A potential role for integrins in host cell entry by SARS-CoV-2

Improved binding of SARS-CoV-2 Envelope protein to tight junction-associated PALS1 could play a key role in COVID-19 pathogenesis

The Envelope (E) protein of SARS-CoV-2 is the most enigmatic protein among the four structural ones. Most of its current knowledge is based on the direct comparison to the SARS E protein, initially mistakenly undervalued and subsequently proved to be a key factor in the ER-Golgi localization and in tight junction disruption. We compared the genomic sequences of E protein of SARS-CoV-2, SARS-CoV and the closely related genomes of bats and pangolins obtained from the GISAID and GenBank databases. When compared to the known SARS E protein, we observed a significant difference in amino acid sequence in the C-terminal end of SARS-CoV-2 E protein. Subsequently, in silico modelling analyses of E proteins conformation and docking provide evidences of a strengthened binding of SARS-CoV-2 E protein with the tight junction-associated PALS1 protein. Based on our computational evidences and on data related to SARS-CoV, we believe that SARS-CoV-2 E protein interferes more stably with PALS1 leading to an enhanced epithelial barrier disruption, amplifying the inflammatory processes, and promoting tissue remodelling. These findings raise a warning on the underestimated role of the E protein in the pathogenic mechanism and open the route to detailed experimental investigations.

Tumor markers as an entry for SARS-CoV-2 infection?

Coronavirus disease 2019 (COVID‐19), the highly contagious illness caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has spread across the globe, becoming one of the most challenging public health crisis of our times. SARS‐CoV‐2 can cause severe disease associated with multiple organ damage. Cancer patients have a higher risk of SARS‐CoV‐2 infection and death. While the virus uses angiotensin‐converting enzyme 2 (ACE2) as the primary entry receptor, the recent experimental and clinical findings suggest that some tumor markers, including CD147 (basigin), can provide an additional entry for SARS‐CoV‐2 infection through binding to the viral spike (S) protein. In the absence of specific viral drugs, blocking of CD147 might be a way to prevent virus invasion. Identifying other target proteins is of high importance as targeting the alternative receptors for SARS‐CoV‐2 might open up a promising avenue for the treatment of COVID‐19 patients, including those who have cancer.

From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses

Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.

From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses

Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.

Elovanoid-N32 or RvD6-isomer decrease ACE2 and binding of S protein RBD after injury or INFγ in the eye

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that causes coronavirus disease 2019 (COVID-19) has resulted in a pandemic affecting the most vulnerable in society, triggering a public health crisis and economic tall around the world. Effective treatments to mitigate this virus infection are needed. Since the eye is a route of virus entrance, we use an in vivo rat model of corneal inflammation as well as human corneal epithelial cells in culture challenged with IFNγ to study this issue. We explore ways to block the receptor-binding domain (RBD) of SARS-CoV-2 spike (S) protein to angiotensin-converting enzyme 2 (ACE2). Elovanoid (ELV)-N32 or Resolvin D6-isomer (RvD6i), among the lipid mediators studied, consistently decreased the expression of the ACE2 receptor, furin, and integrins in damaged corneas or IFNγ stimulated human corneal epithelial cells (HCEC). There was also a concomitant decrease in the binding of spike RBD with the lipid treatments. Concurrently, we uncovered that the lipid mediators also attenuated the expression of cytokines that participate in the cytokine storm, hyper-inflammation and senescence programming. Thus, the bioactivity of these lipid mediators will contribute to opening therapeutic avenues for COVID-19 by counteracting virus attachment and entrance to the eye and other cells and the ensuing disruptions of homeostasis.

Medicinal Plants as Sources of Active Molecules Against COVID-19

The Severe Acute Respiratory Syndrome-related Coronavirus 2 (SARS-CoV-2) or novel coronavirus (COVID-19) infection has been declared world pandemic causing a worrisome number of deaths, especially among vulnerable citizens, in 209 countries around the world. Although several therapeutic molecules are being tested, no effective vaccines or specific treatments have been developed. Since the COVID-19 outbreak, different traditional herbal medicines with promising results have been used alone or in combination with conventional drugs to treat infected patients. Here, we review the recent findings regarding the use of natural products to prevent or treat COVID-19 infection. Furthermore, the mechanisms responsible for this preventive or therapeutic effect are discussed. We conducted literature research using PubMed, Google Scholar, Scopus, and WHO website. Dissertations and theses were not considered. Only the situation reports edited by the WHO were included. The different herbal products (extracts) and purified molecules may exert their anti-SARS-CoV-2 actions by direct inhibition of the virus replication or entry. Interestingly, some products may block the ACE-2 receptor or the serine protease TMPRRS2 required by SARS-CoV-2 to infect human cells. In addition, natural products were shown to inhibit the SARS-CoV-2 life-cycle related proteins such as papain-like or chymotrypsin-like proteases. In conclusion, we suggest that natural products could be used alone or in combination as alternative medicines to treat/prevent COVID-19 infection. Moreover, their structures may offer clues for the development of anti-SARS-CoV-2 drugs.

SARS-CoV-2 Dissemination Through Peripheral Nerves Explains Multiple Organ Injury

Coronavirus disease (CoVID-19), caused by recently identified severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2), is characterized by inconsistent clinical presentations. While many infected individuals remain asymptomatic or show mild respiratory symptoms, others develop severe pneumonia or even respiratory distress syndrome. SARS-CoV-2 is reported to be able to infect the lungs, the intestines, blood vessels, the bile ducts, the conjunctiva, macrophages, T lymphocytes, the heart, liver, kidneys, and brain. More than a third of cases displayed neurological involvement, and many severely ill patients developed multiple organ infection and injury. However, less than 1% of patients had a detectable level of SARS-CoV-2 in the blood, raising a question of how the virus spreads throughout the body. We propose that nerve terminals in the orofacial mucosa, eyes, and olfactory neuroepithelium act as entry points for the brain invasion, allowing SARS-CoV-2 to infect the brainstem. By exploiting the subcellular membrane compartments of infected cells, a feature common to all coronaviruses, SARS-CoV-2 is capable to disseminate from the brain to periphery via vesicular axonal transport and passive diffusion through axonal endoplasmic reticula, causing multiple organ injury independently of an underlying respiratory infection. The proposed model clarifies a wide range of clinically observed phenomena in CoVID-19 patients, such as neurological symptoms unassociated with lung pathology, protracted presence of the virus in samples obtained from recovered patients, exaggerated immune response, and multiple organ failure in severe cases with variable course and dynamics of the disease. We believe that this model can provide novel insights into CoVID-19 and its long-term sequelae, and establish a framework for further research.

COVID-19: The Immune Responses and Clinical Therapy Candidates

The pandemic of coronavirus disease 2019 (COVID-19), with rising numbers of patients worldwide, presents an urgent need for effective treatments. To date, there are no therapies or vaccines that are proven to be effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several potential candidates or repurposed drugs are under investigation, including drugs that inhibit SARS-CoV-2 replication and block infection. The most promising therapy to date is remdesivir, which is US Food and Drug Administration (FDA) approved for emergency use in adults and children hospitalized with severe suspected or laboratory-confirmed COVID-19. Herein we summarize the general features of SARS-CoV-2's molecular and immune pathogenesis and discuss available pharmacological strategies, based on our present understanding of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Finally, we outline clinical trials currently in progress to investigate the efficacy of potential therapies for COVID-19.

Coronaviruses and Integrin αvβ3: Does Thyroid Hormone Modify the Relationship?

BACKGROUND

Uptake of coronaviruses by target cells involves binding of the virus by cell ectoenzymes. For the etiologic agent of COVID-19 (SARS-CoV-2), a receptor has been identified as angiotensin-converting enzyme-2 (ACE2). Recently it has been suggested that plasma membrane integrins may be involved in the internalization and replication of clinically important coronaviruses. For example, integrin αvβ3 is involved in the cell uptake of a model porcine enteric α-coronavirus that causes human epidemics. ACE2 modulates the intracellular signaling generated by integrins.

OBJECTIVE

We propose that the cellular internalization of αvβ3 applies to uptake of coronaviruses bound to the integrin, and we evaluate the possibility that clinical host T4 may contribute to target cell uptake of coronavirus and to the consequence of cell uptake of the virus.

DISCUSSION AND CONCLUSIONS

The viral binding domain of the integrin is near the Arg-Gly-Asp (RGD) peptide-binding site and RGD molecules can affect virus binding. In this same locale on integrin αvβ3 is the receptor for thyroid hormone analogues, particularly, L-thyroxine (T4). By binding to the integrin, T4 has been shown to modulate the affinity of the integrin for other proteins, to control internalization of αvβ3 and to regulate the expression of a panel of cytokine genes, some of which are components of the 'cytokine storm' of viral infections. If T4 does influence coronavirus uptake by target cells, other thyroid hormone analogues, such as deaminated T4 and deaminated 3,5,3'-triiodo-L-thyronine (T3), are candidate agents to block the virus-relevant actions of T4 at integrin αvβ3 and possibly restrict virus uptake.

Analysis of the molecular mechanism of Pudilan (PDL) treatment for COVID-19 by network pharmacology tools

BACKGROUND

Pudilan (PDL), a four-herb prescription with the traditional function of heat-clearing and detoxifying, has been clinically used as an anti-SARS-CoV-2 infectory agent in China. PDL might also have therapeutic potentials for COVID-19 while the underlying mechanisms remain to be clarified.

METHODS

We used network pharmacology analysis and selected 68 co-targeted genes/proteins as targets of both PDL and COVID-19. These co-targeted genes/proteins were predicted by SwissDock Server for their high-precision docking simulation, and analyzed by STRING for proteins to protein interaction (PPI), pathway and GO (gene ontology) enrichment. The therapeutic effect for PDL treatment on COVID-19 was validated by the TCMATCOV (TCM Anti COVID-19) platform.

RESULTS

PDL might prevent the entrance of SARS-CoV-2 entry into cells by blocking the angiotensin-converting enzyme 2 (ACE2). It might inhibit the cytokine storm by affecting C-reactive protein (CRP), interferon-γ (IFN-γ), interleukin- 6 (IL-6), interleukin- 10 (IL-10), tumor necrosis factor (TNF), epidermal growth factor receptor (EGFR), C-C motif chemokine ligand 5 (CCL5), transforming growth factor-β1 (TGFβ1), and other proteins. PDL might moderate the immune system to shorten the course of the disease, delay disease progression, and reduce the mortality rate.

CONCLUSION

PDL might have a therapeutic effect on COVID-19 through three aspects, including the moderate immune system, anti-inflammation, and anti-virus entry into cells.

Drug Discovery Strategies for SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is a novel disease caused by the severe acute respiratory syndrome coronavirus (SARS-CoV)-2 virus that was first detected in December of 2019 in Wuhan, China, and has rapidly spread worldwide. The search for a suitable vaccine as well as effective therapeutics for the treatment of COVID-19 is underway. Drug repurposing screens provide a useful and effective solution for identifying potential therapeutics against SARS-CoV-2. For example, the experimental drug remdesivir, originally developed for Ebola virus infections, has been approved by the US Food and Drug Administration as an emergency use treatment of COVID-19. However, the efficacy and toxicity of this drug need further improvements. In this review, we discuss recent findings on the pathology of coronaviruses and the drug targets for the treatment of COVID-19. Both SARS-CoV-2–specific inhibitors and broad-spectrum anticoronavirus drugs against SARS-CoV, Middle East respiratory syndrome coronavirus, and SARS-CoV-2 will be valuable additions to the anti–SARS-CoV-2 armament. A multitarget treatment approach with synergistic drug combinations containing different mechanisms of action may be a practical therapeutic strategy for the treatment of severe COVID-19.

The Integrin Binding Peptide, ATN-161, as a Novel Therapy for SARS-CoV-2 Infection

Many efforts to design and screen therapeutics for severe acute respiratory syndrome coronavirus (SARS-CoV-2) have focused on inhibiting viral cell entry by disrupting ACE2 binding with the SARS-CoV-2 spike protein. This work focuses on inhibiting SARS-CoV-2 entry through a hypothesized α5β1 integrin-based mechanism, and indicates that inhibiting the spike protein interaction with α5β1 integrin (+/- ACE2), and the interaction between α5β1 integrin and ACE2 using a molecule ATN-161 represents a promising approach to treat COVID-19.

Comparison of Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein Binding to ACE2 Receptors from Human, Pets, Farm Animals, and Putative Intermediate Hosts

The emergence of a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulted in a pandemic. Here, we used X-ray structures of human ACE2 bound to the receptor-binding domain (RBD) of the spike protein (S) from SARS-CoV-2 to predict its binding to ACE2 proteins from different animals, including pets, farm animals, and putative intermediate hosts of SARS-CoV-2. Comparing the interaction sites of ACE2 proteins known to serve or not serve as receptors allows the definition of residues important for binding. From the 20 amino acids in ACE2 that contact S, up to 7 can be replaced and ACE2 can still function as the SARS-CoV-2 receptor. These variable amino acids are clustered at certain positions, mostly at the periphery of the binding site, while changes of the invariable residues prevent S binding or infection of the respective animal. Some ACE2 proteins even tolerate the loss or acquisition of N-glycosylation sites located near the S interface. Of note, pigs and dogs, which are not infected or are not effectively infected and have only a few changes in the binding site, exhibit relatively low levels of ACE2 in the respiratory tract. Comparison of the RBD of S of SARS-CoV-2 with that from bat coronavirus strain RaTG13 (Bat-CoV-RaTG13) and pangolin coronavirus (Pangolin-CoV) strain hCoV-19/pangolin/Guangdong/1/2019 revealed that the latter contains only one substitution, whereas Bat-CoV-RaTG13 exhibits five. However, ACE2 of pangolin exhibits seven changes relative to human ACE2, and a similar number of substitutions is present in ACE2 of bats, raccoon dogs, and civets, suggesting that SARS-CoV-2 may not be especially adapted to ACE2 of any of its putative intermediate hosts. These analyses provide new insight into the receptor usage and animal source/origin of SARS-CoV-2.IMPORTANCE SARS-CoV-2 is threatening people worldwide, and there are no drugs or vaccines available to mitigate its spread. The origin of the virus is still unclear, and whether pets and livestock can be infected and transmit SARS-CoV-2 are important and unknown scientific questions. Effective binding to the host receptor ACE2 is the first prerequisite for infection of cells and determines the host range. Our analysis provides a framework for the prediction of potential hosts of SARS-CoV-2. We found that ACE2 from species known to support SARS-CoV-2 infection tolerate many amino acid changes, indicating that the species barrier might be low. Exceptions are dogs and especially pigs, which revealed relatively low ACE2 expression levels in the respiratory tract. Monitoring of animals is necessary to prevent the generation of a new coronavirus reservoir. Finally, our analysis also showed that SARS-CoV-2 may not be specifically adapted to any of its putative intermediate hosts.

Neurological immunotherapy in the era of COVID-19 - looking for consensus in the literature

The coronavirus disease 2019 (COVID-19) pandemic is concerning for patients with neuroimmunological diseases who are receiving immunotherapy. Uncertainty remains about whether immunotherapies increase the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or increase the risk of severe disease and death upon infection. National and international societies have developed guidelines and statements, but consensus does not exist in several areas. In this Review, we attempt to clarify where consensus exists and where uncertainty remains to inform management approaches based on the first principles of neuroimmunology. We identified key questions that have been addressed in the literature and collated the recommendations to generate a consensus calculation in a Delphi-like approach to summarize the information. We summarize the international recommendations, discuss them in light of the first available data from patients with COVID-19 receiving immunotherapy and provide an overview of management approaches in the COVID-19 era. We stress the principles of medicine in general and neuroimmunology in particular because, although the risk of viral infection has become more relevant, most of the considerations apply to the general management of neurological immunotherapy. We also give special consideration to immunosuppressive treatment and cell-depleting therapies that might increase susceptibility to SARS-CoV-2 infection but reduce the risk of severe COVID-19.

In this Review, the authors synthesize recommendations on the management of neuroimmunological disease in the context of the COVID-19 pandemic. They consider these recommendations alongside the first available data from patients, and provide an overview of management approaches in the COVID-19 era.

The risk that the coronavirus disease 2019 (COVID-19) pandemic poses for people who are receiving immunotherapy for neuroimmunological disease remains unclear.

Guidelines and statements have been published by societies and individuals, but the level of consensus differs for different aspects; we use a Delphi-like process to clarify where consensus exists.

Without evidence, management of neuroimmunological diseases in the context of COVID-19 requires application of the first principles of immunotherapy, taking into account disease-related, patient-related, physician-related, environment-related and COVID-19-related factors.

In general, corticosteroids, intravenous immunoglobulin and/or plasma exchange for the treatment of acute neuroimmunological deteriorations can be administered with low risk in the COVID-19 pandemic.

In general, ongoing immunotherapy should not be stopped because of the COVID-19 pandemic; treatment initiation and optimization are also recommended.

For some aspects of immunotherapy in the context of COVID-19, consensus in the literature is low, and collection of data in patient registries is important for resolving these uncertainties.

Narrative review of the immune response against coronavirus: An overview, applicability for SARS-COV-2, and therapeutic implications

The new coronavirus (SARS-CoV-2) that causes a severe acute respiratory syndrome emerges in Wuhan, China, in December 2019. It produces the aforementioned disease due to coronavirus 2019 (COVID-19), and has led to a declaration of a world public health emergency by the World Health Organisation. This new SARS-CoV-2 virus could share characteristics and an immune response similar to those described for other coronavirus. Given its activity on the interferon pathway, and the manner in which it dysregulates innate immunity, the use of treatments directed at modulating or containing this could be of interest. A narrative review was made of the current evidence about immunity against coronavirus and its applicability to SARS-CoV-2. The physiopathogenesis is also described, along with the underlying leucocyte activity, with the intention of clarifying the possible usefulness of inflammatory biomarkers and the development of personalised treatments.

Ivermectin, antiviral properties and COVID-19: a possible new mechanism of action

Ivermectin is an antiparasitic drug that has shown also an effective pharmacological activity towards various infective agents, including viruses. This paper proposes an alternative mechanism of action for this drug that makes it capable of having an antiviral action, also against the novel coronavirus, in addition to the processes already reported in literature.

Is SARS-CoV-2 Also an Enteric Pathogen With Potential Fecal-Oral Transmission? A COVID-19 Virological and Clinical Review

In as few as 3 months, coronavirus disease 2019 (COVID-19) has spread and ravaged the world at an unprecedented speed in modern history, rivaling the 1918 flu pandemic. Severe acute respiratory syndrome coronavirus-2, the culprit virus, is highly contagious and stable in the environment and transmits predominantly among humans via the respiratory route. Accumulating evidence suggest that this virus, like many of its related viruses, may also be an enteric virus that can spread via the fecal-oral route. Such a hypothesis would also contribute to the rapidity and proliferation of this pandemic. Here we briefly summarize what is known about this family of viruses and literature basis of the hypothesis that severe acute respiratory syndrome coronavirus-2 is capable of infecting the gastrointestinal tract and shedding in the environment for potential human-to-human transmission.

[Narrative review of the immune response against coronavirus: An overview, applicability for SARS-COV-2, and therapeutic implications]

The new coronavirus (SARS-CoV-2) that causes a severe acute respiratory syndrome emerges in Wuhan, China, in December 2019. It produces the aforementioned disease due to coronavirus 2019 (COVID-19), and has led to a declaration of a world public health emergency by the World Health Organisation. This new SARS-CoV-2 virus could share characteristics and an immune response similar to those described for other coronavirus. Given its activity on the interferon pathway, and the manner in which it dysregulates innate immunity, the use of treatments directed at modulating or containing this could be of interest. A narrative review was made of the current evidence about immunity against coronavirus and its applicability to SARS-CoV-2. The physiopathogenesis is also described, along with the underlying leucocyte activity, with the intention of clarifying the possible usefulness of inflammatory biomarkers and the development of personalised treatments.

Dynamic Regulation of SARS-Cov-2 Binding and Cell Entry Mechanisms in Remodeled Human Ventricular Myocardium

Using serial analysis of myocardial gene expression employing endomyocardial biopsy starting material in a dilated cardiomyopathy cohort, we show that mRNA expression of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) cardiac myocyte receptor ACE2 is up-regulated with remodeling and with reverse remodeling down-regulates into the normal range. The proteases responsible for virus-cell membrane fusion were expressed but not regulated with remodeling. In addition, a new candidate for SARS-CoV-2 cell binding and entry was identified, the integrin encoded by ITGA5. Up-regulation in ACE2 in remodeled left ventricles may explain worse outcomes in patients with coronavirus disease 2019 who have underlying myocardial disorders, and counteracting ACE2 up-regulation is a possible therapeutic approach to minimizing cardiac damage.

The pressing questions in multiple sclerosis Care in the era of COVID-19

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MS patients should continue their disease modifying therapy during the pandemic.

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Newly diagnosed patients should start disease modifying therapy without delay.

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The effect on COVID-19 infection and future vaccination should be considered.

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Agents that cause prolonged non-selective lymphopenia are not preferred.

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Only severe relapses should be treated preferably with oral steroids at home.

Characterization of the SARS-CoV-2 S Protein: Biophysical, Biochemical, Structural, and Antigenic Analysis

Coronavirus disease 2019 ( COVID-19 ) is a global health crisis caused by the novel severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), and there is a critical need to produce large quantities of high-quality SARS-CoV-2 Spike ( S ) protein for use in both clinical and basic science settings. To address this need, we have evaluated the expression and purification of two previously reported S protein constructs in Expi293F ™ and ExpiCHO-S ™ cells, two different cell lines selected for increased expression of secreted glycoproteins. We show that ExpiCHO-S ™ cells produce enhanced yields of both SARS-CoV-2 S proteins. Biochemical, biophysical, and structural ( cryo-EM ) characterization of the SARS-CoV-2 S proteins produced in both cell lines demonstrate that the reported purification strategy yields high quality S protein (non-aggregated, uniform material with appropriate biochemical and biophysical properties). Importantly, we show that multiple preparations of these two recombinant S proteins from either cell line exhibit identical behavior in two different serology assays. We also evaluate the specificity of S protein-mediated host cell binding by examining interactions with proposed binding partners in the human secretome. In addition, the antigenicity of these proteins is demonstrated by standard ELISAs, and in a flexible protein microarray format. Collectively, we establish an array of metrics for ensuring the production of high-quality S protein to support clinical, biological, biochemical, structural and mechanistic studies to combat the global pandemic caused by SARS-CoV-2.

αvβ8 integrin adhesion and signaling pathways in development, physiology and disease

Cells must interpret a complex milieu of extracellular cues to modulate intracellular signaling events linked to proliferation, differentiation, migration and other cellular processes. Integrins are heterodimeric transmembrane proteins that link the extracellular matrix (ECM) to the cytoskeleton and control intracellular signaling events. A great deal is known about the structural and functional properties for most integrins; however, the adhesion and signaling pathways controlled by αvβ8 integrin, which was discovered nearly 30 years ago, have only recently been characterized. αvβ8 integrin is a receptor for ECM-bound forms of latent transforming growth factor β (TGFβ) proteins and promotes the activation of TGFβ signaling pathways. Studies of the brain, lung and immune system reveal that the αvβ8 integrin-TGFβ axis mediates cell-cell contact and communication within complex multicellular structures. Perturbing components of this axis results in aberrant cell-cell adhesion and signaling leading to the initiation of various pathologies, including neurodegeneration, fibrosis and cancer. As discussed in this Review, understanding the functions for αvβ8 integrin, its ECM ligands and intracellular effector proteins is not only an important topic in cell biology, but may lead to new therapeutic strategies to treat human pathologies related to integrin dysfunction.

Covid-19 in a patient with multiple sclerosis treated with natalizumab: May the blockade of integrins have a protective role?

The disease caused by the new coronavirus SARS-CoV-2 (COVID-19) is currently spread worldwide .

Recent data supports SARS-CoV-2 may use integrins to enter human cells. Therefore, anti-integrins therapies might be an alternative against the infection .

Natalizumab, approved for Multiple Sclerosis (MS) treatment, acts blocking α4-integrin.

We report a MS patient treated with natalizumab who develops COVID-19, with excellent recovery and repeated negative results in 5 consecutive microbiological studies. We postulate this may be due to the blockade of integrins induced by natalizumab.

Empirical Treatment and Prevention of COVID-19

The rapid spread of severe acute respiratory coronavirus syndrome 2 (SARS-CoV-2) in the population and throughout the cells within our body has been developing. Another major cycle of coronavirus disease 2019 (COVID-19), which is expected in the coming fall, could be even more severe than the current one. Therefore, effective countermeasures should be developed based on the already obtained clinical and research information about SARS-CoV-2. The aim of this review was to summarize the data on the empirical treatment of COVID-19 acquired during this SARS-CoV-2 infection cycle; this would aid the establishment of an appropriate healthcare policy to meet the challenges in the future. The infectious disease caused by SARS-CoV-2 is characterized by common cold along with hypersensitivity reaction. Thus, in addition to treating common cold, it is essential to minimize the exposure of cells to the virus and to mitigate the uncontrolled immune response. A proper combination of antiviral agents, immune modulators such as prednisolone, and anticoagulants such as heparin and anti-C5a antagonists could be employed to minimize lung damage and prevent systemic involvements. Finally, strategies to achieve population immunity against SARS-CoV-2 should be developed through understanding of the interaction between the immune system and the virus.

COVID-19: Review of a 21st Century Pandemic from Etiology to Neuro-psychiatric Implications

COVID-19 is a severe infectious disease that has claimed >150,000 lives and infected millions in the United States thus far, especially the elderly population. Emerging evidence has shown the virus to cause hemorrhagic and immunologic responses, which impact all organs, including lungs, kidneys, and the brain, as well as extremities. SARS-CoV-2 also affects patients', families', and society's mental health at large. There is growing evidence of re-infection in some patients. The goal of this paper is to provide a comprehensive review of SARS-CoV-2-induced disease, its mechanism of infection, diagnostics, therapeutics, and treatment strategies, while also focusing on less attended aspects by previous studies, including nutritional support, psychological, and rehabilitation of the pandemic and its management. We performed a systematic review of >1,000 articles and included 425 references from online databases, including, PubMed, Google Scholar, and California Baptist University's library. COVID-19 patients go through acute respiratory distress syndrome, cytokine storm, acute hypercoagulable state, and autonomic dysfunction, which must be managed by a multidisciplinary team including nursing, nutrition, and rehabilitation. The elderly population and those who are suffering from Alzheimer's disease and dementia related illnesses seem to be at the higher risk. There are 28 vaccines under development, and new treatment strategies/protocols are being investigated. The future management for COVID-19 should include B-cell and T-cell immunotherapy in combination with emerging prophylaxis. The mental health and illness aspect of COVID-19 are among the most important side effects of this pandemic which requires a national plan for prevention, diagnosis and treatment.

Multiple Sclerosis Disease-Modifying Therapy and the COVID-19 Pandemic: Implications on the Risk of Infection and Future Vaccination

The coronavirus 2019 (COVID-19) pandemic is expected to linger. Decisions regarding initiation or continuation of disease-modifying therapy for multiple sclerosis have to consider the potential relevance to the pandemic. Understanding the mechanism of action and the possible idiosyncratic effects of each therapeutic agent on the immune system is imperative during this special time. The infectious side-effect profile as well as the route and frequency of administration of each therapeutic agent should be carefully considered when selecting a new treatment or deciding on risk mitigation strategies for existing therapy. More importantly, the impact of each agent on the future severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2) vaccine should be carefully considered in treatment decisions. Moreover, some multiple sclerosis therapies may have beneficial antiviral effects against SARS-CoV-2 while others may have beneficial immune-modulating effects against the cytokine storm and hyperinflammatory phase of the disease. Conventional injectables have a favorable immune profile without an increased exposure risk and therefore may be suitable for mild multiple sclerosis during the pandemic. However, moderate and highly active multiple sclerosis will continue to require treatment with oral or intravenous high-potency agents but a number of risk mitigation strategies may have to be implemented. Immune-modulating therapies such as the fumerates, sphinogosine-1P modulators, and natalizumab may be anecdotally preferred over cell-depleting immunosuppressants during the pandemic from the immune profile standpoint. Within the cell-depleting agents, selective (ocrelizumab) or preferential (cladribine) depletion of B cells may be relatively safer than non-selective depletion of lymphocytes and innate immune cells (alemtuzumab). Patients who develop severe iatrogenic or idiosyncratic lymphopenia should be advised to maintain social distancing even in areas where lockdown has been removed or ameliorated. Patients with iatrogenic hypogammaglobulinemia may require prophylactic intravenous immunoglobulin therapy in certain situations. When the future SARS-CoV-2 vaccine becomes available, patients with multiple sclerosis should be advised that certain therapies may interfere with mounting a protective immune response to the vaccine and that serological confirmation of a response may be required after vaccination. They should also be aware that most multiple sclerosis therapies are incompatible with live vaccines if a live SARS-CoV-2 vaccine is developed. In this article, we review and compare disease-modifying therapies in terms of their effect on the immune system, published infection rates, potential impact on SARS-CoV-2 susceptibility, and vaccine-related implications. We propose risk mitigation strategies and practical approaches to disease-modifying therapy during the COVID-19 pandemic.

Genomics insights of SARS-CoV-2 (COVID-19) into target-based drug discovery

Coronavirus disease (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 is a global health emergency and no clinically approved vaccines or antiviral drugs available to date. Intensive research on SARS-CoV-2 is urgently warranted to understand its pathogenesis and virulence mechanisms and to discover target-based antiviral therapeutics. Among various research logics, current bioinformatics highlights novel testable hypotheses for systematic drug repositioning and designing against COVID-19. A total of 121 articles related to bioinformatics facets of this virus were collected from the PubMed Central. The content of each investigation was comprehensively reviewed, manually curated, and included herein. Interestingly, 109 COVID-19-related literature published in 2020 (January-June) were included in this review. The present article emphasizes novel resource development on its genome structure, evolution, therapeutic targets, drug designing, and drug repurposing strategies. Genome organization, the function of coding genes, origin, and evolution of SARS-CoV-2 is described in detail. Genomic insights into understanding the structure-function relationships of drug targets including spike, main protease, and RNA-dependent RNA polymerase of SARS-CoV-2 are discussed intensively. Several molecular docking and systems pharmacology approaches have been investigated some promising antiviral drugs against SARS-CoV-2 based on its genomic characteristics, pathogenesis mechanism, and host specificity. Perhaps, the present genomic insights of this virus will provide a lead to the researchers to design or repurpose of antiviral drugs soon and future directions to control the spread of COVID-19.