scholarly journals Roles of host small RNAs in the evolution and host tropism of coronaviruses

2021 ◽  
Author(s):  
Qingren Meng ◽  
Yanan Chu ◽  
Changjun Shao ◽  
Jing Chen ◽  
Jian Wang ◽  
...  
Keyword(s):  
Small Rnas ◽  
Viral Infections ◽  
Animal Origin ◽  
Epidemiological Modeling ◽  
Host Tropism ◽  
Adaptive Mutations ◽  
Human Lungs ◽  
Target Sites ◽  
Human Coronaviruses ◽  
Host Jumping

Abstract Human coronaviruses (CoVs) can cause respiratory infection epidemics that sometimes expand into globally relevant pandemics. All human CoVs have sister strains isolated from animal hosts and seem to have an animal origin, yet the process of host jumping is largely unknown. RNA interference (RNAi) is an ancient mechanism in many eukaryotes to defend against viral infections through the hybridization of host endogenous small RNAs (miRNAs) with target sites in invading RNAs. Here, we developed a method to identify potential RNAi-sensitive sites in the viral genome and discovered that human-adapted coronavirus strains had deleted some of their sites targeted by miRNAs in human lungs when compared to their close zoonic relatives. We further confirmed using a phylogenetic analysis that the loss of RNAi-sensitive target sites could be a major driver of the host-jumping process, and adaptive mutations that lead to the loss-of-target might be as simple as point mutation. Up-to-date genomic data of severe acute respiratory syndrome coronavirus 2 and Middle-East respiratory syndromes-CoV strains demonstrate that the stress from host miRNA milieus sustained even after their epidemics in humans. Thus, this study illustrates a new mechanism about coronavirus to explain its host-jumping process and provides a novel avenue for pathogenesis research, epidemiological modeling, and development of drugs and vaccines against coronavirus, taking into consideration these findings.

scholarly journals Persistent COVID-19 Symptoms Minimally Impact the Development of SARS-CoV-2-Specific T Cell Immunity

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 916
Author(s):  
Hengsheng Fang ◽  
Adam D. Wegman ◽  
Kianna Ripich ◽  
Heather Friberg ◽  
Jeffrey R. Currier ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Viral Infections ◽  
T Cell Immunity ◽  
N Protein ◽  
Cell Immunity ◽  
Public Health Challenge ◽  
Human Coronaviruses ◽  
Cellular Immune ◽  
Persistent Viral Infections ◽  
Insight Into

SARS-CoV-2 represents an unprecedented public health challenge. While the majority of SARS-CoV-2-infected individuals with mild-to-moderate COVID-19 resolve their infection with few complications, some individuals experience prolonged symptoms lasting for weeks after initial diagnosis. Persistent viral infections are commonly accompanied by immunologic dysregulation, but it is unclear if persistent COVID-19 impacts the development of virus-specific cellular immunity. To this end, we analyzed SARS-CoV-2-specific cellular immunity in convalescent COVID-19 patients who experienced eight days or fewer of COVID-19 symptoms or symptoms persisting for 18 days or more. We observed that persistent COVID-19 symptoms were not associated with the development of an overtly dysregulated cellular immune response. Furthermore, we observed that reactivity against the N protein from SARS-CoV-2 correlates with the amount of reactivity against the seasonal human coronaviruses 229E and NL63. These results provide insight into the processes that regulate the development of cellular immunity against SARS-CoV-2 and related human coronaviruses.

scholarly journals Aquatic Biota is Not Exempt from Coronavirus Infections: An Overview

2020 ◽  
Author(s):  
Gabriel Núñez-Nogueira ◽  
Andres Arturo Granados-Berber
Keyword(s):  
Marine Mammals ◽  
Viral Infections ◽  
Aquatic Organisms ◽  
Marine Sponges ◽  
Animal Origin ◽  
Aquatic Biota ◽  
Bird Populations ◽  
Terrestrial Environments ◽  
In The Wild ◽  
Human Health Effects

Coronaviruses are pathogens recognized for having an animal origin, commonly associated with terrestrial environments. However, although in a few cases, there are reports of their presence in aquatic organisms like fish, frogs, waterfowls and marine mammals. None of these cases has led to human health effects when contact with these infected organisms has taken place, whether they are alive or dead. Aquatic birds seem to be the main group carrying and circulating these types of viruses among healthy bird populations. Although the route of infection for CoVID-19 by water or aquatic organisms has not yet been observed in the wild, the relevance of its study is highlighted because there are cases of other viral infections known to have been transferred to humans by aquatic biota. It is encouraging to know that aquatic species, such as fish, marine mammals, and amphibians, shows very few cases of coronaviruses and that some other aquatic animals may also be a possible source of cure or treatment against then, as some evidence with algae and marine sponges suggest.

scholarly journals Aquatic Biota is Not Exempt from Coronavirus Infections: An Overview

2020 ◽  
Author(s):  
GABRIEL NÚÑEZ-NOGUEIRA ◽  
Andres Arturo Granados-Berber
Keyword(s):  
Marine Mammals ◽  
Viral Infections ◽  
Aquatic Organisms ◽  
Marine Sponges ◽  
Animal Origin ◽  
Aquatic Biota ◽  
Bird Populations ◽  
Terrestrial Environments ◽  
In The Wild ◽  
Human Health Effects

Coronaviruses are pathogens recognized for having an animal origin and commonly associated with terrestrial environments. However, although in few cases, there are reports of their presence in aquatic organisms like fish, crustaceans, waterfowls and marine mammals. None of these cases have even led to human health effects, when contact with these infected organisms, whether they are alive or dead. Aquatic birds seem to be the main group in carrying and circulating these types of viruses in healthy bird populations and play an important role in these environments. Although the route of infection for CoVID-19 (Coronavirus disease 2019) by water or aquatic organisms, has not yet been observed in the wild, the relevance of its study is highlighted , because there are cases of other viral infections (no coronavirus), which are known to have been transferred to the human by aquatic biota. What is even better, it becomes encouraging to know that aquatic species shows very few cases in fishes, marine mammals, and crustaceans, and some other aquatic animals may also be a possible source of cure or treatment against coronaviruses, as some evidence with algae and marine sponges suggests.

scholarly journals Detection of canonical A-to-G editing events at 3′ UTRs and microRNA target sites in human lungs using next-generation sequencing

Oncotarget ◽  
2015 ◽  
Vol 6 (34) ◽  
pp. 35726-35736 ◽  
Author(s):  
Ramani Soundararajan ◽  
Timothy M. Stearns ◽  
Anthony J. Griswold ◽  
Arpit Mehta ◽  
Alexander Czachor ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Next Generation ◽  
Microrna Target ◽  
Human Lungs ◽  
Target Sites ◽  
Generation Sequencing

scholarly journals Persistent viral infections in farm and companion animals: mechanisms of establishment and maintenance of viral persistence

2017 ◽  
Vol 55 (4) ◽  
pp. 353
Author(s):  
M. PAPANASTASOPOULOU (Μ. ΠΑΠΑΝΑΣΤΑΣΟΠΟΥΛΟΥ)
Keyword(s):  
Viral Infections ◽  
National Level ◽  
Companion Animals ◽  
Clinical Signs ◽  
Host Cells ◽  
Animal Origin ◽  
Economic Losses ◽  
Neoplastic Disease ◽  
Persistent Infections ◽  
Persistent Viral Infections

In persistent viral infections the responsible virus is not eliminated by the host's immune system, but it is maintained in infected cells for months, years or lifetime and it is excreted periodically or continuously. The carrier animal may either appear healthy or show clinical signs. The epizootiologic importance of persistent infections is of compelling interest, since the asymptomatic carriers become a permanent source of viral dissemination that can transport the virus across long-distances and reintroduce it into a given herd, region or country, where the disease had been eliminated. Moreover, a persistent viral infection may be reactivated and cause recrudescent episodes of disease, may lead to immunopathologic or neoplastic disease in the individual host and yet may be transmitted to other animals or to the humans via contaminated materials of animal origin. The economic losses are significant at both farm and national level. Fifty four RNA or DNA viruses induce persistent infections in farm and companion animals. In particular, 14 viruses cause persistent infections in bovines, 7 in small ruminants, 9 in swine, 11 in equines, 8 in cats and 5 in dogs. The majority of these infections are caused by retroviruses and herpesviruses. For a virus to establish and maintain persistent infection, it should have limited cytolytic action, it should be able to maintain its genome within host cells over time and to evade the immune defence mechanisms of the host. The preventive measures are largely based either on the immunization of susceptible animals or on the eradication of the disease by stamping-out policy. The currendy available vaccines are inactivated or live attenuated. Most of them are prepared by conventional methods, but they also exist those that are biotechnologicaUy engineered, such as vector vaccines marker vaccines or subunit vaccines. A major advantage related to the use of marker vaccines is that vaccinated animals can potentially be differentiated from the naturally infected ones by this process.

scholarly journals SARS-CoV-2 may regulate cellular responses through depletion of specific host miRNAs

2020 ◽  
Vol 319 (3) ◽  
pp. L444-L455 ◽  
Author(s):  
Rafal Bartoszewski ◽  
Michal Dabrowski ◽  
Bogdan Jakiela ◽  
Sadis Matalon ◽  
Kevin S. Harrod ◽  
...  
Keyword(s):  
Immune Responses ◽  
Mirna Target ◽  
Cellular Responses ◽  
Specific Host ◽  
Global Pandemic ◽  
Target Sites ◽  
Bioinformatic Approaches ◽  
Mirna Sponges ◽  
Human Coronaviruses ◽  
Respiratory Coronavirus

Cold viruses have generally been considered fairly innocuous until the appearance of the severe acute respiratory coronavirus 2 (SARS-CoV-2) in 2019, which caused the coronavirus disease 2019 (COVID-19) global pandemic. Two previous viruses foreshadowed that a coronavirus could potentially have devastating consequences in 2002 [severe acute respiratory coronavirus (SARS-CoV)] and in 2012 [Middle East respiratory syndrome coronavirus (MERS-CoV)]. The question that arises is why these viruses are so different from the relatively harmless cold viruses. On the basis of an analysis of the current literature and using bioinformatic approaches, we examined the potential human miRNA interactions with the SARS-CoV-2’s genome and compared the miRNA target sites in seven coronavirus genomes that include SARS-CoV-2, MERS-CoV, SARS-CoV, and four nonpathogenic coronaviruses. Here, we discuss the possibility that pathogenic human coronaviruses, including SARS-CoV-2, could modulate host miRNA levels by acting as miRNA sponges to facilitate viral replication and/or to avoid immune responses.

scholarly journals The Importance of Research on the Origin of SARS-CoV-2

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1203
Author(s):  
Kenneth Lundstrom ◽  
Murat Seyran ◽  
Damiano Pizzol ◽  
Parise Adadi ◽  
Tarek Mohamed Abd El-Aziz ◽  
...  
Keyword(s):  
Natural Selection ◽  
Receptor Binding ◽  
Hot Spot ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Host Tropism ◽  
Protein Receptor ◽  
Sialic Acid Binding ◽  
Human Coronaviruses ◽  
Very High

The origin of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus causing the COVID-19 pandemic has not yet been fully determined. Despite the consensus about the SARS-CoV-2 origin from bat CoV RaTG13, discrepancy to host tropism to other human Coronaviruses exist. SARS-CoV-2 also possesses some differences in its S protein receptor-binding domain, glycan-binding N-terminal domain and the surface of the sialic acid-binding domain. Despite similarities based on cryo-EM and biochemical studies, the SARS-CoV-2 shows higher stability and binding affinity to the ACE2 receptor. The SARS-CoV-2 does not appear to present a mutational “hot spot” as only the D614G mutation has been identified from clinical isolates. As laboratory manipulation is highly unlikely for the origin of SARS-CoV-2, the current possibilities comprise either natural selection in animal host before zoonotic transfer or natural selection in humans following zoonotic transfer. In the former case, despite SARS-CoV-2 and bat RaTG13 showing 96% identity some pangolin Coronaviruses exhibit very high similarity to particularly the receptor-binding domain of SARS-CoV-2. In the latter case, it can be hypothesized that the SARS-CoV-2 genome has adapted during human-to-human transmission and based on available data, the isolated SARS-CoV-2 genomes derive from a common origin. Before the origin of SARS-CoV-2 can be confirmed additional research is required

scholarly journals Secondary siRNAs in Plants: Biosynthesis, Various Functions, and Applications in Virology

2021 ◽  
Vol 12 ◽  
Author(s):  
Neeti Sanan-Mishra ◽  
A. Abdul Kader Jailani ◽  
Bikash Mandal ◽  
Sunil K. Mukherjee
Keyword(s):  
Gene Silencing ◽  
Small Rnas ◽  
Rna Silencing ◽  
Viral Infections ◽  
Natural Resistance ◽  
Virus Induced Gene Silencing ◽  
Systemic Spread ◽  
Secondary Sirnas ◽  
Silencing Pathways ◽  
Virus Interactions

The major components of RNA silencing include both transitive and systemic small RNAs, which are technically called secondary sRNAs. Double-stranded RNAs trigger systemic silencing pathways to negatively regulate gene expression. The secondary siRNAs generated as a result of transitive silencing also play a substantial role in gene silencing especially in antiviral defense. In this review, we first describe the discovery and pathways of transitivity with emphasis on RNA-dependent RNA polymerases followed by description on the short range and systemic spread of silencing. We also provide an in-depth view on the various size classes of secondary siRNAs and their different roles in RNA silencing including their categorization based on their biogenesis. The other regulatory roles of secondary siRNAs in transgene silencing, virus-induced gene silencing, transitivity, and trans-species transfer have also been detailed. The possible implications and applications of systemic silencing and the different gene silencing tools developed are also described. The details on mobility and roles of secondary siRNAs derived from viral genome in plant defense against the respective viruses are presented. This entails the description of other compatible plant–virus interactions and the corresponding small RNAs that determine recovery from disease symptoms, exclusion of viruses from shoot meristems, and natural resistance. The last section presents an overview on the usefulness of RNA silencing for management of viral infections in crop plants.

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