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Molecules (Basel, Switzerland) Aug 2022The discovery and the development of safe and efficient therapeutics against arthritogenic alphaviruses (e.g., chikungunya virus) remain a continuous challenge.... (Review)
Review
The discovery and the development of safe and efficient therapeutics against arthritogenic alphaviruses (e.g., chikungunya virus) remain a continuous challenge. Alkaloids are structurally diverse and naturally occurring compounds in plants, with a wide range of biological activities including beneficial effects against prominent pathogenic viruses and inflammation. In this short review, we discuss the effects of some alkaloids of three biologically relevant structural classes (isoquinolines, indoles and quinolizidines). Based on various experimental models (viral infections and chronic diseases), we highlight the immunomodulatory effects of these alkaloids. The data established the capacity of these alkaloids to interfere in host antiviral and inflammatory responses through key components (antiviral interferon response, ROS production, inflammatory signaling pathways and pro- and anti-inflammatory cytokines production) also involved in alphavirus infection and resulting inflammation. Thus, these data may provide a convincing perspective of research for the use of alkaloids as immunomodulators against arthritogenic alphavirus infection and induced inflammation.
Topics: Alkaloids; Alphavirus Infections; Antiviral Agents; Chikungunya virus; Humans; Indoles; Inflammation; Isoquinolines; Quinolizidines
PubMed: 36014321
DOI: 10.3390/molecules27165080 -
Viruses Jun 2023Retinopathy is a recently recognized complication of dengue, affecting up to 10% of hospitalized patients. Research on the pathogenesis has focused largely on effects of...
Retinopathy is a recently recognized complication of dengue, affecting up to 10% of hospitalized patients. Research on the pathogenesis has focused largely on effects of dengue virus (DENV) at the blood-retinal barrier. Involvement of retinal Müller glial cells has received little attention, although this cell population contributes to the pathology of other intraocular infections. The goal of our work was to establish the susceptibility of Müller cells to infection with DENV and to identify characteristics of the cellular antiviral, inflammatory, and immunomodulatory responses to DENV infection in vitro. Primary human Müller cell isolates and the MIO-M1 human Müller cell line were infected with the laboratory-adapted Mon601 strain and DENV serotype 1 and 2 field isolates, and cell-DENV interactions were investigated by immunolabelling and quantitative real-time polymerase chain reaction. Müller cells were susceptible to DENV infection, but experiments involving primary cell isolates indicated inter-individual variation. Viral infection induced an inflammatory response (including tumour necrosis factor-α, interleukin [IL]-1β, and IL-6) and an immunomodulatory response (including programmed death-ligand [PD-L]1 and PD-L2). The type I interferon response was muted in the Müller cell line compared to primary cell isolates. The highest infectivity and cell responses were observed in the laboratory-adapted strain, and overall, infectivity and cell responses were stronger in DENV2 strains. This work demonstrates that Müller cells mount an antiviral and immune response to DENV infection, and that this response varies across cell isolates and DENV strain. The research provides a direction for future efforts to understand the role of human retinal Müller glial cells in dengue retinopathy.
Topics: Humans; Dengue; Dengue Virus; Ependymoglial Cells; Cell Line; Antiviral Agents
PubMed: 37515098
DOI: 10.3390/v15071410 -
Carbohydrate Research Jul 2021The viral infection caused by SARS-CoV-2 has increased the mortality rate and engaged several adverse effects on the affected individuals. Currently available antiviral... (Review)
Review
The viral infection caused by SARS-CoV-2 has increased the mortality rate and engaged several adverse effects on the affected individuals. Currently available antiviral drugs have found to be unsuccessful in the treatment of COVID-19 patients. The demand for efficient antiviral drugs has created a huge burden on physicians and health workers. Plasma therapy seems to be less accomplishable due to insufficient donors to donate plasma and low recovery rate from viral infection. Repurposing of antivirals has been evolved as a suitable strategy in the current treatment and preventive measures. The concept of drug repurposing represents new experimental approaches for effective therapeutic benefits. Besides, SARS-CoV-2 exhibits several complications such as lung damage, blood clot formation, respiratory illness and organ failures in most of the patients. Based on the accumulation of data, sulfated marine polysaccharides have exerted successful inhibition of virus entry, attachment and replication with known or unknown possible mechanisms against deadly animal and human viruses so far. Since the virus entry into the host cells is the key process, the prevention of such entry mechanism makes any antiviral strategy effective. Enveloped viruses are more sensitive to polyanions than non-enveloped viruses. Besides, the viral infection caused by RNA virus types embarks severe oxidative stress in the human body that leads to malfunction of tissues and organs. In this context, polysaccharides play a very significant role in providing shielding effect against the virus due to their polyanionic rich features and a molecular weight that hinders their reactive surface glycoproteins. Significantly the functional groups especially sulfate, sulfate pattern and addition, uronic acids, monosaccharides, glycosidic linkage and high molecular weight have greater influence in the antiviral activity. Moreover, they are very good antioxidants that can reduce the free radical generation and provokes intracellular antioxidant enzymes. Additionally, polysaccharides enable a host-virus immune response, activate phagocytosis and stimulate interferon systems. Therefore, polysaccharides can be used as candidate drugs, adjuvants in vaccines or combination with other antivirals, antioxidants and immune-activating nutritional supplements and antiviral materials in healthcare products to prevent SARS-CoV-2 infection.
Topics: Anticoagulants; Antiviral Agents; Blood Platelets; COVID-19; Humans; Immunologic Factors; Lung; Phaeophyceae; Polysaccharides; Pulmonary Embolism; Respiratory Insufficiency; Rhodophyta; SARS-CoV-2; Sulfuric Acid Esters; Virus Attachment; Virus Internalization; COVID-19 Drug Treatment
PubMed: 34015720
DOI: 10.1016/j.carres.2021.108326 -
International Journal of Molecular... Apr 2020Since the infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China during December 2019, the coronavirus disease... (Review)
Review
Since the infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China during December 2019, the coronavirus disease 2019 (COVID-19) has spread on a global scale, causing the World Health Organization (WHO) to issue a warning. While novel vaccines and drugs that target SARS-CoV-2 are under development, this review provides information on therapeutics which are under clinical trials or are proposed to antagonize SARS-CoV-2. Based on the information gained from the responses to other RNA coronaviruses, including the strains that cause severe acute respiratory syndrome (SARS)-coronaviruses and Middle East respiratory syndrome (MERS), drug repurposing might be a viable strategy. Since several antiviral therapies can inhibit viral replication cycles or relieve symptoms, mechanisms unique to RNA viruses will be important for the clinical development of antivirals against SARS-CoV-2. Given that several currently marketed drugs may be efficient therapeutic agents for severe COVID-19 cases, they may be beneficial for future viral pandemics and other infections caused by RNA viruses when standard treatments are unavailable.
Topics: Antiviral Agents; Betacoronavirus; COVID-19; China; Coronavirus Infections; Drug Discovery; Humans; Pandemics; Pneumonia, Viral; SARS-CoV-2; COVID-19 Drug Treatment
PubMed: 32325767
DOI: 10.3390/ijms21082839 -
International Journal of Molecular... Aug 2022Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a viral agent that causes Coronavirus disease 2019 (COVID-19), a disease that causes flu-like symptoms... (Review)
Review
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a viral agent that causes Coronavirus disease 2019 (COVID-19), a disease that causes flu-like symptoms that, when exacerbated, can have life-threatening consequences. COVID-19 has been linked to persistent symptoms, sequelae, and medical complications that can last months after the initial infection. This systematic review aims to elucidate the innate and adaptive immune mechanisms involved and identify potential characteristics of COVID-19 pathology that may increase symptom duration. We also describe he three different stages of COVID-19-viral replication, immune hyperactivation, and post-acute sequelae-as well as each phase's corresponding immune response. Finally, we use this multiphasic approach to describe different treatment approaches for each of the three stages-antivirals, immunosuppressants and monoclonal antibodies, and continued immunosuppressants-to fully curate the treatment to the stage of disease.
Topics: Antiviral Agents; Humans; Immunosuppressive Agents; SARS-CoV-2; COVID-19 Drug Treatment
PubMed: 35955740
DOI: 10.3390/ijms23158606 -
Nature Communications Jul 2023Prediction, prevention and treatment of virus infections require understanding of cell-to-cell variability that leads to heterogenous disease outcomes, but the source of...
Prediction, prevention and treatment of virus infections require understanding of cell-to-cell variability that leads to heterogenous disease outcomes, but the source of this heterogeneity has yet to be clarified. To study the multimodal response of single human cells to herpes simplex virus type 1 (HSV-1) infection, we mapped high-dimensional viral and cellular state spaces throughout the infection using multiplexed imaging and quantitative single-cell measurements of viral and cellular mRNAs and proteins. Here we show that the high-dimensional cellular state scape can predict heterogenous infections, and cells move through the cellular state landscape according to infection progression. Spatial information reveals that infection changes the cellular state of both infected cells and of their neighbors. The multiplexed imaging of HSV-1-induced cellular modifications links infection progression to changes in signaling responses, transcriptional activity, and processing bodies. Our data show that multiplexed quantification of responses at the single-cell level, across thousands of cells helps predict infections and identify new targets for antivirals.
Topics: Humans; Herpesvirus 1, Human; Herpes Simplex; Antiviral Agents; RNA, Messenger; Virus Replication
PubMed: 37500668
DOI: 10.1038/s41467-023-40148-6 -
Cytometry. Part B, Clinical Cytometry Jan 2021With the morbidity and mortality associated with the COVID-19 pandemic that we are witnessing this year, the risks posed by emerging viral diseases to global health are... (Review)
Review
With the morbidity and mortality associated with the COVID-19 pandemic that we are witnessing this year, the risks posed by emerging viral diseases to global health are all too obvious. This pandemic highlights the importance of antiviral drug discovery, which targets emerging viral pathogens, as well as existing pathogenic viruses that undergo continuous evolution. Drug discovery and development is a long and resource intensive process; however, the use of biomarkers can accelerate clinical development of antivirals by providing information regarding diagnosis of specific viral infections, status of infection, potential safety parameters, and antiviral responses. In clinical practice, many of the biomarkers initially utilized to support clinical development are also used for patient care. While viral load is a standard and essential biomarker used to detect the desired viral suppression induced by an antiviral agent, it has become apparent that additional biomarkers, whether related to the virus, the host or as a consequence of the drug's mechanistic effects, are also important for monitoring clinical outcomes associated with an antiviral therapy. This review summarizes the biomarkers used in the clinical development (as well as in clinical practice, where appropriate) of antiviral therapies for hepatitis C virus, hepatitis B virus, human immunodeficiency virus, and severe acute respiratory syndrome coronavirus 2.
Topics: Animals; Antiviral Agents; Biomarkers; COVID-19; Clinical Trials as Topic; Humans; SARS-CoV-2; Virus Diseases; COVID-19 Drug Treatment
PubMed: 34542933
DOI: 10.1002/cyto.b.21974 -
Genes Jun 2023Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are... (Review)
Review
Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are absent or incompatible, there are (at least) two types of inducible antiviral immunity: RNA silencing (RNAi) and immune responses mounted upon activation of nucleotide-binding domain leucine-rich repeat (NLR) receptors. RNAi is associated with viral symptom recovery through translational repression and transcript degradation following recognition of viral double-stranded RNA produced during infection. NLR-mediated immunity is induced upon (in)direct recognition of a viral protein by an NLR receptor, triggering either a hypersensitive response (HR) or an extreme resistance response (ER). During ER, host cell death is not apparent, and it has been proposed that this resistance is mediated by a translational arrest (TA) of viral transcripts. Recent research indicates that translational repression plays a crucial role in plant antiviral resistance. This paper reviews current knowledge on viral translational repression during viral recovery and NLR-mediated immunity. Our findings are summarized in a model detailing the pathways and processes leading to translational arrest of plant viruses. This model can serve as a framework to formulate hypotheses on how TA halts viral replication, inspiring new leads for the development of antiviral resistance in crops.
Topics: RNA Interference; Plant Viruses; Antiviral Agents; Viral Proteins; RNA, Double-Stranded
PubMed: 37372472
DOI: 10.3390/genes14061293 -
Viruses Feb 2023Despite the great technological and medical advances in fighting viral diseases, new therapies for most of them are still lacking, and existing antivirals suffer from... (Review)
Review
Despite the great technological and medical advances in fighting viral diseases, new therapies for most of them are still lacking, and existing antivirals suffer from major limitations regarding drug resistance and a limited spectrum of activity. In fact, most approved antivirals are directly acting antiviral (DAA) drugs, which interfere with viral proteins and confer great selectivity towards their viral targets but suffer from resistance and limited spectrum. Nowadays, host-targeted antivirals (HTAs) are on the rise, in the drug discovery and development pipelines, in academia and in the pharmaceutical industry. These drugs target host proteins involved in the virus life cycle and are considered promising alternatives to DAAs due to their broader spectrum and lower potential for resistance. Herein, we discuss an important class of HTAs that modulate signal transduction pathways by targeting host kinases. Kinases are considered key enzymes that control virus-host interactions. We also provide a synopsis of the antiviral drug discovery and development pipeline detailing antiviral kinase targets, drug types, therapeutic classes for repurposed drugs, and top developing organizations. Furthermore, we detail the drug design and repurposing considerations, as well as the limitations and challenges, for kinase-targeted antivirals, including the choice of the binding sites, physicochemical properties, and drug combinations.
Topics: Humans; Protein Kinases; Antiviral Agents; Drug Repositioning; Drug Discovery; Drug Design
PubMed: 36851782
DOI: 10.3390/v15020568 -
Microbiology Spectrum Oct 2022Three directly acting antivirals (DAAs) demonstrated substantial reduction in COVID-19 hospitalizations and deaths in clinical trials. However, these agents did not...
Three directly acting antivirals (DAAs) demonstrated substantial reduction in COVID-19 hospitalizations and deaths in clinical trials. However, these agents did not completely prevent severe illness and are associated with cases of rebound illness and viral shedding. Combination regimens can enhance antiviral potency, reduce the emergence of drug-resistant variants, and lower the dose of each component in the combination. Concurrently targeting virus entry and virus replication offers opportunities to discover synergistic drug combinations. While combination antiviral drug treatments are standard for chronic RNA virus infections, no antiviral combination therapy has been approved for SARS-CoV-2. Here, we demonstrate that combining host-targeting antivirals (HTAs) that target TMPRSS2 and hence SARS-CoV-2 entry, with the DAA molnupiravir, which targets SARS-CoV-2 replication, synergistically suppresses SARS-CoV-2 infection in Calu-3 lung epithelial cells. Strong synergy was observed when molnupiravir, an oral drug, was combined with three TMPRSS2 (HTA) oral or inhaled inhibitors: camostat, avoralstat, or nafamostat. The combination of camostat plus molnupiravir was also effective against the beta and delta variants of concern. The pyrimidine biosynthesis inhibitor brequinar combined with molnupiravir also conferred robust synergistic inhibition. These HTA+DAA combinations had similar potency to the synergistic all-DAA combination of molnupiravir plus nirmatrelvir, the protease inhibitor found in paxlovid. Pharmacodynamic modeling allowed estimates of antiviral potency at all possible concentrations of each agent within plausible therapeutic ranges, suggesting possible efficacy. The triple combination of camostat, brequinar, and molnupiravir further increased antiviral potency. These findings support the development of HTA+DAA combinations for pandemic response and preparedness. Imagine a future viral pandemic where if you test positive for the new virus, you can quickly take some medicines at home for a few days so that you do not get too sick. To date, only single drugs have been approved for outpatient use against SARS-CoV-2, and we are learning that these have some limitations and may succumb to drug resistance. Here, we show that combinations of two oral drugs are better than the single ones in blocking SARS-CoV-2, and we use mathematical modeling to show that these drug combinations are likely to work in people. We also show that a combination of three oral drugs works even better at eradicating the virus. Our findings therefore bode well for the development of oral drug cocktails for at home use at the first sign of an infection by a coronavirus or other emerging viral pathogens.
Topics: Humans; SARS-CoV-2; Antiviral Agents; Protease Inhibitors; Drug Combinations; Pyrimidines; COVID-19 Drug Treatment
PubMed: 36190406
DOI: 10.1128/spectrum.03331-22