What is the tropism of a virus?
Key Points. Viral tropism is the ability of a given virus to productively infect a particular cell (cellular tropism), tissue (tissue tropism) or host species (host tropism).
What 3 stages do viruses have to move through?
The virus life cycle can be divided into three stages—entry, genome replication, and exit (Fig. 3.1 ).
How does viral structure determine host range and tissue tropism?
Host tropism is determined by the biochemical receptor complexes on cell surfaces that are permissive or non-permissive to the docking or attachment of various viruses. Various factors determine the ability of a pathogen to infect a particular cell.
What cells do the influenza A virus has tropism for?
Influenza viruses primarily target airway epithelial cells via α2,3- and α2,6-type receptors, but the distribution of these receptors in many species is uncertain and may be a significant factor influencing infection.
Why are some viruses tissue specific?
Most viruses have an affinity for specific tissues; that is, they display tissue specificity or tropism. This specificity is determined by selective susceptibility of cells, physical barriers, local temperature and pH, and host defenses. Many examples of viral tissue tropism are known.
What kind of virus is Corona?
Coronaviruses are a type of virus. There are many different kinds, and some cause disease. A coronavirus identified in 2019, SARS-CoV-2, has caused a pandemic of respiratory illness, called COVID-19.
What are the 2 life cycles of viruses?
Lytic “life” cycle of viruses. Viruses can interact with their hosts in two distinct ways: the lytic pathway and the lysogenic pathway. Some viruses are able to switch between the two pathways while others only use one.
What are the 4 main ways viruses cause tissue damage?
Direct cell damage and death from viral infection may result from (1) diversion of the cell’s energy, (2) shutoff of cell macromolecular synthesis, (3) competition of viral mRNA for cellular ribosomes, (4) competition of viral promoters and transcriptional enhancers for cellular transcriptional factors such as RNA …
What causes tissue tropism?
Factors influencing viral tissue tropism include: 1) the presence of cellular receptors permitting viral entry, 2) availability of transcription factors involved in viral replication, 3) the molecular nature of the viral tropogen, and 4) the cellular receptors are the proteins found on a cell or viral surface.
Why does tissue tropism occur?
Factors influencing viral tissue tropism include: The presence of cellular receptors permitting viral entry. Availability of transcription factors involved in viral replication. The molecular nature of the viral tropogen or virus surface, such as the glycoprotein, which interacts with the corresponding cell receptor.
What is a viral tropism?
Viral tropism can be defined by the ability of different viral strains or isolates to infect different cell types or tissues and to induce syncytia formation and/or acute or chronic infectious virus production as a result of infection.
What are the stages of tissue tropism?
Tissue tropism develops in the following stages: Virus with GPX enters body (where GP – glycoprotein and X is the numeric value given to the GP) Viral cell “targets” cell with a GPX receptors. Viral cell fuses with the host cell and inserts its contents into the host cell.
What is the molecular nature of the viral tropogen?
The molecular nature of the viral tropogen. The cellular receptors are the proteins found on a cell or viral surface. These receptors are like keys, allowing the viral cell to fuse with or attach itself to a cell.
What is the role of tonsillar crypt epithelium in viral infection?
The tonsillar crypt epithelium supports viral replication and may be the source of replication at other sites, as well as of viremia, leading to neuroinvasion, possibly via a retrograde peripheral motor nerve route. 38–41 EV-A71 infection triggers apoptosis of brain-derived neural progenitor cells responsible for neurological sequelae. 42