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The SARS-CoV-2 pandemic has confirmed that the ability to rapidly mutate may be extremely beneficial for a virus. Not long after the first wave, new variants emerged with altered infectivity, disease severity, and mortality. These new strains most notably had numerous mutations of the spike (S) protein, a surface protein responsible for binding to and entering the host cell. The Delta and Omicron strains demonstrated increased immune evasion and improved binding affinity to the host cell receptor, angiotensin-converting enzyme 2 (ACE2). This study examines the ability of wild-type SARS-CoV-2 IgG to bind Delta and Omicron antigens, as well as their functional binding capabilities to two different S-ACE2 complexes. Twenty SARS-CoV-2 positive samples from patients who had recovered from infection with ancestral SARS-CoV-2 in the first wave of COVID-19 and 10 pre-pandemic control samples were studied. SARS-CoV-2 exposed patients showed significantly higher levels of IgG to SARS-CoV-2 S1/RBD (p < 0.001), N protein (p < 0.001), and Omicron spike variant (p = 0.01), but not to Delta spike variant (p = 0.966) when compared with controls. Furthermore, patient samples showed significantly greater inhibition of SARS-CoV-2 S1/RBD and E484K spike to ACE2 binding (p < 0.001 and p = 0.015, respectively). Conversely, there was no correlation between the binding inhibition of S1/RBD and E484K spike to ACE2 receptor. This study shows there is considerable cross-reactivity of IgG generated by wild-type SARS-CoV-2 infection to the Delta and Omicron variants.
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Background The COVID-19 pandemic has had a profound impact on global healthcare systems, often compared to seasonal influenza due to similarities in clinical presentation. This study aims to compare the clinical characteristics, comorbidities, and outcomes of critically ill patients with COVID-19 and those with influenza admitted to a tertiary care hospital in Islamabad, Pakistan. Methods This retrospective cohort study included 120 patients, 60 with confirmed COVID-19 and 60 with confirmed influenza, all of whom required ICU admission and mechanical ventilation between January 1, 2021, and January 1, 2024. Data were collected from electronic medical records, including demographic information, comorbidities, and clinical outcomes. Descriptive statistics were used to compare the two groups. Results The median age of COVID-19 patients was 55 years (range 30-78), while that of influenza patients was 58 years (range 31-80). Both groups had a slight male predominance (COVID-19: 66.7%, Influenza: 63.3%). Comorbidities were common in both groups, with 75.0% of COVID-19 patients and 83.3% of influenza patients having at least one comorbidity. The most common comorbidities included hypertension (COVID-19: 30.0%, Influenza: 33.3%) and diabetes (COVID-19: 20.0%, Influenza: 25.0%). Clinical outcomes revealed a higher mortality rate among influenza patients (43.3%) compared to COVID-19 patients (28.3%). ICU admission rates were identical for both groups at 66.7%, and mechanical ventilation was required for 66.7% of ICU-admitted patients in both groups. The presence of cardiovascular comorbidities significantly impacted patient outcomes, with higher mortality observed in influenza patients with such comorbidities (44.7%) compared to COVID-19 patients (28.9%). Conclusion This study highlights the significant burden of both COVID-19 and influenza on critically ill patients, particularly those with cardiovascular comorbidities. While influenza patients in this cohort exhibited higher mortality rates, both groups demonstrated substantial ICU admission rates and a need for mechanical ventilation.
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Epigenetic changes have long-lasting impacts, which influence the epigenome and are maintained during cell division. Thus, human genome changes have required a very long timescale to become a major contributor to the current obesity pandemic. Whereas bidirectional effects of coronavirus disease 2019 (COVID-19) and obesity pandemics have given the opportunity to explore, how the viral microribonucleic acids (miRNAs) use the human's transcriptional machinery that regulate gene expression at a posttranscriptional level. Obesity and its related comorbidity, type 2 diabetes (T2D), and new-onset diabetes due to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) are additional risk factors, which increase the severity of COVID-19 and its related mortality. The higher mortality rate of these patients is dependent on severe cytokine storm, which is the sum of the additional cytokine production by concomitant comorbidities and own cytokine synthesis of COVID-19. Patients with obesity facilitate the SARS-CoV-2 entry to host cell via increasing the host's cell receptor expression and modifying the host cell proteases. After entering the host cells, the SARS-CoV-2 genome directly functions as a messenger ribonucleic acid (mRNA) and encodes a set of nonstructural proteins via processing by the own proteases, main protease (Mpro), and papain-like protease (PLpro) to initiate viral genome replication and transcription. Following viral invasion, SARS-CoV-2 infection reduces insulin secretion via either inducing ß-cell apoptosis or reducing intensity of angiotensin-converting enzyme 2 (ACE2) receptors and leads to new-onset diabetes. Since both T2D and severity of COVID-19 are associated with the increased serum levels of pro-inflammatory cytokines, high glucose levels in T2D aggravate SARS-CoV-2 infection. Elevated neopterin (NPT) value due to persistent interferon gamma (IFN-γ)-mediated monocyte-macrophage activation is an indicator of hyperactivated pro-inflammatory phenotype M1 macrophages. Thus, NPT could be a reliable biomarker for the simultaneously occurring COVID-19-, obesity- and T2D-induced cytokine storm. While host miRNAs attack viral RNAs, viral miRNAs target host transcripts. Eventually, the expression rate and type of miRNAs also are different in COVID-19 patients with different viral loads. It is concluded that specific miRNA signatures in macrophage activation phase may provide an opportunity to become aware of the severity of COVID-19 in patients with obesity and obesity-related T2D.
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COVID-19 , Síndrome de Activación Macrofágica , Obesidad , SARS-CoV-2 , Humanos , COVID-19/virología , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/complicaciones , Obesidad/complicaciones , Obesidad/metabolismo , Obesidad/epidemiología , Obesidad/virología , SARS-CoV-2/fisiología , SARS-CoV-2/patogenicidad , Síndrome de Activación Macrofágica/virología , Síndrome de Activación Macrofágica/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/virología , Diabetes Mellitus Tipo 2/metabolismo , Pandemias , MicroARNs/genética , MicroARNs/metabolismo , Citocinas/metabolismo , Síndrome de Liberación de Citoquinas/inmunología , Síndrome de Liberación de Citoquinas/virologíaRESUMEN
Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.
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Anosmia , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/metabolismo , COVID-19/complicaciones , COVID-19/fisiopatología , COVID-19/virología , Anosmia/fisiopatología , Anosmia/etiología , Anosmia/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Mucosa Olfatoria/metabolismo , Mucosa Olfatoria/virología , Transducción de Señal , Serina Endopeptidasas/metabolismo , Neuropilina-1/metabolismo , Basigina/metabolismo , Canales Catiónicos TRPV/metabolismoRESUMEN
The COVID-19 pandemic response has been hindered by the absence of an efficient antiviral therapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The reason why the previous preventative approach to COVID-19 solely through vaccines has failed could be a lack of understanding of how quickly the SARS-CoV-2 virus evolves. Given the absence of specific treatments for the virus, efforts have been underway to explore treatment options. Drug repurposing involves identifying new therapeutic uses for approved drugs, proving to be a time-saving strategy with minimal risk of failure. In this study, we report the successful use of a multidrug approach in patients with COVID-19. Successful administration of multidrug therapy, such as combinations of hydroxychloroquine and azithromycin, doxycycline and ivermectin, or ivermectin, doxycycline, and azithromycin, has been reported. Multidrug therapy is effective because of the differing mechanisms of action of these drugs, and it may also mitigate the emergence of drug-resistant SARS-CoV-2 strains. The medicines were lopinavir/ritonavir (Kaletra), bamlanivimab (monoclonal antibody), glycopyrrolate-formoterol (Bevespi), ciclesonide (Alvesco), famotidine (Pepcid), and diphenhydramine (Benadryl).
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Antivirales , Azitromicina , Tratamiento Farmacológico de COVID-19 , COVID-19 , Reposicionamiento de Medicamentos , Hidroxicloroquina , Ivermectina , Lopinavir , Ritonavir , SARS-CoV-2 , Humanos , Antivirales/uso terapéutico , SARS-CoV-2/efectos de los fármacos , Hidroxicloroquina/uso terapéutico , Ivermectina/uso terapéutico , Ritonavir/uso terapéutico , Azitromicina/uso terapéutico , Lopinavir/uso terapéutico , Masculino , Quimioterapia Combinada , Doxiciclina/uso terapéutico , Combinación de Medicamentos , Persona de Mediana Edad , Femenino , Anticuerpos Monoclonales Humanizados/uso terapéutico , Resultado del Tratamiento , Anciano , Pregnenodionas/uso terapéuticoRESUMEN
At the beginning of the 2019 coronavirus disease (COVID-19) pandemic, airway allergic diseases such as asthma and allergic rhinitis (AR) were considered as risk factors for COVID-19, as they would aggravate symptoms. With further research, more and more literature has shown that airway allergic disease may not be a high-risk factor, but may be a protective factor for COVID-19 infection, which is closely related to its low-level expression of the ACE2 receptor and the complex cytokines network as underlying molecular regulatory mechanisms. In addition, steroid hormones and age factors could not be ignored. In this review, we have summarized some current evidence on the relationship between COVID-19 and allergic rhinitis to highlight the underlying mechanisms of COVID-19 infection and provide novel insights for its prevention and treatment. The key findings show that allergic rhinitis and its related molecular mechanisms may have a protective effect against COVID-19 infection.
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The emergence of SARS-CoV-2 in 2019 and its rapid spread throughout the world has caused the largest pandemic of our modern era. The zoonotic origin of this pathogen highlights the importance of the One Health concept and the need for a coordinated response to this kind of threats. Since its emergence, the virus has caused >7 million deaths worldwide. However, the animal source for human outbreaks remains unknown. The ability of the virus to jump between hosts is facilitated by the presence of the virus receptor, the highly conserved angiotensin-converting enzyme 2 (ACE2), found in various mammals. Positivity for SARS-CoV-2 has been reported in various species, including domestic animals and livestock, but their potential role in bridging viral transmission to humans is still unknown. Additionally, the virus has evolved over the pandemic, resulting in variants with different impacts on human health. Therefore, suitable animal models are crucial to evaluate the susceptibility of different mammalian species to this pathogen and the adaptability of different variants. In this work, we established a transgenic mouse model that expresses the feline ACE2 protein receptor (cACE2) under the human cytokeratin 18 (K18) gene promoter's control, enabling high expression in epithelial cells, which the virus targets. Using this model, we assessed the susceptibility, pathogenicity, and transmission of SARS-CoV-2 variants. Our results show that the sole expression of the cACE2 receptor in these mice makes them susceptible to SARS-CoV-2 variants from the initial pandemic wave but does not enhance susceptibility to omicron variants. Furthermore, we demonstrated efficient contact transmission of SARS-CoV-2 between transgenic mice that express either the feline or the human ACE2 receptor.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic, uses the surface angiotensin-converting enzyme 2 (ACE2) receptor as the site of entry into host cardiac, respiratory, intestinal, renal, and nervous system cells. Predisposing risk factors such as cardiovascular disease increase the risk of developing severe disease. Hypertension is characterized by the stimulation of the renin-angiotensin-aldosterone system (RAAS). Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin 2 receptor blockers (ARBs), medications used to treat hypertension, inhibit RAAS and its downstream effects; however, they have also been shown to upregulate ACE2 receptors. In this review, we aim to evaluate the effectiveness of ACEi/ARBs as an adjunct therapy in patients with SARS-CoV-2 as well as examine the possible protective effects and impact on infection rate and disease severity. A PubMed literature search excluding sources outside the United States and duplicates was performed using the following search criteria: "COVID-19 AND cardiovascular disease AND ACEi AND ARB", "SARS-COVID-19 OR COVID-19, AND ACEi AND ARB AND Infection rate", "COVID-19 AND ACEi and ARB", "Omicron BA.1 and BA.2 AND ACE2 OR ARBs", "Omicron AND ACEi AND ARBs". This resulted in 33 final sources. The review concluded that ACEi/ARB therapy may continue to improve COVID-19 survival as previous treatment is associated with positive clinical outcomes. Patients taking ACEis or ARBs were found to have a decreased risk of hospitalization, reduced severity of COVID-19 pneumonia, a lesser need for mechanical ventilation, and an overall reduction in mortality rate. No statistically significant association between ACEi/ARB use and enhanced COVID-19 infectivity was found. The Omicron variant is theoretically more infectious and was associated with increased negative clinical outcomes in those undertreated with ACEis/ARBs. The majority of the literature supports the current guidelines from the American College of Cardiology (ACC), American Heart Association (AHA), European Society of Cardiology (ESC), and Heart Failure Society of America (HFSA), which state that ACEi and ARB medications should not be withdrawn from or initiated on patients with cardiovascular disease who are infected with SARS-CoV-2. More research needs to be conducted on the association between the emerging COVID-19 variants and ACEis/ARBs to give clinicians confidence when treating patients within this subgroup of the population.
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The host receptor is a key element in the initial stage of the virus entry into the host. The use of this host receptor is valuable as a sensing element for selectively and sensitively detecting specific viruses. Also, viruses tend to escape neutralizing antibodies through viral mutation but still utilize the cell entry process using the same host receptors, so it would be a powerful detection tool even for the mutant viruses. The angiotensin-converting enzyme 2 (ACE2) receptor, which is the representative host receptor, performs an essential function in facilitating viral penetration by interacting with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. In this study, we introduce a novel approach, where we fabricated a carbon nanotube field-effect transistor (CNT-FET) sensor and combined it with ACE2 receptor-embedded nanodisc (ND). ACE2 was produced using an E. coli expression system, purified, and integrated into the ND platform. ACE2 NDs showed robust functionality through interactions with a pseudotyped virus (PV) containing the spike protein, enabling sensitive detection of both SARS-CoV-2 and its genetic variations at 102 PFU/mL. The ACE ND-based sensor exhibited excellent selectivity by accurately differentiating SARS-CoV-2 wild-type and variants (Omicron, Delta) from other viruses (ZIKA and MERS-CoV). As a result of comparative analysis, ACE2 ND showed approximately 49% superior long-term functionality up to the second week compared to that of soluble ACE2. These findings highlight the high selectivity and sensitivity of host receptor-based sensors for detecting viral variants and provide a promising tool to prevent the spread of unknown viruses.
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According to the data from the World Health Organization, about 800 million of the world population had contracted coronavirus infection caused by SARS-CoV-2 by mid-2023. Properties of this virus have allowed it to circulate in the human population for a long time, evolving defense mechanisms against the host immune system. Severity of the disease depends largely on the degree of activation of the systemic immune response, including overstimulation of macrophages and monocytes, cytokine production, and triggering of adaptive T- and B-cell responses, while SARS-CoV-2 evades the immune system actions. In this review, we discuss immune responses triggered in response to the SARS-CoV-2 virus entry into the cell and malfunctions of the immune system that lead to the development of severe disease.
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COVID-19 , Humanos , SARS-CoV-2RESUMEN
SARS-Cov-2, the virus causing COVID-19, penetrates host target cells via the receptor of angiotensin-converting enzyme 2 (ACE2). Disrupting the virus interaction with ACE2 affords a plausible mechanism for prevention of cell penetration and inhibiting dissemination of the virus. Our studies demonstrate that ACE2 interaction with the receptor binding domain of SARS-Cov-2 spike protein (RBD) can be impaired by modulating the α7 nicotinic acetylcholine receptor (α7 nAChR) contiguous with ACE2. U373 cells of human astrocytoma origin were shown to bind both ACE2-specific antibody and recombinant RBD in Cell-ELISA. ACE2 was found to interact with α7 nAChR in U373 cell lysates studied by Sandwich ELISA. Our studies demonstrate that inhibition of RBD binding to ACE2-expressing U373 cells were defined with α7 nAChR agonists choline and PNU282987, but not a competitive antagonist methyllicaconitine (MLA). Additionally, the type 2 positive allosteric modulator (PAM2) PNU120596 and hydroxyurea (HU) also inhibited the binding. Our studies demonstrate that activation of α7 AChRs has efficacy in inhibiting the SARS-Cov-2 interaction with the ACE2 receptor and in such a way can prevent virus target cell penetration. These studies also help to clarify the consistent efficacy and positive outcomes for utilizing HU in treating COVID-19.
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Receptores Nicotínicos , Receptor Nicotínico de Acetilcolina alfa 7 , Humanos , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19 , Unión Proteica , Receptores Nicotínicos/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/químicaRESUMEN
The emergence of SARS-CoV-2 variants like Delta (AY.29) and Omicron (EG.5) poses continued challenges for vaccines and therapeutics. Mutations in the viral spike protein are key in altering infectivity and immune evasion. This study uses computational modeling to investigate the molecular binding mechanisms between spike protein variants and the ACE2 host receptor. Using the MARTNI force field, coarse-grained molecular dynamics (CGMD) simulations and nudged elastic band (NEB) calculations explore spike-ACE2 interactions for the wild type, Delta variant, and Omicron variant. The simulations reveal Omicron has the strongest binding affinity at -128.35 ± 10.91 kcal/mol, followed by Delta and wild type. Key mutations in Delta and Omicron, like Q493R and Q498R, optimize electrostatic contacts, enhancing ACE2 interactions. The wild-type spike has the highest transition state energy barrier at 17.87 kcal/mol, while Delta has the lowest barrier at 9.21 kcal/mol. Despite slightly higher dual barriers, Omicron's increased binding energy lowers its overall barrier to rapidly bind ACE2. These findings provide residue-level insights into mutation effects on SARS-CoV-2 infectivity. The computational modeling elucidates mechanisms underlying spike-ACE2 binding kinetics, aiding the development of vaccines and therapies targeting emerging viral strains.
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Various SARS-CoV-2-related coronaviruses have been increasingly identified in pangolins, showing a potential threat to humans. Here we report the infectivity and pathogenicity of the SARS-CoV-2-related virus, PCoV-GX/P2V, which was isolated from a Malayan pangolin (Manis javanica). PCoV-GX/P2V could grow in human hepatoma, colorectal adenocarcinoma cells, and human primary nasal epithelial cells. It replicated more efficiently in cells expressing human angiotensin-converting enzyme 2 (hACE2) as SARS-CoV-2 did. After intranasal inoculation to the hACE2-transgenic mice, PCoV-GX/P2V not only replicated in nasal turbinate and lungs, but also caused interstitial pneumonia, characterized by infiltration of mixed inflammatory cells and multifocal alveolar hemorrhage. Existing population immunity established by SARS-CoV-2 infection and vaccination may not protect people from PCoV-GX/P2V infection. These findings further verify the hACE2 utility of PCoV-GX/P2V by in vivo experiments using authentic viruses and highlight the importance for intensive surveillance to prevent possible cross-species transmission.
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Enzima Convertidora de Angiotensina 2 , COVID-19 , Ratones Transgénicos , Pangolines , SARS-CoV-2 , Animales , Humanos , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/genética , SARS-CoV-2/patogenicidad , SARS-CoV-2/genética , COVID-19/virología , Pangolines/virología , Ratones , Replicación Viral , Pulmón/virología , Pulmón/patología , Chlorocebus aethiops , Células VeroRESUMEN
Surface plasmon resonance (SPR)-based biosensing enables the characterization of protein-protein interactions. Several SPR-based approaches have been designed to evaluate the binding mechanism between the angiotensin-converting enzyme 2 (ACE2) receptor and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein leading to a large range of kinetic and thermodynamic constants. This chapter describes a robust SPR assay based on the K5/E5 coiled-coil capture strategy that reduces artifacts. In this method, ACE2 receptors were produced with an E5-tag and immobilized as ligands in the SPR assay. This chapter details methods for high-yield production and purification of the studied proteins, functionalization of the sensor chip, conduction of the SPR assay, and data analysis.
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Técnicas Biosensibles , COVID-19 , Humanos , SARS-CoV-2/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Técnicas Biosensibles/métodos , Unión ProteicaRESUMEN
The contagiousness of SARS-CoV-2 ß-coronavirus is determined by the virus-receptor electrostatic association of its positively charged spike (S) protein with the negatively charged angiotensin converting enzyme-2 (ACE2 receptor) of the epithelial cells. If some mutations occur, the electrostatic potential on the surface of the receptor-binding domain (RBD) could be altered, and the S-ACE2 association could become stronger or weaker. The aim of the current research is to investigate whether point mutations can noticeably alter the electrostatic potential on the RBD and the 3D stability of the S1-subunit of the S-protein. For this purpose, 15 mutants with different hydrophilicity and electric charge (positive, negative, or uncharged) of the substituted and substituting amino acid residues, located on the RBD at the S1-ACE2 interface, are selected, and the 3D structure of the S1-subunit is reconstructed on the base of the crystallographic structure of the S-protein of the wild-type strain and the amino acid sequence of the unfolded polypeptide chain of the mutants. Then, the Gibbs free energy of folding, isoelectric point, and pH-dependent surface electrostatic potential of the S1-subunit are computed using programs for protein electrostatics. The results show alterations in the local electrostatic potential in the vicinity of the mutant amino acid residue, which can influence the S-ACE2 association. This approach allows prediction of the relative infectivity, transmissibility, and contagiousness (at equal social immune status) of new SARS-CoV-2 mutants by reconstruction of the 3D structure of the S1-subunit and calculation of the surface electrostatic potential.
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COVID-19 , Mutación Puntual , Glicoproteína de la Espiga del Coronavirus , Humanos , Aminoácidos , Enzima Convertidora de Angiotensina 2 , Mutación , Unión Proteica , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/fisiología , Electricidad EstáticaRESUMEN
Self-assembling nanoparticles (saNP) and nanofibers were found in the recombinant coronavirus SARS-CoV-2 S1, S2, RBD and N proteins purified by affinity chromatography using Ni Sepharose. Scanning electron (SEM), atomic force (AFM) microscopy on mica or graphite surface and in liquid as well as dynamic light scattering (DLS) revealed nanostructures of various sizes. AFM in liquid cell without drying on the surface showed mean height of S1 saNP 80.03 nm, polydispersity index (PDI) 0.006; for S2 saNP mean height 93.32 nm, PDI = 0.008; for N saNP mean height 16.71 nm, PDI = 0.99; for RBD saNP mean height 16.25 nm, PDI = 0.55. Ratios between the height and radius of each saNP in the range 0.1-0.5 suggested solid protein NP but not vesicles with internal empty spaces. The solid but not empty structures of the protein saNP were also confirmed by STEM after treatment of saNP with the standard contrasting agent uranyl acetate. The saNP remained stable after multiple freeze-thaw cycles in water and hyperosmotic solutions for 2 years at -20 °C. Receptor-mediated penetration of the SARS-CoV-2 S1 and RBD saNP in the African green mokey kidney Vero cells with the specific receptors for ß-coronavirus reproduction was more efficient compared to unspecific endocytosis into MDCK cells without the specific receptors. Amyloid-like structures were revealed in the SARS-CoV-2 S1, S2, RBD and N saNP by means of their interaction with Thioflavin T and Congo Red dyes. Taken together, spontaneous formation of the amyloid-like self-assembling nanostructures due to the internal affinity of the SARS-CoV-2 virion proteins might induce proteinopathy in patients, including conformational neurodegenerative diseases, change stability of vaccines and diagnostic systems.
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COVID-19 , Nanoestructuras , Animales , Humanos , Chlorocebus aethiops , SARS-CoV-2 , Células Vero , Proteínas Recombinantes , Amiloide , Proteínas AmiloidogénicasRESUMEN
Recently, a global outbreak of COVID-19 has rapidly spread to various national regions. As the number of COVID-19 patients has increased, some of those infected with SARS-CoV-2 have developed a variety of psychiatric symptoms, including depression, cognitive impairment, and fatigue. A distinct storm of inflammatory factors that contribute to the initial disease but also a persistent post-acute phase syndrome has been reported in patients with COVID-19. Neuropsychological symptoms including depression, cognitive impairment, and fatigue are closely related to circulating and local (brain) inflammatory factors. Natural products are currently being examined for their ability to treat numerous complications caused by COVID-19. Among them, ginseng has anti-inflammatory, immune system stimulating, neuroendocrine modulating, and other effects, which may help improve psychiatric symptoms. This review summarizes the basic mechanisms of COVID-19 pneumonia, psychiatric symptoms following coronavirus infections, effects of ginseng on depression, restlessness, and other psychiatric symptoms associated with post-COVID syn-dromes, as well as possible mechanisms underlying these effects.
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COVID-19 , Panax , Humanos , Depresión/tratamiento farmacológico , COVID-19/complicaciones , SARS-CoV-2 , FatigaRESUMEN
Mucosal vaccines protect against respiratory virus infection by stimulating the production of IgA antibodies that protect against virus invasion of the mucosal epithelium. In this study, a novel protein subunit mucosal vaccine was constructed for protection against infection by the beta coronavirus SARS-CoV-2. The vaccine was assembled by linking a gene encoding the SARS-CoV-2 virus S1 angiotensin converting enzyme receptor binding domain (ACE-2-RBD) downstream from a DNA fragment encoding the cholera toxin B subunit (CTB), a mucosal adjuvant known to stimulate vaccine immunogenicity. A 42 kDa vaccine fusion protein was identified in homogenates of transformed E. coli BL-21 cells by acrylamide gel electrophoresis and by immunoblotting against anti-CTB and anti-ACE-2-RBD primary antibodies. The chimeric CTB-SARS-CoV-2-ACE-2-RBD vaccine fusion protein was partially purified from clarified bacterial homogenates by nickel affinity column chromatography. Further vaccine purification was accomplished by polyacrylamide gel electrophoresis and electro-elution of the 42 kDa chimeric vaccine protein. Vaccine protection against SARS-CoV-2 infection was assessed by oral, nasal, and parenteral immunization of BALB/c mice with the CTB-SARS-CoV-2-ACE-2-RBD protein. Vaccine-induced SARS-CoV-2 specific antibodies were quantified in immunized mouse serum by ELISA analysis. Serum from immunized mice contained IgG and IgA antibodies that neutralized SARS-CoV-2 infection in Vero E6 cell cultures. In contrast to unimmunized mice, cytological examination of cell necrosis in lung tissues excised from immunized mice revealed no detectable cellular abnormalities. Mouse behavior following vaccine immunization remained normal throughout the duration of the experiments. Together, our data show that a CTB-adjuvant-stimulated CTB-SARS-CoV-2-ACE-2-RBD chimeric mucosal vaccine protein synthesized in bacteria can produce durable and persistent IgA antibodies in mice that neutralize the SARS-CoV-2 subvariant Omicron BA.1.1.
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The COVID-19 pandemic was declared due to the spread of the novel coronavirus, SARS-CoV-2. Viral infection is caused by the interaction between the SARS-CoV-2 receptor binding domain (RBD) and the human ACE2 receptor (hACE2). Previous computational studies have identified repurposed small molecules that target the RBD, but very few have screened drugs in the RBD-hACE2 interface. When studies focus solely on the binding affinity between the drug and the RBD, they ignore the effect of hACE2, resulting in an incomplete analysis. We screened ACE inhibitors and previously identified SARS-CoV-2 inhibitors for binding to the RBD-hACE2 interface, and then conducted 500 ns of unrestrained molecular dynamics (MD) simulations of fosinopril, fosinoprilat, lisinopril, emodin, diquafosol, and physcion bound to the interface to assess the binding characteristics of these ligands. Based on MM-GBSA analysis, all six ligands bind favorably in the interface and inhibit the RBD-hACE2 interaction. However, when we repeat our simulation by first binding the drug to the RBD before interacting with hACE2, we find that fosinopril, fosinoprilat, and lisinopril result in a strongly interacting trimeric complex (RBD-drug-hACE2). Hydrogen bonding and pairwise decomposition analyses further suggest that fosinopril is the best RBD inhibitor. However, when lisinopril is bound, it stabilizes the trimeric complex and, therefore, is not an ideal potential drug candidate. Overall, these results reveal important atomistic interactions critical to the binding of the RBD to hACE2 and highlight the significance of including all protein partners in the evaluation of a potential drug candidate.
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Since the start of the SARS-CoV-2 pandemic, the rapid replacement of one lineage by another has been observed. Indeed, SARS-CoV-2 is evolving through a quasispecies mechanism leading to post-infection mutation selection under positive evolutionary pressure (host-driven viral evolution). These mutations may reduce the effectiveness of the specific neutralizing immune response against the virus. We provide here evidence that apart from the selection of SARS-CoV-2 variants by the immune system, selection by the cellular receptor can just as well select variants which escape neutralization.