Virus Specific Information Research Articles

Median Tissue Culture Infectious Dose 50 (TCID50) Assay to Determine Infectivity of Cytopathic Viruses.

The emergence of zoonotic viruses like severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2 have significantly impacted global health and economy. The discovery of other viruses in wildlife reservoir species present a threatforfuture emergence in humans and animals. Therefore, assays that are less reliant on virus-specific information, such as neutralization assays, are crucial to rapidlydevelop diagnostics, understand virus replication and pathogenicity, and assess the efficacy of therapeutics against newly emerging viruses. Here, we describe the discontinuous median tissue culture infectious dose 50 (TCID50) assay to quantitatively determine the titer of any virus that can produce a visible cytopathic effect in infected cells.

VIPERdb v3.0: a structure-based data analytics platform for viral capsids.

VIrus Particle ExploreR data base (VIPERdb) (http://viperdb.scripps.edu) is a curated repository of virus capsid structures and a database of structure-derived data along with various virus specific information. VIPERdb has been continuously improved for over 20 years and contains a number of virus structure analysis tools. The release of VIPERdb v3.0 contains new structure-based data analytics tools like Multiple Structure-based and Sequence Alignment (MSSA) to identify hot-spot residues within a selected group of structures and an anomaly detection application to analyze and curate the structure-derived data within individual virus families. At the time of this writing, there are 931 virus structures from 62 different virus families in the database. Significantly, the new release also contains a standalone database called ‘Virus World database’ (VWdb) that comprises all the characterized viruses (∼181 000) known to date, gathered from ICTVdb and NCBI, and their capsid protein sequences, organized according to their virus taxonomy with links to known structures in VIPERdb and PDB. Moreover, the new release of VIPERdb includes a service-oriented data engine to handle all the data access requests and provides an interface for futuristic data analytics using machine leaning applications.

Psychological correlates of COVID-19 pandemic in the Austrian population

BackgroundCOVID-19 poses the greatest challenge for the entire world since the Second World War. Governments are forced to define strict measures to avoid the spreading of the virus, which may further impose psychological burden for the majority of the population. The aim of this study was to evaluate the psychological distress in Austria during the initial stage of the COVID-19 outbreak.MethodsFrom 25 March to 3 April 2020, an anonymous online survey was conducted. Target group included all members of the Austrian population older than 16 years. The survey addressed the following areas (1) and sociodemographic data, (2) physical and mental health; (3) knowledge and concerns about COVID-19; (4) contact with infected people; (5) prevention efforts; (6) need for further information. The Impact of Event Scale-Revised (IES-R) and the Depression, Anxiety and Stress Scale (DASS-21) were used to assess mental health. Analyses were based on 4126 individuals (74% female, age: M = 38.68, SD = 13.36).Results43.3% rated the psychological impact as moderate (5.6%) or severe (37.7%). 26.5% reported moderate (13.3%) to severe (13.2%) depression; 20.3% moderate (8.9%) to severe (11.4%) anxiety and 21.2% reported to suffer from moderate (10.5%) or severe stress (10.7%). Being female, higher age, lower levels of education, concern about family members, internet as main source of information, student or pupil status, poor self-rated health, and downplaying the seriousness of the problem were significantly associated with higher psychological burden. Protective factors were the possibility to work in home office, frequent (indirect) contact with family or friends, the availability of virus-specific information, confidence in the diagnosis capability, and physical activity during the crisis.ConclusionThis study is among the first in Europe on the psychological correlates of the COVID-19 pandemic. 37.7% of the Austrian study population reported a severe psychological impact on the event and 1 in 10 is considered to suffer from severe depression, anxiety or stress. The present findings inform about the identification of protective factors, psychologically vulnerable groups and may guide the development of psychological interventions.

Characterization of RNA from noninfectious virions produced by sarcoma positive-leukemia negative transformed 3T3 cells.

RNA from noninfectious virions produced by two established clonal lines of sarcoma positive-leukemia negative (S+L-)-transformed 3T3 cells has been characterized. RNA from virions or nucleoids of S+L--(C243) cells consisted of three to four sizes: +/-44 S (6%), 28 S (17%), 18 S (38%), and <18 S (39%). 28S virion RNA contained some virus-specific information demonstrable by RNA.DNA hybridization with a DNA probe derived from the RNA-directed DNA polymerase product of murine sarcoma-leukemia virus, while parallel studies indicated that 28S ribosomal RNA from ribosomal subunits of transformed and nontransformed 3T3 cells did not contain virus-specific information. In contrast to the S+L-(C243) virions, RNA from virions or nucleoids of S+L-(D56) cells consisted of five sizes: 80 S (6%), 68 S (8%), 56 S (5%), 28 S (28%), and <28 S (53%). Thermal dissociation studies suggested that this S+L- genome is comprised of 28S RNA subunits. From these studies we postulate that the 28S viral RNA is most probably the monomeric genome of S+L- virions.

Surface alterations of cells carrying RNA tumour virus genetic information.

CELLS transformed by the DNA tumour viruses, polyoma virus and SV40, are agglutinated by lectins such as wheat germ agglutinin1, concanavalin A (Con A)2 and soybean agglutinin3. Agglutination in these cases presumably reflects changes in the cell surface related to the transformed properties of the cell; studies with a temperature-dependent mutant of polyoma virus has shown that cell surface changes are controlled by viral genes4. Here we describe experiments in which we investigated the agglutinability of cells transformed by RNA tumour viruses. One recent report had suggested that cells transformed by RNA tumour viruses were not specifically agglutinated5, whereas a second more recent report claimed the specific agglutination of cells transformed by RSV6. We find that transformed rat, mouse and cat cells that replicate the sarcoma-leukaemia virus complex of murine (MSV) and feline (FeSV) origin are strongly agglutinated by Con A, but mouse and human cells that replicate the murine and feline leukaemia virus components alone are not agglutinated. The ability to agglutinate is rapidly acquired by normal mouse cells on infection with the murine sarcoma virus at a rate that parallels virus replication. In contrast to the results obtained with cells producing virus, non-virus-producing transformed hamster and mouse cells that synthesize virus-specific RNA are either not agglutinated or are agglutinated to a lesser degree. These results suggest that the cell surface alterations responsible for agglutination are not necessarily associated with the transformed state of the cell, but rather with the possession of sarcoma virus-specific information.