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Topic Review
Tanzania Peste des Petits Ruminants
Peste des petits ruminants (PPR) is an important transboundary animal disease of domestic small ruminants, camels, and wild artiodactyls. The disease has significant socio-economic impact on communities that depend on livestock for their livelihood and is a threat to endangered susceptible wild species. 
  • 1.2K
  • 22 Jun 2021
Topic Review
Plant Immunity
In the plant immune system, according to the ‘gene-for-gene’ model, a resistance (R) gene product in the plant specifically surveils a corresponding effector protein functioning as an avirulence (Avr) gene product.
  • 1.2K
  • 02 Jun 2021
Topic Review
Human Coronaviruses
The ongoing pandemic of the severe acute respiratory syndrome (SARS), caused by the SARS-CoV-2 human coronavirus (HCoV), has brought the international scientific community before a state of emergency that needs to be addressed with intensive research for the discovery of pharmacological agents with antiviral activity. 
  • 1.2K
  • 23 Feb 2021
Topic Review
Proprotein Convertases and Enveloped Viruses
There are seven known human coronaviruses (CoV), which are enveloped positive-stranded RNA viruses belonging to the orderNidoviralesand are mostly responsible for upper respiratory tract infections. All these coronaviruses exhibit a “crown-like” structure composed of a trimeric spike (S) protein. The S-protein is a ~180–200 kDa type I transmembrane protein, with the N-terminus facing the extracellular space and anchored to the viral membrane via its transmembrane domain followed by a C-terminal short tail facing the cytosol.
  • 1.2K
  • 08 Jul 2021
Topic Review
Septins in Infections
Human septins comprise a family of 13 genes that encode conserved GTP-binding proteins. They form nonpolar complexes, which assemble into higher-order structures, such as bundles, scaffolding structures, or rings. Septins are counted among the cytoskeletal elements. They interact with the actin and microtubule networks and can bind to membranes. Many cellular functions with septin participation have been described in the literature, including cytokinesis, motility, forming of scaffolding platforms or lateral diffusion barriers, vesicle transport, exocytosis, and recognition of micron-scale curvature. Septin dysfunction has been implicated in diverse human pathologies, including neurodegeneration and tumorigenesis. Moreover, septins are thought to affect the outcome of host–microbe interactions. Implication of septins has been demonstrated in fungal, bacterial, and viral infections. Knowledge on the precise function of a particular septin in the different steps of the virus infection and replication cycle is still limited. Published data for vaccinia virus (VACV), hepatitis C virus (HCV), influenza A virus (H1N1 and H5N1), human herpesvirus 8 (HHV-8), and Zika virus (ZIKV), all of major concern for public health, will be discussed here.
  • 1.2K
  • 26 Mar 2021
Topic Review
Phage-Based Vaccines for COVID-19
Phages are highly ubiquitous biological agents, which means they are ideal tools for molecular biology and recombinant DNA technology. The development of a phage display technology was a turning point in the design of phage-based vaccines. Phages are now recognized as universal adjuvant-free nanovaccine platforms. Phages are well-suited for vaccine design owing to their high stability in harsh conditions and simple and inexpensive large-scale production. Phage vaccines induce a strong and specific humoral response by targeted phage particles carrying the epitopes of SARS-CoV-2.
  • 1.2K
  • 28 Jan 2023
Topic Review
Raptors in WNV Epidemiology
West Nile virus exists in a natural cycle between mosquitoes and wild birds, with humans and horses acting as dead-end hosts. Avian species are key in WNV transmission cycle and, therefore, have been the focus of surveillance across many countries. Raptors appear particularly susceptible to WNV infection, resulting in higher prevalence, resulting in clinical disease and death. Birds of prey are known to play an important role as WNV reservoir and potentially act as amplifying hosts of infection. Importantly, raptor higher susceptibility/prevalence may indicate infection through predation of infected prey. Consequently, becoming and important target species when designing cost-effective surveillance for monitoring both seasonal WNV circulation in endemic countries and its emergence into new areas, even outside the mosquito season. 
  • 1.2K
  • 27 Oct 2020
Topic Review
Gene annotation for 'Flaviviridae' genomes
Responding to the ongoing and severe public health threat of viruses of the family Flaviviridae, including dengue, hepatitis C, West Nile, yellow fever, and Zika, demands a greater understanding of how these viruses emerge and spread. Updated phylogenies are central to this understanding. Most cladograms of Flaviviridae focus on specific lineages and ignore outgroups, thus hampering the efficacy of the analysis to test ingroup monophyly and relationships. This is due to the lack of annotated Flaviviridae genomes, which has gene content variation among genera. This variation makes analysis without partitioning difficult. Therefore, we developed an annotation pipeline for the genera of Flaviviridae (Flavirirus, Hepacivirus, Pegivirus, and Pestivirus), named “Fast Loci Annotation of Viruses” (FLAVi: flavi-web.com), that combines ab initio and homology-based strategies. FLAVi recovered 100% of the genes in Flavivirus and Hepacivirus genomes. In Pegivirus and Pestivirus, annotation efficiency was 100% except for one partition each. There were no false positives. The combined phylogenetic analysis of multiple genes made possible by annotation has clear impacts over the tree topology compared to phylogenies that we inferred without outgroups or data partitioning. The final tree is largely congruent with previous hypotheses and adds evidence supporting the close phylogenetic relationship between dengue and Zika.
  • 1.2K
  • 27 Oct 2020
Topic Review
Evolution of Non-Polio Enteroviruses
Enteroviruses (EVs) are positive-sense RNA viruses, with over 50,000 nucleotide sequences publicly available as of October 9th, 2020. While most human infections are typically associated with mild respiratory symptoms, several different EV types have also been associated with severe human disease, especially acute flaccid paralysis (AFP), particularly with endemic members of the EV-B species and two pandemic types—EV-A71 and EV-D68—that appear to be responsible for recent widespread outbreaks. Phylogenetic analysis of the EV genus shows the evolutionary relatedness of different EV types. 
  • 1.2K
  • 16 Dec 2020
Topic Review
Chikungunya Virus
Arboviruses, in general, are a global threat due to their morbidity and mortality, which results in an important social and economic impact. Chikungunya virus (CHIKV), one of the most relevant arbovirus currently known, is a re-emergent virus that causes a disease named chikungunya fever, characterized by a severe arthralgia (joint pains) that can persist for several months or years in some individuals. Until now, no vaccine or specific antiviral drug is commercially available. Nitrogen heterocyclic scaffolds are found in medications, such as aristeromycin, favipiravir, fluorouracil, 6-azauridine, thioguanine, pyrimethamine, among others. New families of natural and synthetic nitrogen analogous compounds are reported to have significant anti-CHIKV effects. In the present work, we focus on these nitrogen-based heterocyclic compounds as an important class with CHIKV antiviral activity.
  • 1.2K
  • 16 Jan 2021
Topic Review
HIV- and HERV-Cancer Paradigm
Animal retroviruses are known for their transforming potential, and this is also true for the ones hosted by humans, which have gathered expanding attention as one of the potent causative agents in various diseases, including specific cancer types. For instance, Human T Lymphotropic virus (HTLV) is a well-studied class of oncoviruses causing T cell leukemia, while human immunodeficiency virus (HIV) leads to acquired immunodeficiency syndrome (AIDS), which is linked to a series of defining cancers including Kaposi sarcoma, certain types of non-Hodgkin lymphoma, and cervical cancer. Of note, in addition to these “modern” exogenous retroviruses, our genome harbors a staggering number of human endogenous retroviruses (HERVs). HERVs are the genetic remnants of ancient retroviral germline infection of human ancestors and are typically silenced in normal tissues due to inactivating mutations and sequence loss. While some HERV elements have been appropriated and contribute to human physiological functions, others can be reactivated through epigenetic dysregulations to express retroviral elements and promote carcinogenesis. Conversely, HERV replication intermediates or protein products can also serve as intrinsic pathogen-associated molecular patterns that cause the immune system to interpret it as an exogenous infection, thereby stimulating immune responses against tumors. As such, HERVs have also been targeted as a potential internal strategy to sensitize tumor cells for promising immunotherapies. Further studies should help promote our understanding on the dynamic role of human retroviruses in cancer development including contribution from HIV and HERVs.
  • 1.2K
  • 27 Aug 2020
Topic Review
Nuclear Import of EBV Proteins
Epstein–Barr virus (EBV) is a human pathogen that infects most of the world’s population and is associated with several well-known malignancies. Within the nucleus, the replicated viral DNA is packaged into capsids, which subsequently egress from the nucleus into the cytoplasm for tegumentation and final envelopment. There is increasing evidence that viral lytic gene expression or replication contributes to the pathogenesis of EBV. Various EBV lytic proteins regulate and modulate the nuclear envelope structure in different ways, especially the viral BGLF4 kinase and the nuclear egress complex BFRF1/BFRF2. 
  • 1.2K
  • 08 Jul 2021
Topic Review
Human Norovirus GII.3
Noroviruses (NoVs) are a group of non-enveloped RNA viruses belonging to the Norovirus genus in the Caliciviridae family, and they are the leading cause of sporadic and epidemic nonbacterial acute gastroenteritis (AGE) in humans.
  • 1.2K
  • 28 Oct 2021
Topic Review
Sphingomonas Turrisvirgatae Bacteriophage vB_StuS_MMDA13
Sphingomonas turrisvirgatae is a recently described species within the Sphingomonas genus. This species is endowed of agarolytic activity, a feature never reported before among sphingomonads. The capability of Sphingomonas sp. MCT13 to degrade agar, suggests that this strain could be potentially interesting for industrial applications in the field of complex carbohydrates degradation. Sphingomonas is a very large and heterogeneous genus, and its huge biodiversity is responsible for the challenges of obtaining a reliable identification at the species level through conventional biochemical analyses. Indeed, bacteriophages specific for S. turrisvirgatae have been looked for, both as a rapid tool to identify and collect more isolates of this species, and for obtaining hints of its ecology. vB_StuS_MMDA13 was isolated from a surface freshwater sample, obtained from a pond near Viterbo (Italy), by using the Sphingomonas turrisvirgatae MCT13T strain as host. The phage is lytic, belongs to the Siphoviridae family, and, as such, represents the first characterized lytic siphovirus able to infect a Sphingomonas species. vB_StuS_MMDA13 has a genome of ≈ 64 kb which encodes 89 potential proteins. A module for the biosynthesis of 7-deazaguanine derivatives, with a unique organization, is also present. The lysis module, which includes the endolysin, a holin/antiholin system and a Rz/Rz1 system, does not share significant similarities with other viral proteins in the databases. At the genome level vB_StuS_MMDA13 is loosely related to the Pseudomonas aeruginosa-infecting Nipunaviruses; however, both the 7-deazaguanine derivatives biosynthetic- and the lysis-modules are very different from these and other related bacteriophages. According to these features, we feel that vB_StuS_MMDA13 should be regarded as the type strain of a newly discovered genus within the Siphoviridae family, which we propose to name Ememdadecimater-like virus, after the short name of the first characterized phage of the genus.
  • 1.2K
  • 28 Aug 2020
Topic Review
Koala Retrovirus
Koala retrovirus (KoRV) is assumed to cause immunosuppression and neoplastic diseases, favoring chlamydiosis in koalas. Koala populations are currently declining and under threat from KoRV infection both in the wild and in captivity. Currently, 10 KoRV subtypes have been identified, including an endogenous subtype (KoRV-A) and nine exogenous subtypes (KoRV-B to KoRV-J). The host’s immune response acts as a safeguard against pathogens. Therefore, a proper understanding of the immune response mechanisms against infection is of great importance for the host’s survival, as well as for the development of therapeutic and prophylactic interventions. A vaccine is an important protective as well as being a therapeutic tool against infectious disease, and several studies have shown promise for the development of an effective vaccine against KoRV. Moreover, CRISPR/Cas9-based genome editing has opened a new window for gene therapy, and it appears to be a potential therapeutic tool in many viral infections, which could also be investigated for the treatment of KoRV infection.
  • 1.2K
  • 13 May 2021
Topic Review
Malarial Protozoan Parasites Infection
Malaria is an infectious disease caused by protozoan parasites of the Plasmodium genus through the bite of female Anopheles mosquitoes, affecting 228 million people and causing 415 thousand deaths in 2018. Artemisinin-based combination therapies (ACTs) are the most recommended treatment for malaria; however, the emergence of multidrug resistance has unfortunately limited their effects and challenged the field.
  • 1.2K
  • 17 Mar 2021
Topic Review
Oropharyngeal Mucosal Epithelium in HIV-1 Transmission
The oropharyngeal mucosal epithelia have a polarized organization, which is critical for maintaining a highly efficient barrier as well as innate immune functions. In human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) disease, the barrier and innate immune functions of the oral mucosa are impaired via a number of mechanisms.
  • 1.2K
  • 25 May 2023
Topic Review
HIV-1 Capsid
HIV-1 capsid has been recognized to have an important role as a structural protein that holds the viral genome, together with viral proteins essential for viral life cycle, such as the reverse transcriptase (RT) and the integrase (IN). The reverse transcription process takes place between the cytoplasm and the nucleus of the host cell, thus the Reverse Transcription Complexes (RTCs)/Pre-integration Complexes (PICs) are hosted in intact or partial cores. Early biochemical assays failed to identify the viral CA associated to the RTC/PIC, possibly due to the stringent detergent conditions used to fractionate the cells or to isolate the viral complexes. More recently, it has been observed that some host partners of capsid, such as Nup153 and CPSF6, can only bind multimeric CA proteins organized in hexamers. Those host factors are mainly located in the nuclear compartment, suggesting the entrance of the viral CA as multimeric structure inside the nucleus. Recent data show CA complexes within the nucleus having a different morphology from the cytoplasmic ones, clearly highlighting the remodeling of the viral cores during nuclear translocation. Thus, the multimeric CA complexes lead the viral genome into the host nuclear compartment, piloting the intranuclear journey of HIV-1 in order to successfully replicate.
  • 1.2K
  • 26 Feb 2021
Topic Review
Bluetongue Virus Vector Vaccines
In this work, we show a deep revision of the viral vector vaccines that have been developed to counteract bluetongue virus (BTV), an arthropod-borne disease that whips domestic and wild ruminants. We analyzed the main advantages and disadvantages of every of them, as well as the immunological features and efficacy that these candidates provided in both murine models and natural hosts.
  • 1.2K
  • 08 Jan 2021
Topic Review
Vaccine and Variant-modified Covid-19 Trajectories
Covid-19 transmission in US and UK have diverged 1.73 times faster than predicted by recursion models after November 2020. Transmission follows a 20% infection rate compared to the previous 10% rate, attributed to a more contagious variant of covid-19. The effect of vaccination on covid-19 trajectory is analysed for US data. Modelling indicates case numbers continue to rise for some time after vaccination.
  • 1.2K
  • 26 Jan 2021
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