Therapeutic Options for Coronavirus Disease 2019 (COVID-19) - Modulation of Type I Interferon Response as a Promising Strategy?

Immunoediting in SARS-CoV-2: Mutual relationship between the virus and the host

Immunoediting is a well-known concept that occurs in cancer through three steps of elimination, equilibrium, and escape (3Es), where the immune system first suppresses the growth of tumor cells and then promotes them towards the malignancy. This phenomenon has been conceptualized in some chronic viral infections such as HTLV-1 and HIV by obtaining the resistance to elimination and making a persistent form of infected cells especially in untreated patients. Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a heterogeneous disease characterizing from mild/asymptomatic to severe/critical courses with some behavioral aspects in an immunoediting setting. In this context, a coordinated effort between innate and adaptive immune system leads to detection and destruction of early infection followed by equilibrium between virus-specific responses and infected cells, which eventually ends up with an uncontrolled inflammatory response in severe/critical patients. Although the SARS-CoV-2 applies several escape strategies such as mutations in viral epitopes, modulating the interferon response and inhibiting the MHC I molecules similar to the cancer cells, the 3Es hallmark may not occur in all clinical conditions. Here, we discuss how the lesson learnt from cancer immunoediting and accurate understanding of these pathophysiological mechanisms helps to develop more effective therapeutic strategies for COVID-19.

COVID-19 as a mediator of interferon deficiency and hyperinflammation: Rationale for the use of JAK1/2 inhibitors in combination with interferon

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicits an interferon (IFN) deficiency state, which aggravates the type I interferon deficiency and slow IFN responses, which associate with e.g. aging and obesity. Additionally, SARS-CoV-2 may also elicit a cytokine storm, which accounts for disease progression and ultimately the urgent need of ventilator support. Based upon several reports, it has been argued that early treatment with IFN-alpha2 or IFN-beta, preferentially in the early disease stage, may prohibit disease progression. Similarly, preliminary studies have shown that JAK1/2 inhibitor treatment with ruxolitinib or baricitinib may decrease mortality by dampening the deadly cytokine storm, which - in addition to the virus itself - also contributes to multi-organ thrombosis and multi-organ failure. Herein, we describe the rationale for treatment with IFNs (alpha2 or beta) and ruxolitinib emphasizing the urgent need to explore these agents in the treatment of SARS-CoV-2 - both as monotherapies and in combination. In this context, we take advantage of several safety and efficacy studies in patients with the chronic myeloproliferative blood cancers (essential thrombocythemia, polycythemia vera and myelofibrosis) (MPNs), in whom IFN-alpha2 and ruxolitinib have been used successfully for the last 10 (ruxolitinib) to 30 years (IFN) as monotherapies and most recently in combination as well. In the context of these agents being highly immunomodulating (IFN boosting immune cells and JAK1/2 inhibitors being highly immunosuppressive and anti-inflammatory), we also discuss if statins and hydroxyurea, both agents possessing anti-inflammatory, antithrombotic and antiviral potentials, might be inexpensive agents to be repurposed in the treatment of SARS-CoV-2.

COVID-19: Characteristics and Therapeutics

Novel coronavirus (COVID-19 or 2019-nCoV or SARS-CoV-2), which suddenly emerged in December 2019 is still haunting the entire human race and has affected not only the healthcare system but also the global socioeconomic balances. COVID-19 was quickly designated as a global pandemic by the World Health Organization as there have been about 98.0 million confirmed cases and about 2.0 million confirmed deaths, as of January 2021. Although, our understanding of COVID-19 has significantly increased since its outbreak, and multiple treatment approaches and pharmacological interventions have been tested or are currently under development to mitigate its risk-factors. Recently, some vaccine candidates showed around 95% clinical efficacy, and now receiving emergency use approvals in different countries. US FDA recently approved BNT162 and mRNA-1273 vaccines developed by Pfizer/BioNTech and Moderna Inc. for emergency use and vaccination in the USA. In this review, we present a succinct overview of the SARS-CoV-2 virus structure, molecular mechanisms of infection, COVID-19 epidemiology, diagnosis, and clinical manifestations. We also systematize different treatment strategies and clinical trials initiated after the pandemic outbreak, based on viral infection and replication mechanisms. Additionally, we reviewed the novel pharmacological intervention approaches and vaccine development strategies against COVID-19. We speculate that the current pandemic emergency will trigger detailed studies of coronaviruses, their mechanism of infection, development of systematic drug repurposing approaches, and novel drug discoveries for current and future pandemic outbreaks.

Possible therapeutic targets for SARS-CoV-2 infection and COVID-19

SARS-CoV-2 infection causes COVID-19, which has emerged as a health emergency worldwide. SARS-CoV-2 infects cells by binding to ACE2 receptors and enters into the cytoplasm following its escape from endolysosomes. Once in the cytoplasm, the virus replicates and eventually causes various pathological conditions including acute respiratory distress syndrome (ARDS) that is caused by pro-inflammatory cytokine storms. Thus, endolysosomes and cytokine storms are important therapeutic targets to suppress SARS-CoV-2 infection and COVID-19. Here, we discuss therapeutic targets of SARS-CoV-2 infection and available drugs that could be helpful in the suppression of the SARS-CoV-2 infection and pathological condition COVID-19. The urgency of the COVID-19 pandemic precludes the development of new drugs and increased focus on drug repurposing might provide the quickest way to finding effective medicines.

Type I interferon: From innate response to treatment for COVID-19

Effective prophylactic and therapeutic interventions are urgently needed to address the coronavirus disease 2019 (COVID-19) pandemic. Various antiviral drugs have recently been tested. Type I interferon (IFN) is a regulatory protein involved in the innate immune response, with broad-spectrum antiviral activities and the ability to directly block viral replication and support the immune response to eliminate virus infection. Insufficient virus-induced type I IFN production is characteristic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, because SARS-CoV-2 suppresses the IFN response by interacting with essential IFN signaling pathways. Exogenous type I IFN is recommended for treating COVID-19. Unexpectedly however, angiotensin converting enzyme-2 (ACE2) receptor, which acts as a SARS-CoV-2 receptor, was shown to be stimulated by IFN, raising doubts about the suitability of IFN use. However, further studies have excluded concerns regarding IFN administration. Type I IFNs, including IFN-α1b, have been used clinically as antiviral drugs for many years and have shown strong antiviral activity against SARS-CoV-2 in vitro. Preliminary clinical studies of type I IFNs, especially when delivered via aerosol inhalation, have demonstrated efficacy for the treatment and prevention of COVID-19. Randomized controlled trials of IFN for COVID-19 treatment are ongoing.

Rationale for COVID-19 Treatment by Nebulized Interferon-β-1b-Literature Review and Personal Preliminary Experience

The inflammatory response to COVID-19 is specifically associated with an impaired type I interferon (IFN) response and complete blockade of IFN-β secretion. Clinically, nebulization of IFN-α-2b has been historically used in China to treat viral pneumonia associated with SARS-CoV. Very recent data show that the use of inhaled type I IFN is associated with decreased mortality in Chinese COVID-19 patients. However, IFN nebulization is currently not standard in Europe and the United States. Therefore, our group has set up a project aimed to evaluate the possibility to nebulize IFN-β-1b (a drug currently used in Europe to treat multiple sclerosis via subcutaneous injections) and to assess the safety of this new mode of administration in SARS-CoV-2 infected patients. We present here literature data that allowed us to build our hypothesis and to develop collaboration between clinical pharmacists, intensivists and nebulization engineers in order to gain first pre-clinical and clinical experience of IFN-β-1b nebulization. After validation of the nebulization method and verification of droplet size compatible with nebulization, the method has been applied to four intensive care patients treated at our university hospital, for whom none of the COVID-19 therapies initially used in France led to significant clinical improvement. All patients exhibited negative viral carriage and experienced clinical improvement 7-16 days after having initiated nebulized IFN-β-1b inhalation therapy. No side effects were observed. All patients were alive within a 90-days follow-up. Although it is not possible to draw firm conclusions on treatment efficacy based on this case report, our study shows that pulmonary IFN-β-1b administration is feasible, with a good safety profile. This procedure, which presents the advantage of directly targeting the lungs and reducing the risks of systemic side effects, may represent a promising therapeutic strategy for the care of patients with severe COVID-19. However, our preliminary observation requires confirmation by randomized controlled trials.

Recent Advances in Pathophysiology, Drug Development and Future Perspectives of SARS-CoV-2

The coronavirus (SARS-CoV-2) pandemic is a rapidly transmitting and highly pathogenic disease. The spike protein of SARS-CoV-2 binds to the surface of angiotensin-converting enzyme-2 (ACE2) receptors along the upper respiratory tract and intestinal epithelial cells. SARS-CoV-2 patients develop acute respiratory distress, lymphocytic myocarditis, disseminated intravascular coagulation, lymphocytic infiltration, and other serious complications. A SARS-CoV-2 diagnosis is conducted using quantitative reverse-transcription PCR and computed tomography (CT) imaging. In addition, IgM or IgG antibodies are used to identify acute and convalescent illness. Recent clinical data have been generated by health workers and researchers and have shown that there is an urgent requirement in the effective clinical and treatment of patients, as well as other developments for dealing with SARS-CoV-2 infection. A broad spectrum of clinical trials of different vaccines and drug treatment has been evaluated for use against SARS-CoV-2. This review includes the emergence of SARS-CoV-2 pneumonia as a way to recognize and eliminate any barriers that affect rapid patient care and public health management against the SARS-CoV-2 epidemic based on the natural history of the disease, its transmission, pathogenesis, immune response, epidemiology, diagnosis, clinical presentation, possible treatment, drug and vaccine development, prevention, and future perspective.