Role In Viral Infection Research Articles

Herpesvirus and endoplasmic reticulum stress

Endoplasmic reticulum (ER) is an important organelle where folding and post-translational modification of secretory and transmembrane proteins take place. During virus infection, cellular or viral unfolded and misfolded proteins accumulate in the ER in an event called ER stress. To maintain the equilibrium homeostasis of the ER, signal-transduction pathways, known as unfolded protein response (UPR), are activated. The viruses in turn manipulate UPR to maintain an environment favorable for virus survival and replication. Herpesviruses are enveloped DNA viruses that produce over 70 viral proteins. Modification and maturation of large quantities of viral glycosylated envelope proteins during virus replication may induce ER stress, while ER stress play both positive and negative roles in virus infection. Here we summarize the research progress of crosstalk between herpesvirus infection and the virus-induced ER stress.

Viral inosine triphosphatase: A mysterious enzyme with typical activity, but an atypical function.

Plant viruses typically have highly condensed genomes, yet the plant‐pathogenic viruses Cassava brown streak virus, Ugandan cassava brown streak virus, and Euphorbia ringspot virus are unusual in encoding an enzyme not yet found in any other virus, the “house‐cleaning” enzyme inosine triphosphatase. Inosine triphosphatases (ITPases) are highly conserved enzymes that occur in all kingdoms of life and perform a house‐cleaning function by hydrolysing the noncanonical nucleotide inosine triphosphate to inosine monophosphate. The ITPases encoded by cassava brown streak virus and Ugandan cassava brown streak virus have been characterized biochemically and are shown to have typical ITPase activity. However, their biological role in virus infection has yet to be elucidated. Here we review what is known of viral‐encoded ITPases and speculate on potential roles in infection with the aim of generating a greater understanding of cassava brown streak viruses, a group of the world's most devastating viruses.

The potential association between PARP14 and SARS-CoV-2 infection (COVID-19).

Understanding the potential association between the poly (ADP-ribose) polymerase member 14 (PARP14) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may aid in understanding the host immunopathological response to the virus. PARP14 has an emerging role in viral infections, and this article considers its potential mechanisms for action in either a pro- or anti-viral manner. It is evident that more experimental work is required; however, PARP14 appears vital in controlling the interferon response to the SARS-CoV-2 infection and has potential roles in balancing the proinflammatory cytokines of the cytokine storm. Furthermore, the SARS-CoV-2 macrodomain can prevent the PARP14-mediated antiviral response, suggesting a more complex relationship between PARP14 activity and SARS-CoV-2 infections.

Systematic identification of autophagy-related proteins in Aedes albopictus.

Autophagy is a conserved cellular process playing a role in maintenance of cellular homeostasis and response to changing nutrient conditions via degradation and recirculation of cellular redundant components. Autophagy-related proteins (Atg) play important function in autophagy pathway. Aedes albopictus mosquito is an effective vector transmitting multiple viruses which cause serious human diseases. Moreover, Aedes albopictus mosquito is becoming a serious threat to human health due to its widening distribution in recent years and thus worth of more research attention. It was reported that autophagy might play a role in viral infection in Aedes mosquito. To better understand the interaction between autophagy and arbovirus infection in mosquito system, it is necessary to identify autophagy pathway in the system. However, autophagy in Aedes albopictus mosquito is still poorly understood so far. We recently identified AaAtg8, the first Atg protein reported in Aedes albopictus mosquito. This work further identified twelve atg genes in Aedes albopictus mosquito. Sequence and phylogenetic analysis of the twelve atg genes were performed. Expression profiles of all the twelve Aaatg genes in different developmental stages and genders of Aedes albopictus mosquito were conducted. Effects of chemicals inhibiting or inducing autophagy on the levels of eight identified AaAtg proteins were examined. The function of two identified AaAtg proteins AaAtg6 and AaAtg16 and their response to arbovirus SINV infection were studied preliminarily. Taken together, this work systematically identified Aedes albopictus atg genes and provided basic information which might help to elucidate the autophagy pathway and the role of autophagy in arbovirus infection in Aedes mosquito system.

Elucidating Interactions Between SARS-CoV-2 Trimeric Spike Protein and ACE2 Using Homology Modeling and Molecular Dynamics Simulations.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). As of October 21, 2020, more than 41.4 million confirmed cases and 1.1 million deaths have been reported. Thus, it is immensely important to develop drugs and vaccines to combat COVID-19. The spike protein present on the outer surface of the virion plays a major role in viral infection by binding to receptor proteins present on the outer membrane of host cells, triggering membrane fusion and internalization, which enables release of viral ssRNA into the host cell. Understanding the interactions between the SARS-CoV-2 trimeric spike protein and its host cell receptor protein, angiotensin converting enzyme 2 (ACE2), is important for developing drugs and vaccines to prevent and treat COVID-19. Several crystal structures of partial and mutant SARS-CoV-2 spike proteins have been reported; however, an atomistic structure of the wild-type SARS-CoV-2 trimeric spike protein complexed with ACE2 is not yet available. Therefore, in our study, homology modeling was used to build the trimeric form of the spike protein complexed with human ACE2, followed by all-atom molecular dynamics simulations to elucidate interactions at the interface between the spike protein and ACE2. Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) and in silico alanine scanning were employed to characterize the interacting residues at the interface. Twenty interacting residues in the spike protein were identified that are likely to be responsible for tightly binding to ACE2, of which five residues (Val445, Thr478, Gly485, Phe490, and Ser494) were not reported in the crystal structure of the truncated spike protein receptor binding domain (RBD) complexed with ACE2. These data indicate that the interactions between ACE2 and the tertiary structure of the full-length spike protein trimer are different from those between ACE2 and the truncated monomer of the spike protein RBD. These findings could facilitate the development of drugs and vaccines to prevent SARS-CoV-2 infection and combat COVID-19.

Role of Viral Infections in Multiple Sclerosis Pathogenesis among Indian Population.

The role of viral infections in multiple sclerosis (MS) pathogenesis is unclear. Certain neurotropic viruses previously linked with MS among white population were studied including Epstein-Barr virus, human herpesvirus-6 (HHV-6) and MS-associated retrovirus (MSRV). Sixty-two MS patients (37 had a recent clinical relapse) and 65 controls with other neurological disorders were included. Blood and cerebrospinal fluid (CSF) samples were obtained and processed with the primary objective of determining whether there was intrathecal multiplication of viruses under study (EBV, HHV6 A and B and human endogenous retrovirus) or a breach in blood-brain barrier associated with viral presence in both peripheral blood and CSF. Evidence of breach in blood-brain barrier was seen in 86.5% of patients as evidenced by abnormal CSF/serum albumin index and or MRI. EBV nuclear antigen (EBNA1 IgG) was seen in 89% of MS patients and 58% controls (P = <0.001). However, HHV6 IgG was similar in both groups (85% versus 81%; P = 0.45). In affinity immunoblotting reaction intrathecal IgG synthesis against EBNA1 antigen was demonstrable in 26% (16/62) of patients and none against HHV6. A subset of patients showed significant elevation in mean copy number of plasma EBV DNA during relapse and there was a trend for the same among patients harboring HHV-6B. No evidence of isolated intrathecal viral presence or multiplication was seen. The results of our study suggest that viruses studied namely EBV and HHV6 have a role in triggering relapses through a peripheral mechanism, rather than a direct role through intrathecal multiplication.

One step carboxyl group isotopic labeling for quantitative analysis of intact N-glycopeptides by mass spectrometry.

Here, we have developed an approach termed methylamine stable isotope labeling (MeSIL) to relatively quantify N-glycopeptides through one step labeling. It is the first time that this approach is applied to measure N-glycopeptide changes in huh7 cells after Zika virus infection and it has been revealed that differentially expressed N-glycopeptides played important roles in virus infection at the glycosylation site-specific level.

As Evidence-Based Tumorigenic Role of Epstein-Barr Virus miR-BART1-3p in Neurological Tumors.

Introduction:Central nervous system tumors are a diverse group of tumors that account for 2% of all adult cancers and 17% of childhood malignancies. Several internal and external risk factors are involved in the development of this cancer such as viral infections. The aim of this study was to the determination of the EBV infection frequency and the expression level of miR-122 and miR-BART in CNS tumors samples. Methods:One hundred and thirty-eight fresh tissue sample (106 case and 32 control) was collected from CNS specimens. The presence of Epstein-Barr virus (EBV) DNA was examined by PCR assay and the expression level of miR-122 and miR-BART were evaluated by using real-time PCR assay in CNS tissue samples. Results:EBV DNA was detected in 17% (18 of 106) of tumors tissue samples and 6.4% (2 of 32) of control samples. according to results, there was a significant relationship between the presence of EBV-DNA with CNS tumors. Additionally, the expression level of miR-122 was significantly downregulated in the EBV-positive sample compared to that of the EBV-negative sample. Also, the level of EBV-BART1-3p expression was significantly higher in EBV-positive tumors samples than EBV-positive normal samples. Conclusion:The results of this study suggest that the EBV could change the condition of cancer cells by altering the expression of miR-122 and EBV-BART1-3p and maybe contribute to the development of cancer cells. However, the role of viral infections in CNS cancer requires further studies.

Biochemical role of zinc in dengue fever

Background: Zinc is an essential trace element that has been shown to play a crucial role in viral infections. As a part of RNA polymerases, zinc helps in the replication of many viruses. Cholinesterases are low-grade inflammatory markers that have zinc-dependent carboxypeptidase activity. Plasma butyrylcholine esterase is an indicator of dietary zinc level. Matrix metalloproteinases (MMP) that participate in inflammatory processes and contribute to tissue remodeling and repair are zinc containing endopeptidases. The present study attempts to establish the association of zinc with these enzymes in dengue. Materials and Methods: Plasma zinc, butyrylcholinesterase (BChE), and erythrocyte acetylcholinesterase (AChE) were estimated spectrophotometrically in 100 dengue patients and 50 healthy controls. MMP9 was determined using ELISA. Results: Plasma zinc was markedly lower in dengue fever patients compared to healthy controls (P

Activation of Heterophils and Monocytes in Chicken with a Formulation Containing a Seaweed Extract from Ulva armoricana

Responsiveness to invasive pathogens, clearance via the inflammatory response, and activation of appropriate acquired responses are all coordinated by innate host defenses. We have previously demonstrated that a purified ulvan extract of Ulva armoricana is able to activate avian heterophils and monocytes in vitro and in vivo , leading to in vivo release of cytokines including interleukin 1 β (IL1β), interferon α (IFNα) and interferon γ (IFNγ), in a transient and dose-dependent manner. In this study, we used the same protocol to evaluate a formulated version of this extract, called Searup ® . Our experiments showed that a single oral administration of this product at the dose recommended for use in the farm, results in heterophils and monocytes activation. In heterophils, activation was evidenced by β-D-glucuronidase release and increased mRNA expression of IL1β, IFNα and IFNγ. In monocytes, the expression of IFNγ and inducible nitrite oxide synthase (iNOS) were also up-regulated. Finally, plasmatic NO increased significantly on day 1, decreased on day 2 and was no longer significant at day 3. A similar pattern was observed for β-D-glucuronidase and for the modifications of the transcription profiles in monocytes as well as in heterophils. The only notable exception is gene transcription of 2'-5' Oligoadenylate Synthase, which is maximal at day 2 in monocytes. Due to its protective role in virus infection, this may constitute an additional layer of protection for this class of pathogens. Together our results show that the formulated solution, Searup ® , similarly to the purified extract allow to activate monocytes and heterophils but with some variations in the cytokines profiles and may provide protection against a larger variety of pathogens.

Structure-based design and characterization of novel fusion-inhibitory lipopeptides against SARS-CoV-2 and emerging variants

ABSTRACT The ongoing pandemic of COVID-19, caused by SARS-CoV-2, has severely impacted the global public health and socio-economic stability, calling for effective vaccines and therapeutics. In this study, we continued our efforts to develop more efficient SARS-CoV-2 fusion inhibitors and achieved significant findings. First, we found that the membrane-proximal external region (MPER) sequence of SARS-CoV-2 spike fusion protein plays a critical role in viral infectivity and can serve as an ideal template for design of fusion-inhibitory peptides. Second, a panel of novel lipopeptides was generated with greatly improved activity in inhibiting SARS-CoV-2 fusion and infection. Third, we showed that the new inhibitors maintained the potent inhibitory activity against emerging SARS-CoV-2 variants, including those with the major mutations of the B.1.1.7 and B.1.351 strains circulating in the United Kingdom and South Africa, respectively. Fourth, the new inhibitors also cross-inhibited other human CoVs, including SARS-CoV, MERS-CoV, HCoV-229E, and HCoV-NL63. Fifth, the structural properties of the new inhibitors were characterized by circular dichroism (CD) spectroscopy and crystallographic approach, which revealed the mechanisms underlying the high binding and inhibition. Combined, our studies provide important information for understanding the mechanism of SARS-CoV-2 fusion and a framework for the development of peptide therapeutics for the treatment of SARS-CoV-2 and other CoVs.

RNAi silencing of rice black-streaked dwarf virus P10 and two insect vector genes to reduce virus transmission protects rice plants against RBSDV

ABSTRACT Rice black-streaked dwarf virus (RBSDV) is a virus transmitted by Laodelphax striatellus (L. striatellus), which poses a serious threat to rice production. P10, a major outer capsid protein of RBSDV, which plays a key role in viral infection. In this study, two L. striatellus transmission-related proteins, novel cuticular protein (NCuP) and receptor for activated protein kinase C (RACK), were identified as interacting with P10. Results demonstrated that virus-induced NCuP and RACK were silenced using double-stranded RNA (dsRNA) to reduce the quantity of virus in L. striatellus. The detection results after inoculation of RBSDV by L. striatellus showed that rice plants sprayed with dsP10+NCuP and dsP10+RACK and transgenic rice plants expressing both had higher disease resistance than those expressing dsP10, dsNCuP and dsRACK alone. Therefore, simultaneously interfering with both the expression of viral protein and the proteins that interact with them from insect vectors could enhance the control of viral transmission.

A recent perspective on fiber and hexon genes proteins analyses of fowl adenovirus toward virus infectivity-A review.

Fowl adenovirus (FAdV) is a double-stranded DNA virus with a non-enveloped structure comprising three major proteins known as hexon, penton, and fiber. Molecular analysis which emphasizes on hexon and fiber proteins is currently the major focus of curiosity for FAdV antigenicity and pathogenicity. Recently, disease outbreaks associated with FAdV infections such as inclusion body hepatitis, hepatitis hydropericardium syndrome, and gizzard erosion, were commonly reported and continue to increase worldwide. Studies on the virulence gene of the virus were intensively conducted to provide a better understanding on the role of these major capsid proteins in the development of a safe and effective vaccine against the disease in the poultry industry. This paper highlights the variations of the fiber and hexon genes, their importance in genotypes and serotypes differentiation, and infectivity between FAdV strains. It appears that the L1 loop of hexon and the knob of fiber genes are the infectivity markers for FAdV infection. The fiber-2 protein plays a major role in FAdV pathogenicity than the hexon protein, while the fiber-1 protein is important for viral replication and assembly, regardless of virulence capability instead of infectivity. The hexon protein plays a major role in virus infectivity and tissue tropism. These findings could further enhance the knowledge of FAdV strains’ classification and evolution, diagnosis, and strategies to prevent and control FAdV infection and outbreaks in chicken farms.

DCs-based therapies: potential strategies in severe SARS-CoV-2 infection

Pneumonia caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is spreading globally. There have been strenuous efforts to reveal the mechanisms that the host defends itself against invasion by this virus. The immune system could play a crucial role in virus infection. Dendritic cell as sentinel of the immune system plays an irreplaceable role. Dendritic cells-based therapeutic approach may be a potential strategy for SARS-CoV-2 infection. In this review, the characteristics of coronavirus are described briefly. We focus on the essential functions of dendritic cell in severe SARS-CoV-2 infection. Basis of treatment based dendritic cells to combat coronavirus infections is summarized. Finally, we propose that the combination of DCs based vaccine and other therapy is worth further study.

ARMS as a Genotyping PCR, a New Technique for Detection of Liver Transplantation Recipients’ C3FF, C3FS, C3SS Allotypes as Predisposing Factor For Post-Transplantation Infections

Background: Complement is a crucial branch of both non-specific and specific immune system. C3 is the third complement component which plays a protective role in viral infections. There are two co-dominant inherited variants or allotypes for C3: C3 fast (C3F) and C3 slow (C3S). C3F variant has been linked to multiple diseases production including infections among liver transplantation recipients. Objectives: To investigate the most common risk factors for post-liver transplantation infections especially preoperative colonization. To identify types and rates of post-liver transplantation infections and their causing organisms. To identify C3 allotypes for both liver transplantation donors and recipients, and to correlate recipients’ allotypes with post-transplantation infections. Methodology: This study is a prospective study; it was conducted from January 2017 to August 2019 on 64 chronic cirrhotic patients, experienced liver transplantation in the National Liver Institute ICU, Menoufia, Egypt, and their donors. Blood cultures and other samples were collected according to site of infection using standard Microbiological sample collection methods and bacterial isolated were identified by standard microbiological methods using VITEK2 Compact automated ID/AST instrument. CMV IgG and IgM were detected by ELISA method. DNA was extracted and the extract was used for detection of C3S and C3F alleles by using Amplification Refractory Mutation System (ARMS). Results: The most common cause for liver transplantation was HCV related liver cirrhosis (26.56%). Risk factors for postliver transplantation were Pre-operative microbial colonization (100%) and long operative time (9.875±2.45 h). 39.8% of post-transplantation infections occurred during second week post-operatively and the commonest infections were drain infections (29.5%) and urinary tract infection (27.3%). 51.7% of liver transplantation recipients were C3FF, 32.8% were C3FS and 15.6% were C3SS. C3FF recipients showed increased relative risk to develop CMV (5.2) and bacterial &amp; fungal infections (2.2) than other recipients’ allotypes. Conclusion: A comprehensive infectious diseases workup including detection of C3 allotype of the candidate for liver transplantation should be done pre-operatively to early detect and treat infections which can improve the outcome of the operation dramatically and improve patients’ life style. More studies should be done to find out if there is relation between donors’ and recipients’ C3 allotypes as currently no clear data still present.

Proteomes, kinases and signalling pathways in virus-induced filopodia, as potential antiviral therapeutics targets.

SummaryFilopodia are thin finger‐like protrusions at the surface of cells that are internally occupied with bundles of tightly parallel actin filaments. They play significant roles in cellular physiological processes, such as adhesion to extracellular matrix, guidance towards chemo‐attractants and in wound healing. Filopodia were recently reported to play important roles in viral infection including initial viral attachment to host cells, cell surfing, viral trafficking, internalization, budding, virus release and spread to other cells in a form that would avoid the host immune system. The detailed virus‐host protein interactions underlying most of these processes remain to be elucidated. This review will describe some reported virus‐host protein interactions on filopodia with the aim of identifying potential new anti‐virus therapeutic targets. Exploring this research area may lead to the development of novel classes of anti‐viral therapeutics that can block signalling pathways used by the virus to trigger filopodia formation. Successful compounds would inhibit initial virus attachment, formation of filopodia, expression of putative virus binding protein, extracellular virus trafficking, and budding.

NSs, the Silencing Suppressor of Tomato Spotted Wilt Orthotospovirus, Interferes With JA-Regulated Host Terpenoids Expression to Attract Frankliniella occidentalis.

Tomato spotted wilt orthotospovirus (TSWV) causes serious crop losses worldwide and is transmitted by Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). NSs protein is the silencing suppressor of TSWV and plays an important role in virus infection, cycling, and transmission process. In this research, we investigated the influences of NSs protein on the interaction of TSWV, plants, and F. occidentalis with the transgenic Arabidopsis thaliana. Compared with the wild-type Col-0 plant, F. occidentalis showed an increased number and induced feeding behavior on transgenic Arabidopsis thaliana expressing exogenous NSs. Further analysis showed that NSs reduced the expression of terpenoids synthesis-related genes and the content of monoterpene volatiles in Arabidopsis. These monoterpene volatiles played a repellent role in respect to F. occidentalis. In addition, the expression level of plant immune-related genes and the content of the plant resistance hormone jasmonic acid (JA) in transgenic Arabidopsis were reduced. The silencing suppressor of TSWV NSs alters the emission of plant volatiles and reduces the JA-regulated plant defenses, resulting in enhanced attractiveness of plants to F. occidentalis and may increase the transmission probability of TSWV.

Druggability assessment of precursor membrane protein as a target for inhibiting the Zika virus

The Zika virus (ZIKV), a significant zoonotic flavivirus, was neglected as a human pathogen until the recent epidemic. The rapid geographic spread of the virus and association with neurological disorders has created a global public health concern pressing the need for anti-ZIKV drugs. Previous ZIKV drug discovery research has focused on three primary targets, RNA-dependent RNA polymerase, envelope protein, and viral proteases, and none has yet resulted in a commercially viable inhibitor. In the quest for finding effective inhibitors, it is important to expand the number of targets available for drug discovery research. To this end, the ZIKV precursor membrane protein (prM) comes to the forefront as a potential target due to its critical role in virus infectivity and pathogenicity. prM acts as a chaperone for envelope protein folding and prevents premature fusion of virions to the host membrane and has not been attempted as a drug target before. One critical requirement for a protein to be an effective target is the ability of the protein to be druggable, i.e. having active sites that can bind to specific ligands. In this work, the druggability of prM was assessed via molecular docking combined molecular dynamics simulations followed binding affinity kinetics studies. Compounds that had a high affinity to the prM protein were screened in silico and ligand-binding free energies were computed using molecular mechanics with generalized Born and surface area continuum solvation (MM-GBSA) method. In vitro binding kinetics via biolayer interferometry (BLI) and interaction analysis confirmed that prM could be targeted for drug discovery to combat ZIKV infection. Communicated by Ramaswamy H. Sarma

Understanding the relationship between viral infections and trace elements from a metallomics perspective: implications for COVID-19.

Recently, the World Health Organization (WHO) declared a pandemic situation due to a new viral infection (COVID-19) caused by a novel virus (Sars-CoV-2). COVID-19 is today the leading cause of death from viral infections in the world. It is known that many elements play important roles in viral infections, both in virus survival, and in the activation of the host's immune system, which depends on the presence of micronutrients to maintain the integrity of its functions. In this sense, the metallome can be an important object of study for understanding viral infections. Therefore, this work presents an overview of the role of trace elements in the immune system and the state of the art in metallomics, highlighting the challenges found in studies focusing on viral infections.

Low METTL3 level in midgut of the Bombyx mori inhibit the proliferation of nucleopolyhedrovirus

• Expression of m 6 A-modifciation-genes in BmN cell changed with infection of BmNPV. • Low METTL3 expression inhibited the proliferation of BV in BmN cell. • Lower METTL3 expression inhibited BmNPV proliferation in Bombyx mori. N6 -methyladeosine (m 6 A) plays an important role in virus infection and replication. Bombyx mori nuclear polyhedrosis is caused by Bombyx mori nucleopolyhedrovirus ( BmNPV ) infection. Expression levels of m 6 A-modification-related genes after the infection of BmNPV were detected at first. Then, expression levels of BmNPV nucleocapsid protein gene VP 39 and envelope fusion protein gene GP 64 after knockdown of METTL 3 in vitro were quantified to identify the effect of m 6 A modification on BmNPV. BmNPV firstly infects the larval midgut in case of oral infection. Subsequently, to clarify the relationship between m 6 A modification and resistance of the silkworm to BmNPV, we detected the expression levels of m 6 A-modification-related genes invivo before and after infection of BmNPV. The results indicated that low METTL3 level hindered the proliferation of BmNPV to some extent, and silkworm strain with low METTL3 level showed stronger resistance against BmNPV. This study will accumulate new experimental data for elucidating the resistance mechanism of silkworm against BmNPV.