scholarly journals N6-Methyladenosine Modification and Its Regulation of Respiratory Viruses

2021 ◽  
Vol 9 ◽  
Author(s):  
Qianyu Feng ◽  
Hongwei Zhao ◽  
Lili Xu ◽  
Zhengde Xie
Keyword(s):  
Life Cycle ◽  
Disease Burden ◽  
Respiratory Virus ◽  
Respiratory Viruses ◽  
Host Immunity ◽  
Rna Modification ◽  
Host Interactions ◽  
Wide Range ◽  
Pathogenic Viruses

N6-methyladenosine (m6A) is a ubiquitous RNA modification in eukaryotes. It plays important roles in the translocation, stabilization and translation of mRNA. Many recent studies have shown that the dysregulation of m6A modification is connected with diseases caused by pathogenic viruses, and studies on the role of m6A in virus-host interactions have shown that m6A plays a wide range of regulatory roles in the life cycle of viruses. Respiratory viruses are common pathogens that can impose a large disease burden on young children and elderly people. Here, we review the effects of m6A modification on respiratory virus replication and life cycle and host immunity against viruses.

scholarly journals The Role of Host-Generated H2S in Microbial Pathogenesis: New Perspectives on Tuberculosis

2020 ◽  
Vol 10 ◽  
Author(s):  
Md. Aejazur Rahman ◽  
Joel N. Glasgow ◽  
Sajid Nadeem ◽  
Vineel P. Reddy ◽  
Ritesh R. Sevalkar ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Hydrogen Sulfide ◽  
Host Immunity ◽  
Microbial Pathogens ◽  
Microbial Pathogenesis ◽  
Enzymatic Production ◽  
Growth And Survival ◽  
Wide Range

For centuries, hydrogen sulfide (H2S) was considered primarily as a poisonous gas and environmental hazard. However, with the discovery of prokaryotic and eukaryotic enzymes for H2S production, breakdown, and utilization, H2S has emerged as an important signaling molecule in a wide range of physiological and pathological processes. Hence, H2S is considered a gasotransmitter along with nitric oxide (•NO) and carbon monoxide (CO). Surprisingly, despite having overlapping functions with •NO and CO, the role of host H2S in microbial pathogenesis is understudied and represents a gap in our knowledge. Given the numerous reports that followed the discovery of •NO and CO and their respective roles in microbial pathogenesis, we anticipate a rapid increase in studies that further define the importance of H2S in microbial pathogenesis, which may lead to new virulence paradigms. Therefore, this review provides an overview of sulfide chemistry, enzymatic production of H2S, and the importance of H2S in metabolism and immunity in response to microbial pathogens. We then describe our current understanding of the role of host-derived H2S in tuberculosis (TB) disease, including its influences on host immunity and bioenergetics, and on Mycobacterium tuberculosis (Mtb) growth and survival. Finally, this review discusses the utility of H2S-donor compounds, inhibitors of H2S-producing enzymes, and their potential clinical significance.

scholarly journals The role of the liver in the migration of parasites of global significance

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Gwendoline Deslyper ◽  
Derek G. Doherty ◽  
James C. Carolan ◽  
Celia V. Holland
Keyword(s):  
Life Cycle ◽  
Molecular Mechanisms ◽  
Immune Status ◽  
Host Immunity ◽  
Morbidity And Mortality ◽  
Different Tissues

Abstract Many parasites migrate through different tissues during their life-cycle, possibly with the aim to enhance their fitness. This is true for species of three parasite genera of global importance, Ascaris, Schistosoma and Plasmodium, which cause significant global morbidity and mortality. Interestingly, these parasites all incorporate the liver in their life-cycle. The liver has a special immune status being able to preferentially induce tolerance over immunity. This function may be exploited by parasites to evade host immunity, with Plasmodium spp. in particular using this organ for its multiplication. However, hepatic larval attrition occurs in both ascariasis and schistosomiasis. A better understanding of the molecular mechanisms involved in hepatic infection could be useful in developing novel vaccines and therapies for these parasites.

scholarly journals Recent Updates on Research Models and Tools to Study Virus–Host Interactions at the Placenta

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 5 ◽  
Author(s):  
Jae Kyung Lee ◽  
Soo-Jin Oh ◽  
Hosun Park ◽  
Ok Sarah Shin
Keyword(s):  
Viral Infections ◽  
Protective Role ◽  
Biological Mechanisms ◽  
Cellular Targets ◽  
Host Interactions ◽  
Wide Range ◽  
Hofbauer Cells ◽  
Maternal Fetal Transmission ◽  
Immunological Barrier

The placenta is a unique mixed organ, composed of both maternal and fetal tissues, that is formed only during pregnancy and serves as the key physiological and immunological barrier preventing maternal–fetal transmission of pathogens. Several viruses can circumvent this physical barrier and enter the fetal compartment, resulting in miscarriage, preterm birth, and birth defects, including microcephaly. The mechanisms underlying viral strategies to evade the protective role of placenta are poorly understood. Here, we reviewed the role of trophoblasts and Hofbauer cells in the placenta and have highlighted characteristics of vertical and perinatal infections caused by a wide range of viruses. Moreover, we explored current progress and future opportunities in cellular targets, pathogenesis, and underlying biological mechanisms of congenital viral infections, as well as novel research models and tools to study the placenta.

scholarly journals HIV reprograms host m6Am RNA methylome by viral Vpr protein-mediated degradation of PCIF1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiong Zhang ◽  
Yuqi Kang ◽  
Shaobo Wang ◽  
Gwendolyn Michelle Gonzalez ◽  
Wanyu Li ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Hiv Infection ◽  
Viral Protein ◽  
Rna Modification ◽  
Hiv Replication ◽  
Dramatic Decrease ◽  
Host Interactions ◽  
Cellular Mrnas

AbstractN6,2′-O-dimethyladenosine (m6Am) is an abundant RNA modification located adjacent to the 5′-end of the mRNA 7-methylguanosine (m7G) cap structure. m6A methylation on 2′-O-methylated A at the 5′-ends of mRNAs is catalyzed by the methyltransferase Phosphorylated CTD Interacting Factor 1 (PCIF1). The role of m6Am and the function of PCIF1 in regulating host–pathogens interactions are unknown. Here, we investigate the dynamics and reprogramming of the host m6Am RNA methylome during HIV infection. We show that HIV infection induces a dramatic decrease in m6Am of cellular mRNAs. By using PCIF1 depleted T cells, we identify 2237 m6Am genes and 854 are affected by HIV infection. Strikingly, we find that PCIF1 methyltransferase function restricts HIV replication. Further mechanism studies show that HIV viral protein R (Vpr) interacts with PCIF1 and induces PCIF1 ubiquitination and degradation. Among the m6Am genes, we find that PCIF1 inhibits HIV infection by enhancing a transcription factor ETS1 (ETS Proto-Oncogene 1, transcription factor) stability that binds HIV promoter to regulate viral transcription. Altogether, our study discovers the role of PCIF1 in HIV–host interactions, identifies m6Am modified genes in T cells which are affected by viral infection, and reveals how HIV regulates host RNA epitranscriptomics through PCIF1 degradation.

scholarly journals Prevalence of Co-Infections With Respiratory Viruses in Individuals Investigated for Sars-Cov-2 in Ontario, Canada

2020 ◽  
Author(s):  
Adriana Peci ◽  
Vanessa Tran ◽  
Jennifer L Gurtherie ◽  
Ye Li ◽  
Paul Nelson ◽  
...  
Keyword(s):  
Respiratory Symptoms ◽  
Patient Management ◽  
Respiratory Virus ◽  
Severe Disease ◽  
Respiratory Viruses ◽  
Single Infection ◽  
Clinical Testing ◽  
Routine Testing ◽  
Wide Range ◽  
Bacteria And Fungi

Background: Co-infections of SARS-CoV-2 with respiratory viruses, bacteria and fungi have been reported to cause a wide range of illness. Objectives: We asses s the prevalence of co-infection of SARS-CoV-2 with seasonal respiratory viruses, document the respiratory viruses detected among individuals tested for SARS-CoV-2, and describe characteristics of individuals with respiratory virus co-infection detected. Methods: Specimens included in this study were submitted as part of routine clinical testing to Public Health Ontario Laboratory from individuals requiring testing for SARS-CoV-2 and/or seasonal respiratory viruses. Results: Co-infection was detected in a smaller proportion (2.5%) of individuals with laboratory confirmed SARS-CoV-2 than those with seasonal respiratory viruses (4.3%); this difference was not significant. Individuals with any respiratory virus co-infection were more likely to be younger than 65 years of age and male than those with single infection. Those with SARS-CoV-2 co-infection manifested mostly mild respiratory symptoms. Conclusions: Findings of this study may not support routine testing for seasonal respiratory viruses among all individuals tested for SARS-CoV-2, as they were rare during the study period nor associated with severe disease. However, testing for seasonal respiratory viruses should be performed in severely ill individuals, in which detection of other viruses may assist with patient management.

scholarly journals Surveillance of respiratory viruses among children attending a primary school in rural coastal Kenya

2020 ◽  
Vol 5 ◽  
pp. 63 ◽  
Author(s):  
Irene Wangwa Adema ◽  
Everlyn Kamau ◽  
Joyce Uchi Nyiro ◽  
Grieven P. Otieno ◽  
Clement Lewa ◽  
...  
Keyword(s):  
Primary School ◽  
School Children ◽  
Respiratory Virus ◽  
Healthcare Facility ◽  
Respiratory Viruses ◽  
Outpatient Setting ◽  
Nasopharyngeal Swab ◽  
Coastal Kenya ◽  
Syncytial Virus

Background: Respiratory viruses are primary agents of respiratory tract diseases. Knowledge on the types and frequency of respiratory viruses affecting school-children is important in determining the role of schools in transmission in the community and identifying targets for interventions. Methods: We conducted a one-year (term-time) surveillance of respiratory viruses in a rural primary school in Kilifi County, coastal Kenya between May 2017 and April 2018. A sample of 60 students with symptoms of ARI were targeted for nasopharyngeal swab (NPS) collection weekly.  Swabs were screened for 15 respiratory virus targets using real time PCR diagnostics. Data from respiratory virus surveillance at the local primary healthcare facility was used for comparison. Results: Overall, 469 students aged 2-19 years were followed up for 220 days. A total of 1726 samples were collected from 325 symptomatic students; median age of 7 years (IQR 5-11). At least one virus target was detected in 384 (22%) of the samples with a frequency of 288 (16.7%) for rhinovirus, 47 (2.7%) parainfluenza virus, 35 (2.0%) coronavirus, 15 (0.9%) adenovirus, 11 (0.6%) respiratory syncytial virus (RSV) and 5 (0.3%) influenza virus.  The proportion of virus positive samples was higher among lower grades compared to upper grades (25.9% vs 17.5% respectively; χ2 = 17.2, P -value <0.001). Individual virus target frequencies did not differ by age, sex, grade, school term or class size. Rhinovirus was predominant in both the school and outpatient setting. Conclusion: Multiple respiratory viruses circulated in this rural school population.  Rhinovirus was dominant in both the school and outpatient setting and RSV was of notably low frequency in the school. The role of school children in transmitting viruses to the household setting is still unclear and further studies linking molecular data to contact patterns between the school children and their households are required.

scholarly journals Phyto-oestrogens through the life cycle

2000 ◽  
Vol 59 (3) ◽  
pp. 489-496 ◽  
Author(s):  
Aedin Cassidy ◽  
Marian Faughnan
Keyword(s):  
Life Cycle ◽  
Human Health ◽  
Intestinal Microflora ◽  
Human Subjects ◽  
Epidemiological Data ◽  
Potential Health ◽  
Wide Range

The growing interest in the role of phyto-oestrogens in human health has prompted scientists to evaluate the risk : benefit which would result from consuming high levels of these compounds at different stages of the life cycle. These compounds have been shown to exert a wide range of hormonal and non-hormonal activities in animals and in vitro, and these activities suggest plausible mechanisms for potential health effects in human subjects consuming phyto-oestrogen-rich diets. In addition, experimental and epidemiological data are available supporting the concept that phyto-oestrogen-rich diets exert physiological effects in vivo; however, their relative importance to human health remains to be elucidated. Our understanding of factors involved in their absorption and metabolism, including the role of intestinal microflora, is limited, and these factors together with dose-related effects may well be important in determining clinical efficacy.

scholarly journals The Role of Deubiquitinases in Oncovirus and Host Interactions

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yueshuo Li ◽  
Feng Shi ◽  
Jianmin Hu ◽  
Longlong Xie ◽  
Ann M. Bode ◽  
...  
Keyword(s):  
Life Cycle ◽  
Signaling Pathways ◽  
Protein Function ◽  
Deubiquitinating Enzymes ◽  
Antiviral Signaling ◽  
Host Interactions ◽  
Cellular Processes ◽  
Ubiquitin System ◽  
Almost All

Infection-related cancer comprises one-sixth of the global cancer burden. Oncoviruses can directly or indirectly contribute to tumorigenesis. Ubiquitination is a dynamic and reversible posttranslational modification that participates in almost all cellular processes. Hijacking of the ubiquitin system by viruses continues to emerge as a central theme around the viral life cycle. Deubiquitinating enzymes (DUBs) maintain ubiquitin homeostasis by removing ubiquitin modifications from target proteins, thereby altering protein function, stability, and signaling pathways, as well as acting as key mediators between the virus and its host. In this review, we focus on the multiple functions of DUBs in RIG-I-like receptors (RLRs) and stimulator of interferon genes (STING)-mediated antiviral signaling pathways, oncoviruses regulation of NF-κB activation, oncoviral life cycle, and the potential of DUB inhibitors as therapeutic strategies.

scholarly journals Surveillance of respiratory viruses among children attending a primary school in rural coastal Kenya

2020 ◽  
Vol 5 ◽  
pp. 63
Author(s):  
Irene Wangwa Adema ◽  
Everlyn Kamau ◽  
Joyce Uchi Nyiro ◽  
Grieven P. Otieno ◽  
Clement Lewa ◽  
...  
Keyword(s):  
Primary School ◽  
School Children ◽  
Respiratory Virus ◽  
Healthcare Facility ◽  
Respiratory Viruses ◽  
Outpatient Setting ◽  
Nasopharyngeal Swab ◽  
Coastal Kenya ◽  
Syncytial Virus

Background: Respiratory viruses are primary agents of respiratory tract diseases. Knowledge on the types and frequency of respiratory viruses affecting school-children is important in determining the role of schools in transmission in the community and identifying targets for interventions. Methods: We conducted a one-year (term-time) surveillance of respiratory viruses in a rural primary school in Kilifi County, coastal Kenya between May 2017 and April 2018. A sample of 60 students with symptoms of ARI were targeted for nasopharyngeal swab (NPS) collection weekly.  Swabs were screened for 15 respiratory virus targets using real time PCR diagnostics. Data from respiratory virus surveillance at the local primary healthcare facility was used for comparison. Results: Overall, 469 students aged 2-19 years were followed up for 220 days. A total of 1726 samples were collected from 325 symptomatic students; median age of 7 years (IQR 5-11). At least one virus target was detected in 384 (22%) of the samples with a frequency of 288 (16.7%) for rhinovirus, 47 (2.7%) parainfluenza virus, 35 (2.0%) coronavirus, 15 (0.9%) adenovirus, 11 (0.6%) respiratory syncytial virus (RSV) and 5 (0.3%) influenza virus.  The proportion of virus positive samples was higher among lower grades compared to upper grades (25.9% vs 17.5% respectively; χ2 = 17.2, P -value <0.001). Individual virus target frequencies did not differ by age, sex, grade, school term or class size. Rhinovirus was predominant in both the school and outpatient setting. Conclusion: Multiple respiratory viruses circulated in this rural school population.  Rhinovirus was dominant in both the school and outpatient setting and RSV was of notably low frequency in the school. The role of school children in transmitting viruses to the household setting is still unclear and further studies linking molecular data to contact patterns between the school children and their households are required.

scholarly journals The Etiological Role of Common Respiratory Viruses in Acute Respiratory Infections in Older Adults: A Systematic Review and Meta-analysis

2019 ◽  
Vol 222 (Supplement_7) ◽  
pp. S563-S569 ◽  
Author(s):  
Ting Shi ◽  
Andrew Arnott ◽  
Indre Semogas ◽  
Ann R Falsey ◽  
Peter Openshaw ◽  
...  
Keyword(s):  
Older Adults ◽  
Disease Burden ◽  
Causal Attribution ◽  
Respiratory Viruses ◽  
Case Control ◽  
Case Control Studies ◽  
Significant Difference ◽  
Syncytial Virus ◽  
Tract Infections

Abstract Acute respiratory tract infections (ARI) constitute a substantial disease burden in adults and elderly individuals. We aimed to identify all case-control studies investigating the potential role of respiratory viruses in the etiology of ARI in older adults aged ≥65 years. We conducted a systematic literature review (across 7 databases) of case-control studies published from 1996 to 2017 that investigated the viral profile of older adults with and those without ARI. We then computed a pooled odds ratio (OR) with a 95% confidence interval and virus-specific attributable fraction among the exposed (AFE) for 8 common viruses: respiratory syncytial virus (RSV), influenza virus (Flu), parainfluenza virus (PIV), human metapneumovirus (HMPV), adenovirus (AdV), rhinovirus (RV), bocavirus (BoV), and coronavirus (CoV). From the 16 studies included, there was strong evidence of possible causal attribution for RSV (OR, 8.5 [95% CI, 3.9–18.5]; AFE, 88%), Flu (OR, 8.3 [95% CI, 4.4–15.9]; AFE, 88%), PIV (OR, not available; AFE, approximately 100%), HMPV (OR, 9.8 [95% CI, 2.3–41.0]; AFE, 90%), AdV (OR, not available; AFE, approximately 100%), RV (OR, 7.1 [95% CI, 3.7–13.6]; AFE, 86%) and CoV (OR, 2.8 [95% CI, 2.0–4.1]; AFE, 65%) in older adults presenting with ARI, compared with those without respiratory symptoms (ie, asymptomatic individuals) or healthy older adults. However, there was no significant difference in the detection of BoV in cases and controls. This review supports RSV, Flu, PIV, HMPV, AdV, RV, and CoV as important causes of ARI in older adults and provides quantitative estimates of the absolute proportion of virus-associated ARI cases to which a viral cause can be attributed. Disease burden estimates should take into account the appropriate AFE estimates (for older adults) that we report.

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