Early reduction of SARS-CoV-2-replication in bronchial epithelium by kinin B2 receptor antagonism

Phytoconstituents as modulator of inflammatory pathways for COVID-19: A comprehensive review and recommendations

SARS-CoV-2 infection causes disruptions in inflammatory pathways, which fundamentally contribute to COVID-19 pathophysiology. The present review critically evaluates the gaps in scientific literature and presents the current status regarding the inflammatory signaling pathways in COVID-19. We propose that phytoconstituents can be used to treat COVID-19 associated inflammation, several already formulated in traditional medications. For this purpose, extensive literature analysis was conducted in the PubMed database to collect relevant in vitro, in vivo, and human patient studies where inflammation pathways were shown to be upregulated in COVID-19. Parallelly, scientific literature was screened for phytoconstituents with known cellular mechanisms implicated for inflammation or COVID-19 associated inflammation. Studies with insufficient evidence on cellular pathways for autophagy and mitophagy were considered out of scope and excluded from the study. The final analysis was visualized in figures and evaluated for accuracy. Our findings demonstrate the frequent participation of NF-κB, a transcription factor, in inflammatory signaling pathways linked to COVID-19. Moreover, the MAPK signaling pathway is also implicated in producing inflammatory molecules. Furthermore, it was also analyzed that the phytoconstituents with flavonoid and phenolic backbones could inhibit either the TLR4 receptor or its consecutive signaling molecules, thereby, decreasing NF-κB activity and suppressing cytokine production. Although, allopathy has treated the early phase of COVID-19, anti-inflammatory phytoconstituents and existing ayurvedic formulations may act on the COVID-19 associated inflammatory pathways and provide an additional treatment strategy. Therefore, we recommend the usage of flavonoids and phenolic phytoconstituents for the treatment of inflammation associated with COVID-19 infection and similar viral ailments.

Inhibition of SARS-CoV-2 infection and replication by Petasites hybridus CO2-extract (Ze 339)

BACKGROUND

The intensified search for low-threshold herbal anti-viral drugs would be of great advantage in prevention of early stages of infection. Since the SARS-CoV-2 Omicron variant has prevailed in western countries, the course has only been mild, but there are still no widely available drugs that can alleviate or shorten disease progression and counteract the development of Long-COVID. This study aimed to investigate the antiviral effects of a CO2-extract from Petasites hybridus (Ze 339).

METHODS

We analyzed the infection and replication rate of SARS-CoV-2 in primary normal human bronchial epithelial cells (NHBEs) using a GFP-expressing version of the wild-type SARS-CoV-2 virus and live cell imaging. Upon infection with a clinical isolate of the Omicron variant, viral RNA content was quantified, and plaque assays were performed. In addition, the human transcriptome was analyzed after 4- and 24-hours post infection using whole genome microarrays.

RESULTS

Ze 339 had a protective effect on primary airway epithelial cells during SARS-CoV-2 infection and impeded SARS-CoV-2 infection and replication in NHBE. Notably, Ze 339 inhibited the expression of infection-induced IFNA10 by 8.6-fold (p < 0.05) and additionally reduced a wide range of other interferons (IFNA6, IFNA7, IFNA8, IFNA21, IFNE, IFNW1).

CONCLUSION

Thereby, Ze 339 attenuated epithelial infection by SARS-CoV-2 and modeled the IFN response. In conclusion, this study highlights Ze 339 as a potential treatment option for COVID-19 that limits infection-associated cell intrinsic immune responses.

Resurgence of SARS-CoV-2 Delta after Omicron variant superinfection in an immunocompromised pediatric patient

BACKGROUND

Persistent SARS-CoV-2 infection in immunocompromised hosts is thought to contribute to viral evolution by facilitating long-term natural selection and viral recombination in cases of viral co-infection or superinfection. However, there are limited data on the longitudinal intra-host population dynamics of SARS-CoV-2 co-infection/superinfection, especially in pediatric populations. Here, we report a case of Delta-Omicron superinfection in a hospitalized, immunocompromised pediatric patient.

METHODS

We conducted Illumina whole genome sequencing (WGS) for longitudinal specimens to investigate intra-host dynamics of SARS-CoV-2 strains. Topoisomerase PCR cloning of Spike open-reading frame and Sanger sequencing of samples was performed for four specimens to validate the findings. Analysis of publicly available SARS-CoV-2 sequence data was performed to investigate the co-circulation and persistence of SARS-CoV-2 variants.

RESULTS

Results of WGS indicate the patient was initially infected with the SARS-CoV-2 Delta variant before developing a SARS-CoV-2 Omicron variant superinfection, which became predominant. Shortly thereafter, viral loads decreased below the level of detection before resurgence of the original Delta variant with no residual trace of Omicron. After 54 days of persistent infection, the patient tested negative for SARS-CoV-2 but ultimately succumbed to a COVID-19-related death. Despite protracted treatment with remdesivir, no antiviral resistance mutations emerged. These results indicate a unique case of persistent SARS-CoV-2 infection with the Delta variant interposed by a transient superinfection with the Omicron variant. Analysis of publicly available sequence data suggests the persistence and ongoing evolution of Delta subvariants despite the global predominance of Omicron, potentially indicative of continued transmission in an unknown population or niche.

CONCLUSION

A better understanding of SARS-CoV-2 intra-host population dynamics, persistence, and evolution during co-infections and/or superinfections will be required to continue optimizing patient care and to better predict the emergence of new variants of concern.

Genome-Wide Gene Expression Analysis Reveals Unique Genes Signatures of Epithelial Reorganization in Primary Airway Epithelium Induced by Type-I, -II and -III Interferons

Biosensors such as toll-like receptors (TLR) induce the expression of interferons (IFNs) after viral infection that are critical to the first step in cell-intrinsic host defense mechanisms. Their differential influence on epithelial integrity genes, however, remains elusive. A genome-wide gene expression biosensor chip for gene expression sensing was used to examine the effects of type-I, -II, and -III IFN stimulation on the epithelial expression profiles of primary organotypic 3D air-liquid interface airway cultures. All types of IFNs induced similar interferon-stimulated genes (ISGs): OAS1, OAS2, and IFIT2. However, they differentially induced transcription factors, epithelial modulators, and pro-inflammatory genes. Type-I IFN-induced genes were associated with cell-cell adhesion and tight junctions, while type-III IFNs promoted genes important for transepithelial transport. In contrast, type-II IFN stimulated proliferation-triggering genes associated and enhanced pro-inflammatory mediator secretion. In conclusion, with our microarray system, we provide evidence that the three IFN types exceed their antiviral ISG-response by inducing distinct remodeling processes, thereby likely strengthening the epithelial airway barrier by enhancing cross-cell-integrity (I), transepithelial transport (III) and finally reconstruction through proliferation (II).

A Review of Potential Therapeutic Strategies for COVID-19

Coronavirus disease 2019 is a rather heterogeneous disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The ongoing pandemic is a global threat with increasing death tolls worldwide. SARS-CoV-2 belongs to lineage B β-CoV, a subgroup of Sarbecovirus. These enveloped, large, positive-sense single-stranded RNA viruses are easily spread among individuals, mainly via the respiratory system and droplets. Although the disease has been gradually controlled in many countries, once social restrictions are relaxed the virus may rebound, leading to a more severe and uncontrollable situation again, as occurred in Shanghai, China, in 2022. The current global health threat calls for the urgent development of effective therapeutic options for the treatment and prevention of SARS-CoV-2 infection. This systematic overview of possible SARS-CoV-2 therapeutic strategies from 2019 to 2022 indicates three potential targets: virus entry, virus replication, and the immune system. The information provided in this review will aid the development of more potent and specific antiviral compounds.

ADAM10 and ADAM17 promote SARS-CoV-2 cell entry and spike protein-mediated lung cell fusion

The severe‐acute‐respiratory‐syndrome‐coronavirus‐2 (SARS‐CoV‐2) is the causative agent of COVID‐19, but host cell factors contributing to COVID‐19 pathogenesis remain only partly understood. We identify the host metalloprotease ADAM17 as a facilitator of SARS‐CoV‐2 cell entry and the metalloprotease ADAM10 as a host factor required for lung cell syncytia formation, a hallmark of COVID‐19 pathology. ADAM10 and ADAM17, which are broadly expressed in the human lung, cleave the SARS‐CoV‐2 spike protein (S) in vitro, indicating that ADAM10 and ADAM17 contribute to the priming of S, an essential step for viral entry and cell fusion. ADAM protease‐targeted inhibitors severely impair lung cell infection by the SARS‐CoV‐2 variants of concern alpha, beta, delta, and omicron and also reduce SARS‐CoV‐2 infection of primary human lung cells in a TMPRSS2 protease‐independent manner. Our study establishes ADAM10 and ADAM17 as host cell factors for viral entry and syncytia formation and defines both proteases as potential targets for antiviral drug development.