Thiopurine analogs and mycophenolic acid synergistically inhibit the papain-like protease of Middle East respiratory syndrome coronavirus

Therapeutic approaches against coronaviruses acute respiratory syndrome

Coronaviruses represent global health threat. In this century, they have already caused two epidemics and one serious pandemic. Although, at present, there are no approved drugs and therapies for the treatment and prevention of human coronaviruses, several agents, FDA-approved, and preclinical, have shown in vitro and/or in vivo antiviral activity. An in-depth analysis of the current situation leads to the identification of several potential drugs that could have an impact on the fight against coronaviruses infections. In this review, we discuss the virology of human coronaviruses highlighting the main biological targets and summarize the current state-of-the-art of possible therapeutic options to inhibit coronaviruses infections. We mostly focus on FDA-approved and preclinical drugs targeting viral conserved elements.

Thiopurines: Recent Topics and Their Role in the Treatment of Inflammatory Bowel Diseases

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic inflammatory bowel diseases (IBD) of unknown etiology, characterized by repeated relapse and remission. The efficacy of thiopurine in IBD was first reported in the late 1960s. Thiopurines are used to alleviate the symptoms of IBD, especially UC. These drugs have a steroid-sparing potential and are widely used for the purpose of maintaining long-term remission in steroid-dependent cases. Therefore, thiopurines tend to be used long-term, but adverse events that accompany long-term use, such as lymphoproliferative disorders, must be monitored with care. In contrast, thiopurine plays a critical role in controlling the immunogenicity of biologics. Furthermore, although thiopurine is an old drug, new findings, including the prediction of serious adverse events such as severe alopecia and acute advanced leukopenia, by nudix hydrolase 15 gene polymorphism analysis, as well as the possibility of appropriate drug monitoring by detailed analysis of 6-thioguanine nucleotides have been clarified. However, the consequences of thiopurine withdrawal have not been determined and further studies, including randomized controlled trials, are necessary to answer the clinical question regarding the scenarios in which thiopurine withdrawal is possible.

The complex structure of GRL0617 and SARS-CoV-2 PLpro reveals a hot spot for antiviral drug discovery

SARS-CoV-2 is the pathogen responsible for the COVID-19 pandemic. The SARS-CoV-2 papain-like cysteine protease (PLpro) has been implicated in playing important roles in virus maturation, dysregulation of host inflammation, and antiviral immune responses. The multiple functions of PLpro render it a promising drug target. Therefore, we screened a library of approved drugs and also examined available inhibitors against PLpro. Inhibitor GRL0617 showed a promising in vitro IC50 of 2.1 μM and an effective antiviral inhibition in cell-based assays. The co-crystal structure of SARS-CoV-2 PLproC111S in complex with GRL0617 indicates that GRL0617 is a non-covalent inhibitor and it resides in the ubiquitin-specific proteases (USP) domain of PLpro. NMR data indicate that GRL0617 blocks the binding of ISG15 C-terminus to PLpro. Using truncated ISG15 mutants, we show that the C-terminus of ISG15 plays a dominant role in binding PLpro. Structural analysis reveals that the ISG15 C-terminus binding pocket in PLpro contributes a disproportionately large portion of binding energy, thus this pocket is a hot spot for antiviral drug discovery targeting PLpro.

Therapeutic targets and potential agents for the treatment of COVID-19

The outbreak of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has become a global crisis. As of November 9, COVID-19 has already spread to more than 190 countries with 50,000,000 infections and 1,250,000 deaths. Effective therapeutics and drugs are in high demand. The structure of SARS-CoV-2 is highly conserved with those of SARS-CoV and Middle East respiratory syndrome-CoV. Enzymes, including RdRp, M^pro /3CL^pro , and PL^pro , which play important roles in viral transcription and replication, have been regarded as key targets for therapies against coronaviruses, including SARS-CoV-2. The identification of readily available drugs for repositioning in COVID-19 therapy is a relatively rapid approach for clinical treatment, and a series of approved or candidate drugs have been proven to be efficient against COVID-19 in preclinical or clinical studies. This review summarizes recent progress in the development of drugs against SARS-CoV-2 and the targets involved.

Structure-Based Screening to Discover New Inhibitors for Papain-like Proteinase of SARS-CoV-2: An In Silico Study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) expresses a multifunctional papain-like proteinase (PLpro), which mediates the processing of the viral replicase polyprotein. Inhibition of PLpro has been shown to suppress the viral replication. This study aimed to explore new anti-PLpro candidates by applying virtual screening based on GRL0617, a known PLpro inhibitor of SARS coronavirus (SARS-CoV). The three-dimensional (3D) structure of SARS-CoV-2 PLpro was built by homology modeling, using SARS-CoV PLpro as the template. The model was refined and studied through molecular dynamic simulation. AutoDock Vina was then used to perform virtual screening where 50 chemicals with at least 65% similarity to GRL0617 were docked with the optimized SARS-CoV-2 PLpro. In this screening, 5-(aminomethyl)-2-methyl-N-[(1R)-1-naphthalen-1-ylethyl]benzamide outperformed GRL0617 in terms of binding affinity (-9.7 kcal/mol). Furthermore, 2-(4-fluorobenzyl)-5-nitro-1H-isoindole-1,3(2H)-dione (previously introduced as an inhibitor of cyclooxygenase-2), 3-nitro-N-[(1r)-1-phenylethyl]-5-(trifluoromethyl)benzamide (inhibitor against Mycobacterium tuberculosis), as well as the recently introduced SARS-CoV-2 PLpro inhibitor 5-acetamido-2-methyl-N-[(1S)-1-naphthalen-1-ylethyl]benzamide showed promising affinity for the viral proteinase. All of the identified compounds demonstrated an acceptable pharmacokinetic profile. In conclusion, our findings represent rediscovery of analgesic, anti-inflammatory, antibacterial, or antiviral drugs as promising pharmaceutical candidates against the ongoing coronavirus.

Crystal structure of SARS-CoV-2 papain-like protease

The pandemic of coronavirus disease 2019 (COVID-19) is changing the world like never before. This crisis is unlikely contained in the absence of effective therapeutics or vaccine. The papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays essential roles in virus replication and immune evasion, presenting a charming drug target. Given the PLpro proteases of SARS-CoV-2 and SARS-CoV share significant homology, inhibitor developed for SARS-CoV PLpro is a promising starting point of therapeutic development. In this study, we sought to provide structural frameworks for PLpro inhibitor design. We determined the unliganded structure of SARS-CoV-2 PLpro mutant C111S, which shares many structural features of SARS-CoV PLpro. This crystal form has unique packing, high solvent content and reasonable resolution 2.5 Å, hence provides a good possibility for fragment-based screening using crystallographic approach. We characterized the protease activity of PLpro in cleaving synthetic peptide harboring nsp2/nsp3 juncture. We demonstrate that a potent SARS-CoV PLpro inhibitor GRL0617 is highly effective in inhibiting protease activity of SARS-CoV-2 with the IC50 of 2.2 ± 0.3 μmol/L. We then determined the structure of SARS-CoV-2 PLpro complexed by GRL0617 to 2.6 Å, showing the inhibitor accommodates the S3-S4 pockets of the substrate binding cleft. The binding of GRL0617 induces closure of the BL2 loop and narrows the substrate binding cleft, whereas the binding of a tetrapeptide substrate enlarges the cleft. Hence, our results suggest a mechanism of GRL0617 inhibition, that GRL0617 not only occupies the substrate pockets, but also seals the entrance to the substrate binding cleft hence prevents the binding of the LXGG motif of the substrate.

Biomarkers of Cytokine Release Syndrome Predict Disease Severity and Mortality From COVID-19 in Kidney Transplant Recipients

BACKGROUND

Data on coronavirus disease 2019 (COVID-19) in immunocompromised kidney transplant recipients (KTR) remain scanty. Although markers of inflammation, cardiac injury, and coagulopathy have been previously associated with mortality in the general population of patients with COVID-19, their prognostic impact amongst KTR with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has not been specifically investigated.

METHODS

We conducted a cohort study of 49 KTR who presented with COVID-19. Clinical and laboratory risk factors for severe disease and mortality were prospectively collected and analyzed with respect to outcomes. The study participants were divided into 3 groups: (1) mild disease manageable in an outpatient setting (n = 8), (2) nonsevere disease requiring hospitalization (n = 21), and (3) severe disease (n = 20).

RESULTS

Gastrointestinal manifestations were common at diagnosis. The 30-day mortality rate in hospitalized patients was 19.5%. Early elevations of C-reactive protein (>100 mg/L) and interleukin-6 (>65 ng/L) followed by increases in high-sensitivity troponin I (>30 ng/L) and D-dimer (>960 ng/mL) were significantly associated with severe disease and mortality. Viral load did not have prognostic significance in our sample, suggesting that outcomes were chiefly driven by a cytokine release syndrome (CRS).

CONCLUSIONS

Regular monitoring of CRS biomarkers in KTR with COVID-19 is paramount to improve clinical outcomes.

COVID-19: biologic and immunosuppressive therapy in gastroenterology and hepatology

The coronavirus disease 2019 (COVID-19) pandemic is an ongoing global health crisis causing major challenges for clinical care in patients with gastrointestinal diseases. Although triggering of anti-viral immune responses is essential for clearance of infection, some patients have severe lung inflammation and multiorgan failure due to marked immune cell dysregulation and cytokine storm syndrome. Importantly, the activation of cytotoxic follicular helper T cells and a reduction of regulatory T cells have a crucial, negative prognostic role. These findings lead to the question of whether immunosuppressive and biologic therapies for gastrointestinal diseases affect the incidence or prognosis of COVID-19 and, thus, whether they should be adjusted to prevent or affect the course of the disease. In this Review, data on the use of such therapies are discussed with a primary focus on inflammatory bowel disease, autoimmune hepatitis and liver transplantation. In particular, the roles of corticosteroids, classic immunosuppressive agents (such as thiopurines and mycophenolate mofetil), small molecules (such as Janus kinase (JAK) inhibitors), and biologic agents (such as tumour necrosis factor (TNF) blockers, vedolizumab and ustekinumab) are reviewed. Finally, the use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines for the prevention of infection in patients with gastrointestinal diseases and concomitant immunosuppressive or biologic therapy will be discussed.

Association of prescribed medications with the risk of COVID-19 infection and severity among adults in South Korea

OBJECTIVES

Concerns have been expressed that some drugs may increase susceptibility to SARS-CoV-2 infection. In contrast, other drugs have generated interest as potential therapeutic agents.

METHODS

All adults aged ≥18 years who were tested for COVID-19 were included. Exposure was defined as a prescription of study drugs which would have been continued until 7 days prior to test for COVID-19 or later. The outcome measures were the diagnosis of COVID-19 and severe COVID-19. Disease risk score matching and multiple logistic regression was used.

RESULTS

Matched claims and testing results were available for 219,961 subjects, of whom 7,341 (3.34%) were diagnosed with COVID-19. Patients were matched to 36,705 controls, and the subset of 878 patients of severe COVID-19 also matched with 1,927 mild-to-moderate patients. Angiotensin receptor blockers were not associated with either the diagnosis of COVID-19 (adjusted OR [aOR], 1.02; 95% confidence interval [CI], 0.90-1.15) or severe disease (aOR, 1.11; 95% CI, 0.87-1.42). The use of hydroxychloroquine was not associated with a lower risk for COVID-19 (aOR, 0.94; 95% CI, 0.53-1.66) or severe disease (aOR, 3.51; 95% CI, 0.76-16.22).

CONCLUSIONS

In this national claims data-based case-control study, no commonly prescribed medications were associated with risk of COVID-19 infection or COVID-19 severity.

A pocket guide on how to structure SARS-CoV-2 drugs and therapies

The race to identify a successful treatment for COVID19 will be defined by fundamental research into the replication cycle of the SARS-CoV-2 virus. This has identified five distinct stages from which numerous vaccination and clinical trials have emerged alongside an innumerable number of drug discovery studies currently in development for disease intervention. Informing every step of the viral replication cycle has been an unprecedented 'call-to-arms' by the global structural biology community. Of the 20 main SARS-CoV-2 proteins, 13 have been resolved structurally for SARS-CoV-2 with most having a related SARS-CoV and MERS-CoV structural homologue totalling some 300 structures currently available in public repositories. Herein, we review the contribution of structural studies to our understanding of the virus and their role in structure-based development of therapeutics.

COVID-19 in patients with inflammatory bowel disease

INTRODUCTION

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread world over causing morbidity and mortality in affected patients, especially elderly and those with co-morbidities. Inflammatory Bowel Disease (IBD) patients frequently require immunosuppressive therapy and are known to be at risk of opportunistic infections.

AREAS COVERED

We hereby review the available literature pertaining to COVID-19 in IBD based on published consensus guidelines, expert opinions, case series, registries and reports.

EXPERT OPINION

Preliminary data suggests no increase in incidence of COVID-19 in IBD patients as compared to general population. Morbidity and mortality rates attributable to COVID-19 are also similar in IBD patients as compared to general population. Though exact reason is unknown, some aspects of COVID-19 pathogenesis may explain this paradox. Medications for IBD need to be carefully reviewed during COVID-19 crisis. Steroids may need dose tapering or substitution to avoid complications based on anecdotal evidence. Endoscopic procedures for IBD maybe deferred unless absolutely necessary. General measures recommended for COVID-19 tailored to specific needs of IBD patients maybe the best way to prevent infection. Our understanding of the disease outcomes and optimal management protocols are likely to evolve as we move ahead in this pandemic.

Identification of novel human USP2 inhibitor and its putative role in treatment of COVID-19 by inhibiting SARS-CoV-2 papain-like (PLpro) protease

Human ubiquitin carboxyl-terminal hydrolase-2 (USP2) inhibitors, such as thiopurine analogs, have been reported to inhibit SARS-CoV papain-like proteases (PLpro). The PLpro have significant functional implications in the innate immune response during SARS-CoV-2 infection and considered an important antiviral target. Both proteases share strikingly similar USP fold with right-handed thumb-palm-fingers structural scaffold and conserved catalytic triad Cys-His-Asp/Asn. In this urgency situation of COVID-19 outbreak, there is a lack of in-vitro facilities readily available to test SARS-CoV-2 inhibitors in whole-cell assays. Therefore, we adopted an alternate route to identify potential USP2 inhibitor through integrated in-silico efforts. After an extensive virtual screening protocol, the best compounds were selected and tested. The compound Z93 showed significant IC50 value against Jurkat (9.67 μM) and MOTL-4 cells (11.8 μM). The binding mode of Z93 was extensively analyzed through molecular docking, followed by MD simulations, and molecular interactions were compared with SARS-CoV-2. The relative binding poses of Z93 fitted well in the binding site of both proteases and showed consensus π-π stacking and H-bond interactions with histidine and aspartate/asparagine residues of the catalytic triad. These results led us to speculate that compound Z93 might be the first potential chemical lead against SARS-CoV-2 PLpro, which warrants in-vitro evaluations.

Interferon-inducer antivirals: Potential candidates to combat COVID-19

Coronavirus disease 2019 (COVID-19) is an infective disease generated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the pandemic urgency and lack of an effective cure for this disease, drug repurposing could open the way for finding a solution. Lots of investigations are ongoing to test the compounds already identified as antivirals. On the other hand, induction of type I interferons are found to play an important role in the generation of immune responses against SARS-CoV-2. Therefore, it was opined that the antivirals capable of triggering the interferons and their signaling pathway, could rationally be beneficial for treating COVID-19. On this basis, using a database of antivirals, called drugvirus, some antiviral agents were derived, followed by searches on their relevance to interferon induction. The examined list included drugs from different categories such as antibiotics, immunosuppressants, anti-cancers, non-steroidal anti-inflammatory drugs (NSAID), calcium channel blocker compounds, and some others. The results as briefed here, could help in finding potential drug candidates for COVID-19 treatment. However, their advantages and risks should be taken into account through precise studies, considering a systemic approach. Even though the adverse effects of some of these drugs may overweight their benefits, considering their mechanisms and structures may give a clue for designing novel drugs in the future. Furthermore, the antiviral effect and IFN-modifying mechanisms possessed by some of these drugs might lead to a synergistic effect against SARS-CoV-2, which deserve to be evaluated in further investigations.

Virtual screening and molecular simulation study of natural products database for lead identification of novel coronavirus main protease inhibitors

3CL like protease (3CLpro or Mpro) is one of the main proteases of 2019-nCoV. The 3CLpro is a nonstructural protein of SARS-CoV and has an essential role in viral replication and transcription, thus, could be a potential target for anti-SARS drug development. The present study employed ligand- and structure-based approaches to identify the potent inhibitors of 2019-nCoV protease. The e-pharmacophore developed from 3CLpro-1 yielded virtual hits, that were subjected through drug likeliness and PAINS filters to remove interfering compounds. Further comprehensive docking studies, free energy calculations and ADMET studies resulted in two virtual leads- MolPort-000-410-348 and MolPort-002-530-156. The compounds MolPort-000-410-348 and MolPort-002-530-156 displayed good docking score of -12.09 and -13.38 Kcal/mol and free binding energy of -63.34 ± 2.03 and -61.52 ± 2.24 Kcal/mol, respectively. The compounds also exhibited satisfactory predicted ADMET profile and were subjected to molecular dynamic (MD) studies. The MD simulation produced stable complexes of these ligands with 3CLpro protein and ligand RMSD in acceptable limits. Communicated by Ramaswamy H. Sarma.

Potential molecular targets of nonstructural proteins for the development of antiviral drugs against SARS-CoV-2 infection

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The pandemic of SARS-CoV-2 has posed significant threats to public health worldwide.

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Target-based drug development is a promising approach against SARS-CoV-2 infection.

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Nonstructural proteins may play critical roles from drug design perspectives.

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Insights into NSPs of different viruses could streamline novel drug development.

Outbreaks of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2 have produced high pathogenicity and mortality rates in human populations. However, to meet the increasing demand for treatment of these pathogenic coronaviruses, accelerating novel antiviral drug development as much as possible has become a public concern. Target-based drug development may be a promising approach to achieve this goal. In this review, the relevant features of potential molecular targets in human coronaviruses (HCoVs) are highlighted, including the viral protease, RNA-dependent RNA polymerase, and methyltransferases. Additionally, recent advances in the development of antivirals based on these targets are summarized. This review is expected to provide new insights and potential strategies for the development of novel antiviral drugs to treat SARS-CoV-2 infection.

Combining Antivirals and Immunomodulators to Fight COVID-19

The majority of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals remain paucisymptomatic, contrasting with a minority of infected individuals in danger of death. Here, we speculate that the robust disease resistance of most individuals is due to a swift production of type I interferon (IFNα/β), presumably sufficient to lower the viremia. A minority of infected individuals with a preexisting chronic inflammatory state fail to mount this early efficient response, leading to a delayed harmful inflammatory response. To improve the epidemiological scenario, we propose combining: (i) the development of efficient antivirals administered early enough to assist in the production of endogenous IFNα/β; (ii) potentiating early IFN responses; (iii) administering anti-inflammatory treatments when needed, but not too early to interfere with endogenous antiviral responses.

Although the coronavirus disease 2019 (COVID-19) pandemic is exceptional, lessons may be learned from previous outbreaks (coronavirus, dengue, influenza viruses), especially when considering drug design and cytokine storms.

We propose that efficient treatments for COVID-19 patients should combine antivirals and immunomodulators. This combination and, especially the use of immunomodulators, might be adapted according to the disease stage.

Among the repurposed antiviral drugs currently being tested against COVID-19, none shows high potency.

We posit that the innate type 1 interferon (IFNα/β)-dependent antiviral immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection should be amplified. To this end, we propose two putative approaches: the inhibition of transforming growth factor (TGFβ) signaling, and perhaps, the administration of 1,8-cineole.

We suggest that an early diagnosis during COVID-19 is essential when aiming to purposely combine antivirals with the use of an immunomodulator (e.g., a drug to potentiate IFNα/β), ideally early in the disease course to lower the risk of cytokine storm manifestation. When the disease becomes severe, the new combination should prioritize targeting of the cytokine storm.

Implications of COVID-19 for inflammatory bowel disease: Opportunities and challenges amidst the pandemic

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic various measures have been taken to mitigate the effects of the global health crisis in this unprecedented time. According to the World Health Organization, more than 5 million people have been infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and with more than 300000 deaths attributed to COVID-19 worldwide. There is emerging evidence that SARS-CoV-2 utilizes angiotensin-converting enzyme 2 receptors to enter human cells which are found in abundance in the alveoli and intestines. In addition, the infection is noted to be more severe in patients with co-morbid conditions, those who are malnourished, immunosuppressed and immunocompromised. Inflammatory bowel disease (IBD) which includes ulcerative colitis and Crohn’s disease is chronic remitting and relapsing disorders with intestinal and extraintestinal manifestation. IBD patients are often malnourished and on immunosuppressive medications and there is a hypothetical concern that IBD patients are at substantial risk of COVID-19 infection. The management of IBD patients is often complex and poses unique challenges for gastroenterologists during the pandemic. The purpose of this review article is to summarize the growing level of evidence and understanding of the management of IBD during the COVID-19 pandemic, in the light of international and national gastroenterology society guidelines. We performed a thorough literature search on IBD, SARS-CoV-2 and COVID-19 on PubMed, EMBASE, OVID Medline and Google Scholar and pertaining literature was critically examined and summarized. Per national and international society guidelines and recommendations, IBD is not a risk factor for SARS-CoV-2 infection. IBD patients should continue with their medications and they should follow universal precautions i.e. masks, hand and respiratory hygiene and avoidance of health care facilities and public toilets as general population. Among IBD patients older age, having active disease, and co-morbid conditions are risk factors for a severe SARS-CoV-2 infection. Furthermore, elective endoscopic and surgical procedures can be delayed or deferred until discussing the risks and benefits with patients.

Approaches and advances in the development of potential therapeutic targets and antiviral agents for the management of SARS-CoV-2 infection

Virus onslaughts continue to spread fear and cause rampage across the world every now and then. The twenty first century is yet again witnessing a gross global pandemic, Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Globally no vaccines or drug specific to COVID-19 is available. Corona viruses have been in mutual relationship with humans and other hosts over many decades though aggressive zoonotic strains have caused havoc. Zoonotic emergent corona viruses prior to SARS-COV-2 included severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), with the former leading to aggressive infectious spread and the later with high mortality rate. Although they emerged in the early period of the twenty first century, resilient biomedical and expertise in pharmaceutical domain could not appropriate any proprietary therapeutics. Studies envisaged towards curtailing their spread employed different stages of the virus life cycle with all zoonotic coronaviruses (CoVs) sharing genomic and structural similarities. Hence the strategies against SARS-CoV and MERS-CoV could prove effective against the recent outbreak of SAR-CoV-2. The review unravels key events involved in the lifecycle of SARS-CoV-2 while highlighting the possible avenues of therapy. The review also holds the scope in better understanding a broad-spectrum antivirals, monoclonal antibodies and small molecule inhibitors against viral glycoproteins, host cell receptor, viral mRNA synthesis, RNA-dependent RNA polymerase (RdRp) and viral proteases in order to design and develop antiviral drugs for SARS-CoV-2.

Coronavirus in human diseases: Mechanisms and advances in clinical treatment

Coronaviruses (CoVs), a subfamily of coronavirinae, are a panel of single-stranded RNA virus. Human coronavirus (HCoV) strains (HCoV-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63) usually cause mild upper respiratory diseases and are believed to be harmless. However, other HCoVs, associated with severe acute respiratory syndrome, Middle East respiratory syndrome, and COVID-19, have been identified as important pathogens due to their potent infectivity and lethality worldwide. Moreover, currently, no effective antiviral drugs treatments are available so far. In this review, we summarize the biological characters of HCoVs, their association with human diseases, and current therapeutic options for the three severe HCoVs. We also highlight the discussion about novel treatment strategies for HCoVs infections.

The COVID-19 pandemic: A community approach

An unprecedented global pandemic caused by a novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) has quickly overwhelmed the health care systems worldwide. While there is an absence of consensus among the community in how to manage solid organ transplant recipients and donors, a platform provided by the American Society of Transplantation online community “Outstanding Questions in Transplantation,” hosted a collaborative multicenter, multinational discussions to share knowledge in a rapidly evolving global situation. Here, we present a summary of the discussion in addition to the latest published literature.

Papain-Like Proteases as Coronaviral Drug Targets: Current Inhibitors, Opportunities, and Limitations

Papain-like proteases (PLpro) of coronaviruses (CoVs) support viral reproduction and suppress the immune response of the host, which makes CoV PLpro perspective pharmaceutical targets. Their inhibition could both prevent viral replication and boost the immune system of the host, leading to the speedy recovery of the patient. Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the third CoV outbreak in the last 20 years. Frequent mutations of the viral genome likely lead to the emergence of more CoVs. Inhibitors for CoV PLpro can be broad-spectrum and can diminish present and prevent future CoV outbreaks as PLpro from different CoVs have conservative structures. Several inhibitors have been developed to withstand SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV). This review summarizes the structural features of CoV PLpro, the inhibitors that have been identified over the last 20 years, and the compounds that have the potential to become novel effective therapeutics against CoVs in the near future.

Immunosuppressive Drugs and COVID-19: A Review

BACKGROUND

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is currently unknown whether immunosuppressive drugs are advantageous or detrimental in patients with COVID-19. Immunosuppressive drugs could be harmful in the initial phase of COVID-19. In this phase, the host immune response is necessary to inhibit viral replication. However, immunosuppressive drugs might have a beneficial effect in the later, more severe phase of COVID-19. In this phase, an overshoot of the host immune response (the "cytokine storm") can cause ARDS, multiorgan failure and mortality.

AIM

To summarize the available evidence on the effect of immunosuppressive drugs on infection with SARS-CoV-2. The effects of immunosuppressive drugs on similar pandemic coronaviruses may resemble the effects on SARS-CoV-2. Thus, we also included studies on the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV).

METHODS

The study protocol was registered in PROSPERO (registration number CRD42020181137). We included randomized controlled trials (RCTs), cohort studies with a control group and case-control studies concerning humans ≥ 18 years old. We also included in-vitro studies and animal studies with a control group.

RESULTS AND CONCLUSION

Sixty-nine studies were included. Interestingly, MPA inhibits SARS-CoV-2 replication in-vitro. Clinical studies are needed to confirm the inhibitory effect of MPA on SARS-CoV-2 replication in-vivo. There are indications that corticosteroids and IL-6 inhibitors, like tocilizumab, can reduce mortality and prevent mechanical ventilation in patients with COVID-19. However, observational studies have contradictory results and the risk of bias is high. Thus, these results have to be confirmed in high-quality clinical trials before these drugs can be implemented as standard care. Based on the positive results of CNIs, mTOR inhibitors and thiopurine analogues in in-vitro studies with SARS-CoV and MERS-CoV, it would be interesting to investigate their effects on SARS-CoV-2 replication.

The recent outbreaks of human coronaviruses: A medicinal chemistry perspective

Coronaviruses (CoVs) infect both humans and animals. In humans, CoVs can cause respiratory, kidney, heart, brain, and intestinal infections that can range from mild to lethal. Since the start of the 21st century, three β‐coronaviruses have crossed the species barrier to infect humans: severe‐acute respiratory syndrome (SARS)‐CoV‐1, Middle East respiratory syndrome (MERS)‐CoV, and SARS‐CoV‐2 (2019‐nCoV). These viruses are dangerous and can easily be transmitted from human to human. Therefore, the development of anticoronaviral therapies is urgently needed. However, to date, no approved vaccines or drugs against CoV infections are available. In this review, we focus on the medicinal chemistry efforts toward the development of antiviral agents against SARS‐CoV‐1, MERS‐CoV, SARS‐CoV‐2, targeting biochemical events important for viral replication and its life cycle. These targets include the spike glycoprotein and its host‐receptors for viral entry, proteases that are essential for cleaving polyproteins to produce functional proteins, and RNA‐dependent RNA polymerase for viral RNA replication.

A Review on Novel Drug Targets and Future Directions for COVID-19 Treatment

Severe acute respiratory syndrome coronavirus-2 causes coronavirus disease-19 (COVID-19) that spreads quickly in the world. Considering the impact of this pandemic, researchers have been racing to understand the peculiar nature of the virus and the pathogenesis of the disease to uncover possible drug targets, effective therapeutic agents, and vaccines. Accordingly, numerous drug targets are identified by scientists. Among them, structural glycoproteins, virulence factors, host-specific receptors and enzymes, non-structure proteins, the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway, and pro-inflammatory cytokines are discussed herein. This review summarizes the promising drug targets for COVID-19, and highlights antiviral strategies which depend on molecular interactions between viral small molecules and host biologic machinery for repurposing the available clinical drugs. In addition, it gives a strong rational basis for the ongoing discovery of new drugs and vaccines.

Immunosuppression in the Management of Presumed Non-infective Uveitis; Are We Sure What We are Treating? Notes on the Antimicrobial Properties of the Systemic Immunosuppressants

PURPOSE

To describe the antimicrobial effects of immunosuppressants used for presumed autoimmune uveitis, and to discuss the potential importance of these effects in the context of increasing knowledge of the human microbiomes and their influence on inflammation.

METHODS

Literature review.

REVIEW OF EVIDENCE

All immunosuppressants have intrinsic antimicrobial effects; these vary considerably between drugs, and include antibacterial, antiviral and antifungal action. Immunosuppression is known to affect the composition of the gut microbiome, and alterations in microbiome composition are known to affect inflammations including uveitis.

CONCLUSIONS

Oral immunosuppressants are assumed to act on presumed autoimmune uveitis by downregulation of, or other interference with, an aberrant immune response. However, their antimicrobial properties are usually forgotten, and in the context of increasing knowledge of the involvement of microbes in the initiation of, and also potentially the perpetuation of, tissue inflammation, these effects may prove to be a fundamental part of their action.

Early Outcomes of Outpatient Management of Kidney Transplant Recipients with Coronavirus Disease 2019

BACKGROUND AND OBJECTIVES

Outcomes of kidney transplant recipients diagnosed with coronavirus disease 2019 as outpatients have not been described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We obtained clinical data for 41 consecutive outpatient kidney transplant recipients with known or suspected coronavirus disease 2019. Chi-squared and Wilcoxon rank sum tests were used to compare characteristics of patients who required hospitalization versus those who did not.

RESULTS

Of 41 patients, 22 (54%) had confirmed coronavirus disease 2019, and 19 (46%) were suspected cases. Patients most commonly reported fever (80%), cough (56%), and dyspnea (39%). At the end of follow-up, 13 patients (32%) required hospitalization a median of 8 days (range, 1-16) after symptom onset, and 23 (56%) had outpatient symptom resolution a median of 12 days (4-23) after onset. Patients who required hospitalization were more likely to have reported dyspnea (77% versus 21%, P=0.003) and had higher baseline creatinine (median, 2.0 versus 1.3 mg/dl, P=0.02), but there were no other differences between groups.

CONCLUSIONS

In an early cohort of outpatient kidney transplant recipients with known or suspected coronavirus disease 2019, many had symptomatic resolution without requiring hospitalization.

COVID-19 and immunological regulations - from basic and translational aspects to clinical implications

The COVID‐19 pandemic caused by SARS‐CoV‐2 has far‐reaching direct and indirect medical consequences. These include both the course and treatment of diseases. It is becoming increasingly clear that infections with SARS‐CoV‐2 can cause considerable immunological alterations, which particularly also affect pathogenetically and/or therapeutically relevant factors.

Against this background we summarize here the current state of knowledge on the interaction of SARS‐CoV‐2/COVID‐19 with mediators of the acute phase of inflammation (TNF, IL‐1, IL‐6), type 1 and type 17 immune responses (IL‐12, IL‐23, IL‐17, IL‐36), type 2 immune reactions (IL‐4, IL‐13, IL‐5, IL‐31, IgE), B‐cell immunity, checkpoint regulators (PD‐1, PD‐L1, CTLA4), and orally druggable signaling pathways (JAK, PDE4, calcineurin). In addition, we discuss in this context non‐specific immune modulation by glucocorticosteroids, methotrexate, antimalarial drugs, azathioprine, dapsone, mycophenolate mofetil and fumaric acid esters, as well as neutrophil granulocyte‐mediated innate immune mechanisms.

From these recent findings we derive possible implications for the therapeutic modulation of said immunological mechanisms in connection with SARS‐CoV‐2/COVID‐19. Although, of course, the greatest care should be taken with patients with immunologically mediated diseases or immunomodulating therapies, it appears that many treatments can also be carried out during the COVID‐19 pandemic; some even appear to alleviate COVID‐19.

Insights Into Dynamics of Inhibitor and Ubiquitin-Like Protein Binding in SARS-CoV-2 Papain-Like Protease

Covid-19 is caused by a novel form of coronavirus for which there are currently no vaccines or anti-viral drugs. This virus, termed SARS-CoV-2 (CoV2), contains Papain-like protease (PLpro) involved in viral replication and immune response evasion. Drugs targeting this protease therefore have great potential for inhibiting the virus, and have proven successful in older coronaviruses. Here, we introduce two effective inhibitors of SARS-CoV-1 (CoV1) and MERS-CoV to assess their potential for inhibiting CoV2 PLpro. We ran 1 μs molecular dynamics (MD) simulations of CoV2, CoV1, and MERS-CoV ligand-free PLpro to characterize the dynamics of CoV2 PLpro, and made comparisons between the three to elucidate important similarities and differences relevant to drug design and ubiquitin-like protein binding for deubiquitinating and deISGylating activity of CoV2. Next, we simulated the inhibitors bound to CoV1 and CoV2 PLpro in various poses and at different known binding sites to analyze their binding modes. We found that the naphthalene-based ligand shows strong potential as an inhibitor of CoV2 PLpro by binding at the putative naphthalene inhibitor binding site in both computational predictions and experimental assays. Our modeling work suggested strategies to improve naphthalene-based compounds, and our results from molecular docking showed that the newly designed compounds exhibited improved binding affinity. The other ligand, chemotherapy drug 6-mercaptopurine (6MP), showed little to no stable intermolecular interaction with PLpro and quickly dissociated or remained highly mobile. We demonstrate multiple ways to improve the binding affinity of the naphthalene-based inhibitor scaffold by engaging new residues in the unused space of the binding site. Analysis of CoV2 PLpro also brings insights into recognition of ubiquitin-like proteins that may alter innate immune response.

A review of therapeutic agents and Chinese herbal medicines against SARS-COV-2 (COVID-19)

The epidemic of pneumonia (COVID-19) caused by novel coronavirus (SARS-CoV-2) infection has been listed as a public health emergency of international concern by the World Health Organization (WHO), and its harm degree is defined as a global "pandemic". At present, the efforts of various countries focus on the rapid diagnosis and isolation of patients, as well as to find a treatment that can combat the most serious impact of the disease. The number of reported COVID-19 virus infections is still increasing. Unfortunately, no drugs or vaccines have been approved for the treatment of human coronaviruses, but there is an urgent need for in-depth research on emerging human infectious coronaviruses. Clarification transmission routes and pathogenic mechanisms, and identification of potential drug treatment targets will promote the development of effective prevention and treatment measures. In the absence of confirmed effective treatments, due to public health emergencies, it is essential to study the possible effects of existing approved antivirals drugs or Chinese herbal medicines for SARS-CoV-2. This review summarizes the epidemiological characteristics, pathogenesis, virus structure and targeting strategies of COVID-19. Meanwhile, this review also focus on the re-purposing of clinically approved drugs and Chinese herbal medicines that may be used to treat COVID-19 and provide new ideas for the discovery of small molecular compounds with potential therapeutic effects on novel COVID-19.

COVID‐19 und Immunregulation – von grundlegenden und translationalen Aspekten zu klinischen Implikationen

Die durch SARS‐CoV‐2 verursachte Pandemie COVID‐19 hat weitreichende direkte und indirekte medizinische Folgen. Dazu gehören sowohl der Verlauf als auch die Behandlung vieler Krankheiten. Es wird immer deutlicher, dass Infektionen mit SARS‐CoV‐2 erhebliche immunologische Veränderungen verursachen können, die insbesondere auch pathogenetisch und/oder therapeutisch relevante Faktoren betreffen.

Vor diesem Hintergrund fassen wir hier den aktuellen Wissensstand zur Interaktion von SARS‐CoV‐2/COVID‐19 mit Mediatoren der akuten Phase der Entzündung (TNF, IL‐1, IL‐6), der Typ‐1‐ und Typ‐17‐Immunantwort (IL‐12, IL‐23, IL‐17, IL‐36), Typ‐2‐Immunreaktionen (IL‐4, IL‐13, IL‐5, IL‐31, IgE), B‐Zell‐Immunität, Checkpoint‐Regulatoren (PD‐1, PD‐L1, CTLA4) und Signalwegen, die durch oral applizierte Medikamente moduliert werden (JAK, PDE4, Calcineurin), zusammen. Darüber hinaus diskutieren wir in diesem Zusammenhang die unspezifische Immunmodulation durch Glukokortikosteroide, Methotrexat, Malariamittel, Azathioprin, Dapson, Mycophenolsäure‐Derivate und Fumarsäureester sowie angeborene Immunmechanismen neutrophiler Granulozyten.

Aus diesen neueren Erkenntnissen leiten wir mögliche Implikationen für die therapeutische Modulation der genannten immunologischen Mechanismen im Zusammenhang mit SARS‐CoV‐2/COVID‐19 ab. Obwohl natürlich bei Patienten mit immunologisch vermittelten Krankheiten oder immunmodulierenden Therapien größte Vorsicht geboten ist, scheint es, dass viele Behandlungen auch während der COVID‐19‐Pandemie durchgeführt werden können; einige scheinen COVID‐19 sogar zu lindern.

Inflammatory Bowel Disease Management During the COVID-19 Outbreak: The Ten Do's and Don'ts from the ECCO-COVID Taskforce

Our knowledge of COVID-19 is changing and evolving rapidly, with novel insights and recommendations, almost on a daily basis. It behooves the medical community to provide updated information on a regular basis, on best practice to facilitate optimal care of infected patients and on appropriate advice for the general population. This is particularly important in the case of patients with chronic conditions, such as inflammatory bowel disease [IBD]. In this review, we have compiled existing evidence on the impact of COVID-19 in IBD patients and provide guidance on the most appropriate care to adopt during the pandemic. Our review highlights that IBD, per se, is not a risk factor for COVID-19. However, all IBD patients with symptoms should be tested for SARS-CoV-2 and the procedures for disease management should be carefully adapted: [i] in SARS-CoV-2-positive IBD patients, medical treatments should be re-evaluated [with a particular focus on corticosteroids] always with the purpose of treating active disease and maintaining remission; [ii] non-urgent surgeries and endoscopic procedures should be postponed for all patients; [iii] online consultancy should be implemented; and [iv] hospitalization and surgery should be limited to life-threatening situations.

Antiviral activities of mycophenolic acid and IMD-0354 against SARS-CoV-2

In this study, the anti–severe acute respiratory syndrome coronavirus‐2 (anti‐SARS‐CoV‐2) activity of mycophenolic acid (MPA) and IMD‐0354 was analyzed. These compounds were chosen based on their antiviral activities against other coronaviruses. Because they also inhibit dengue virus (DENV) infection, other anti‐DENV compounds/drugs were also assessed. On SARS‐CoV‐2‐infected VeroE6/TMPRSS2 monolayers, both MPA and IMD‐0354, but not other anti‐DENV compounds/drugs, showed significant anti‐SARS‐CoV‐2 activity. Although MPA reduced the viral RNA level by only approximately 100‐fold, its half maximal effective concentration was as low as 0.87 µ m, which is easily achievable at therapeutic doses of mycophenolate mofetil. MPA targets the coronaviral papain‐like protease and an in‐depth study on its mechanism of action would be useful in the development of novel anti‐SARS‐CoV‐2 drugs.

A Multi-Pronged Approach Targeting SARS-CoV-2 Proteins Using Ultra-Large Virtual Screening

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), previously known as 2019 novel coronavirus (2019-nCoV), has spread rapidly across the globe, creating an unparalleled global health burden and spurring a deepening economic crisis. As of July 7th, 2020, almost seven months into the outbreak, there are no approved vaccines and few treatments available. Developing drugs that target multiple points in the viral life cycle could serve as a strategy to tackle the current as well as future coronavirus pandemics. Here we leverage the power of our recently developed in silico screening platform, VirtualFlow, to identify inhibitors that target SARS-CoV-2. VirtualFlow is able to efficiently harness the power of computing clusters and cloud-based computing platforms to carry out ultra-large scale virtual screens. In this unprecedented structure-based multi-target virtual screening campaign, we have used VirtualFlow to screen an average of approximately 1 billion molecules against each of 40 different target sites on 17 different potential viral and host targets in the cloud. In addition to targeting the active sites of viral enzymes, we also target critical auxiliary sites such as functionally important protein-protein interaction interfaces. This multi-target approach not only increases the likelihood of finding a potent inhibitor, but could also help identify a collection of anti-coronavirus drugs that would retain efficacy in the face of viral mutation. Drugs belonging to different regimen classes could be combined to develop possible combination therapies, and top hits that bind at highly conserved sites would be potential candidates for further development as coronavirus drugs. Here, we present the top 200 in silico hits for each target site. While in-house experimental validation of some of these compounds is currently underway, we want to make this array of potential inhibitor candidates available to researchers worldwide in consideration of the pressing need for fast-tracked drug development.

Practical management of inflammatory bowel disease patients during the COVID-19 pandemic: expert commentary from the Gastroenterological Society of Australia Inflammatory Bowel Disease faculty

The COVID‐19 pandemic, caused by the novel coronavirus SARS‐CoV‐2, has emerged as a public health emergency and challenged healthcare systems globally. In a minority of patients, SARS‐CoV‐2 manifests with a severe acute respiratory illness and currently there are insufficient data regarding the virulence of COVID‐19 in inflammatory bowel disease patients taking immunosuppressive therapy. This review aims to summarise the current literature and provide guidance on the management of inflammatory bowel disease (IBD) patients in the context of the COVID‐19 pandemic in the Australasian setting.

SARS-CoV2 and immunosuppression: A double-edged sword

Severe acute respiratory syndrome Coronavirus 2 (SARS‐Cov2) outbreak has caused a pandemic rapidly impacting on the way of life of the entire world. This impact in the specific setting of transplantation and immunosuppression has been poorly explored to date. Discordant data exist on the impact of previous coronavirus outbreaks on immunosuppressed patients. Overall, only a very limited number of cases have been reported in literature, suggesting that transplanted patients not necessarily present an increased risk of severe SARS‐Cov2‐related disease compared to the general population. We conducted a literature review related to the impact of immunosuppression on coronavirus infections including case reports and series describing immunosuppression management in transplant recipients. The role of steroids, calcineurin inhibitors, and mycophenolic acid has been explored more in detail. A point‐in‐time snapshot of the yet released literature and some considerations in relation to the use of immunosuppression in SARS‐Cov2 infected transplant recipients are provided here for the physicians dealing with immunocompromised patients.

COVID-19 and Inflammatory Bowel Diseases: Risk Assessment, Shared Molecular Pathways, and Therapeutic Challenges

Background

The novel coronavirus SARS-CoV-2 causing COVID-19 disease is yielding a global outbreak with severe threats to public health. In this paper, we aimed at reviewing the current knowledge about COVID-19 infectious risk status in inflammatory bowel disease (IBD) patients requiring immunosuppressive medication. We also focused on several molecular insights that could explain why IBD patients appear not to have higher risks of infection and worse outcomes in COVID-19 than the general population in an attempt to provide scientific support for safer decisions in IBD patient care.

Methods

PubMed electronic database was interrogated for relevant articles involving data about common molecular pathways and shared treatment strategies between SARS-CoV-2, SARS-CoV-1, MERS-CoV, and inflammatory bowel diseases. Besides, Neural Covidex, an artificial intelligence tool, was used to answer queries about pathogenic coronaviruses and possible IBD interactions using the COVID-19 Open Research Dataset (CORD-19). Discussions. Few molecular and therapeutic interactions between IBD and pathogenic coronaviruses were explored. First, we showed how the activity of soluble angiotensin-converting enzyme 2, CD209L other receptors, and phosphorylated α subunit of eukaryotic translation initiation factor 2 might exert protective impact in IBD in case of coronavirus infection. Second, IBD medication was discussed in the context of possible beneficial effects on COVID-19 pathogeny, including “cytokine storm” prevention and treatment, immunomodulation, interferon signaling blocking, and viral endocytosis inhibition.

Conclusions

Using the current understanding of SARS-CoV-2 as well as other pathogenic coronaviruses immunopathology, we showed why IBD patients should not be considered at an increased risk of infection or more severe outcomes. Whether our findings are entirely applicable to the pathogenesis, disease susceptibility, and treatment management of SARS-CoV-2 infection in IBD must be further explored.

6-Thioguanine blocks SARS-CoV-2 replication by inhibition of PLpro protease activities

A recently emerged betacoronavirus, SARS-CoV-2, has led to a global health crisis that calls for the identification of effective therapeutics for COVID-19 disease. Coronavirus papain-like protease (PLpro) is an attractive drug target as it is essential for viral polyprotein cleavage and for deconjugation of ISG15, an antiviral ubiquitin-like protein. We show here that 6-Thioguanine (6-TG) inhibits SARS-CoV-2 PLpro-catalyzed viral polyprotein cleavage and ISG15 deconjugation in cells and inhibits replication of SARS-CoV-2 in Vero-E6 cells and Calu3 cells at submicromolar levels. As a well-characterized FDA-approved orally delivered drug, 6-TG represents a promising therapeutic for COVID-19 and other emerging coronaviruses.

ONE SENTENCE SUMMARY

A repurposed drug that targets an essential enzymatic activity of SARS-CoV-2 represents a promising COVID-19 therapeutic.

Kidney allograft recipients, immunosuppression, and coronavirus disease-2019: a report of consecutive cases from a New York City transplant center

BACKGROUND

Kidney graft recipients receiving immunosuppressive therapy may be at heightened risk for coronavirus disease 2019 (Covid-19) and adverse outcomes. It is therefore important to characterize the clinical course and outcome of Covid-19 in this population and identify safe therapeutic strategies.

METHODS

We performed a retrospective chart review of 73 adult kidney graft recipients evaluated for Covid-19 from 13 March to 20 April 2020. Primary outcomes included recovery from symptoms, acute kidney injury, graft failure and case fatality rate.

RESULTS

Of the 73 patients screened, 54 tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-39 with moderate to severe symptoms requiring hospital admission and 15 with mild symptoms managed in the ambulatory setting. Hospitalized patients were more likely to be male, of Hispanic ethnicity and to have cardiovascular disease. In the hospitalized group, tacrolimus dosage was reduced in 46% of patients and mycophenolate mofetil (MMF) therapy was stopped in 61% of patients. None of the ambulatory patients had tacrolimus reduction or discontinuation of MMF. Azithromycin or doxycycline was prescribed at a similar rate among hospitalized and ambulatory patients (38% versus 40%). Hydroxychloroquine was prescribed in 79% of hospitalized patients. Graft failure requiring hemodialysis occurred in 3 of 39 hospitalized patients (8%) and 7 patients died, resulting in a case fatality rate of 13% among Covid-19-positive patients and 18% among hospitalized Covid-19-positive patients.

CONCLUSIONS

Data from our study suggest that a strategy of systematic triage to outpatient or inpatient care, early management of concurrent bacterial infections and judicious adjustment of immunosuppressive drugs rather than cessation is feasible in kidney transplant recipients with Covid-19.

Risiken und Chancen von Immuntherapien in Zeiten der Coronavirus-2019-Pandemie

Immuntherapien stellen die essenzielle Grundlage der Behandlung von neuroinflammatorischen Erkrankungen dar. In Zeiten der Coronavirus-2019 (COVID-19)-Pandemie ergibt sich im klinischen Alltag jedoch zunehmend die Frage, ob eine Immuntherapie bei neurologischen Patienten aufgrund des potenziellen Infektionsrisikos eingeleitet, intensiviert, pausiert oder gar beendet werden sollte. Unsicherheit besteht v. a. deshalb, weil verschiedene nationale und internationale Fachgesellschaften diesbezüglich unterschiedliche Empfehlungen veröffentlichten. In diesem Artikel soll ein Überblick über die Wirkmechanismen von Immuntherapien und den daraus abzuleitenden Infektionsrisiken in Bezug auf COVID-19 (durch den Coronavirus verursachte Erkrankung) gegeben werden. Potenzielle Chancen und vorteilhafte Effekte einzelner Substrate in der Akuttherapie von COVID-19 werden diskutiert.

Potential therapeutic targets and promising drugs for combating SARS-CoV-2

As of April 9, 2020, a novel coronavirus (SARS-CoV-2) had caused 89,931 deaths and 1,503,900 confirmed cases worldwide, which indicates an increasingly severe and uncontrollable situation. Initially, little was known about the virus. As research continues, we now know the genome structure, epidemiological and clinical characteristics, and pathogenic mechanisms of SARS-CoV-2. Based on this knowledge, potential targets involved in the processes of virus pathogenesis need to be identified, and the discovery or development of drugs based on these potential targets is the most pressing need. Here, we have summarized the potential therapeutic targets involved in virus pathogenesis and discuss the advances, possibilities, and significance of drugs based on these targets for treating SARS-CoV-2. This review will facilitate the identification of potential targets and provide clues for drug development that can be translated into clinical applications for combating SARS-CoV-2.

Review article: prevention, diagnosis and management of COVID-19 in the IBD patient

BACKGROUND

The current COVID-19 pandemic, caused by SARS-CoV-2, has emerged as a public health emergency. All nations are seriously challenged as the virus spreads rapidly across the globe with no regard for borders. The primary management of IBD involves treating uncontrolled inflammation with most patients requiring immune-based therapies. However, these therapies may weaken the immune system and potentially place IBD patients at increased risk of infections and infectious complications including those from COVID-19.

AIM

To summarise the scale of the COVID-19 pandemic, review unique concerns regarding IBD management and infection risk during the pandemic and assess COVID-19 management options and drug interactions in the IBD population.

METHODS

A literature review on IBD, SARS-CoV-2 and COVID-19 was undertaken and relevant literature was summarised and critically examined.

RESULTS

IBD patients do not appear to be more susceptible to SARS-CoV-2 infection and there is no evidence of an association between IBD therapies and increased risk of COVID-19. IBD medication adherence should be encouraged to prevent disease flare but where possible high-dose systemic corticosteroids should be avoided. Patients should exercise social distancing, optimise co-morbidities and be up to date with influenza and pneumococcal vaccines. If a patient develops COVID-19, immune suppressing medications should be withheld until infection resolution and if trial medications for COVID-19 are being considered, potential drug interactions should be checked.

CONCLUSIONS

IBD patient management presents a challenge in the current COVID-19 pandemic. The primary focus should remain on keeping bowel inflammation controlled and encouraging medication adherence.

AGA Clinical Practice Update on Management of Inflammatory Bowel Disease During the COVID-19 Pandemic: Expert Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update was to rapidly review the emerging evidence and provide timely expert recommendations regarding the management of patients with inflammatory bowel disease during the coronavirus disease 2019 pandemic. This expert commentary was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely perspective on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology.

SARS-CoV-2: An Update on Potential Antivirals in Light of SARS-CoV Antiviral Drug Discoveries

Coronaviruses (CoVs) are a group of RNA viruses that are associated with different diseases in animals, birds, and humans. Human CoVs (HCoVs) have long been known to be the causative agents of mild respiratory illnesses. However, two HCoVs associated with severe respiratory diseases are Severe Acute Respiratory Syndrome-CoV (SARS-CoV) and Middle East Respiratory Syndrome-CoV (MERS-CoV). Both viruses resulted in hundreds of deaths after spreading to several countries. Most recently, SARS-CoV-2 has emerged as the third HCoV causing severe respiratory distress syndrome and viral pneumonia (known as COVID-19) in patients from Wuhan, China, in December 2019. Soon after its discovery, SARS-CoV-2 spread to all countries, resulting in millions of cases and thousands of deaths. Since the emergence of SARS-CoV, many research groups have dedicated their resources to discovering effective antivirals that can treat such life-threatening infections. The rapid spread and high fatality rate of SARS-CoV-2 necessitate the quick discovery of effective antivirals to control this outbreak. Since SARS-CoV-2 shares 79% sequence identity with SARS-CoV, several anti-SARS-CoV drugs have shown promise in limiting SARS-CoV-2 replication in vitro and in vivo. In this review, we discuss antivirals described for SARS-CoV and provide an update on therapeutic strategies and antivirals against SARS-CoV-2. The control of the current outbreak will strongly depend on the discovery of effective and safe anti-SARS-CoV-2 drugs.

COVID-19 in pancreas transplant recipients

Coronavirus disease 2019 (COVID‐19) has become a pandemic since first being described in January 2020. Clinical manifestations in non‐transplant patients range from asymptomatic infection to severe pneumonia with acute respiratory distress syndrome, multiorgan system failure, and death. Limited reports in kidney transplant recipients suggest similar characteristics in that population. We report here the first case series of COVID‐19 infection occurring in pancreas transplant recipients.

Chemical-informatics approach to COVID-19 drug discovery: Monte Carlo based QSAR, virtual screening and molecular docking study of some in-house molecules as papain-like protease (PLpro) inhibitors

World Health Organization characterized novel coronavirus disease (COVID-19), caused by severe acute respiratory syndrome (SARS) coronavirus-2 (SARS-CoV-2) as world pandemic. This infection has been spreading alarmingly by causing huge social and economic disruption. In order to response quickly, the inhibitors already designed against different targets of previous human coronavirus infections will be a great starting point for anti-SARS-CoV-2 inhibitors. In this study, our approach integrates different ligand based drug design strategies of some in-house chemicals. The study design was composed of some major aspects: (a) classification QSAR based data mining of diverse SARS-CoV papain-like protease (PLpro) inhibitors, (b) QSAR based virtual screening (VS) to identify in-house molecules that could be effective against putative target SARS-CoV PLpro and (c) finally validation of hits through receptor-ligand interaction analysis. This approach could be used to aid in the process of COVID-19 drug discovery. It will introduce key concepts, set the stage for QSAR based screening of active molecules against putative SARS-CoV-2 PLpro enzyme. Moreover, the QSAR models reported here would be of further use to screen large database. This study will assume that the reader is approaching the field of QSAR and molecular docking based drug discovery against SARS-CoV-2 PLpro with little prior knowledge.

Communicated by Ramaswamy H. Sarma

Covid-19: current knowledge, disease potential, prevention and clinical advances

The top priority of any nation is to lead the nation towards prosperity, progress, and economic growth, confronting several challenges and concerns arisen from global situations. The sudden outbreak of any disease defies the health care systems and economy of nations. COVID-19 is one of the viral diseases which broke out in Wuhan city of China in 2019. COVID-19 outbreak intermittently prevailed all over the world. It exposes the fragility of the established health care systems across the world in spite of comprising modern science and technology. Unfortunately, there is no chemotherapeutic agent in the regimen of antiviral drugs or no vaccine available to curb this infectious disease. As a consequence, this deadly infection has prevailed all over the world. The antiviral drugs used for viral diseases excluding COVID-19 infection are Ramdesvir, Favipiravir, and Ribavarin, and antimalarial agents (Chloroquine & Hydroxychloroquine) are being administered to the patients for redemption of this infection. Fortunately, these existing drugs have been found clinically active and are being used. In this review, we present the current scenario and status of epidemiology, diagnosis, treatment, vaccine development for COVID-19, and its impact on the socio-economic structure.

Overview of lethal human coronaviruses

Coronavirus infections of multiple origins have spread to date worldwide, causing severe respiratory diseases. Seven coronaviruses that infect humans have been identified: HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1, SARS-CoV, MERS-CoV, and SARS-CoV-2. Among them, SARS-CoV and MERS-CoV caused outbreaks in 2002 and 2012, respectively. SARS-CoV-2 (COVID-19) is the most recently discovered. It has created a severe worldwide outbreak beginning in late 2019, leading to date to over 4 million cases globally. Viruses are genetically simple, yet highly diverse. However, the recent outbreaks of SARS-CoV and MERS-CoV, and the ongoing outbreak of SARS-CoV-2, indicate that there remains a long way to go to identify and develop specific therapeutic treatments. Only after gaining a better understanding of their pathogenic mechanisms can we minimize viral pandemics. This paper mainly focuses on SARS-CoV, MERS-CoV, and SARS-CoV-2. Here, recent studies are summarized and reviewed, with a focus on virus-host interactions, vaccine-based and drug-targeted therapies, and the development of new approaches for clinical diagnosis and treatment.

Safety of Drugs During Previous and Current Coronavirus Pandemics: Lessons for Inflammatory Bowel Disease

The coronavirus 2019 [COVID-19] pandemic has posed challenges in the routine care of patients with inflammatory bowel disease [IBD]. One of the key challenges is quantification of the risks of immunosuppressive and biological therapies in IBD patients during the pandemic. The similarities and differences between previous coronavirus outbreaks and the pathobiology of the infections can give useful information in understanding the risks, and perhaps potential beneficial aspects of drugs used in IBD. Although clinical, immunological and pharmacological data from the experience with previous coronavirus outbreaks cannot be automatically translated to predict the safety of IBD therapies during the COVID-19 pandemic, the signals so far from these outbreaks on IBD patients who are on immunomodulators and biologics are reassuring to patients and clinicians alike.