Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
1.
PLoS Biol ; 19(4): e3001135, 2021 04.
Article in English | MEDLINE | ID: covidwho-1508487

ABSTRACT

Identifying the animal reservoirs from which zoonotic viruses will likely emerge is central to understanding the determinants of disease emergence. Accordingly, there has been an increase in studies attempting zoonotic "risk assessment." Herein, we demonstrate that the virological data on which these analyses are conducted are incomplete, biased, and rapidly changing with ongoing virus discovery. Together, these shortcomings suggest that attempts to assess zoonotic risk using available virological data are likely to be inaccurate and largely only identify those host taxa that have been studied most extensively. We suggest that virus surveillance at the human-animal interface may be more productive.


Subject(s)
Environmental Monitoring , Virus Diseases , Zoonoses/etiology , Zoonoses/prevention & control , Animals , Biodiversity , Disease Reservoirs/classification , Disease Reservoirs/statistics & numerical data , Environmental Monitoring/methods , Environmental Monitoring/standards , Host Specificity/genetics , Humans , Metagenomics/methods , Metagenomics/organization & administration , Metagenomics/standards , Phylogeny , Risk Assessment , Risk Factors , Selection Bias , Virus Diseases/epidemiology , Virus Diseases/etiology , Virus Diseases/prevention & control , Virus Diseases/transmission , Viruses/classification , Viruses/genetics , Viruses/isolation & purification , Viruses/pathogenicity , Zoonoses/epidemiology , Zoonoses/virology
2.
Viruses ; 13(9)2021 09 13.
Article in English | MEDLINE | ID: covidwho-1411081

ABSTRACT

Over the decades, the world has witnessed diverse virus associated pandemics. The significant inhibitory effects of marine sulfated polysaccharides against SARS-CoV-2 shows its therapeutic potential in future biomedical applications and drug development. Algal polysaccharides exhibited significant role in antimicrobial, antitumor, antioxidative, antiviral, anticoagulant, antihepatotoxic and immunomodulating activities. Owing to their health benefits, the sulfated polysaccharides from marine algae are a great deal of interest globally. Algal polysaccharides such as agar, alginate, carrageenans, porphyran, fucoidan, laminaran and ulvans are investigated for their nutraceutical potential at different stages of infection processes, structural diversity, complexity and mechanism of action. In this review, we focus on the recent antiviral studies of the marine algae-based polysaccharides and their potential towards antiviral medicines.


Subject(s)
Antiviral Agents/pharmacology , Aquatic Organisms/chemistry , Polysaccharides/pharmacology , Seaweed/chemistry , Virus Diseases/epidemiology , Alginates/chemistry , Alginates/pharmacology , Antiviral Agents/chemistry , Glucans/chemistry , Glucans/pharmacology , Humans , Molecular Structure , Pandemics , Polysaccharides/chemistry , Virus Diseases/drug therapy , Virus Diseases/etiology , Virus Diseases/prevention & control
3.
Viruses ; 13(9)2021 09 13.
Article in English | MEDLINE | ID: covidwho-1411075

ABSTRACT

We introduce an explicit function that describes virus-load curves on a patient-specific level. This function is based on simple and intuitive model parameters. It allows virus load analysis of acute viral infections without solving a full virus load dynamic model. We validate our model on data from mice influenza A, human rhinovirus data, human influenza A data, and monkey and human SARS-CoV-2 data. We find wide distributions for the model parameters, reflecting large variability in the disease outcomes between individuals. Further, we compare the virus load function to an established target model of virus dynamics, and we provide a new way to estimate the exponential growth rates of the corresponding infection phases. The virus load function, the target model, and the exponential approximations show excellent fits for the data considered. Our virus-load function offers a new way to analyze patient-specific virus load data, and it can be used as input for higher level models for the physiological effects of a virus infection, for models of tissue damage, and to estimate patient risks.


Subject(s)
Viral Load , Virus Diseases/epidemiology , Virus Diseases/etiology , Acute Disease , Algorithms , Animals , Biological Variation, Population , COVID-19/epidemiology , COVID-19/virology , Humans , Influenza, Human/epidemiology , Influenza, Human/virology , Macaca mulatta , Mice , Models, Theoretical , Rhinovirus , SARS-CoV-2
4.
Viruses ; 13(5)2021 05 04.
Article in English | MEDLINE | ID: covidwho-1383920

ABSTRACT

Viral infections are responsible for several chronic and acute diseases in both humans and animals. Despite the incredible progress in human medicine, several viral diseases, such as acquired immunodeficiency syndrome, respiratory syndromes, and hepatitis, are still associated with high morbidity and mortality rates in humans. Natural products from plants or other organisms are a rich source of structurally novel chemical compounds including antivirals. Indeed, in traditional medicine, many pathological conditions have been treated using plant-derived medicines. Thus, the identification of novel alternative antiviral agents is of critical importance. In this review, we summarize novel phytochemicals with antiviral activity against human viruses and their potential application in treating or preventing viral disease.


Subject(s)
Antiviral Agents/pharmacology , Biological Products/pharmacology , Drug Discovery , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Biological Products/chemistry , Biological Products/therapeutic use , DNA Viruses/drug effects , DNA Viruses/physiology , Drug Development , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , RNA Viruses/drug effects , RNA Viruses/physiology , Virus Diseases/diagnosis , Virus Diseases/drug therapy , Virus Diseases/etiology , Virus Diseases/metabolism , Virus Replication/drug effects
6.
Front Immunol ; 12: 680891, 2021.
Article in English | MEDLINE | ID: covidwho-1291922

ABSTRACT

The network of tunneling nanotubes (TNTs) represents the filamentous (F)-actin rich tubular structure which is connected to the cytoplasm of the adjacent and or distant cells to mediate efficient cell-to-cell communication. They are long cytoplasmic bridges with an extraordinary ability to perform diverse array of function ranging from maintaining cellular physiology and cell survival to promoting immune surveillance. Ironically, TNTs are now widely documented to promote the spread of various pathogens including viruses either during early or late phase of their lifecycle. In addition, TNTs have also been associated with multiple pathologies in a complex multicellular environment. While the recent work from multiple laboratories has elucidated the role of TNTs in cellular communication and maintenance of homeostasis, this review focuses on their exploitation by the diverse group of viruses such as retroviruses, herpesviruses, influenza A, human metapneumovirus and SARS CoV-2 to promote viral entry, virus trafficking and cell-to-cell spread. The later process may aggravate disease severity and the associated complications due to widespread dissemination of the viruses to multiple organ system as observed in current coronavirus disease 2019 (COVID-19) patients. In addition, the TNT-mediated intracellular spread can be protective to the viruses from the circulating immune surveillance and possible neutralization activity present in the extracellular matrix. This review further highlights the relevance of TNTs in ocular and cardiac tissues including neurodegenerative diseases, chemotherapeutic resistance, and cancer pathogenesis. Taken together, we suggest that effective therapies should consider precise targeting of TNTs in several diseases including virus infections.


Subject(s)
COVID-19/etiology , Cytoplasm/ultrastructure , Cytoplasm/virology , Nanotubes/virology , Neurodegenerative Diseases/etiology , Virus Diseases/etiology , Animals , COVID-19/virology , Cell Communication , Humans
7.
Adv Food Nutr Res ; 96: 417-429, 2021.
Article in English | MEDLINE | ID: covidwho-1265623

ABSTRACT

Selenium (Se) is an element commonly found in the environment at different levels. Its compounds are found in soil, water, and air. This element is also present in raw materials of plant and animal origin, so it can be introduced into human organisms through food. Selenium is a cofactor of enzymes responsible for the antioxidant protection of the body and plays an important role in regulating inflammatory processes in the body. A deficiency in selenium is associated with a number of viral diseases, including COVID-19. This element, taken in excess, may have a toxic effect in the form of joint diseases and diseases of the blood system. Persistent selenium deficiency in the body may also impact infertility, and in such cases supplementation is needed.


Subject(s)
COVID-19/blood , Nutritional Status , Selenium/blood , COVID-19/etiology , Female , Humans , Infertility/blood , Infertility/drug therapy , Infertility/etiology , Male , Selenium/deficiency , Selenium/therapeutic use , Selenium/toxicity , Virus Diseases/blood , Virus Diseases/etiology
8.
Genome Med ; 12(1): 93, 2020 10 27.
Article in English | MEDLINE | ID: covidwho-897564

ABSTRACT

BACKGROUND: Humans and viruses have co-evolved for millennia resulting in a complex host genetic architecture. Understanding the genetic mechanisms of immune response to viral infection provides insight into disease etiology and therapeutic opportunities. METHODS: We conducted a comprehensive study including genome-wide and transcriptome-wide association analyses to identify genetic loci associated with immunoglobulin G antibody response to 28 antigens for 16 viruses using serological data from 7924 European ancestry participants in the UK Biobank cohort. RESULTS: Signals in human leukocyte antigen (HLA) class II region dominated the landscape of viral antibody response, with 40 independent loci and 14 independent classical alleles, 7 of which exhibited pleiotropic effects across viral families. We identified specific amino acid (AA) residues that are associated with seroreactivity, the strongest associations presented in a range of AA positions within DRß1 at positions 11, 13, 71, and 74 for Epstein-Barr virus (EBV), Varicella zoster virus (VZV), human herpesvirus 7, (HHV7), and Merkel cell polyomavirus (MCV). Genome-wide association analyses discovered 7 novel genetic loci outside the HLA associated with viral antibody response (P < 5.0 × 10-8), including FUT2 (19q13.33) for human polyomavirus BK (BKV), STING1 (5q31.2) for MCV, and CXCR5 (11q23.3) and TBKBP1 (17q21.32) for HHV7. Transcriptome-wide association analyses identified 114 genes associated with response to viral infection, 12 outside of the HLA region, including ECSCR: P = 5.0 × 10-15 (MCV), NTN5: P = 1.1 × 10-9 (BKV), and P2RY13: P = 1.1 × 10-8 EBV nuclear antigen. We also demonstrated pleiotropy between viral response genes and complex diseases, from autoimmune disorders to cancer to neurodegenerative and psychiatric conditions. CONCLUSIONS: Our study confirms the importance of the HLA region in host response to viral infection and elucidates novel genetic determinants beyond the HLA that contribute to host-virus interaction.


Subject(s)
Disease Susceptibility , Genetic Predisposition to Disease , Host-Pathogen Interactions/genetics , Virus Diseases/etiology , Antibody Formation/genetics , Disease Susceptibility/immunology , Gene Expression Profiling , Genome-Wide Association Study , HLA Antigens/genetics , HLA Antigens/immunology , Humans , Immunity , Immunoglobulin G/immunology , Quantitative Trait, Heritable
9.
Trends Microbiol ; 29(11): 973-982, 2021 11.
Article in English | MEDLINE | ID: covidwho-1142259

ABSTRACT

Pandemics are caused by novel pathogens to which pre-existing antibody immunity is lacking. Under these circumstances, the body must rely on innate interferon-mediated defenses to limit pathogen replication and allow development of critical humoral protection. Here, we highlight studies on disease susceptibility during H1N1 influenza and COVID-19 (SARS-CoV-2) pandemics. An emerging concept is that genetic and non-genetic deficiencies in interferon system components lead to uncontrolled virus replication and severe illness in a subset of people. Intriguingly, new findings suggest that individuals with autoantibodies neutralizing the antiviral function of interferon are at increased risk of severe COVID-19. We discuss key questions surrounding how such autoantibodies develop and function, as well as the general implications of diagnosing interferon deficiencies for personalized therapies.


Subject(s)
Disease Resistance , Host-Pathogen Interactions , Interferons/metabolism , Virus Diseases/etiology , Virus Diseases/metabolism , Alleles , Animals , Antibodies, Neutralizing/immunology , Autoantibodies/immunology , Autoimmunity , Disease Progression , Disease Resistance/immunology , Disease Susceptibility , Genetic Predisposition to Disease , Host-Pathogen Interactions/immunology , Humans , Interferons/antagonists & inhibitors , Interferons/immunology , Loss of Function Mutation , Polymorphism, Single Nucleotide , Severity of Illness Index , Virus Diseases/diagnosis , Virus Diseases/epidemiology
10.
Front Public Health ; 9: 559595, 2021.
Article in English | MEDLINE | ID: covidwho-1119561

ABSTRACT

Uncontrolled diabetes results in several metabolic alterations including hyperglycemia. Indeed, several preclinical and clinical studies have suggested that this condition may induce susceptibility and the development of more aggressive infectious diseases, especially those caused by some bacteria (including Chlamydophila pneumoniae, Haemophilus influenzae, and Streptococcus pneumoniae, among others) and viruses [such as coronavirus 2 (CoV2), Influenza A virus, Hepatitis B, etc.]. Although the precise mechanisms that link glycemia to the exacerbated infections remain elusive, hyperglycemia is known to induce a wide array of changes in the immune system activity, including alterations in: (i) the microenvironment of immune cells (e.g., pH, blood viscosity and other biochemical parameters); (ii) the supply of energy to infectious bacteria; (iii) the inflammatory response; and (iv) oxidative stress as a result of bacterial proliferative metabolism. Consistent with this evidence, some bacterial infections are typical (and/or have a worse prognosis) in patients with hypercaloric diets and a stressful lifestyle (conditions that promote hyperglycemic episodes). On this basis, the present review is particularly focused on: (i) the role of diabetes in the development of some bacterial and viral infections by analyzing preclinical and clinical findings; (ii) discussing the possible mechanisms by which hyperglycemia may increase the susceptibility for developing infections; and (iii) further understanding the impact of hyperglycemia on the immune system.


Subject(s)
Bacterial Infections/etiology , COVID-19/etiology , Diabetes Complications/immunology , Diabetes Complications/physiopathology , Disease Susceptibility , Hyperglycemia/complications , Virus Diseases/etiology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged
11.
Best Pract Res Clin Gastroenterol ; 46-47: 101689, 2020.
Article in English | MEDLINE | ID: covidwho-1081345

ABSTRACT

Survival following liver transplantation has changed dramatically owing to improvement in surgical techniques, peri-operative care and optimal immunosuppressive therapy. Post-Liver transplant (LT) de novo or recurrent viral infection continues to cause major allograft dysfunction, leading to poor graft and patient survival in untreated patients. Availability of highly effective antiviral drugs has significantly improved post-LT survival. Patients transplanted for chronic hepatitis B infection should receive life-long nucleos(t)ide analogues, with or without HBIg for effective viral control. Patients with chronic hepatitis C should be commenced on directly acting antiviral (DAA) drugs prior to transplantation. DAA therapy for post-LT recurrent hepatitis C infection is associated with close to 100% sustained virological response (SVR), irrespective of genotype. De novo chronic Hepatitis E infection is an increasingly recognised cause of allograft dysfunction in LT recipients. Untreated chronic HEV infection of the graft may lead to liver fibrosis and allograft failure. CMV and EBV can reactivate leading to systemic illness following liver transplantation. With COVID-19 pandemic, post-transplant patients are at risk of SARS-Co-V2 infection. Majority of the LT recipients require hospitalization, and the mortality in this population is around 20%. Early recognition of allograft dysfunction and identification of viral aetiology is essential in the management of post-LT de novo or recurrent infections. Optimising immunosuppression is an important step in reducing the severity of allograft damage in the treatment of post-transplant viral infections. Viral clearance or control can be achieved by early initiation of high potency antiviral therapy.


Subject(s)
Liver Transplantation/adverse effects , Virus Diseases/etiology , Humans , Liver Transplantation/mortality , Recurrence , Risk Factors , Survival Analysis
12.
Crit Rev Microbiol ; 47(3): 307-322, 2021 May.
Article in English | MEDLINE | ID: covidwho-1078679

ABSTRACT

The ongoing COVID-19 pandemic has made us wonder what led to its occurrence and what can be done to avoid such events in the future. As we document, one changing circumstance that is resulting in the emergence and changing the expression of viral diseases in both plants and animals is climate change. Of note, the rapidly changing environment and weather conditions such as excessive flooding, droughts, and forest fires have raised concerns about the global ecosystem's security, sustainability, and balance. In this review, we discuss the main consequences of climate change and link these to how they impact the appearance of new viral pathogens, how they may facilitate transmission between usual and novel hosts, and how they may also affect the host's ability to manage the infection. We emphasize how changes in temperature and humidity and other events associated with climate change influence the reservoirs of viral infections, their transmission by insects and other intermediates, their survival outside the host as well the success of infection in plants and animals. We conclude that climate change has mainly detrimental consequences for the emergence, transmission, and outcome of viral infections and plead the case for halting and hopefully reversing this dangerous event.


Subject(s)
COVID-19/transmission , Climate Change , Communicable Diseases, Emerging/transmission , Plant Diseases/virology , Virus Diseases/transmission , Animals , Aquatic Organisms/virology , COVID-19/complications , COVID-19/etiology , COVID-19/immunology , Chiroptera/virology , Communicable Diseases, Emerging/complications , Communicable Diseases, Emerging/etiology , Communicable Diseases, Emerging/immunology , Crops, Agricultural/virology , Disease Reservoirs/virology , Disease Vectors/classification , Food Supply , Humans , Humidity , Plant Diseases/immunology , Primate Diseases/transmission , Primate Diseases/virology , Primates , Rain , Seasons , Temperature , Virus Diseases/complications , Virus Diseases/etiology , Virus Diseases/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...