pathogenic viruses
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2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Palayakotai R. Raghavan

Increasing outbreaks of new pathogenic viruses have promoted the exploration of novel alternatives to time-consuming vaccines. Thus, it is necessary to develop a universal approach to halt the spread of new and unknown viruses as they are discovered. One such promising approach is to target lipid membranes, which are common to all viruses and bacteria. The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has reaffirmed the importance of interactions between the virus envelope and the host cell plasma membrane as a critical mechanism of infection. Metadichol®, a nanolipid emulsion of long-chain alcohols, has been demonstrated as a strong candidate that inhibits the proliferation of SARS-CoV-2. Naturally derived substances, such as long-chain saturated lipid alcohols, reduce viral infectivity, including that of coronaviruses (such as SARS-CoV-2) by modifying their lipid-dependent attachment mechanism to human host cells. The receptor ACE2 mediates the entry of SARS-CoV-2 into the host cells, whereas the serine protease TMPRSS2 primes the viral S protein. In this study, Metadichol® was found to be 270 times more potent an inhibitor of TMPRSS2 ( E C 50 = 96   ng / mL ) than camostat mesylate ( E C 50 = 26000   ng / mL ). Additionally, it inhibits ACE with an EC50 of 71 ng/mL, but it is a very weak inhibitor of ACE2 at an EC50 of 31 μg/mL. Furthermore, the live viral assay performed in Caco-2 cells revealed that Metadichol® inhibits SARS-CoV-2 replication at an EC90 of 0.16 μg/mL. Moreover, Metadichol® had an EC90 of 0.00037 μM, making it 2081 and 3371 times more potent than remdesivir ( E C 50 = 0.77   μ M ) and chloroquine ( E C 50 = 1.14   μ M ), respectively.


2022 ◽  
Vol 8 ◽  
Author(s):  
Zhenkai Tong ◽  
Wenfeng He ◽  
Xiao Fan ◽  
Aiwei Guo

Plant tannins are widely found in plants and can be divided into hydrolyzed tannins and condensed tannins. In recent years, researchers have become more and more interested in using tannin-rich plants and plant extracts in ruminant diets to improve the quality of animal products. Some research results show that plant tannins can effectively improve the quality of meat and milk, and enhance the oxidative stability of the product. In this paper, the classification and extraction sources of plant tannins are reviewed, as well as the biological functions of plant tannins in animals. The antioxidant function of plant tannins is discussed, and the influence of their structure on antioxidation is analyzed. The effects of plant tannins against pathogenic bacteria and the mechanism of action are discussed, and the relationship between antibacterial action and antioxidant action is analyzed. The inhibitory effect of plant tannins on many kinds of pathogenic viruses and their action pathways are discussed, as are the antiparasitic properties of plant tannins. The anti-inflammatory action of tannins and its mechanism are analyzed. The function of plant tannins in antidiarrheal action and its influencing factors are discussed. In addition, the effects of plant tannins as feed additives on animals and the influencing factors are reviewed in this paper to provide a reference for further research.


2022 ◽  
Vol 12 ◽  
Author(s):  
Felix B. He ◽  
Hira Khan ◽  
Moona Huttunen ◽  
Pekka Kolehmainen ◽  
Krister Melén ◽  
...  

Filovirus family consists of highly pathogenic viruses that have caused fatal outbreaks especially in many African countries. Previously, research focus has been on Ebola, Sudan and Marburg viruses leaving other filoviruses less well studied. Filoviruses, in general, pose a significant global threat since they are highly virulent and potentially transmissible between humans causing sporadic infections and local or widespread epidemics. Filoviruses have the ability to downregulate innate immunity, and especially viral protein 24 (VP24), VP35 and VP40 have variably been shown to interfere with interferon (IFN) gene expression and signaling. Here we systematically analyzed the ability of VP24 proteins of nine filovirus family members to interfere with retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated antigen 5 (MDA5) induced IFN-β and IFN-λ1 promoter activation. All VP24 proteins were localized both in the cell cytoplasm and nucleus in variable amounts. VP24 proteins of Zaire and Sudan ebolaviruses, Lloviu, Taï Forest, Reston, Marburg and Bundibugyo viruses (EBOV, SUDV, LLOV, TAFV, RESTV, MARV and BDBV, respectively) were found to inhibit both RIG-I and MDA5 stimulated IFN-β and IFN-λ1 promoter activation. The inhibition takes place downstream of interferon regulatory factor 3 phosphorylation suggesting the inhibition to occur in the nucleus. VP24 proteins of Mengla (MLAV) or Bombali viruses (BOMV) did not inhibit IFN-β or IFN-λ1 promoter activation. Six ebolavirus VP24s and Lloviu VP24 bound tightly, whereas MARV and MLAV VP24s bound weakly, to importin α5, the subtype that regulates the nuclear import of STAT complexes. MARV and MLAV VP24 binding to importin α5 was very weak. Our data provides new information on the innate immune inhibitory mechanisms of filovirus VP24 proteins, which may contribute to the pathogenesis of filovirus infections.


Author(s):  
Songyi Ning ◽  
Ziyuan Dai ◽  
Chunyan Zhao ◽  
Zhanghao Feng ◽  
Kexin Jin ◽  
...  

2022 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Tautvydas Shuipys ◽  
Naim Montazeri

Murine hepatitis virus (MHV) is a non-human pathogen betacoronavirus that is evolutionarily and structurally related to the human pathogenic viruses SARS-CoV, MERS-CoV, and SARS-CoV-2. However, unlike the human SARS and MERS viruses, MHV requires a biosafety level 2 laboratory for propagating and safe handling, making it a potentially suitable surrogate virus. Despite this utility, few papers discussed the propagation and quantification of MHV using cell lines readily available in biorepositories making their implementations not easily reproducible. This article provides protocols for propagating and quantifying MHV-A59 using the recommended NCTC clone 1469 and clone 929 cell lines from American Type Culture Collection (ATCC). More specifically, the methods detail reviving cells, routine cell passaging, preparing freeze stocks, infection of NCTC clone 1469 with MHV and subsequent harvesting, and plaque assay quantification of MHV using NCTC clone 929 cells. Using these protocols, a BSL-2 laboratory equipped for cell culture work would generate at least 6.0 log plaque-forming units (PFU) per mL of MHV lysate and provide an optimized overlay assay using either methylcellulose or agarose as overlays for the titration of infectious virus particles. The protocols described here are intended to be utilized for persistence and inactivation studies of coronaviruses.


Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 35
Author(s):  
Bimalendu Ray ◽  
Imran Ali ◽  
Subrata Jana ◽  
Shuvam Mukherjee ◽  
Saikat Pal ◽  
...  

Only a mere fraction of the huge variety of human pathogenic viruses can be targeted by the currently available spectrum of antiviral drugs. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has highlighted the urgent need for molecules that can be deployed quickly to treat novel, developing or re-emerging viral infections. Sulfated polysaccharides are found on the surfaces of both the susceptible host cells and the majority of human viruses, and thus can play an important role during viral infection. Such polysaccharides widely occurring in natural sources, specifically those converted into sulfated varieties, have already proved to possess a high level and sometimes also broad-spectrum antiviral activity. This antiviral potency can be determined through multifold molecular pathways, which in many cases have low profiles of cytotoxicity. Consequently, several new polysaccharide-derived drugs are currently being investigated in clinical settings. We reviewed the present status of research on sulfated polysaccharide-based antiviral agents, their structural characteristics, structure–activity relationships, and the potential of clinical application. Furthermore, the molecular mechanisms of sulfated polysaccharides involved in viral infection or in antiviral activity, respectively, are discussed, together with a focus on the emerging methodology contributing to polysaccharide-based drug development.


2021 ◽  
Vol 8 ◽  
Author(s):  
Md Abu Noman ◽  
Jun Sun ◽  
Mohammad Belal Hossain

The world has already experienced the severe adverse effects of COVID-19 at every level. When it became understood that the COVID-19 infection is spread in the community via respiratory transmission from humans, then the widespread use of plastic-made personal protective equipments (PPEs) like face masks and hand gloves tremendously increased throughout the world. Although it has reduced the spreading of virus, however, careless disposal or mismanagement of these single use PPEs has created another major concern for the environment, as plastics are a known source of environmental contamination. On one hand, they are infected with SARS-CoV-2, while on the other, they act as a carrier or vector or pathway for other pathogens or diseases, and hence can increase the degree of continuing the pandemic. Besides, there might be a chance that plastics or microplastics may be responsible for introducing new pathogenic viruses or bacteria to humankind. As such, it is clear that more research needs to be conducted to clarify this fact, and its underlying mechanisms. In this review, we briefly explored how PPE used in the COVID-19 pandemic aggravated existing microplastic pollution, how they could act as disease routes or vectors, and how they could introduce new pathogens to the terrestrial and marine environment. Addressing these questions may create awareness of plastic use, waste management, and enact relevant policy which may protect our environment and health.


Author(s):  
Anders Melin

Synthetic biology has many valuable applications, but it also gives rise to certain risks. In this paper I discuss the risk of bioterrorism, which often attracts attention in both the mass media and scientific debate, as well as in government reports. While some authors argue that there is a significant risk of bioterrorism connected to synthetic biology, other scholars claim that the risk is exaggerated and that actors often have motives for overstating the risk. In this paper, I argue that some estimates of the risk may be overstated but that certain risks of bioterrorism, such as the creation and spread of known pathogenic viruses, need to be taken seriously. Actors may also have scientific and financial motives for understating the risk. Such understatements are sometimes based on a principle of hope, which says that technological progress is important for the future welfare of humanity and that too much precaution would have bad consequences. I argue that this principle is problematic as the burdens and benefits of synthetic biology may not be equally divided between different social groups. Instead, I claim that the principle of precaution is more justified as a point of departure for assessing advancements within synthetic biology. It tells us that we need strong evidence that such advancements are safe, because there is a potential risk that they may make it easier for terrorist groups to create and spread known pathogenic viruses.


mBio ◽  
2021 ◽  
Author(s):  
Boris Bogdanow ◽  
Quang Vinh Phan ◽  
Lüder Wiebusch

Cytomegaloviruses (CMVs) are among the largest pathogenic viruses in mammals. To enable replication of their long double-stranded DNA genomes, CMVs induce profound changes in cell cycle regulation.


2021 ◽  
Author(s):  
Pascal Mutz ◽  
Nash D. Rochman ◽  
Yuri I. Wolf ◽  
Guilhem Faure ◽  
Feng Zhang ◽  
...  

AbstractMany pathogenic viruses are endemic among human populations and can cause a broad variety of diseases, some potentially leading to devastating pandemics. How virus populations maintain diversity and what selective pressures drive population turnover, is not thoroughly understood. We conducted a large-scale phylodynamic analysis of 27 human pathogenic RNA viruses spanning diverse life history traits in search of unifying trends that shape virus evolution. For most virus species, we identify multiple, co-circulating lineages with low turnover rates. These lineages appear to be largely noncompeting and likely occupy semi-independent epidemiological niches that are not regionally or seasonally defined. Typically, intra-lineage mutational signatures are similar to inter-lineage signatures. The principal exception are members of the family Picornaviridae, for which mutations in capsid protein genes are primarily lineage-defining. The persistence of virus lineages appears to stem from limited outbreaks within small communities so that only a minor fraction of the global susceptible population is infected at any time. As disparate communities become increasingly connected through globalization, interaction and competition between lineages might increase as well, which could result in changing selective pressures and increased diversification and/or pathogenicity. Thus, in addition to zoonotic events, ongoing surveillance of familiar, endemic viruses appears to merit global attention with respect to the prevention or mitigation of future pandemics.SignificanceNumerous pathogenic viruses are endemic in humans and cause a broad variety of diseases, but what is their potential of causing new pandemics? We show that most human pathogenic RNA viruses form multiple, co-circulating lineages with low turnover rates. These lineages appear to be largely noncompeting and occupy distinct epidemiological niches that are not regionally or seasonally defined, and their persistence appears to stem from limited outbreaks in small communities so that a minor fraction of the global susceptible population is infected at any time. However, due to globalization, interaction and competition between lineages might increase, potentially leading to increased diversification and pathogenicity. Thus, endemic viruses appear to merit global attention with respect to the prevention of future pandemics.


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