain reaction (mRT-PCR), which can recognize HPIV1-4 in clinical samples.

BACKGROUND

Human parainfluenza virus (HPIV) is one of the major causes of viral respiratory infections and can affect people at any age, especially infants and young children.

METHODS

Four sets of specific primers targeting conserved areas of hemagglutinin-neuraminidase (HN) genes of HPIV1-4, were designed and tested with type-related plasmid controls. Specificity and sensitivity of mPCR were tested. One-step mRT-PCR was set up using a viral panel containing 10 respiratory viruses, including HPIVs. One hundred nasopharyngeal samples of respiratory infection patients were tested using the set One-step mRT-PCR.

RESULTS

The specificity of set mPCR for HPIV1-4 using plasmid positive controls was proved and reaction sensitivity was measured. The specificity of set mRT-PCR was confirmed and 4 and 5 out of 100 clinical samples were HPIV1 and HPIV2 positive, respectively.

CONCLUSION

The developed one-step mRT-PCR in this study is an effective and specific assay for clinical diagnosis of HPIV1 to 4 (Tab. 1, Fig. 6, Ref. 28).

Immunomodulatory properties of quercetin-3-O-α-L-rhamnopyranoside from Rapanea melanophloeos against influenza a virus

BACKGROUND

Influenza infection is a major public health threat. The role of influenza A virus-induced inflammatory response in severe cases of this disease is widely recognized. Drug resistance and side effects of chemical treatments have been observed, resulting in increased interest in alternative use of herbal medications for prophylaxis against this infection. The South African medicinal plant, Rapanea melanophloeos (RM) (L.) Mez of the family Myrsinaceae was selected owing to its traditional use for the treatment of several diseases such as respiratory ailments and also previous preliminary studies of anti-influenza activity of its methanolic extract. The aim of this study was to investigate the immunomodulatory properties of a glycoside flavone isolated from RM against influenza A virus.

METHODS

The non-cytotoxic concentration of the quercetin-3-O-α-L-rhamnopyranoside (Q3R) was determined by MTT assay and tested for activity against influenza A virus (IAV) in simultaneous, pre-penetration and post-penetration combination treatments over 1 h incubation on MDCK cells. The virus titer and viral load targeting NP and M2 viral genes were determined using HA and qPCR, respectively. TNF-α and IL-27 as pro- and anti-inflammatory cytokines were measured at RNA and protein levels by qPCR and ELISA, respectively.

RESULTS

Quercetin-3-O-α-L-rhamnopyranoside at 150 μg/ml decreased the viral titer by 6 logs (p < 0.01) in the simultaneous procedure. The NP and M2 genes copy numbers as viral target genes, calculated based on the Ct values and standard formula, significantly decreased in simultaneous treatment (p < 0.01). The expression of cytokines was also considerably affected by the compound treatment.

CONCLUSIONS

This is the first report of quercetin-3-O-α-L-rhamnopyranoside from RM and its immunomodulatory properties against influenza A virus. Further research will focus on detecting the specific mechanism of virus-host interactions.

Designing Two Individual AcMNPV Polyhedrin-Plus Bac-to-Bac Expression System in order to Express GFP and CPV-VP2 in Insect Cells

Background: The importance of viral protein-2 (VP2) of canine parvovirus (CPV) in binding to human cancer cells, production of veterinary vaccines and diagnostic kits has motivated several researches on producing this protein. Objectives: Our purpose was to construct recombinant bacmid shuttle vectors expressing VP2 of CPV using Bac-to-Bac baculoviral expression system. Materials and Methods: Mini-Tn7 transposones engineered in pFastBac1 donor vectors were used to construct expression cassettes of GFP and CPV-VP2. The plasmids were transferred into E. coli DH₁₀Bac competent cells. Site-specific transposition of the genes into bacmid was accomplished using helper plasmid. Occurrence of Transposition was confirmed via PCR using specific primers and PUC/M₁₃ universal primers. The recombinant bacmid DNAs were transfected into Sf9 cells using cationic lipids to generate new recombinant baculoviruses expressing GFP and CPV-VP2. GFP and VP2 expressions were evaluated by fluorescence microscopy and western analysis, respectively. Results: Cloning, subcloning and recombination processes of both GFP and VP2 were accomplished and verified. Accuracy of transfection process was confirmed by GFP fluorescence microscopy.VP2 expression was verified by SDS-PAGE and western analysis. Conclusions: Two Bac-to-Bac expression systems were designed to produce recombinant VP2 and GFP in insect cells.

South African medicinal plant extracts active against influenza A virus

BACKGROUND

Influenza infection remains a major health threat for animals and humans which crucially requires effective antiviral remedies. The usage of herbal medications as readily available alternatives for their compatibility with the body and fewer side effects compared to synthetic chemical treatments has become popular globally. The aim of this study was to investigate and screen in vitro anti-influenza activity of extracts of five South African medicinal plants, namely Tabernaemontana ventricosa, Cussonia spicata, Rapanea melanophloeos, Pittosporum viridiflorum and Clerodendrum glabrum, species which are used traditionally for the treatment of several diseases such as inflammatory and respiratory diseases.

METHODS

Methanol, ethanol (100% and 30%), acetone, hot and cold water extracts of the powdered plants leaves were obtained by standard methods. The cytotoxicity was determined by the MTT colorimetric assay on MDCK cells. The concentrations below CC₅₀ values were tested for antiviral activity against influenza A virus (IAV) in different combination treatments. The effect of extracts on viral surface glycoproteins and viral titer were tested by HI and HA virological assays, respectively.

RESULTS

Based on the applied methods, the most effective results against IAV were obtained from Rapanea melanophloeos methanol leaf extract (EC₅₀ = 113.3 μg/ml) and Pittosporum viridiflorum methanol, 100% and 30% ethanol and acetone leaf extracts (EC₅₀ values = 3.6, 3.4, 19.2, 82.3 μg/ml, respectively) in all types of combined treatments especially in pre- and post-penetration combined treatments with highly significant effects against viral titer (P ≤ 0.01).

CONCLUSION

The outcomes offer for the first time a scientific basis for the use of extracts of Rapanea melanophloeos and Pittosporum viridiflorum against IAV. It is worth focusing on the isolation and identification of effective active compounds and elucidating the mechanism of action from these species. However, Tabernaemontana ventricosa, Cussonia spicata and Clerodendrum glabrum leaf extracts were ineffective in vitro in this study.

Evaluation of autophagy induction on HEV 239 vaccine immune response in a mouse model

Hepatitis E virus (HEV) infection remains a serious threat to life and productivity in developing world. Vaccine seems to be an effective, safe, and affordable approach to address HEV disease burden. The HEV genome consists of three open reading frames (ORFs). Of these, ORF2 encodes a single structural protein (pORF2) for the HEV capsid which has been studied extensively as vaccine candidates. Recently, it has been recognized that autophagy plays an important role in innate and adaptive immunity defense against intracellular pathogens. This mechanism could therefore promote a protective immune response by inducing CD4⁺ and CD8⁺ T cells. In this study, HEV 239 and Beclin1 proteins were expressed in prokaryotic host cell [Escherichia coli (BL21)]. HEV 239 protein with different formulations (+Alum, +Beclin1, and +Alum-Beclin1) were used as candidate vaccines and administrated subcutaneously in BALB/c mice on 0, 14, and 28 days. Finally, elicited cellular and humoral immunity were evaluated. Taken together, although our results indicated that mice immunized with HEV 239 protein formulated with Alum, Beclin1, and Alum + Beclin1 displayed humoral and cellular response that was not significant in comparison with each other (P > 0.05); whereas they were significant while compared with control groups (P < 0.05). A comprehensive understanding of the intricate interplay between autophagy and immune response remains to be unraveled. Further study will clear the detailed impact of autophagy manipulation to enhance vaccine efficacy and boost the immune responses against the disease. © 2018 IUBMB Life, 70(3):207-214, 2018.

Association of IFITM3 rs12252 polymorphisms, BMI, diabetes, and hypercholesterolemia with mild flu in an Iranian population

Background

IFITM3 has been suggested to be associated with infection in some ethnic groups. Diabetes and hypercholesterolemia are also important clinical conditions that can predispose individuals to infection. The aim of this study was to investigate the association of rs12252 C polymorphism, BMI, diabetes, and hypercholesterolemia with mild flu in an Iranian population.

Methods

We conducted a case-control study, including 79 mild flu and 125 flu-negative individuals attending primary care centers of three provinces of Iran (i.e, Markazi, Semnan, and Zanjan). Pharyngeal swab specimens were collected from all participants, and were subjected to RNA and DNA extractions for Real-time PCR and PCR tests. All PCR products were then sequenced to find T/C polymorphisms in the rs12252 region. Data on demographic, anthropometric, and clinical variables were collected from participants’ medical records available in the primary care centers. The data was analyzed using DNASIS (v. 2.5) and Stata (v.11) software.

Results

All participants were of Fars ethnic background. The allele frequency for rs12252-C was found to be 9.49% among cases and 2.40% among controls. Carriers of the rs12252 C allele (CT + CC genotypes) showed 5.92 folds increase in the risk of mild flu comparing to the T allele homozygotes (P value: 0.007). We also found a significant positive association between rs12252 C allele heterozygote and mild flu (OR: 7.62, P value: 0.008), but not in C allele homozygote group (OR: 2.71, P value: 0.406). Similarly, we did not find a significant association between mild flu and BMI (OR: 1.06, P value: 0.087), diabetes (OR: 0.61, P value: 0.392), and hypercholesterolemia (OR: 0.50, P value: 0.393) in multivariable logistic regression.

Conclusions

This is the first study evaluating the association between rs12252 polymorphisms, diabetes, hypercholesterolemia, and BMI and susceptibility to mild flu in an Iranian population. Our results suggest a significant positive association between mild flu and rs12252 C allele heterozygous and carriage. Future replication of the strong association observed here between rs12252 C allele carriage and mild flu might candidate this polymorphism as a genetic marker for early screening of susceptibility to mild flu. Lack of significant association between C allele homozygous and mild flu, observed in this study, might be the result of small sample size in this group.

Trial registration

IR.PII.REC.1395.3.

Electronic supplementary material

The online version of this article (10.1186/s12985-017-0884-4) contains supplementary material, which is available to authorized users.

Antitumor Response to a Codon-Optimized HPV-16 E7/HSP70 Fusion Antigen DNA Vaccine

BACKGROUND

Vaccines based on virus-like particles are effective against Human Papilloma Virus (HPV) infection; however, they have not shown a therapeutic effect against HPV-associated diseases. New immunotherapy strategies based on immune responses against tumor antigens can positively affect the clearance of HPV-associated lesions.

OBJECTIVE

To generate two therapeutic fusion DNA vaccines (optimizedE7/mouseHSP70 and wildE7/mouseHSP70) to induce antitumor specific responses in mice models.

METHODS

Mice were immunized with recombinant DNA vaccines. The splenocytes of immunized mice were collected and lactate dehydrogenase and IFN-γ productions were measured after three injections in order to evaluate cytotoxic T lymphocytes (CTLs) activity. MTT assay was carried out for lymphocyte stimulation.

RESULTS

The fusion DNA vaccines, specifically uE7-HSP70, elicited varying levels of IFN-γ and CTLs responses compared to the control group (P<0.05). Furthermore, antitumor response and tumor size reduction in fusion DNA vaccines groups were significantly higher than in the negative control group (P<0.05).

CONCLUSION

It is concluded that our fusion DNA vaccines considerably enhanced specific cellular responses against HPV tumor model. In addition, optimized E7 showed a notable immunogenicity and inhibitory effect on the reduction of tumor size.

In vitro antiviral effects of Peganum harmala seed extract and its total alkaloids against Influenza virus

This research was aimed to evaluate the in vitro antiviral effect and the mechanism of the effect of Peganum. harmala seeds extract against influenza A virus infection using Madin-Darby canine kidney (MDCK) cells. In this research, ethyl alcohol extract of P. harmala seeds and its total alkaloids was prepared. The potential antiviral activity of the extract and its total alkaloids against influenza A/Puerto Rico/8/34 (H1N1; PR8) virus was assessed. The mode of action of the extract to inhibit influenza replication was investigated using virucidal activity, hemagglutination inhibition assay, time of addition assays, RNA replication, western blot analysis and RNA polymerase blocking assay. The crud extract of P. harmala seed and its total alkaloids showed the best inhibitory effect against influenza A virus replication in MDCK cells using MTT assay, TCID₅₀ method and hemagglutination assay. Our results indicated that the extract inhibits viral RNA replication and viral polymerase activity but did not effect on hemagglutination inhibition and virucidal activity. This study showed that, in vitro antiviral activity of P. harmala seed extract against influenza virus is most probably associated with inhibiting viral RNA transcription. Therefore, this extract and its total alkaloid should be further characterized to be developed as anti-influenza A virus agent.

Autophagy induction regulates influenza virus replication in a time-dependent manner

PURPOSE

Autophagy plays a key role in host defence responses against microbial infections by promoting degradation of pathogens and participating in acquired immunity. The interaction between autophagy and viruses is complex, and this pathway is hijacked by several viruses. Influenza virus (IV) interferes with autophagy through its replication and increases the accumulation of autophagosomes by blocking lysosome fusion. Thus, autophagy could be an effective area for antiviral research.

METHODOLOGY

In this study, we evaluated the effect of autophagy on IV replication. Two cell lines were transfected with Beclin-1 expression plasmid before (prophylactic approach) and after (therapeutic approach) IV inoculation.Results/Key findings. Beclin-1 overexpression in the cells infected by virus induced autophagy to 26 %. The log10haemagglutinin titre and TCID50 (tissue culture infective dose giving 50 % infection) of replicating virus were measured at 24 and 48 h post-infection. In the prophylactic approach, the virus titre was enhanced significantly at 24 h post-infection (P≤0.01), but it was not significantly different from the control at 48 h post-infection. In contrast, the therapeutic approach of autophagy induction inhibited the virus replication at 24 and 48 h post-infection. Additionally, we showed that inhibition of autophagy using 3-methyladenine reduced viral replication.

CONCLUSION

This study revealed that the virus (H1N1) titre was controlled in a time-dependent manner following autophagy induction in host cells. Manipulation of autophagy during the IV life cycle can be targeted both for antiviral aims and for increasing viral yield for virus production.

Molecular characterization and phylogenetic analysis of human influenza A viruses isolated in Iran during the 2014-2015 season

Influenza A viruses are an important cause of severe infectious diseases in humans and are characterized by their fast evolution rate. Global monitoring of these viruses is critical to detect newly emerging variants during annual epidemics. Here, we sought to genetically characterize influenza A/H1N1pdm09 and A/H3N2 viruses collected in Iran during the 2014-2015 influenza season. A total of 200 nasopharyngeal swabs were collected from patients with influenza-like illnesses. Swabs were screened for influenza A and B using real-time PCR. Furthermore, positive specimens with high virus load underwent virus isolation and genetic characterization of their hemagglutinin (HA) and M genes. Of the 200 specimens, 80 were influenza A-positive, including 44 A/H1N1pdm09 and 36 A/H3N2, while 18 were influenza B-positive. Phylogenetic analysis of the HA genes of the A/H1N1pdm09 viruses revealed the circulation of clade 6C, characterized by amino acid substitutions D97N, V234I and K283E. Analysis of the A/H3N2 viruses showed a genetic drift from the vaccine strain A/Texas/50/2012 with 5 mutations (T128A, R142G, N145S, P198S and S219F) belonging to the antigenic sites A, B, and D of the HA protein. The A/H3N2 viruses belonged to phylogenetic clades 3C.2 and 3C.3. The M gene trees of the Iranian A/H1N1pdm09 and A/H3N2 mirrored the clustering patterns of their corresponding HA trees. Our results reveal co-circulation of several influenza A virus strains in Iran during the 2014-2015 influenza season.

Expression and characterization of codon-optimized Crimean-Congo hemorrhagic fever virus Gn glycoprotein in insect cells

Crimean-Congo hemorrhagic fever virus (CCHFV) is a major cause of tick-borne viral hemorrhagic disease in the world. Despite of its importance as a deadly pathogen, there is currently no licensed vaccine against CCHF disease. The attachment glycoprotein of CCHFV (Gn) is a potentially important target for protective antiviral immune responses. To characterize the expression of recombinant CCHFV Gn in an insect-cell-based system, we developed a gene expression system expressing the full-length coding sequence under a polyhedron promoter in Sf9 cells using recombinant baculovirus. Recombinant Gn was purified by affinity chromatography, and the immunoreactivity of the protein was evaluated using sera from patients with confirmed CCHF infection. Codon-optimized Gn was successfully expressed, and the product had the expected molecular weight for CCHFV Gn glycoprotein of 37 kDa. In time course studies, the optimum expression of Gn occurred between 36 and 48 hours postinfection. The immunoreactivity of the recombinant protein in Western blot assay against human sera was positive and was similar to the results obtained with the anti-V5 tag antibody. Additionally, mice were subjected to subcutaneous injection with recombinant Gn, and the cellular and humoral immune response was monitored. The results showed that recombinant Gn protein was highly immunogenic and could elicit high titers of antigen-specific antibodies. Induction of the inflammatory cytokine interferon-gamma and the regulatory cytokine IL-10 was also detected. In conclusion, a recombinant baculovirus harboring CCHFV Gn was constructed and expressed in Sf9 host cells for the first time, and it was demonstrated that this approach is a suitable expression system for producing immunogenic CCHFV Gn protein without any biosafety concerns.

Synergistic effect of programmed cell death protein 1 blockade and secondary lymphoid tissue chemokine in the induction of anti-tumor immunity by a therapeutic cancer vaccine

The use of DNA vaccines has become an attractive approach for generating antigen-specific cytotoxic CD8⁺ T lymphocytes (CTLs), which can mediate protective antitumor immunity. The potency of DNA vaccines encoding weakly immunogenic tumor-associated antigens (TAAs) can be improved by using an adjuvant injected together with checkpoint antibodies. In the current study, we evaluated whether the therapeutic effects of a DNA vaccine encoding human papilloma virus type 16 (HPV-16) E7 can be enhanced by combined application of an immune checkpoint blockade directed against the programmed death-1 (PD-1) pathway and secondary lymphoid tissue chemokine (SLC) also known as CCL21 adjuvant, in a mouse cervical cancer model. The therapeutic effects of the DNA vaccine in combination with CCL21 adjuvant plus PD-1 blockade was evaluated using a tumor growth curve. To further investigate the mechanism underlying the antitumor response, cytolytic and lymphocyte proliferation responses in splenocytes were measured using non-radioactive cytotoxicity and MTT assays, respectively. Vascular endothelial growth factor (VEGF) and IL-10 expression in the tumor and the levels of IFN-γ and IL-4 in supernatants of spleno-lymphocyte cultures were measured using ELISA. The immune efficacy was evaluated by in vivo tumor regression assay. The results showed that vaccination with a DNA vaccine in combination with the CCL21 adjuvant plus PD-1 blockade greatly enhanced cytotoxic T lymphocyte production and lymphocyte proliferation rates and greatly inhibited tumor progression. Moreover, the vaccine in combination with adjuvant and blockade significantly reduced intratumoral VEGF, IL-10 and splenic IL-4 but induced the expression of splenic IFN-γ. This formulation could be an effective candidate for a vaccine against cervical cancers and merits further investigation.

Development of a multiplex real-time RT-PCR assay for detection of human parainfluenza viruses in patients with respiratory symptoms

Aim: The human parainfluenza viruses (HPIVs) are common viral causes of both upper and lower respiratory tract infections in infants and children. The purpose of this study was to develop a real-time reverse transcription PCR assay to detect HPIVs in clinical specimens in a single test. Specimens: Specific primers and probes matched to conserved region of hemagglutinin–neuraminidase genes were designed. Clinical specimens were collected from hospitalized children of ≤5 years old. Results & conclusion: Of 230 specimens, 48 samples contained one of HPIV types 1–4. The most percentage of positive HPIVs belonged to HPIV2. HPIVs were found in fall, winter and spring but not in summer months. In conclusion, our in-house multiplex real-time reverse transcription PCR is a suitable technique for simultaneous detection of HPIVs in clinical samples.