Current evidence on the use of anakinra in COVID-19

Adverse drug reactions associated with COVID-19 management

The emergence of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak, which causes COVID-19, had a devastating impact on both people's lives and the global economy. During the course of the pandemic, the lack of specific drugs or treatments tailored for COVID-19 led to extensive repurposing of existing drugs in the pursuit of effective treatments. Some drug molecules demonstrated efficacy, while others proved ineffective. In this context, the approach of drug repurposing emerged as a novel strategy for combating COVID-19. Repurposed drugs and biologics have shown effectiveness, leading to improved clinical outcomes among patients with COVID-19. Similarly, It is equally important to assess the risk-benefit ratio associated with drugs and biologics adapted for COVID-19 treatment. Herein, we primarily focus on evaluating adverse drug events linked to repurposed COVID-19 medications, repurposed biologics, and COVID-specific drug molecules.

Second-line immunotherapy in new onset refractory status epilepticus

Several pieces of evidence suggest immune dysregulation could trigger the onset and modulate sequelae of new onset refractory status epilepticus (NORSE), including its subtype with prior fever known as febrile infection-related epilepsy syndrome (FIRES). Consensus-driven recommendations have been established to guide the initiation of first- and second-line immunotherapies in these patients. Here, we review the literature to date on second-line immunotherapy for NORSE/FIRES, presenting results from 28 case reports and series describing the use of anakinra, tocilizumab, or intrathecal dexamethasone in 75 patients with NORSE. Among them, 52 patients were managed with anakinra, 21 with tocilizumab, and eight with intrathecal dexamethasone. Most had elevated serum or cerebrospinal fluid cytokine levels at treatment initiation. Treatments were predominantly initiated during the acute phase of the disease (92%) and resulted, within the first 2 weeks, in seizure control for up to 73% of patients with anakinra, 70% with tocilizumab, and 50% with intrathecal dexamethasone. Cytokine levels decreased after treatment for most patients. Anakinra and intrathecal dexamethasone were mainly initiated in children with FIRES, whereas tocilizumab was more frequently prescribed for adults, with or without a prior febrile infection. There was no clear correlation between the response to treatment and the time to initiate the treatment. Most patients experienced long-term disability and drug-resistant post-NORSE epilepsy. Initiation of second-line immunotherapies during status epilepticus (SE) had no clear effect on the emergence of post-NORSE epilepsy or long-term functional outcomes. In a small number of cases, the initiation of anakinra or tocilizumab several years after SE onset resulted in a reduction of seizure frequency for 67% of patients. These data highlight the potential utility of anakinra, tocilizumab, and intrathecal dexamethasone in patients with NORSE. There continues to be interest in the utilization of early cytokine measurements to guide treatment selection and response. Prospective studies are necessary to understand the role of early immunomodulation and its associations with epilepsy and functional outcomes.

Lessons we learned during the past four challenging years in the COVID-19 era: pharmacotherapy, long COVID complications, and vaccine development

About four years have passed since the detection of the first cases of COVID-19 in China. During this lethal pandemic, millions of people have lost their lives around the world. Since the first waves of COVID-19 infection, various pharmacotherapeutic agents have been examined in the management of COVID-19. Despite all these efforts in pharmacotherapy, drug repurposing, and design and development of new drugs, multiple organ involvement and various complications occurred during COVID-19. Some of these complications became chronic and long-lasting which led to the "long COVID" syndrome appearance. Therefore, the best way to eradicate this pandemic is prophylaxis through mass vaccination. In this regard, various vaccine platforms including inactivated vaccines, nucleic acid-based vaccines (mRNA and DNA vaccines), adenovirus-vectored vaccines, and protein-based subunit vaccines have been designed and developed to prevent or reduce COVID-19 infection, hospitalization, and mortality rates. In this focused review, at first, the most commonly reported clinical presentations of COVID-19 during these four years have been summarized. In addition, different therapeutic regimens and their latest status in COVID-19 management have been listed. Furthermore, the "long COVID" and related signs, symptoms, and complications have been mentioned. At the end, the effectiveness of available COVID-19 vaccines with different platforms against early SARS-CoV-2 variants and currently circulating variants of interest (VOI) and the necessity of booster vaccine shots have been summarized and discussed in more detail.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

The Potential of Anti-coronavirus Plant Secondary Metabolites in COVID-19 Drug Discovery as an Alternative to Repurposed Drugs: A Review

In early 2020, a global pandemic was announced due to the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), known to cause COVID-19. Despite worldwide efforts, there are only limited options regarding antiviral drug treatments for COVID-19. Although vaccines are now available, issues such as declining efficacy against different SARS-CoV-2 variants and the aging of vaccine-induced immunity highlight the importance of finding more antiviral drugs as a second line of defense against the disease. Drug repurposing has been used to rapidly find COVID-19 therapeutic options. Due to the lack of clinical evidence for the therapeutic benefits and certain serious side effects of repurposed antivirals, the search for an antiviral drug against SARS-CoV-2 with fewer side effects continues. In recent years, numerous studies have included antiviral chemicals from a variety of plant species. A better knowledge of the possible antiviral natural products and their mechanism against SARS-CoV-2 will help to develop stronger and more targeted direct-acting antiviral agents. The aim of the present study was to compile the current data on potential plant metabolites that can be investigated in COVID-19 drug discovery and development. This review represents a collection of plant secondary metabolites and their mode of action against SARS-CoV and SARS-CoV-2.

Drug repurposing for the treatment of COVID-19: Targeting nafamostat to the lungs by a liposomal delivery system

Despite tremendous global efforts since the beginning of the COVID-19 pandemic, still only a limited number of prophylactic and therapeutic options are available. Although vaccination is the most effective measure in preventing morbidity and mortality, there is a need for safe and effective post-infection treatment medication. In this study, we explored a pipeline of 21 potential candidates, examined in the Calu-3 cell line for their antiviral efficacy, for drug repurposing. Ralimetinib and nafamostat, clinically used drugs, have emerged as attractive candidates. Due to the inherent limitations of the selected drugs, we formulated targeted liposomes suitable for both systemic and intranasal administration. Non-targeted and targeted nafamostat liposomes (LipNaf) decorated with an Apolipoprotein B peptide (ApoB-P) as a specific lung-targeting ligand were successfully developed. The developed liposomal formulations of nafamostat were found to possess favorable physicochemical properties including nano size (119-147 nm), long-term stability of the normally rapidly degrading compound in aqueous solution, negligible leakage from the liposomes upon storage, and a neutral surface charge with low polydispersity index (PDI). Both nafamostat and ralimetinib liposomes showed good cellular uptake and lack of cytotoxicity, and non-targeted LipNaf demonstrated enhanced accumulation in the lungs following intranasal (IN) administration in non-infected mice. LipNaf retained its anti-SARS-CoV 2 activity in Calu 3 cells with only a modest decrease, exhibiting complete inhibition at concentrations >100 nM. IN, but not intraperitoneal (IP) treatment with targeted LipNaf resulted in a trend to reduced viral load in the lungs of K18-hACE2 mice compared to targeted empty Lip. Nevertheless, upon removal of outlier data, a statistically significant 1.9-fold reduction in viral load was achieved. This observation further highlights the importance of a targeted delivery into the respiratory tract. In summary, we were able to demonstrate a proof-of-concept of drug repurposing by liposomal formulations with anti-SARS-CoV-2 activity. The biodistribution and bioactivity studies with LipNaf suggest an IN or inhalation route of administration for optimal therapeutic efficacy.

Drug-drug interactions between COVID-19 therapeutics and psychotropic medications

INTRODUCTION

The coronavirus (COVID-19) pandemic has led to as well as exacerbated mental health disorders, leading to increased use of psychotropic medications. Co-administration of COVID-19 and psychotropic medications may result in drug-drug interactions (DDIs), that may compromise both the safety and efficacy of both medications.

AREAS COVERED

This review provides an update of the current evidence on DDIs between COVID-19 and psychotropic medications. The interactions are categorized into pharmacokinetic, pharmacodynamic, and other relevant types. A thorough literature search was conducted using electronic databases to identify relevant studies, and extract data to highlight potential DDIs, clinical implications, and management strategies.

EXPERT OPINION

Understanding and managing potential DDIs between COVID-19 and psychotropic medications is paramount to ensuring safe and effective treatment of patients with COVID-19 and mental illness. Awareness of the diverse spectrum of DDIs, vigilant monitoring, and judicious dose modifications, while choosing pharmacotherapeutic options with low risk of interaction whenever possible, are necessary. Ongoing and future investigations should continue to review the dynamic landscape of COVID-19 therapeutic modalities and their interactions with psychotropic medications.

Insights into COVID-19: Perspectives on Drug Remedies and Host Cell Responses

In light of the COVID-19 global pandemic caused by SARS-CoV-2, ongoing research has centered on minimizing viral spread either by stopping viral entry or inhibiting viral replication. Repurposing antiviral drugs, typically nucleoside analogs, has proven successful at inhibiting virus replication. This review summarizes current information regarding coronavirus classification and characterization and presents the broad clinical consequences of SARS-CoV-2 activation of the angiotensin-converting enzyme 2 (ACE2) receptor expressed in different human cell types. It provides publicly available knowledge on the chemical nature of proposed therapeutics and their target biomolecules to assist in the identification of potentially new drugs for the treatment of SARS-CoV-2 infection.

NLRP3, the inflammasome and COVID-19 infection

Severe coronavirus disease 2019 (COVID-19) is characterized by respiratory failure, shock or multiorgan dysfunction, often accompanied by systemic hyperinflammation and dysregulated cytokine release. These features are linked to the intense and rapid stimulation of the innate immune response. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a central player in inflammatory macrophage activation which via caspase-1 activation leads to the release of the mature forms of the proinflammatory cytokines interleukin (IL)-1β and IL-18, and via cleavage of Gasdermin D pyroptosis, an inflammatory form of cell death. Here, we discuss the role of NLRP3 activation in COVID-19 and clinical trials currently underway to target NLRP3 to treat severe COVID-19.

Advances in attractive therapeutic approach for macrophage activation syndrome in COVID-19

Nowadays, people have relaxed their vigilance against COVID-19 due to its declining infection numbers and attenuated virulence. However, COVID-19 still needs to be concern due to its emerging variants, the relaxation of restrictions as well as breakthrough infections. During the period of the COVID-19 infection, the imbalanced and hyper-responsive immune system plays a critical role in its pathogenesis. Macrophage Activation Syndrome (MAS) is a fatal complication of immune system disease, which is caused by the excessive activation and proliferation of macrophages and cytotoxic T cells (CTL). COVID-19-related hyperinflammation shares common clinical features with the above MAS symptoms, such as hypercytokinemia, hyperferritinemia, and coagulopathy. In MAS, immune exhaustion or defective anti-viral responses leads to the inadequate cytolytic capacity of CTL which contributes to prolonged interaction between CTL, APCs and macrophages. It is possible that the same process also occurred in COVID-19 patients, and further led to a cytokine storm confined to the lungs. It is associated with the poor prognosis of severe patients such as multiple organ failure and even death. The main difference of cytokine storm is that in COVID-19 pneumonia is mainly the specific damage of the lung, while in MAS is easy to develop into a systemic. The attractive therapeutic approach to prevent MAS in COVID-19 mainly includes antiviral, antibiotics, convalescent plasma (CP) therapy and hemadsorption, extensive immunosuppressive agents, and cytokine-targeted therapies. Here, we discuss the role of the therapeutic approaches mentioned above in the two diseases. And we found that the treatment effect of the same therapeutic approach is different.

Beyond an inflammatory mediator: Interleukin-1 in neurophysiology

NEW FINDINGS

What is the topic of this review? This review focuses on the physiological role of the cytokine interleukin-1β in the CNS. What advances does it highlight? Traditionally, interleukin-1β is known as a key mediator of inflammation and immunity. This review highlights the more recent findings describing how interleukin-1β signalling is required to maintain homeostasis in the CNS.

ABSTRACT

Since its discovery in the early 1940s, the interleukin-1 (IL-1) cytokine family has been associated primarily with acute and chronic inflammation. The family member IL-1β is produced by different leucocytes, endothelial cells and epithelial cells. This cytokine has been characterized as a key modulator of inflammation and innate immunity because it induces the transcription of several downstream inflammatory genes. More recently, several groups have demonstrated that IL-1β production is also required to maintain homeostasis in several organ systems. This review focuses on providing an overview of the more recently characterized role of IL-1β in the physiology of the CNS. So far, IL-1β signalling has been implicated in neuronal survival, neurite growth, synaptic pruning, synaptic transmission, neuroplasticity and neuroendocrine functions.

Immunohematologic Biomarkers in COVID-19: Insights into Pathogenesis, Prognosis, and Prevention

Coronavirus disease 2019 (COVID-19) has had profound effects on the health of individuals and on healthcare systems worldwide. While healthcare workers on the frontlines have fought to quell multiple waves of infection, the efforts of the larger research community have changed the arch of this pandemic as well. This review will focus on biomarker discovery and other efforts to identify features that predict outcomes, and in so doing, identify possible effector and passenger mechanisms of adverse outcomes. Identifying measurable soluble factors, cell-types, and clinical parameters that predict a patient's disease course will have a legacy for the study of immunologic responses, especially stimuli, which induce an overactive, yet ineffectual immune system. As prognostic biomarkers were identified, some have served to represent pathways of therapeutic interest in clinical trials. The pandemic conditions have created urgency for accelerated target identification and validation. Collectively, these COVID-19 studies of biomarkers, disease outcomes, and therapeutic efficacy have revealed that immunologic systems and responses to stimuli are more heterogeneous than previously assumed. Understanding the genetic and acquired features that mediate divergent immunologic outcomes in response to this global exposure is ongoing and will ultimately improve our preparedness for future pandemics, as well as impact preventive approaches to other immunologic diseases.

Clinically Evaluated COVID-19 Drugs with Therapeutic Potential for Biological Warfare Agents

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak resulted in hundreds of millions of coronavirus cases, as well as millions of deaths worldwide. Coronavirus Disease 2019 (COVID-19), the disease resulting from exposure to this pathogen, is characterized, among other features, by a pulmonary pathology, which can progress to "cytokine storm", acute respiratory distress syndrome (ARDS), respiratory failure and death. Vaccines are the unsurpassed strategy for prevention and protection against the SARS-CoV-2 infection. However, there is still an extremely high number of severely ill people from at-risk populations. This may be attributed to waning immune response, variant-induced breakthrough infections, unvaccinated population, etc. It is therefore of high importance to utilize pharmacological-based treatments, despite the progression of the global vaccination campaign. Until the approval of Paxlovid, an efficient and highly selective anti-SARS-CoV-2 drug, and the broad-spectrum antiviral agent Lagevrio, many pharmacological-based countermeasures were, and still are, being evaluated in clinical trials. Some of these are host-directed therapies (HDTs), which modulate the endogenic response against the virus, and therefore may confer efficient protection against a wide array of pathogens. These could potentially include Biological Warfare Agents (BWAs), exposure to which may lead to mass casualties due to disease severity and a possible lack of efficient treatment. In this review, we assessed the recent literature on drugs under advanced clinical evaluation for COVID-19 with broad spectrum activity, including antiviral agents and HDTs, which may be relevant for future coping with BWAs, as well as with other agents, in particular respiratory infections.

Interplay of host and viral factors in inflammatory pathway mediated cytokine storm during RNA virus infection

RNA viruses always have been a serious concern for human health by causing several outbreaks, often pandemics. The excessive mortality and deaths associated with the outbreaks caused by these viruses were due to the excessive induction of pro-inflammatory cytokines leading to cytokine storm. Cytokines are important for cell-to-cell communication to maintain cell homeostasis. Disturbances of this homeostasis can lead to intricate chain reactions resulting in a massive release of cytokines. This could lead to a severe self-reinforcement of several feedback processes, which could eventually cause systemic harm, multiple organ failure, or death. Multiple inflammation-associated pathways were involved in the cytokine production and its regulation. Different RNA viruses induce these pathways through the interplay with their viral factors and host proteins and miRNAs regulating these pathways. This review will discuss the interplay of host proteins and miRNAs that can play an important role in the regulation of cytokine storm and the possible therapeutic potential of these molecules for the treatment and the challenges associated with the clinical translation.

A Prospective Cohort Study of COVID-19: Evaluation of the Early Role of IL-1 and IL-6 Antagonists in Improving the Outcome of the Illness and Reduction in the Risk of Death

The COVID-19 pandemic had a profound impact on global health, economies, and social systems. The crucial factor that determines the success of COVID-19 treatments is preventing the need for mechanical ventilation and intensive care admission. In the context of COVID-19, several treatments have been found to play a role in the disease's progression and severity. Interleukins (ILs) have been identified as key mediators of the cytokine storm that can occur in severe cases of COVID-19, leading to respiratory failure and other complications. For instance, IL-1 antagonist (anakinra) and IL-6 antagonist (tocilizumab) are supposed to be promising treatments as well as cortisones for COVID-19. This prospective study aims to evaluate the effectiveness of anakinra or tocilizumab in addition to cortisone in preventing the progression of mild to moderate COVID-19 cases to severe intensive care admission. Biochemical and hematological parameters, such as D-dimer, ferritin, LDH, CRP, and white blood cells (WBCs), were measured after treatment with either anakinra or tocilizumab in addition to cortisone or cortisone alone. The study also recorded the number of deaths and patients admitted to intensive care. The results indicate that anakinra significantly improved outcomes and decreased the number of intensive care admissions compared to tocilizumab or cortisone alone. Therefore, anakinra may play a vital role in controlling the progression of COVID-19, and its use in mild to moderate cases may prevent the worsening of the disease to severe stages.

Anakinra-An Interleukin-1 Receptor Antagonist for COVID-19

BACKGROUND

Coronavirus disease (COVID-19) caused by SARS-CoV-2 virus caused a global pandemic in 2019. There are limited pharmacologic options available. The Food and Drug Administration initiated an emergency use authorization process to expedite pharmacologic agents to treat COVID-19. There are several agents available through the emergency use authorization process, ritonavir-boosted nirmatrelvir, remdesivir, and baricitinib. Anakinra is an interleukin (IL)-1 receptor antagonist that exhibits properties in fighting against COVID-19.

MECHANISM OF ACTION, PHARMACODYNAMICS, AND PHARMACOKINETICS

Anakinra is a recombinant IL-1 receptor antagonist. The epithelial cell damage that may occur with COVID-19 enhances the release of IL-1, which plays a central role in severe cases. Thus, drugs that inhibit the IL-1 receptor may be beneficial in the management of COVID-19. Anakinra has good bioavailability after subcutaneous injection and a half-life of up to 6 hours.

CLINICAL TRIALS

The SAVE-MORE, double-blind, randomized controlled trial, phase 3 evaluated the efficacy and safety of anakinra. Anakinra 100 mg was given subcutaneously daily for up to 10 days in patients with moderate and severe COVID-19 and plasma suPAR ≥6 ng/mL. Anakinra group had a 50.4% fully recovered with no viral RNA detected on day 28 versus 26.5% for placebo, and more than 50% of relative decrease in mortality. A significantly decreased risk of worse clinical outcome was observed.

THERAPEUTIC ADVANCE

COVID-19 causes global pandemic and a serious viral disease. There are limited therapy options to combat this deadly disease. Anakinra is an IL-1 receptor antagonist and shown to be effective for the treatment of COVID-19 in some trials but not others. Anakinra, the first in this class, seems to have a mix result for the treatment of COVID-19.

Evaluation of anakinra in the management of patients with COVID-19 infection: A randomized clinical trial

Background

The global COVID-19 pandemic led to substantial clinical and economic outcomes with catastrophic consequences. While the majority of cases has mild to moderate disease, minority of patients progress into severe disease secondary to the stimulation of the immune response. The hyperinflammatory state contributes towards progression into multi-organ failure which necessitates suppressive therapy with variable outcomes. This study aims to explore the safety and efficacy of anakinra in COVID-19 patients with severe disease leading to cytokine release syndromes.

Methods

In this open-label, multi-center, randomized clinical trial, patients with confirmed COVID-19 infection with evidence of respiratory distress and signs of cytokine release syndrome were randomized in 1:1 ratio to receive either standard of care (SOC) or anakinra (100 mg subcutaneously every 12 h for 3 days then 100 mg subcutaneously once daily for 4 days) in addition to SOC. The primary outcome was treatment success at day 14 as defined by the WHO clinical progression score of ≤3. Primary analysis was based upon intention-to-treat population, with value of p of <0.05.

Results

Out 327 patients screened for eligibility, 80 patients were recruited for the study. The mean age was 49.9 years (SD = 11.7), with male predominance at 82.5% (n = 66). The primary outcome was not statistically different (87.5% (n = 35) in anakinra group vs. 92.5% (n = 37) in SOC group, p = 0.712; OR = 1.762 (95%CI: 0.39-7.93). The majority of reported adverse events were mild in severity and not related to the study treatment. Elevated aspartate aminotransferase was the only significant adverse event which was not associated with discontinuation of therapy.

Conclusion

In patients with severe COVID-19 infection, the addition of anakinra to SOC treatment was safe but was not associated with significant improvement according to the WHO clinical progression scale. Further studies are warranted to explore patients' subgroups characteristics that might benefit from administered therapy.

Clinical Trial Registration

Trial registration at ClinicalTrials.gov, identifier: NCT04643678.

Liver injury in COVID-19: Clinical features, potential mechanisms, risk factors and clinical treatments

The coronavirus disease 2019 (COVID-19) pandemic has been a serious threat to global health for nearly 3 years. In addition to pulmonary complications, liver injury is not uncommon in patients with novel COVID-19. Although the prevalence of liver injury varies widely among COVID-19 patients, its incidence is significantly increased in severe cases. Hence, there is an urgent need to understand liver injury caused by COVID-19. Clinical features of liver injury include detectable liver function abnormalities and liver imaging changes. Liver function tests, computed tomography scans, and ultrasound can help evaluate liver injury. Risk factors for liver injury in patients with COVID-19 include male sex, preexisting liver disease including liver transplantation and chronic liver disease, diabetes, obesity, and hypertension. To date, the mechanism of COVID-19-related liver injury is not fully understood. Its pathophysiological basis can generally be explained by systemic inflammatory response, hypoxic damage, ischemia-reperfusion injury, and drug side effects. In this review, we systematically summarize the existing literature on liver injury caused by COVID-19, including clinical features, underlying mechanisms, and potential risk factors. Finally, we discuss clinical management and provide recommendations for the care of patients with liver injury.

Use of Continuous Intravenous Anakinra Infusion in Multisystem Inflammatory Syndrome in Children

Coronavirus disease (COVID-19) is an emergency pandemic with a high mortality rate worldwide. One of its complications in children is developing multisystemic inflammatory syndrome related to cytokine storm. Anakinra is a recombinant human interleukin-1 (IL-1) receptor antagonist used to suppress the exaggerated inflammatory response in such conditions, and it is potentially lifesaving in a cytokine storm. We present the case of a patient with critical COVID-19 associated with multisystem inflammatory syndrome in children (MIS-C) successfully treated with anakinra intravenous (IV) infusion.

Resolution of the Council of Excperts (16th June, 2022): Therapy of gouty arthritis with an IL-1 inhibitor (anakinra)

.

The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the “Cytokine Storm”, which is a dramatic increase in inflammatory cytokines in the blood. In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or “Long COVID”. Therefore, there is an urgent need to better understand the mechanisms of the virus. The spike protein on the surface of the virus is composed of joined S1–S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm. In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.