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.

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.

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.

Bacteriophage self-counting in the presence of viral replication

When host cells are in low abundance, temperate bacteriophages opt for dormant (lysogenic) infection. Phage lambda implements this strategy by increasing the frequency of lysogeny at higher multiplicity of infection (MOI). However, it remains unclear how the phage reliably counts infecting viral genomes even as their intracellular number increases because of replication. By combining theoretical modeling with single-cell measurements of viral copy number and gene expression, we find that instead of hindering lambda’s decision, replication facilitates it. In a nonreplicating mutant, viral gene expression simply scales with MOI rather than diverging into lytic (virulent) and lysogenic trajectories. A similar pattern is followed during early infection by wild-type phage. However, later in the infection, the modulation of viral replication by the decision genes amplifies the initially modest gene expression differences into divergent trajectories. Replication thus ensures the optimal decision—lysis upon single-phage infection and lysogeny at higher MOI.

Transcriptome Profiling Reveals Features of Immune Response and Metabolism of Acutely Infected, Dead and Asymptomatic Infection of African Swine Fever Virus in Pigs

African swine fever virus (ASFV) infection can result in lethal disease in pigs. ASFV encodes 150-167 proteins, of which only approximately 50 encoded viral structure proteins are functionally known. ASFV also encodes some nonstructural proteins that are involved in the regulation of viral transcription, viral replication and evasion from host defense. However, the understanding of the molecular correlates of the severity of these infections is still limited. The purpose of this study was to compare host and viral gene expression differences and perform functional analysis in acutely infected, dead and cohabiting asymptomatic pigs infected with ASFV by using RNA-Seq technique; healthy pigs were used as controls. A total of 3,760 and 2,874 upregulated genes and 4,176 and 2,899 downregulated genes were found in healthy pigs vs. acutely infected, dead pigs or asymptomatic pigs, respectively. Additionally, 941 upregulated genes and 956 downregulated genes were identified in asymptomatic vs. acutely infected, dead pigs. Different alternative splicing (AS) events were also analyzed, as were gene chromosome locations, and protein-protein interaction (PPI) network prediction analysis was performed for significantly differentially expressed genes (DEGs). In addition, 30 DEGs were validated by RT-qPCR, and the results were consistent with the RNA-Seq results. We further analyzed the interaction between ASFV and its host at the molecular level and predicted the mechanisms responsible for asymptomatic pigs based on the selected DEGs. Interestingly, we found that some viral genes in cohabiting asymptomatic pigs might integrate into host genes (DP96R, I73R and L83L) or remain in the tissues of cohabiting asymptomatic pigs. In conclusion, the data obtained in the present study provide new evidence for further elucidating ASFV-host interactions and the ASFV infection mechanism and will facilitate the implementation of integrated strategies for controlling ASF spread.

Herpesvirus-mediated stabilization of ICP0 expression neutralizes restriction by TRIM23

Herpes simplex virus (HSV) infection relies on immediate early proteins that initiate viral replication. Among them, ICP0 is known, for many years, to facilitate the onset of viral gene expression and reactivation from latency. However, how ICP0 itself is regulated remains elusive. Through genetic analyses, we identify that the viral γ134.5 protein, an HSV virulence factor, interacts with and prevents ICP0 from proteasomal degradation. Furthermore, we show that the host E3 ligase TRIM23, recently shown to restrict the replication of HSV-1 (and certain other viruses) by inducing autophagy, triggers the proteasomal degradation of ICP0 via K11- and K48-linked ubiquitination. Functional analyses reveal that the γ134.5 protein binds to and inactivates TRIM23 through blockade of K27-linked TRIM23 autoubiquitination. Deletion of γ134.5 or ICP0 in a recombinant HSV-1 impairs viral replication, whereas ablation of TRIM23 markedly rescues viral growth. Herein, we show that TRIM23, apart from its role in autophagy-mediated HSV-1 restriction, down-regulates ICP0, whereas viral γ134.5 functions to disable TRIM23. Together, these results demonstrate that posttranslational regulation of ICP0 by virus and host factors determines the outcome of HSV-1 infection.

Therapeutic Effects of Mutian® Xraphconn on 141 Client-Owned Cats with Feline Infectious Peritonitis Predicted by Total Bilirubin Levels

Feline infectious peritonitis (FIP) is a fatal disease caused by feline coronavirus or its variant, referred to as the FIP virus. Recently, favorable treatment outcomes of the anti-viral drug Mutian® Xraphconn (Mutian X) were noted in cats with FIP. Thus, the therapeutic efficacy of Mutian X in cats with FIP must be explored, although the predictors of therapeutic success remain unknown. In the present study, we administered Mutian X to 141 pet cats with effusive FIP following initial veterinarian examinations. Of these, 116 cats survived but the remaining 25 died during treatment. Pre-treatment signalment, viral gene expression, and representative laboratory parameters for routine FIP diagnosis (i.e., hematocrit, albumin-to-globulin ratio, total bilirubin, serum amyloid-A, and α1-acid glycoprotein) were statistically compared between the survivor and non-survivor groups. The majority of these parameters, including hematocrit, albumin-to-globulin ratio, serum amyloid-A, α1-acid glycoprotein, and viral gene expression, were comparable between the two groups. Interestingly, however, total bilirubin levels in the survivor group were significantly lower than those in the non-survivor group (p < 0.0001). Furthermore, in almost all surviving cats with effusive FIP (96.6%, 28/29), the pre-treatment total bilirubin levels were below 0.5 mg/dL; however, the survival rate decreased drastically (14.3%, 1/7) when the pre-treatment total bilirubin levels exceeded 4.0 mg/dL. Thus, circulating total bilirubin levels may act as a prognostic risk factor for severe FIP and may serve as the predictor of the therapeutic efficacy of Mutian X against this fatal disease.