Nanoformulation of Glycyrrhizic acid as a potent antiviral agent against Covid-19

In many previous studies, it has been found that liquorice plant (Glycyrrhiza glabra) extracts contain more than 300 natural compounds, most of which are triterpenoids and flavonoids, and had shown promising results in clinical studies for treating many microbial and viral infections. Triterpenoids like glycyrrhizic acid have shown anti-SARS-CoV activity in- vitro. Experimentally, certain glycyrrhizic acid derivatives have shown increased activity by many folds against SARS-associated viruses. These compounds can potentially inhibit the replication cycle of SARS-associated viruses by interfering with the viral gene expression or by inhibiting the spike protein expression, which in turn inhibits the adhesion and entry of the virus. Although the therapeutic has shown great antiviral activity in vitro, but in vivo its efficiency deteriorates till it reaches the liver for metabolism. In the current review, we analyze the unique replication strategy of SARS-CoV-2 and glycyrrhizic acid as a potential drug against SARS-CoV-2. We also discuss possible nano-formulations of glycyrrhizic acid for efficient drug delivery in humans, as a potent therapeutic strategy for COVID-19.

HCMV exploits STING signaling and counteracts IFN and ISG induction to facilitate dendritic cell infection

Human cytomegalovirus (HCMV) is a widespread obligatory human pathogen causing life-threatening disease in immunocompromised hosts. Myeloid cells such as monocyte-derived dendritic cells (moDCs) are targets of HCMV. Here, we performed single-cell RNA sequencing, which revealed infection of most moDCs upon in vitro HCMV exposure, whereas only a fraction of them initiated viral gene expression. We identified three moDC subsets, of which CD1a−/CD86− cells showed the highest susceptibility. Upon HCMV entry, STING activation not only induced IFN-β, but also promoted viral gene expression. Upon progression of infection, IFN-β but not IFN-λ1 expression was inhibited. Similarly, ISG expression was initially induced and then shut off and thus allowed productive infection. Increased viral gene expression was associated with the induction of several pro- (RHOB, HSP1A1, DNAJB1) and anti-viral (RNF213, TNFSF10, IFI16) genes. Thus, moDC permissiveness to HCMV depends on complex interactions between virus sensing, regulation of IFNs/ISGs and viral gene expression.

A BAFF ligand-based CAR-T cell targeting three receptors and multiple B cell cancers

B cell-activating factor (BAFF) binds the three receptors BAFF-R, BCMA, and TACI, predominantly expressed on mature B cells. Almost all B cell cancers are reported to express at least one of these receptors. Here we develop a BAFF ligand-based chimeric antigen receptor (CAR) and generate BAFF CAR-T cells using a non-viral gene delivery method. We show that BAFF CAR-T cells bind specifically to each of the three BAFF receptors and are effective at killing multiple B cell cancers, including mantle cell lymphoma (MCL), multiple myeloma (MM), and acute lymphoblastic leukemia (ALL), in vitro and in vivo using different xenograft models. Co-culture of BAFF CAR-T cells with these tumor cells results in induction of activation marker CD69, degranulation marker CD107a, and multiple proinflammatory cytokines. In summary, we report a ligand-based BAFF CAR-T capable of binding three different receptors, minimizing the potential for antigen escape in the treatment of B cell cancers.

Interactions between influenza A virus nucleoprotein and gene segment UTRs facilitate selective modulation of viral gene expression

The influenza A virus (IAV) genome is divided into eight negative-sense, single-stranded RNA segments. Each segment exhibits a unique level and temporal pattern of expression, however the exact mechanisms underlying the patterns of individual gene segment expression are poorly understood. We previously demonstrated that a single substitution in the viral nucleoprotein (NP:F346S) selectively modulates neuraminidase (NA) gene segment expression while leaving other segments largely unaffected. Given what is currently known about NP function, there is no obvious explanation for how changes in NP can selectively modulate the replication of individual gene segments. We found that the specificity of this effect for the NA segment is virus strain specific and depends on the UTR sequences of the NA segment. While the NP:F346S substitution did not significantly alter the RNA binding or oligomerization activities of NP in vitro, it specifically decreased the ability of NP to promote NA segment vRNA synthesis. In addition to NP residue F346, we identified two other adjacent aromatic residues in NP (Y385 & F479) capable of similarly regulating NA gene segment expression, suggesting a larger role for this domain in gene-segment specific regulation. Our findings reveal a new role for NP in selective regulation of viral gene segment replication and demonstrate how the expression patterns of individual viral gene segments can be modulated during adaptation to new host environments.

Development of “NEC-SD-LAMP,” a New Non-Electrified Infectious Diseases Testing Method

Here, non-electric-control SalivaDirect loop-mediated isothermal amplification (NEC-SD-LAMP), which can detect infections by analyzing viral gene expression in saliva without electrical control systems, was developed. In this method, viral genes are purified from saliva using SalivaDirect, and gene expression is analyzed by loop-mediated isothermal amplification (LAMP) by adding water to the device, and the results can be visually confirmed. Melting palmitic acid maintains the optimal temperature for the LAMP reaction, as the temperature of palmitic acid is maintained at 62.9°C, its melting point. By taking advantage of the proximity of this melting point to the optimal temperature for LAMP, it is possible to perform LAMP without electricity. Using this method, adenovirus DNA was detected in saliva. Furthermore, the detection limit was 2 copies per µL, indicating that it is possible to detect viral infections in saliva even before the onset of SARS-CoV-2 infection.

Multi-omics reveals principles of gene regulation and pervasive non-productive transcription in the human cytomegalovirus genome

For decades, human cytomegalovirus (HCMV) was thought to express ≈200 viral proteins during lytic infection. In recent years, systems biology approaches uncovered hundreds of additional viral gene products and suggested thousands of viral sites of transcription initiation. Despite all available data, the molecular mechanisms of HCMV gene regulation remain poorly understood. Here, we provide a unifying model of productive HCMV gene expression employing transcription start site profiling combined with metabolic RNA labeling as well as integrative computational analysis of previously published big data. This approach defined the expression of >2,600 high confidence viral transcripts and explained the complex kinetics of viral protein expression by cumulative effects of translation of incoming virion-associated RNA, multiple transcription start sites with distinct kinetics per viral open reading frame, and differences in viral protein stability. Most importantly, we identify pervasive transcription of transient RNAs as a common feature of this large DNA virus with its human host.

Bioinformatic Evaluation of the miRNAs Targeting ACE2 Gene in COVID-19

Introduction: Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which began in late 2019 in Wuhan, China, has become a global epidemic. Angiotensin 2 converting enzyme (ACE2) acts as a receptor for host function to cause acute coronavirus 2 acute respiratory syndrome (SARS-CoV-2). ACE2 is abundantly expressed in different cells of different human organs. In human physiology, ACE2 is a major player in the renin-angiotensin-aldosterone (RAAS) system by degrading angiotensin II. Many factors have been associated with altered ACE2 expression and the severity and progression of COVID-19, including microRNAs that may be effective in it. Identifying pathological changes due to SARS-CoV-2 infection is important because it has major implications for understanding the pathophysiology of COVID-19 and developing evidence-based treatment strategies. Currently, many intervention strategies are being explored in ongoing clinical trials. Objective: The aim of this study is to use bioinformatics databases to find potential antiviral therapies against SARS-CoV-2 through host microRNAs (miRNAs) that can reduce viral gene expression to inhibit virus entry and replication. Methods: Using different algorithms in TargetScan, DIANA, ENCORI and miRWalk databases, the potential microRNAs were identified that target ACE2. Then, a score table was prepared from the candidate microRNAs, based on the affinity of the seed region of microRNAs and the 3`-UTR region of the ACE2 gene. Finally, microRNAs with higher scores were chosen as candidates for practical analysis. Results: The results of Bioinformatical analysis showed that Has-miR-200c-3p, Has-miR-29a, Has-miR-29c, and Has-miR-942 are most likely to inhibit ACE2. These microRNAs are the most potent factors that might be affected on ACE2 during virulence. Conclusion: It seems that ACE2 is under the control of the miR-200c-3p and plays a crucial role in the pathophysiology process. Therefore, this microRNA can be considered as a suitable new candidate for experimental evaluation.

The Thiazole-5-Carboxamide GPS491 Inhibits HIV-1, Adenovirus, and Coronavirus Replication by Altering RNA Processing/Accumulation

Medicinal chemistry optimization of a previously described stilbene inhibitor of HIV-1, 5350150 (2-(2-(5-nitro-2-thienyl)vinyl)quinoline), led to the identification of the thiazole-5-carboxamide derivative (GPS491), which retained potent anti-HIV-1 activity with reduced toxicity. In this report, we demonstrate that the block of HIV-1 replication by GPS491 is accompanied by a drastic inhibition of viral gene expression (IC50 ~ 0.25 µM), and alterations in the production of unspliced, singly spliced, and multiply spliced HIV-1 RNAs. GPS491 also inhibited the replication of adenovirus and multiple coronaviruses. Low µM doses of GPS491 reduced adenovirus infectious yield ~1000 fold, altered virus early gene expression/viral E1A RNA processing, blocked viral DNA amplification, and inhibited late (hexon) gene expression. Loss of replication of multiple coronaviruses (229E, OC43, SARS-CoV2) upon GPS491 addition was associated with the inhibition of viral structural protein expression and the formation of virus particles. Consistent with the observed changes in viral RNA processing, GPS491 treatment induced selective alterations in the accumulation/phosphorylation/function of splicing regulatory SR proteins. Our study establishes that a compound that impacts the activity of cellular factors involved in RNA processing can prevent the replication of several viruses with minimal effect on cell viability.

Clinical Trials of Oncolytic Viruses in Breast Cancer

Breast cancer is the second most common kind of cancer worldwide and oncolytic viruses may offer a new treatment approach. There are three different types of oncolytic viruses used in clinical trials; (i) oncolytic viruses with natural anti-neoplastic properties; (ii) oncolytic viruses designed for tumor-selective replication; (iii) oncolytic viruses modified to activate the immune system. Currently, fourteen different oncolytic viruses have been investigated in eighteen published clinical trials. These trials demonstrate that oncolytic viruses are well tolerated and safe for use in patients and display clinical activity. However, these trials mainly studied a small number of patients with different advanced tumors including some with breast cancer. Future trials should focus on breast cancer and investigate optimal routes of administration, occurrence of neutralizing antibodies, viral gene expression, combinations with other antineoplastic therapies, and identify subtypes that are particularly suitable for oncolytic virotherapy.