A tug-of-war between severe acute respiratory syndrome coronavirus 2 and host antiviral defence: lessons from other pathogenic viruses

Urinary phenotyping of SARS-CoV-2 infection connects clinical diagnostics with metabolomics and uncovers impaired NAD+ pathway and SIRT1 activation

OBJECTIVES

The stratification of individuals suffering from acute and post-acute SARS-CoV-2 infection remains a critical challenge. Notably, biomarkers able to specifically monitor viral progression, providing details about patient clinical status, are still not available. Herein, quantitative metabolomics is progressively recognized as a useful tool to describe the consequences of virus-host interactions considering also clinical metadata.

METHODS

The present study characterized the urinary metabolic profile of 243 infected individuals by quantitative nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography mass spectrometry (LC-MS). Results were compared with a historical cohort of noninfected subjects. Moreover, we assessed the concentration of recently identified antiviral nucleosides and their association with other metabolites and clinical data.

RESULTS

Urinary metabolomics can stratify patients into classes of disease severity, with a discrimination ability comparable to that of clinical biomarkers. Kynurenines showed the highest fold change in clinically-deteriorated patients and higher-risk subjects. Unique metabolite clusters were also generated based on age, sex, and body mass index (BMI). Changes in the concentration of antiviral nucleosides were associated with either other metabolites or clinical variables. Increased kynurenines and reduced trigonelline excretion indicated a disrupted nicotinamide adenine nucleotide (NAD+) and sirtuin 1 (SIRT1) pathway.

CONCLUSIONS

Our results confirm the potential of urinary metabolomics for noninvasive diagnostic/prognostic screening and show that the antiviral nucleosides could represent novel biomarkers linking viral load, immune response, and metabolism. Moreover, we established for the first time a casual link between kynurenine accumulation and deranged NAD+/SIRT1, offering a novel mechanism through which SARS-CoV-2 manipulates host physiology.

Lymphopenia associated with survivin and its downstream pathway in COVID-19 serving as a potential route in COVID-19 pathogenesis

PURPOSE

Starting in 2019, coronavirus disease 2019 (COVID-19) caused an epidemic that was growing rapidly and has harmed millions of people globally. It has been demonstrated that survivin regulates lymphocyte survival, a main route involved in COVID-19 pathogenesis. Survivin belongs to the inhibitor of apoptosis protein (IAP) family, and its primary functions comprise regulating mitosis and inhibiting apoptosis. Since lower survivin expression has been shown to increase the sensitivity of lymphocytes to apoptotic induction, we looked into the function of survivin and its corresponding pathways in COVID-19 pathogenesis.

MATERIALS AND METHODS

The expression of survivin, X-linked inhibitor of apoptosis protein (XIAP), caspases 3, 7, 9, and poly (ADP-ribose) polymerase (PARP) was evaluated at both mRNA and protein levels in peripheral blood mononuclear cells (PBMCs) derived from healthy donors and patients with severe and moderate COVID-19 by qRT-PCR and Western blotting, respectively. Then, we enforced apoptosis to COVID-19 patient-derived lymphocytes, and the percent was assessed by flow cytometry.

RESULTS

Survivin and XIAP were less expressed in PBMCs derived from COVID-19 patients as apoptosis inhibitors than PARP, cleaved-PARP, caspase 9, and cleaved caspases 3 and 7, according to the results of real-time PCR and Western blot analysis. Additionally, according to the flow cytometry results, the down-regulation of survivin served as a potential factor in the lymphocyte depletion observed in patients with COVID-19.

CONCLUSION

The role of survivin and its related pathway was first discovered in the development of COVID-19 and may serve as a potential prognostic and therapeutic target.

Evaluation of long non-coding RNAs EGOT, NRAV, NRIR and mRNAs ISG15 and IFITM3 expressions in COVID-19 patients

Individuals with Coronavirus Disease 2019 (COVID-19) may show no symptoms to moderate or severe complications. This variation may be due to differences in the strength of the immune response, including a delayed interferon (IFN) response in asymptomatic patients and higher IFN levels in severe patients. Some long non-coding RNAs (lncRNAs), as regulators of the IFN pathway, may contribute to the emergence of different COVID-19 symptoms. This study aimed to comparatively investigate the relationship between lncRNAs (eosinophil granule ontogeny transcript (EGOT), negative regulator of antiviral response (NRAV), and negative regulator of interferon response (NRIR)), alongside interferon-stimulated genes (ISGs) like ISG-15 and interferon-induced transmembrane protein 3 (IFITM3) in COVID-19 patients with asymptomatic, moderate, and severe symptoms. Buffy coat samples were collected from 17 asymptomatic, 23 moderate, 22 severe patients, and 44 healthy controls. Quantitative real-time PCR was utilized to determine the expression levels. In a comparison between COVID-19 patients and healthy individuals, higher expression levels of EGOT and NRAV were observed in severe and moderate patients. NRIR expression was increased across all patient groups. Meanwhile, ISG15 expression decreased in all patient groups, and the moderate group showed a significant decrease in IFITM3 expression. Comparing COVID-19 patient groups, EGOT expression was significantly higher in moderate COVID-19 patients compared to asymptomatic patients. NRAV was higher in moderate and severe patients compared to asymptomatic. NRIR levels did not differ significantly between the COVID-19 patient groups. ISG15 was higher in moderate and severe patients compared to asymptomatic. IFITM3 expression was significantly higher in severe patients compared to the moderate group. In severe COVID-19 patients, EGOT expression was positively correlated with NRAV levels. EGOT and NRAV showed a significant positive correlation in asymptomatic patients, and both were positively correlated with IFITM3 expression. This study suggests that EGOT, NRAV, NRIR, ISG15, and IFITM3 may serve as diagnostic biomarkers for COVID-19. The lncRNA NRAV may be a good biomarker in a prognostic panel between asymptomatic and severe patients in combination with other high-sensitivity biomarkers. EGOT, NRAV, and ISG15 could also be considered as specific biomarkers in a prognostic panel comparing asymptomatic and moderate patients with other high-sensitivity biomarkers.

The HN protein of Newcastle disease virus induces cell apoptosis through the induction of lysosomal membrane permeabilization

Lysosomes are acidic organelles that mediate the degradation and recycling of cellular waste materials. Damage to lysosomes can cause lysosomal membrane permeabilization (LMP) and trigger different types of cell death, including apoptosis. Newcastle disease virus (NDV) can naturally infect most birds. Additionally, it serves as a promising oncolytic virus known for its effective infection of tumor cells and induction of intensive apoptotic responses. However, the involvement of lysosomes in NDV-induced apoptosis remains poorly understood. Here, we demonstrate that NDV infection profoundly triggers LMP, leading to the translocation of cathepsin B and D and subsequent mitochondria-dependent apoptosis in various tumor and avian cells. Notably, the released cathepsin B and D exacerbate NDV-induced LMP by inducing the generation of reactive oxygen species. Additionally, we uncover that the viral Hemagglutinin neuraminidase (HN) protein induces the deglycosylation and degradation of lysosome-associated membrane protein 1 (LAMP1) and LAMP2 dependent on its sialidase activity, which finally contributes to NDV-induced LMP and cellular apoptosis. Overall, our findings elucidate the role of LMP in NDV-induced cell apoptosis and provide novel insights into the function of HN during NDV-induced LMP, which provide innovative approaches for the development of NDV-based oncolytic agents.

Herbal Substances with Antiviral Effects: Features and Prospects for the Treatment of Viral Diseases with Emphasis on Pro-Inflammatory Cytokines

Viral diseases have a significant impact on human health, and three novel coronaviruses (CoV) have emerged during the 21st century. In this review, we have emphasized the potential of herbal substances with antiviral effects. Our investigation focused on the features and prospects of viral disease treatment, with a particular emphasis on proinflammatory cytokines. We conducted comprehensive searches of various databases, including Science Direct, CABI Direct, Web of Science, PubMed, and Scopus. Cytokine storm mechanisms play a crucial role in inducing a pro-inflammatory response by triggering the expression of cytokines and chemokines. This response leads to the recruitment of leukocytes and promotes antiviral effects, forming the first line of defense against viruses. Numerous studies have investigated the use of herbal medicine candidates as immunomodulators or antivirals. However, cytokine-storm-targeted therapy is recommended for patients with acute respiratory distress syndrome caused by SARS-CoV to survive severe pulmonary failure. Our reviews have demonstrated that herbal formulations could serve as alternative medicines and significantly reduce complicated viral infections. Furthermore, they hold promising potential as specific antiviral agents in experimental animal models.

Risk factors for death in hospitalized COVID-19 patients in Africa: A systematic review and meta-analysis

BACKGROUND

The coronavirus disease 2019 has quickly spread worldwide since it first appeared in Wuhan, China, in late 2019. The most affected country in Africa was South Africa. This study aimed to identify the risk factors for death in hospitalized COVID-19 patients in Africa.

METHODS

We conducted a systematic review following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We searched articles from the following database: PubMed, Embase, Cochrane Library, Medline, and COVID-19 Research Database. We used Google Scholar for gray literature. The language used in this article was English. The last search was conducted on January 15, 2023. Pooled HRs, or ORs, and 95% confidence intervals, were calculated separately to identify the risk factors for death in hospitalized COVID-19 patients. Heterogeneity was assessed by Cochran's Q statistic and the I2 test. The Egger test was used to assess publication bias. Subgroup analysis was performed to determine the source of heterogeneity. Data analysis was performed using Stata version 17. A P value < .05 was considered significant.

RESULTS

A total of 16,600 articles were obtained from the database search; finally, 16 articles met the inclusion criteria and were eligible for data extraction. The analysis revealed that the pooled prevalence of mortality in hospitalized COVID-19 patients was 13.9%. Advanced age was a significant risk factor for death in hospitalized COVID-19 patients, with the pooled coronavirus mortality HR and OR being 3.73 (95% CI: 2.27-5.19) and 1.04 (95% CI: 1.02-1.06), respectively. In addition, male gender (pOR 1.23; 95% CI: 1.07-1.40), patients with diabetes mellitus (DM) (pOR 1.26; 95% CI: 1.01-1.51), hypertension (HTN) (pOR 1.56; 95% CI: 1.27-1.85), chronic kidney disease (CKD) (pHR 5.43; 95% CI: 0.18-10.67), severe or critical conditions (pOR 9.04; 95% CI: 3.14-14.94) had a significantly increased risk of coronavirus-related mortality. The main limitations of the present study stem from the predominant use of published studies, which could introduce publication bias.

CONCLUSION

According to this study, advanced age, male gender, hypertension, diabetes mellitus, chronic kidney disease, and severe or critical condition were clinical risk factors associated with death outcomes in hospitalized COVID-19 patients in Africa.

Ibuprofen in the Management of Viral Infections: The Lesson of COVID-19 for Its Use in a Clinical Setting

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the management of fever, pain, and inflammation. However, they have always been considered to have a double-faced role, according to their capacity to manage inflammation but also their possible reduction of immune system response and diagnosis delay. This last point could favor a dramatic increase of viral infection diffusion, possibly leading to a more severe outcome. The advent of severe acute respiratory syndrome coronavirus 2 excluded the use of NSAIDs, particularly ibuprofen, and then indicated this drug as the better NSAID to manage infected outpatients and prevent complications. Several authors described the role of NSAIDs and ibuprofen in preventing cytokine storm and modulating the immune system. However, the development of both adverse drug reactions (i.e., gastrointestinal, renal, hepatic, and cardiovascular) and drug interaction recalled the necessity of prescribing the better NSAID for each patient. In this narrative review, we describe the role of NSAIDs, particularly of ibuprofen, in the management of viral symptoms, suggesting that the NSAID may be chosen considering the characteristics of the patient, the comorbidity, and the polytherapy.

Antibody-Dependent Enhancement with a Focus on SARS-CoV-2 and Anti-Glycan Antibodies

Antibody-dependent enhancement (ADE) is a phenomenon where virus-specific antibodies paradoxically cause enhanced viral replication and/or excessive immune responses, leading to infection exacerbation, tissue damage, and multiple organ failure. ADE has been observed in many viral infections and is supposed to complicate the course of COVID-19. However, the evidence is insufficient. Since no specific laboratory markers have been described, the prediction and confirmation of ADE are very challenging. The only possible predictor is the presence of already existing (after previous infection) antibodies that can bind to viral epitopes and promote the disease enhancement. At the same time, the virus-specific antibodies are also a part of immune response against a pathogen. These opposite effects of antibodies make ADE research controversial. The assignment of immunoglobulins to ADE-associated or virus neutralizing is based on their affinity, avidity, and content in blood. However, these criteria are not clearly defined. Another debatable issue (rather terminological, but no less important) is that in most publications about ADE, all immunoglobulins produced by the immune system against pathogens are qualified as pre-existing antibodies, thus ignoring the conventional use of this term for natural antibodies produced without any stimulation by pathogens. Anti-glycan antibodies (AGA) make up a significant part of the natural immunoglobulins pool, and there is some evidence of their antiviral effect, particularly in COVID-19. AGA have been shown to be involved in ADE in bacterial infections, but their role in the development of ADE in viral infections has not been studied. This review focuses on pros and cons for AGA as an ADE trigger. We also present the results of our pilot studies, suggesting that AGAs, which bind to complex epitopes (glycan plus something else in tight proximity), may be involved in the development of the ADE phenomenon.

Nanostructures for prevention, diagnosis, and treatment of viral respiratory infections: from influenza virus to SARS-CoV-2 variants

Viruses are a major cause of mortality and socio-economic downfall despite the plethora of biopharmaceuticals designed for their eradication. Conventional antiviral therapies are often ineffective. Live-attenuated vaccines can pose a safety risk due to the possibility of pathogen reversion, whereas inactivated viral vaccines and subunit vaccines do not generate robust and sustained immune responses. Recent studies have demonstrated the potential of strategies that combine nanotechnology concepts with the diagnosis, prevention, and treatment of viral infectious diseases. The present review provides a comprehensive introduction to the different strains of viruses involved in respiratory diseases and presents an overview of recent advances in the diagnosis and treatment of viral infections based on nanotechnology concepts and applications. Discussions in diagnostic/therapeutic nanotechnology-based approaches will be focused on H1N1 influenza, respiratory syncytial virus, human parainfluenza virus type 3 infections, as well as COVID-19 infections caused by the SARS-CoV-2 virus Delta variant and new emerging Omicron variant.

PI3K/Akt/Nrf2 mediated cellular signaling and virus-host interactions: latest updates on the potential therapeutic management of SARS-CoV-2 infection

The emergence and re-emergence of viral diseases, which cause significant global mortality and morbidity, are the major concerns of this decade. Of these, current research is focused majorly on the etiological agent of the COVID-19 pandemic, SARS-CoV-2. Understanding the host response and metabolic changes during viral infection may provide better therapeutic targets for the proper management of pathophysiological conditions associated with SARS-CoV-2 infection. We have achieved control over most emerging viral diseases; however, a lack of understanding of the underlying molecular events prevents us from exploring novel therapeutic targets, leaving us forced to witness re-emerging viral infections. SARS-CoV-2 infection is usually accompanied by oxidative stress, which leads to an overactive immune response, the release of inflammatory cytokines, increasing lipid production, and also alterations in the endothelial and mitochondrial functions. PI3K/Akt signaling pathway confers protection against oxidative injury by various cell survival mechanisms including Nrf2-ARE mediated antioxidant transcriptional response. SARS-CoV-2 is also reported to hijack this pathway for its survival within host and few studies have suggested the role of antioxidants in modulating the Nrf2 pathway to manage disease severity. This review highlights the interrelated pathophysiological conditions associated with SARS-CoV-2 infection and the host survival mechanisms mediated by PI3K/Akt/Nrf2 signaling pathways that can help ameliorate the severity of the disease and provide effective antiviral targets against SARS-CoV-2.

The Impact of COVID-19 on People Living with HIV-1 and HIV-1-Associated Neurological Complications

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen of the coronavirus disease 2019 (COVID-19) pandemic, a fatal respiratory illness. The associated risk factors for COVID-19 are old age and medical comorbidities. In the current combined antiretroviral therapy (cART) era, a significant portion of people living with HIV-1 (PLWH) with controlled viremia is older and with comorbidities, making these people vulnerable to SARS-CoV-2 infection and COVID-19-associated severe outcomes. Additionally, SARS-CoV-2 is neurotropic and causes neurological complications, resulting in a health burden and an adverse impact on PLWH and exacerbating HIV-1-associated neurocognitive disorder (HAND). The impact of SARS-CoV-2 infection and COVID-19 severity on neuroinflammation, the development of HAND and preexisting HAND is poorly explored. In the present review, we compiled the current knowledge of differences and similarities between SARS-CoV-2 and HIV-1, the conditions of the SARS-CoV-2/COVID-19 and HIV-1/AIDS syndemic and their impact on the central nervous system (CNS). Risk factors of COVID-19 on PLWH and neurological manifestations, inflammatory mechanisms leading to the neurological syndrome, the development of HAND, and its influence on preexisting HAND are also discussed. Finally, we have reviewed the challenges of the present syndemic on the world population, with a particular emphasis on PLWH.

Evaluation of berberine pellet effect on clinical recovery time in COVID-19 outpatients: A pilot clinical trial

Objective

Severe disease onset of COVID-19 may result in alveolar injury and respiratory failure. Apoptosis and inflammation are the main causes of respiratory distress syndrome. Berberine is used in medicine as an analgesic, anti-asthmatic, anti-inflammatory, and antiviral. In the current investigation, the effect of berberine on COVID-19 outpatients was studied.

Materials and Methods

The present clinical trial was performed on 40 outpatients who were randomly assigned to berberine (300 mg, TID, 2 weeks) (n=19) or placebo groups (n=21). Both groups received standard therapy and they were monitored on days 3, 7, and 14 after the beginning of the therapy for clinical symptoms' improvement, quantitative CRP, lymphopenia, CBC, and SpO2. The severity and frequency of these symptoms and the level of the parameters were statistically compared between the two groups.

Results

On days (0, 3, 7, and 14, there was no significant difference between the berberine and placebo groups in the improvement of clinical symptoms (cough, shortness of breath, nausea, loss of smell and taste, diarrhea, dizziness, sore throat, stomachache, body aches, and body temperature), quantitative CRP, lymphopenia, WBC, neutrophils, platelets, or SpO2.

Conclusion

Berberine (300 mg, TID, two weeks) is ineffective in treating COVID-19. More research with a larger sample size is needed to investigate different berberine dosages in other pharmaceutical formulations.

Possible Pathogenesis and Prevention of Long COVID: SARS-CoV-2-Induced Mitochondrial Disorder

Patients who have recovered from coronavirus disease 2019 (COVID-19) infection may experience chronic fatigue when exercising, despite no obvious heart or lung abnormalities. The present lack of effective treatments makes managing long COVID a major challenge. One of the underlying mechanisms of long COVID may be mitochondrial dysfunction. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can alter the mitochondria responsible for energy production in cells. This alteration leads to mitochondrial dysfunction which, in turn, increases oxidative stress. Ultimately, this results in a loss of mitochondrial integrity and cell death. Moreover, viral proteins can bind to mitochondrial complexes, disrupting mitochondrial function and causing the immune cells to over-react. This over-reaction leads to inflammation and potentially long COVID symptoms. It is important to note that the roles of mitochondrial damage and inflammatory responses caused by SARS-CoV-2 in the development of long COVID are still being elucidated. Targeting mitochondrial function may provide promising new clinical approaches for long-COVID patients; however, further studies are needed to evaluate the safety and efficacy of such approaches.

Risk Factors for One-Year Mortality in Hospitalized Adults with Severe COVID-19

As the body's immunity declines with age, elderly-hospitalized patients due to COVID-19 might be at higher mortality risk. Therefore, the aim of this prospective study was to examine the possible risk factors (demographic, social or comorbidities) most associated with mortality one-year after diagnosis of COVID-19. Routine data were collected from a cohort of hospitalized adults with severe COVID-19. The primary endpoint was mortality at one-year after diagnosis of COVID-19. We used a Cox proportional hazard model to estimate the hazard ratios (HRs) for both all-cause and specific cardiorespiratory mortality. A fully adjusted model included sex, socioeconomic status, institutionalization status, disability, smoking habit, and comorbidities as confounders. A total of 368 severe cases hospitalized on average 67.3 ± 15.9 years old were included. Participants aged ≥ 71 years had significantly higher HRs for all-cause mortality (adjusted HRs = 2.86, 95%CI: 2.01-4.07) and cardiorespiratory mortality (adjusted HRs = 2.86, 95%CI: 1.99-4.12). The association between age and mortality after diagnosis of COVID-19 due to both all-causes and cardiorespiratory mortality showed a consistent dose-response fashion. Institutionalization, disability, and socioeconomic status also showed a significant association with mortality. In conclusion, aging itself was the most important risk factor associated with mortality one year after diagnosis of COVID-19. People with disabilities, institutionalized or low socioeconomic status are significantly more likely to die after COVID-19.

Cardiovascular Complications in Coronavirus Disease 2019-Pathogenesis and Management

The coronavirus disease 2019 (COVID-19) pandemic has caused a devastating impact on morbidity and mortality around the world. Severe acute respiratory syndrome-coronavirus-2 has a characteristic tropism for the cardiovascular system by entering the host cells and binding to angiotensin-converting enzyme 2 receptors, which are expressed in different cells, particularly endothelial cells. This endothelial injury is linked by a direct intracellular viral invasion leading to inflammation, microthrombosis, and angiogenesis. COVID-19 has been associated with acute myocarditis, cardiac arrhythmias, new onset or worsening heart failure, ischemic heart disease, stroke, and thromboembolic disease. This review summarizes key relevant literature regarding the epidemiology, diagnosis, treatment, and preventive measures related to cardiovascular complications in the setting of COVID-19.

COVID-19: A Comprehensive Review on Cardiovascular Alterations, Immunity, and Therapeutics in Older Adults

Here, we present a review focusing on three relevant issues related to COVID-19 and its impact in older adults (60 years and older). SARS-CoV-2 infection starts in the respiratory system, but the development of systemic diseases accompanied by severe clinical manifestations has also been reported, with cardiovascular and immune system dysfunction being the major ones. Additionally, the presence of comorbidities and aging represent major risk factors for the severity and poor prognosis of the disease. Since aging-associated decline has been largely related to immune and cardiovascular alterations, we sought to investigate the consequences and the underlying mechanisms of these pathologies to understand the severity of the illness in this population. Understanding the effects of COVID-19 on both systems should translate into comprehensive and improved medical care for elderly COVID-19 patients, preventing cardiovascular as well as immunological alterations in this population. Approved therapies that contribute to the improvement of symptoms and a reduction in mortality, as well as new therapies in development, constitute an approach to managing these disorders. Among them, we describe antivirals, cytokine antagonists, cytokine signaling pathway inhibitors, and vaccines.

Potential Targets and Mechanisms of Bitter Almond-Licorice for COVID-19 Treatment Based on Network Pharmacology and Molecular Docking

BACKGROUND

The outbreak of Corona Virus Disease 2019 (COVID-19) has resulted in millions of infections and raised global attention. Bitter almonds and licorice are both Traditional Chinese Medicines (TCM), often used in combination to treat lung diseases. Several prescriptions in the guidelines for the diagnosis and treatment of coronavirus disease 2019 (trial version ninth) contained bitter almond-licorice, which was effective in the treatment of COVID-19. However, the active ingredients, drug targets and therapeutic mechanisms of bitter almonds-licorice for the treatment of COVID-19 remain to be elucidated.

METHODS

The active ingredients and targets were derived from the Traditional Chinese Medicine Systems Pharmacology (TCMSP). Meanwhile, targets associated with COVID-19 were obtained from the GeneCards database, PharmGkb database and DrugBank database. Then, the potential targets of bitter almond-licorice against COVID-19 were screened out. Protein-protein interaction (PPI) networks and core targets were analyzed through the String database and Cytoscape software. In addition, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed based on potential targets using R statistical software. Finally, molecular docking was used to validate the binding of the active ingredients to the core targets.

RESULTS

The results of the TCMSP database showed that the bitter almond-licorice had 89 active components against COVID-19, involving 102 targets. PPI network and core target analysis indicated that IL-6, TNF, MAPK1, and IL1B were the key targets against COVID-19. In addition, GO and KEGG enrichment analysis showed that the bitter almond-licorice were involved in various biological processes through inflammation-related pathways such as TNF signaling pathway and IL-17 signaling pathway. Finally, molecular docking approaches confirmed the affinity between the active components of the bitter almond-licorice and the therapeutic targets.

CONCLUSION

The bitter almond-licorice could be used to treat COVID-19 by inhibiting inflammatory responses and regulating cellular stress. This work is based on data mining and molecular docking, and the findings need to be interpreted with caution.

Nonsteroidal Anti-Inflammatory Drugs in Viral Infections Disease, Specially COVID-19

During the current SARS-CoV-2 (COVID-19) pandemic, some reports were presented based on those nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids may exacerbate symptoms in COVID-19 patients. According to this, we aimed to collate information available in published articles to identify any evidence behind these statements with the aim of helping clinicians on how best to treat patients. We could not find published conclusive evidence for or against the use of NSAIDs in COVID-19 patients. Meanwhile, there appeared to be some evidence that corticosteroids may be beneficial if utilized in the early acute phase of infection, however, conflicting WHO (World Health Organization) evidence surrounding corticosteroid use in certain viral infections means this evidence is not conclusive. Given the current availability of literature, caution should be exercised until further evidence emerges surrounding the use of NSAIDs and corticosteroids in COVID-19 patients. However, the availability of reliable information for clinicians and patients is paramount.

Small molecules in the treatment of COVID-19

The outbreak of COVID-19 has become a global crisis, and brought severe disruptions to societies and economies. Until now, effective therapeutics against COVID-19 are in high demand. Along with our improved understanding of the structure, function, and pathogenic process of SARS-CoV-2, many small molecules with potential anti-COVID-19 effects have been developed. So far, several antiviral strategies were explored. Besides directly inhibition of viral proteins such as RdRp and M^pro, interference of host enzymes including ACE2 and proteases, and blocking relevant immunoregulatory pathways represented by JAK/STAT, BTK, NF-κB, and NLRP3 pathways, are regarded feasible in drug development. The development of small molecules to treat COVID-19 has been achieved by several strategies, including computer-aided lead compound design and screening, natural product discovery, drug repurposing, and combination therapy. Several small molecules representative by remdesivir and paxlovid have been proved or authorized emergency use in many countries. And many candidates have entered clinical-trial stage. Nevertheless, due to the epidemiological features and variability issues of SARS-CoV-2, it is necessary to continue exploring novel strategies against COVID-19. This review discusses the current findings in the development of small molecules for COVID-19 treatment. Moreover, their detailed mechanism of action, chemical structures, and preclinical and clinical efficacies are discussed.

Therapeutic and diagnostic applications of nanoparticles in the management of COVID-19: a comprehensive overview

In December 2019, Coronavirus Disease 2019 (COVID-19) was reported in Wuhan, China. Comprehensive strategies for quick identification, prevention, control, and remedy of COVID-19 have been implemented until today. Advances in various nanoparticle-based technologies, including organic and inorganic nanoparticles, have created new perspectives in this field. These materials were extensively used to control COVID-19 because of their specific attribution to preparing antiviral face masks, various safety sensors, etc. In this review, the most current nanoparticle-based technologies, applications, and achievements against the coronavirus were summarized and highlighted. This paper also offers nanoparticle preventive, diagnostic, and treatment options to combat this pandemic.

The risk of COVID-19 can be predicted by a nomogram based on m6A-related genes

BACKGROUND

The expression of m6A-related genes and their significance in COVID-19 patients are still unknown.

METHODS

The GSE177477 and GSE157103 datasets of the Gene Expression Omnibus were used to extract RNA-seq data. The expression of 26 m6A-related genes and immune cell infiltration in COVID-19 patients were analyzed. Finally, we built and validated a nomogram model to predict the risk of COVID-19 infection.

RESULTS

There were significant differences in 11 m6A regulatory factors between patients with COVID-19 and healthy individuals. The classification of disease subtypes based on m6A-related gene levels can be distinguished. COVID-19 patients in GSE177477 were classified into two categories based on m6A-related genes. The patients in cluster A were all symptomatic, while those in cluster B were asymptomatic. A significant correlation was also found between immune cells and m6A-related genes. Finally, seven m6A-related disease-characteristic genes, HNRNPA2B1, ELAVL1, RBM15, RBM15B, YTHDC1, HNRNPC, and WTAP, were screened to construct a nomogram model for predicting risk. The calibration curve, decision curve analysis, and clinical impact curve analysis were used to show that the nomogram model was effective and had a high net efficacy for risk prediction.

CONCLUSIONS

m6A-related genes were correlated with immune cells. The nomogram model effectively predicted COVID-19 risk. Moreover, m6A-related genes may be associated with the presence or absence of symptoms in COVID-19 patients.

Circular RNAs as emerging regulators in COVID-19 pathogenesis and progression

Coronavirus disease 2019 (COVID-19), an infectious acute respiratory disease caused by a newly emerging RNA virus, is a still-growing pandemic that has caused more than 6 million deaths globally and has seriously threatened the lives and health of people across the world. Currently, several drugs have been used in the clinical treatment of COVID-19, such as small molecules, neutralizing antibodies, and monoclonal antibodies. In addition, several vaccines have been used to prevent the spread of the pandemic, such as adenovirus vector vaccines, inactivated vaccines, recombinant subunit vaccines, and nucleic acid vaccines. However, the efficacy of vaccines and the onset of adverse reactions vary among individuals. Accumulating evidence has demonstrated that circular RNAs (circRNAs) are crucial regulators of viral infections and antiviral immune responses and are heavily involved in COVID-19 pathologies. During novel coronavirus infection, circRNAs not only directly affect the transcription process and interfere with viral replication but also indirectly regulate biological processes, including virus-host receptor binding and the immune response. Consequently, understanding the expression and function of circRNAs during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will provide novel insights into the development of circRNA-based methods. In this review, we summarize recent progress on the roles and underlying mechanisms of circRNAs that regulate the inflammatory response, viral replication, immune evasion, and cytokines induced by SARS-CoV-2 infection, and thus highlighting the diagnostic and therapeutic challenges in the treatment of COVID-19 and future research directions.

Plant Molecular Pharming and Plant-Derived Compounds towards Generation of Vaccines and Therapeutics against Coronaviruses

The current century has witnessed infections of pandemic proportions caused by Coronaviruses (CoV) including severe acute respiratory syndrome-related CoV (SARS-CoV), Middle East respiratory syndrome-related CoV (MERS-CoV) and the recently identified SARS-CoV2. Significantly, the SARS-CoV2 outbreak, declared a pandemic in early 2020, has wreaked devastation and imposed intense pressure on medical establishments world-wide in a short time period by spreading at a rapid pace, resulting in high morbidity and mortality. Therefore, there is a compelling need to combat and contain the CoV infections. The current review addresses the unique features of the molecular virology of major Coronaviruses that may be tractable towards antiviral targeting and design of novel preventative and therapeutic intervention strategies. Plant-derived vaccines, in particular oral vaccines, afford safer, effectual and low-cost avenues to develop antivirals and fast response vaccines, requiring minimal infrastructure and trained personnel for vaccine administration in developing countries. This review article discusses recent developments in the generation of plant-based vaccines, therapeutic/drug molecules, monoclonal antibodies and phytochemicals to preclude and combat infections caused by SARS-CoV, MERS-CoV and SARS-CoV-2 viruses. Efficacious plant-derived antivirals could contribute significantly to combating emerging and re-emerging pathogenic CoV infections and help stem the tide of any future pandemics.

The m7G Modification Level and Immune Infiltration Characteristics in Patients with COVID-19

Purpose

The 7-methylguanosine (m7G)-related genes were used to identify the clinical severity and prognosis of patients with coronavirus disease 2019 (COVID-19) and to identify possible therapeutic targets.

Patients and Methods

The GSE157103 dataset provides the transcriptional spectrum and clinical information required to analyze the expression of m7G-related genes and the disease subtypes. R language was applied for immune infiltration analysis, functional enrichment analysis, and nomogram model construction.

Results

Most m7G-related genes were up-regulated in COVID-19 and were closely related to immune cell infiltration. Disease subtypes were grouped using a clustering algorithm. It was found that the m7G-cluster B was associated with higher immune infiltration, lower mechanical ventilation, lower intensive care unit (ICU) status, higher ventilator-free days, and lower m7G scores. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that differentially expressed genes (DEGs) between m7G-cluster A and B were enriched in viral infection and immune-related aspects, including COVID-19 infection; Th17, Th1, and Th2 cell differentiation, and human T-cell leukemia virus 1 infection. Finally, through machine learning, six disease characteristic genes, NUDT4B, IFIT5, LARP1, EIF4E, LSM1, and NUDT4, were screened and used to develop a nomogram model to estimate disease risk.

Conclusion

The expression of most m7G genes was higher in COVID-19 patients compared with that in non-COVID-19 patients. The m7G-cluster B showed higher immune infiltration and milder symptoms. The predictive nomogram based on the six m7G genes can be used to accurately assess risk.

Integrated Analgesic Care in the Current Human Monkeypox Outbreak: Perspectives on an Integrated and Holistic Approach Combining Old Allies with Innovative Technologies

Monkeypox (MPX) is a zoonotic infection caused by an orthopoxvirus that is endemic to Central and Western Africa. The MPX virus is a part of the same family of viruses as the variola virus, which causes smallpox. Since May 2022, there has been a global increase in the incidence of MPX infections in multiple countries where the illness is not usually prevalent. A growing number of publications have emphasized on the need for increased awareness among all health professionals for the rapid recognition and diagnosis of this disease and for proper public health measures. However, atypical presentations and occurrence of uncommon symptoms receive less than the desired attention. More specifically, MPX infection related nociceptive symptoms are currently underexposed. Nevertheless, reports from the current outbreak have revealed that (severe) pain is one of the major causes for distress and even hospitalization in these patients. As for all serious pain conditions, an integrated, multidisciplinary, and holistic approach is indicated. This approach should be multimodal and include non-pharmacological therapies alongside pharmacological approaches. Health care professionals should be aware of available alternatives when first choice analgesic therapies fail. Protocols for identification of pain type and prolonged monitoring of clinical status should be implemented to improve patient well-being during acute infection, but also prevent chronic nociceptive syndromes.

Exploring NFκB pathway as a potent strategy to mitigate COVID-19 severe morbidity and mortality

The pandemic of coronavirus disease 2019 (COVID-19), for which there does not appear to be an approved cure, the primary treatment options consist of non-pharmacological preventive measures and supportive treatment that are aimed at halting the progression of the disease. Nuclear factor kappa B (NFkB) presents a promising therapeutic opportunity to mitigate COVID-19-induced cytokine storm and reduce the risk of severe morbidity and mortality resulting from the disease. However, the effective clinical application of NFkB modulators in COVID-19 is hampered by a number of factors that must be taken into consideration. This paper therefore explored the modulation of the NFB pathway as a potential strategy to mitigate the severe morbidity and mortality caused by COVID-19. The paper also discusses the factors that form the barrier, and it offers potential solutions to the various limitations that may impede the clinical use of NFkB modulators against COVID-19. This paper revealed and identified three key potential solutions for the future clinical use of NFkB modulators against COVID-19. These solutions are pulmonary tissue-specific NFkB blockade, agents that target common regulatory proteins of both canonical and non-canonical NFkB pathways, and monitoring clinical indicators of hyperinflammation and cytokine storm in COVID-19 prior to using NFkB modulators.

Recovery of functional fitness, lung function, and immune function in healthcare workers with nonsevere and severe COVID-19 at 13 months after discharge from the hospital: a prospective cohort study

OBJECTIVES

This study aimed to evaluate the recovery of functional fitness, lung function, and immune function in healthcare workers (HCWs) with nonsevere and severe COVID-19 at 13 months after discharge from the hospital.

METHODS

The participants of "Rehabilitation Care Project for Medical Staff Infected with COVID-19" underwent a functional fitness test (muscle strength, flexibility, and agility/dynamic balance), lung function test, and immune function test (including cytokines and lymphocyte subsets) at 13 months after discharge.

RESULTS

The project included 779 HCWs (316 nonsevere COVID-19 and 463 severe COVID-19). This study found that 29.1% (130/446) of the HCWs have not yet recovered their functional fitness. The most affected lung function indicator was lung perfusion capacity (34% with diffusion capacity for carbon monoxide-single breath <80%). The increase of interleukin-6 (64/534, 12.0%) and natural killer cells (44/534, 8.2%) and the decrease of CD3⁺ T cells (58/534, 10.9%) and CD4⁺ T cells (26/534, 4.9%) still existed at 13 months after discharge. No significant difference was found in the HCWs with nonsevere and severe COVID-19 regarding recovery of functional fitness, lung function, and immune function at 13 months after discharge.

CONCLUSION

The majority of Chinese HCWs with COVID-19 had recovered their functional fitness, lung function, and immune function, and the recovery status in HCWs with severe COVID-19 is no worse than that in HCWs with nonsevere COVID-19 at 13 months after discharge from the hospital.

Immediate Effectiveness of Chest Proprioceptive Neuromuscular Facilitation (PNF) Technique on Hemodynamic Status in COVID-19 Patients: An Original Research

Introduction

COVID-19 is an infectious illness that first appeared in Wuhan, China in December 2019, and subsequently spread over the entire world. Those who were affected suffered from fever, cough, weakness, and breathlessness, along with the probability of developing pneumonia which sometimes leads to respiratory failure. The older population with co-morbidities was at higher risk.

Methods

In this experimental study, 59 subjects with COVID-19 were included according to pre-decided inclusion and exclusion criteria. Pre-vitals before the treatment were noted such as heart rate, respiratory rate, and oxygen saturation (SPO₂), and then the chest proprioceptive neuromuscular facilitation (PNF) technique was given as a treatment regime, and its immediate effect was calculated. Post-vitals were noted immediately after the treatment session. The statistical analysis was made using the student's paired t-test.

Results

We found a mean difference of 9.45±5.27 in heart rate before and after the intervention provided which is suggestive of a statistically significant increase within normal limits. Also, the mean value of respiratory rate immediately after the intervention was shown as 22.91 and pre-intervention was 19.18 with a mean difference of 2.93±3.95, showing a statistically significant increase in respiratory rate. Additionally, the mean value of SPO2 immediately after the intervention was shown as 92.76 and pre-intervention was 94.64 and had a mean difference of 1.88±1.67 suggestive of high improvement in oxygen saturation immediately after the intervention.

Conclusion

The present study concludes from the available statistical analysis that chest PNF techniques such as intercostal stretch and anterior basal stretch lift have an immediate impact on improvement in oxygen saturation in COVID-19 patients and can be incorporated as an inpatient treatment regime in the rehabilitation protocol.

SARS-CoV-2 infection: Pathogenesis, Immune Responses, Diagnosis

COVID-19 has emerged as the most alarming infection of the present time instigated by the virus SARS-CoV-2. In spite of advanced research technologies, the exact pathophysiology and treatment of the condition still need to be explored. However, SARS-CoV-2 has several structural and functional similarities that resemble SARS-CoV and MERS-CoV which may be beneficial in exploring the possible treatment and diagnostic strategies for SARS-CoV-2. This review discusses the pathogen phenotype, genotype, replication, pathophysiology, elicited immune response and emerging variants of SARS-CoV-2 and their similarities with other similar viruses. SARS-CoV-2 infection is detected by a number of diagnostics techniques, their advantages and limitations are also discussed in detail. The review also focuses on nanotechnology-based easy and fast detection of SARS-CoV-2 infection. Various pathways which might play a vital role during SARS-CoV-2 infection have been elaborately discussed since immune response plays a major role during viral infections.

Role of aging in Blood-Brain Barrier dysfunction and susceptibility to SARS-CoV-2 infection: impacts on neurological symptoms of COVID-19

COVID-19, which is caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), has resulted in devastating morbidity and mortality worldwide due to lethal pneumonia and respiratory distress. In addition, the central nervous system (CNS) is well documented to be a target of SARS-CoV-2, and studies detected SARS-CoV-2 in the brain and the cerebrospinal fluid of COVID-19 patients. The blood-brain barrier (BBB) was suggested to be the major route of SARS-CoV-2 infection of the brain. Functionally, the BBB is created by an interactome between endothelial cells, pericytes, astrocytes, microglia, and neurons, which form the neurovascular units (NVU). However, at present, the interactions of SARS-CoV-2 with the NVU and the outcomes of this process are largely unknown. Moreover, age was described as one of the most prominent risk factors for hospitalization and deaths, along with other comorbidities such as diabetes and co-infections. This review will discuss the impact of SARS-CoV-2 on the NVU, the expression profile of SARS-CoV-2 receptors in the different cell types of the CNS and the possible role of aging in the neurological outcomes of COVID-19. A special emphasis will be placed on mitochondrial functions because dysfunctional mitochondria are also a strong inducer of inflammatory reactions and the "cytokine storm" associated with SARS-CoV-2 infection. Finally, we will discuss possible drug therapies to treat neural endothelial function in aged patients, and, thus, alleviate the neurological symptoms associated with COVID-19.

The Key Role of Lysosomal Protease Cathepsins in Viral Infections

Cathepsins encompass a family of lysosomal proteases that mediate protein degradation and turnover. Although mainly localized in the endolysosomal compartment, cathepsins are also found in the cytoplasm, nucleus, and extracellular space, where they are involved in cell signaling, extracellular matrix assembly/disassembly, and protein processing and trafficking through the plasma and nuclear membrane and between intracellular organelles. Ubiquitously expressed in the body, cathepsins play regulatory roles in a wide range of physiological processes including coagulation, hormone secretion, immune responses, and others. A dysregulation of cathepsin expression and/or activity has been associated with many human diseases, including cancer, diabetes, obesity, cardiovascular and inflammatory diseases, kidney dysfunctions, and neurodegenerative disorders, as well as infectious diseases. In viral infections, cathepsins may promote (1) activation of the viral attachment glycoproteins and entry of the virus into target cells; (2) antigen processing and presentation, enabling the virus to replicate in infected cells; (3) up-regulation and processing of heparanase that facilitates the release of viral progeny and the spread of infection; and (4) activation of cell death that may either favor viral clearance or assist viral propagation. In this review, we report the most relevant findings on the molecular mechanisms underlying cathepsin involvement in viral infection physiopathology, and we discuss the potential of cathepsin inhibitors for therapeutical applications in viral infectious diseases.

Innate Immune Response and Inflammasome Activation During SARS-CoV-2 Infection

The novel coronavirus SARS-CoV-2, responsible for the COVID-19 outbreak, has become a pandemic threatening millions of lives worldwide. Recently, several vaccine candidates and drugs have shown promising effects in preventing or treating COVID-19, but due to the development of mutant strains through rapid viral evolution, urgent investigations are warranted in order to develop preventive measures and further improve current vaccine candidates. Positive-sense-single-stranded RNA viruses comprise many (re)emerging human pathogens that pose a public health problem. Our innate immune system and, in particular, the interferon response form an important first line of defense against these viruses. Flexibility in the genome aids the virus to develop multiple strategies to evade the innate immune response and efficiently promotes their replication and infective capacity. This review will focus on the innate immune response to SARS-CoV-2 infection and the virus’ evasion of the innate immune system by escaping recognition or inhibiting the production of an antiviral state. Since interferons have been implicated in inflammatory diseases and immunopathology along with their protective role in infection, antagonizing the immune response may have an ambiguous effect on the clinical outcome of the viral disease. This pathology is characterized by intense, rapid stimulation of the innate immune response that triggers activation of the Nod-like receptor family, pyrin-domain-containing 3 (NLRP3) inflammasome pathway, and release of its products including the pro-inflammatory cytokines IL-6, IL-18, and IL-1β. This predictive view may aid in designing an immune intervention or preventive vaccine for COVID-19 in the near future.

Structural aspects of SARS-CoV-2 mutations: Implications to plausible infectivity with ACE-2 using computational modeling approach

Some of the SARS-CoV-2 variants are said to be more infectious than the previous others and are causing panic around the globe. Cases related to Delta plus (δ+) and omicron (ο) variants are on the rise worldwide. This sudden surge warrants an investigation into the reasons for its binding with ACE-2. The present study attempts to find out the structural basis of binding interactions of SARS-CoV-2 mutants based on computational modeling and comparative analysis. In silico strategies including protein-protein docking, mutation analysis, molecular dynamics, and binding energy calculations were used to study the binding of the 'receptor binding domain' (RBD) of the seven 'variants of concern' which include Alpha (α), Beta (β), Gamma (γ), Kappa (κ), Delta (δ), Delta plus (δ+) and omicron (ο) with ACE-2 (human angiotensin-converting enzyme-2) and with antibodies. Among all the variants dealt with in this study, Delta plus and omicron were found to be binding more strongly to ACE-2 than others due to inherent mutations and the consequent change in the hydrophilic and hydrophobic environment of the binding site. Furthermore, molecular dynamic (MD) simulations and subsequent MM/PBSA calculations provided useful structural insights into key residues participating in the interaction. Infectivity of a virus could be dependent on the interplay of evading antibodies and simultaneously attaching strongly with the host receptor. A cross-correlation between mutant spike proteins' binding with ACE-2 and antibodies provides a holistic assessment of the binding nature of these mutants vis-à-vis native virus and offers opportunities for designing potential therapeutics against these new mutants.

Targeting autophagy regulation in NLRP3 inflammasome-mediated lung inflammation in COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Emerging evidence indicates that the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is activated, which results in a cytokine storm at the late stage of COVID-19. Autophagy regulation is involved in the infection and replication of SARS-CoV-2 at the early stage and the inhibition of NLRP3 inflammasome-mediated lung inflammation at the late stage of COVID-19. Here, we discuss the autophagy regulation at different stages of COVID-19. Specifically, we highlight the therapeutic potential of autophagy activators in COVID-19 by inhibiting the NLRP3 inflammasome, thereby avoiding the cytokine storm. We hope this review provides enlightenment for the use of autophagy activators targeting the inhibition of the NLRP3 inflammasome, specifically the combinational therapy of autophagy modulators with the inhibitors of the NLRP3 inflammasome, antiviral drugs, or anti-inflammatory drugs in the fight against COVID-19.

Molecular imaging as a tool for evaluation of COVID-19 sequelae – A review of literature

Coronavirus disease 2019 (COVID-19) is caused by the novel viral pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 primarily involves the lungs. Nucleic acid testing based on reverse-transcription polymerase chain reaction of respiratory samples is the current gold standard for the diagnosis of SARS-CoV-2 infection. Imaging modalities have an established role in triaging, diagnosis, evaluation of disease severity, monitoring disease progression, extra-pulmonary involvement, and complications. As our understanding of the disease improves, there has been substantial evidence to highlight its potential for multi-systemic involvement and development of long-term sequelae. Molecular imaging techniques are highly sensitive, allowing non-invasive visualization of physiological or pathological processes at a cellular or molecular level with potential for detection of functional changes earlier than conventional radiological imaging. The purpose of this review article is to highlight the evolving role of molecular imaging in evaluation of COVID-19 sequelae. Though not ideal for diagnosis, the various modalities of molecular imaging play an important role in assessing pulmonary and extra-pulmonary sequelae of COVID-19. Perfusion imaging using single photon emission computed tomography fused with computed tomography (CT) can be utilized as a first-line imaging modality for COVID-19 related pulmonary embolism. ¹⁸F-fluorodeoxyglucose positron emission tomography (PET)/CT is a sensitive tool to detect multi-systemic inflammation, including myocardial and vascular inflammation. PET in conjunction with magnetic resonance imaging helps in better characterization of neurological sequelae of COVID-19. Despite the fact that the majority of published literature is retrospective in nature with limited sample sizes, it is clear that molecular imaging provides additional valuable information (complimentary to anatomical imaging) with semi-quantitative or quantitative parameters to define inflammatory burden and can be used to guide therapeutic strategies and assess response. However, widespread clinical applicability remains a challenge owing to longer image acquisition times and the need for adoption of infection control protocols.

Cross-variant protection against SARS-CoV-2 infection in hamsters immunized with monovalent and bivalent inactivated vaccines

Rapid development and successful use of vaccines against SARS-CoV-2 might hold the key to curb the ongoing pandemic of COVID-19. Emergence of vaccine-evasive SARS-CoV-2 variants of concern (VOCs) has posed a new challenge to vaccine design and development. One urgent need is to determine what types of variant-specific and bivalent vaccines should be developed. Here, we compared homotypic and heterotypic protection against SARS-CoV-2 infection of hamsters with monovalent and bivalent whole-virion inactivated vaccines derived from representative VOCs. In addition to the ancestral SARS-CoV-2 Wuhan strain, Delta (B.1.617.2; δ) and Theta (P.3; θ) variants were used in vaccine preparation. Additional VOCs including Omicron (B.1.1.529) and Alpha (B.1.1.7) variants were employed in the challenge experiment. Consistent with previous findings, Omicron variant exhibited the highest degree of immune evasion, rendering all different forms of inactivated vaccines substantially less efficacious. Notably, monovalent and bivalent Delta variant-specific inactivated vaccines provided optimal protection against challenge with Delta variant. Yet, some cross-variant protection against Omicron and Alpha variants was seen with all monovalent and bivalent inactivated vaccines tested. Taken together, our findings support the notion that an optimal next-generation inactivated vaccine against SARS-CoV-2 should contain the predominant VOC in circulation. Further investigations are underway to test whether a bivalent vaccine for Delta and Omicron variants can serve this purpose.

The Use of Palmitoylethanolamide in the Treatment of Long COVID: A Real-Life Retrospective Cohort Study

COVID-19 can cause symptoms that last weeks or months after the infection has gone, with a significant impairment of quality of life. Palmitoylethanolamide (PEA) is a naturally occurring lipid mediator that has an entourage effect on the endocannabinoid system mitigating the cytokine storm. The aim of this retrospective study is to evaluate the potential efficacy of PEA in the treatment of long COVID. Patients attending the Neurological Out Clinic of the IRCCS Centro Neurolesi Bonino-Pulejo (Messina, Italy) from August 2020 to September 2021 were screened for potential inclusion in the study. We included only long COVID patients who were treated with PEA 600 mg two times daily for about 3 months. All patients performed the post-COVID-19 Functional Status (PCFS) scale. Thirty-three patients (10 males, 43.5%, mean age 47.8 ± 12.4) were enrolled in the study. Patients were divided into two groups based on hospitalization or home care observation. A substantial difference in the PCFS score between the two groups at baseline and after treatment with PEA were found. We found that smoking was a risk factor with an odds ratio of 8.13 CI 95% [0.233, 1.167]. Our findings encourage the use of PEA as a potentially effective therapy in patients with long COVID.

Cellular immunity in patients with COVID-19: molecular biology, pathophysiology, and clinical implications

The COVID-19 pandemic is caused by the SARS-CoV-2 coronavirus. From the viewpoint of factors critical to contain the virus, the neutralizing antibodies to SARS-CoV-2 garner most of the attention, however, it is essential to acknowledge that it is the level of the virus-specific T cell and B cell response that forms a basis for an effective neutralizing antibody response. T cell responses develop early and correlate with the protection, but they are relatively attenuated in the severe disease, in part due to lymphopenia. Understanding the role of different T cell subpopulations in the protection or the COVID-19 pathogenesis is critical to the prevention and treatment. The expression profile of different T cell subpopulations varies with the COVID-19 severity and is associated with the degree of T cell responses and the disease outcome. The structural changes in the genome, transcriptome, and proteome of SARS-CoV-2 promote the emergence of new variants of the virus and can reduce its interaction with antibodies and result in avoiding the neutralization. There is a strong correlation between the number of virus-specific CD4 T cells and neutralizing IgG antibody titers against SARS-CoV-2. During the primary viral infection, there is a wide variation in the cellular and humoral immune responses, patients with severe and prolonged symptoms showing highly imbalanced cellular and humoral immune responses. This review focuses on the generation and clinical significance of cellular immunity in the protection against severe acute infection and reinfection, as well as the potential involvement of seasonal coronavirus-specific cross-reactive T cells in response to SARS-CoV-2.

Immunity after COVID-19 Recovery and Vaccination: Similarities and Differences

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with a robust immune response. The development of systemic inflammation leads to a hyperinflammatory state due to cytokine release syndrome during severe COVID-19. The emergence of many new SARS-CoV-2 variants across the world deteriorates the protective antiviral immunity induced after infection or vaccination. The innate immune response to SARS-CoV-2 is crucial for determining the fate of COVID-19 symptomatology. T cell-mediated immunity is the main factor of the antiviral immune response; moreover, SARS-CoV-2 infection initiates a rapid B-cell response. In this paper, we present the current state of knowledge on immunity after COVID-19 infection and vaccination. We discuss the mechanisms of immune response to various types of vaccines (nucleoside-modified, adenovirus-vectored, inactivated virus vaccines and recombinant protein adjuvanted formulations). This includes specific aspects of vaccination in selected patient populations with altered immune activity (the elderly, children, pregnant women, solid organ transplant recipients, patients with systemic rheumatic diseases or malignancies). We also present diagnostic and research tools available to study the anti-SARS-CoV-2 cellular and humoral immune responses.

LOW PREVALENCE OF COVID-19 IN LAOS AND CAMBODIA: DOES DIET PLAY A ROLE?

The study aims to review the involvement of different dietary habits in Laotian, Cambodian, and Vietnamese populations in reducing COVID19 impact. Materials and Methods. The methods of collection, systematization, analysis and generalization of information data have been used. The analysis of literature in scientific databases and analytical platforms by the listed keywords has been performed; all relevant references in the found sources have also been reviewed. Results and Discussion. Coronavirus disease (COVID-19) outbreak is an ongoing pandemic caused by a highly pathogenic human coronavirus known as SARS-CoV2. Current epidemiology reported that more than 500 million cases of COVID-19 occurred in more than 180 countries worldwide. When the upper respiratory tract gets infected by low pathogenetic HCoVs, it typically triggers a mild respiratory disease. In contrast, when the lower airways get infected by highly pathogenic HCoVs, such as SARS-CoV2, acute respiratory distress syndrome (ARDS) may occur and even fatal pneumonia. Such a situation causes the need for an urgent search of effective treatment measures. A very low incidence of SARS-CoV-2 in Laos and Cambodia, as well as low mortality rate due to COVID-19 in Vietnam and Laos, are extremely interesting, especially because of their early exposure to the virus, continuing ties to China, relative poverty, and high population density. The use of several spices and aromatic herbs as natural treatments for several illnesses, including viral infections, has been reported since a long time ago. The research reviewed three integral elements of Laotian, Cambodian, and Vietnamese diets, such as special culinary spices and herbs, coconut oil, and palm oil-rich for saturated fatty acids as well as fermented shrimp paste. Environmental and population genetic causes may be forwarded but moreover local dietary habits may have even a role in this evidence. Therefore, all these items highlight the possibility of a significant contribution of local cuisine and diet into the impact on appropriate anti-inflammatory and immune-resistant mechanisms of the human population. Conclusions. The review on Vietnam, Cambodia, and Laos inhabitants' diet helped to suggest the dietary factors having the contributing potential of reducing the severity of SARS-CoV-2 symptoms.

Effect of Key Phytochemicals from Andrographis paniculata, Tinospora cordifolia, and Ocimum sanctum on PLpro-ISG15 De-Conjugation Machinery—A Computational Approach

ISGylation is an important process through which interferon-stimulated genes (ISGs) elicit an antiviral response in the host cells. Several viruses, including the SARS-CoV-2, suppress the host immune response by reversing the ISGylation through a process known as de-ISGylation. The PLpro of SARS-CoV-2 interacts with the host ISG15 and brings about de-ISGylation. Hence, inhibiting the de-ISGylation to restore the activity of ISGs can be an attractive strategy to augment the host immune response against SARS-CoV-2. In the present study, we evaluated several phytochemicals from well-known immunomodulatory herbs, viz. Andrographispaniculata (AG), Tinospora cordifolia (GU), and Ocimum sanctum (TU) for their effect on deISGylation that was mediated by the PLpro of SARS-CoV2. For this purpose, we considered the complex 6XA9, which represents the interaction between SARS-CoV-2 PLpro and ISG15 proteins. The phytochemicals from these herbs were first evaluated for their ability to bind to the interface region between PLpro and ISG15. Molecular docking studies indicated that 14-deoxy-15-isopropylidene-11,12-didehydroandrographolide (AG1), Isocolumbin (GU1), and Orientin (TU1) from AG, GU, and TU, respectively possess better binding energy. The molecular dynamic parameters and MMPBSA calculations indicated that AG1, GU1, and TU1 could favorably bind to the interface and engaged key residues between (PLpro-ISG15)-complex. Protein–protein MMPBSA calculations indicated that GU1 and TU1 could disrupt the interactions between ISG15 and PLpro. Our studies provide a novel molecular basis for the immunomodulatory action of these phytochemicals and open up new strategies to evaluate drug molecules for their effect on de-ISGylation to overcome the virus-mediated immune suppression.

Therapy Targets SARS-CoV-2 Infection-Induced Cell Death

Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV-2 has become a global health issue. The clinical presentation of COVID-19 is highly variable, ranging from asymptomatic and mild disease to severe. However, the mechanisms for the high mortality induced by SARS-CoV-2 infection are still not well understood. Recent studies have indicated that the cytokine storm might play an essential role in the disease progression in patients with COVID-19, which is characterized by the uncontrolled release of cytokines and chemokines leading to acute respiratory distress syndrome (ARDS), multi-organ failure, and even death. Cell death, especially, inflammatory cell death, might be the initiation of a cytokine storm caused by SARS-CoV-2 infection. This review summarizes the forms of cell death caused by SARS-CoV-2 in vivo or in vitro and elaborates on the dedication of apoptosis, necroptosis, NETosis, pyroptosis of syncytia, and even SARS-CoV-2 E proteins forming channel induced cell death, providing insights into targets on the cell death pathway for the treatment of COVID-19.

FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation

SARS-CoV-2 can cause acute respiratory distress and death in some patients1. Although severe COVID-19 is linked to substantial inflammation, how SARS-CoV-2 triggers inflammation is not clear2. Monocytes and macrophages are sentinel cells that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D, leading to inflammatory death (pyroptosis) and the release of potent inflammatory mediators3. Here we show that about 6% of blood monocytes of patients with COVID-19 are infected with SARS-CoV-2. Monocyte infection depends on the uptake of antibody-opsonized virus by Fcγ receptors. The plasma of vaccine recipients does not promote antibody-dependent monocyte infection. SARS-CoV-2 begins to replicate in monocytes, but infection is aborted, and infectious virus is not detected in the supernatants of cultures of infected monocytes. Instead, infected cells undergo pyroptosis mediated by activation of NLRP3 and AIM2 inflammasomes, caspase-1 and gasdermin D. Moreover, tissue-resident macrophages, but not infected epithelial and endothelial cells, from lung autopsies from patients with COVID-19 have activated inflammasomes. Taken together, these findings suggest that antibody-mediated SARS-CoV-2 uptake by monocytes and macrophages triggers inflammatory cell death that aborts the production of infectious virus but causes systemic inflammation that contributes to COVID-19 pathogenesis.

Immune response and cytokine storm in SARS-CoV-2 infection: Risk factors, ways of control and treatment

In 2020, a deadly pandemic caused by the SARS-COV-2 virus spread worldwide and killed many people. In some viral infections, in addition to the pathogenic role of the virus, impaired immune function leads to inflammation and further damage in internal tissues. For example, coronavirus in some patients prevents the stimulation of the acquired immune system. Therefore, innate immunity is over-stimulated to compensate, followed by the overproduction of inflammatory cytokines and cytokine storm. Various underlying factors such as age, gender, blood pressure, diabetes, and obesity affect cytokine storm. It seems that cytokine storm is one of the leading causes of death among COVID-19 patients, and providing that this storm is detected and controlled in time, it can reduce the mortality of COVID-19 patients. This article aims to investigate the immune system response to COVID-19, various factors associated with cytokine storm, and its treatment. In the current situation, in parallel with the progress made in the field of vaccination, it is necessary to carefully examine the various dimensions of the immune system in response to the COVID-19 virus to seek a suitable treatment strategy to save the lives of patients in intensive care units

Airway epithelial interferon response to SARS-CoV-2 is inferior to rhinovirus and heterologous rhinovirus infection suppresses SARS-CoV-2 replication

Common alphacoronaviruses and human rhinoviruses (HRV) induce type I and III interferon (IFN) responses important to limiting viral replication in the airway epithelium. In contrast, highly pathogenic betacoronaviruses including SARS-CoV-2 may evade or antagonize RNA-induced IFN I/III responses. In airway epithelial cells (AECs) from children and older adults we compared IFN I/III responses to SARS-CoV-2 and HRV-16, and assessed whether pre-infection with HRV-16, or pretreatment with recombinant IFN-β or IFN-λ, modified SARS-CoV-2 replication. Bronchial AECs from children (ages 6-18 years) and older adults (ages 60-75 years) were differentiated ex vivo to generate organotypic cultures. In a biosafety level 3 (BSL-3) facility, cultures were infected with SARS-CoV-2 or HRV-16, and RNA and protein was harvested from cell lysates 96 h. following infection and supernatant was collected 48 and 96 h. following infection. In additional experiments cultures were pre-infected with HRV-16, or pre-treated with recombinant IFN-β1 or IFN-λ2 before SARS-CoV-2 infection. In a subset of experiments a range of infectious concentrations of HRV-16, SARS-CoV-2 WA-01, SARS-CoV-2 Delta variant, and SARS-CoV-2 Omicron variant were studied. Despite significant between-donor heterogeneity SARS-CoV-2 replicated 100 times more efficiently than HRV-16. IFNB1, INFL2, and CXCL10 gene expression and protein production following HRV-16 infection was significantly greater than following SARS-CoV-2. IFN gene expression and protein production were inversely correlated with SARS-CoV-2 replication. Treatment of cultures with recombinant IFNβ1 or IFNλ2, or pre-infection of cultures with HRV-16, markedly reduced SARS-CoV-2 replication. In addition to marked between-donor heterogeneity in IFN responses and viral replication, SARS-CoV-2 (WA-01, Delta, and Omicron variants) elicits a less robust IFN response in primary AEC cultures than does rhinovirus, and heterologous rhinovirus infection, or treatment with recombinant IFN-β1 or IFN-λ2, reduces SARS-CoV-2 replication, although to a lesser degree for the Delta and Omicron variants.

Immune Signature of COVID-19: In-Depth Reasons and Consequences of the Cytokine Storm

In the beginning of the third year of the fight against COVID-19, the virus remains at least still one step ahead in the pandemic "war". The key reasons are evolving lineages and mutations, resulting in an increase of transmissibility and ability to evade immune system. However, from the immunologic point of view, the cytokine storm (CS) remains a poorly understood and difficult to combat culprit of the extended number of in-hospital admissions and deaths. It is not fully clear whether the cytokine release is a harmful result of suppression of the immune system or a positive reaction necessary to clear the virus. To develop methods of appropriate treatment and therefore decrease the mortality of the so-called COVID-19-CS, we need to look deeply inside its pathogenesis, which is the purpose of this review.

Cytoplasmic RNA sensors and their interplay with RNA-binding partners in innate antiviral response: theme and variations

Sensing of pathogen-associated molecular patterns including viral RNA by innate immunity represents the first line of defense against viral infection. In addition to RIG-I-like receptors and NOD-like receptors, several other RNA sensors are known to mediate innate antiviral response in the cytoplasm. Double-stranded RNA-binding protein PACT interacts with prototypic RNA sensor RIG-I to facilitate its recognition of viral RNA and induction of host interferon response, but variations of this theme are seen when the functions of RNA sensors are modulated by other RNA-binding proteins to impinge on antiviral defense, proinflammatory cytokine production and cell death programs. Their discrete and coordinated actions are crucial to protect the host from infection. In this review, we will focus on cytoplasmic RNA sensors with an emphasis on their interplay with RNA-binding partners. Classical sensors such as RIG-I will be briefly reviewed. More attention will be brought to new insights on how RNA-binding partners of RNA sensors modulate innate RNA sensing and how viruses perturb the functions of RNA-binding partners.

Programmed cell death: the pathways to severe COVID-19?

Two years after the emergence of SARS-CoV-2, our understanding of COVID-19 disease pathogenesis is still incomplete. Despite unprecedented global collaborative scientific efforts and rapid vaccine development, an uneven vaccine roll-out and the emergence of novel variants of concern such as omicron underscore the critical importance of identifying the mechanisms that contribute to this disease. Overt inflammation and cell death have been proposed to be central drivers of severe pathology in COVID-19 patients and their pathways and molecular components therefore present promising targets for host-directed therapeutics. In our review, we summarize the current knowledge on the role and impact of diverse programmed cell death (PCD) pathways on COVID-19 disease. We dissect the complex connection of cell death and inflammatory signaling at the cellular and molecular level and identify a number of critical questions that remain to be addressed. We provide rationale for targeting of cell death as potential COVID-19 treatment and provide an overview of current therapeutics that could potentially enter clinical trials in the near future.

Experimental Search for New Means of Pathogenetic Therapy COVID-19: Inhibitor of H2-Receptors Famotidine Increases the Effect of Oseltamivir on Survival and Immune Status of Mice Infected by A/PR/8/34 (H1N1)

The development of drugs for the therapy of COVID-19 is one of the main problems of modern physiology, biochemistry and pharmacology. Taking into account the available information on the participation of mast cells and the role of histamine in the pathogenesis of COVID-19, as well as information on the positive role of famotidine in the prevention and treatment of coronavirus infection, an experiment was carried out using famotidine in a mouse model. We used a type A/PR/8/34 (H1N1) virus adapted to mice. The antiviral drug oseltamivir (Tamiflu), which belongs to the group of neuraminidase inhibitors, was used as a reference drug. The use of famotidine in combination with oseltamivir can increase survival, improve the dynamics of animal weight, reduce the level of NKT cells and increase the level of naive T-helpers. Further studies of famotidine in vivo should be aimed at optimizing the regimen of drug use at a higher viral load, as well as with a longer use of famotidine.