What are HIV Quasispecies?
A group (sometimes called a “swarm”) of mutant viruses that develops as a virus replicates within a host. The viruses grouped in a quasispecies are related by a similar mutation(s). During HIV infection, HIV can mutate into multiple quasispecies, which may reduce the immune system’s ability to control HIV infection.
How is HIV Quasispecies generated?
The generation of HIV quasispecies in infected hosts is driven principally by the low replicative fidelity of HIV reverse transcriptase, the rapid kinetics of HIV replication, aspects of the HIV replicative cycle itself that are conducive to mutagenesis, and viral genetic recombination.
Is SARS CoV 2 a Quasispecies?
Quasispecies in RNA viruses have previously been reported for SARS-CoV and MERS-CoV [10,11], as well as within individuals during SARS-CoV-2 infection [3,12]. The present study, allowing the analysis of SARS-CoV-2 minority variants at 1%, supports the previous finding.
What is a viral population?
Viral quasispecies refers to a population structure that consists of extremely large numbers of variant genomes, termed mutant spectra, mutant swarms or mutant clouds. Fueled by high mutation rates, mutants arise continually, and they change in relative frequency as viral replication proceeds.
Why are quasispecies important in virology?
The quasispecies model is most applicable when the genome size is limited and the mutation rate is high, and so is most relevant to RNA viruses (including important pathogens) because they have high mutation rates (approx one error per round of replication), though the concepts can apply to other biological entities …
What requires a helper virus?
A helper virus is a virus that allows an otherwise-deficient coinfecting virus to replicate. These can be naturally occurring as with Hepatitis D virus, which requires Hepatitis B virus to coinfect cells in order to replicate.
What are the implications of quasispecies for antiviral therapy?
Quasispecies theory predicts that a replicating viral population will contain a large number of unique mutants, so there is a probability that an active viral infection will already have resistant mutants upon time of RNAi treatment, which could rapidly become the dominant mutation when placed under selection.
Can DNA viruses be quasispecies?
Viral quasispecies are the mutant distributions (also termed mutant swarms or mutant clouds) that are generated upon replication of RNA viruses, and some DNA viruses in infected cells and organisms.
Which of these viruses need a helper virus for their replication?
Which needs a helper virus to Coinfect host cells?
Unlike the plant virusoids, satellite RNAs may encode for proteins; however, like plant virusoids, satellite RNAs must coinfect with a helper virus to replicate.
What causes antigenic drift to occur in viral infections?
Infectious Diseases Antigenic drift: A subtle change in the surface glycoprotein (either hemagglutinin or neuraminidase) caused by a point mutation or deletion in the viral gene. This results in a new strain that requires yearly reformulation of the seasonal influenza vaccine.
Is SARS CoV 2 a quasispecies?