Virus Detection Mechanisms Final Year Project by Chaitanya kumar CH K.S. Karthik.
Mechanisms in virus latency. THIS WILL NOT BE ON THE FINAL EXAM!
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Transcript of Mechanisms in virus latency. THIS WILL NOT BE ON THE FINAL EXAM!
Why is every viral infection not productive?
Why is every viral infection not productive?
Bacteriophages - - When infects a bacterial cell, there are two possible outcomes a lytic infection in which new viruses are made, or lysogeny in which the bacteriophage integrates its DNA
genome into the host cell DNA and new viruses are not made. What benefit does lysogeny provide for the virus?
To exchange a chancy existence for one in which reproduction of progeny is assured.
As long as the bacteria keep reproducing, the virus, in the form of the viral genome, will also be reproduced.
Does lysogeny provide any benefit to the host? It may carry a selective value for the host and confer new
characteristics to the host.
Bacteriophages - - When infects a bacterial cell, there are two possible outcomes a lytic infection in which new viruses are made, or lysogeny in which the bacteriophage integrates its DNA
genome into the host cell DNA and new viruses are not made. What benefit does lysogeny provide for the virus?
To exchange a chancy existence for one in which reproduction of progeny is assured.
As long as the bacteria keep reproducing, the virus, in the form of the viral genome, will also be reproduced.
Does lysogeny provide any benefit to the host? It may carry a selective value for the host and confer new
characteristics to the host.
Do animal viruses undergo lysogeny?
Do animal viruses undergo lysogeny?
Animal viruses Animal viruses don’t undergo “lysogeny”, but some
do cause latent infections. Latent infections in animal viruses are similar to
lysogeny in bacteriophages in that: During a latent infection, the virus is quiescent with no
progeny being produced. The virus co-exists with the host and survives as long as
the host survives Latent infections in animal viruses differ from
lysogeny in bacteriophages in several ways: With the exception of HIV, which is a retrovirus, the virus
does not integrate its DNA, into the host cell DNA, but remains as a episome.
Animal viruses Animal viruses don’t undergo “lysogeny”, but some
do cause latent infections. Latent infections in animal viruses are similar to
lysogeny in bacteriophages in that: During a latent infection, the virus is quiescent with no
progeny being produced. The virus co-exists with the host and survives as long as
the host survives Latent infections in animal viruses differ from
lysogeny in bacteriophages in several ways: With the exception of HIV, which is a retrovirus, the virus
does not integrate its DNA, into the host cell DNA, but remains as a episome.
Latent infectionsLatent infections The latent infection begins with a productive infection
and then the virus becomes latent. The productive infection may occur in one cell type while
the latent infection is found in a different cell type. Latent infections can reactivate to cause a
productive infection, and the new virus particles can infect a new susceptible host. The original host still retains a latent infection. Reactivation may be due to a breakdown of the immune
system or the patient may be experiencing some sort of stress.
The reactivation disease may be different from the original productive infection (chicken pox versus shingles in varicella-zoster infections).
The latent infection begins with a productive infection and then the virus becomes latent.
The productive infection may occur in one cell type while the latent infection is found in a different cell type.
Latent infections can reactivate to cause a productive infection, and the new virus particles can infect a new susceptible host. The original host still retains a latent infection. Reactivation may be due to a breakdown of the immune
system or the patient may be experiencing some sort of stress.
The reactivation disease may be different from the original productive infection (chicken pox versus shingles in varicella-zoster infections).
What animal viruses cause latent infections?
What animal viruses cause latent infections?
All Herpesvirus infections HSV I and II EBV VZV CMV Human herpes viruses 6, 7, and 8
HIV
All Herpesvirus infections HSV I and II EBV VZV CMV Human herpes viruses 6, 7, and 8
HIV
HSV-I HSV-I
The initial productive infection takes place in epithelial cells of the oral cavity.
HSV is neurotropic and it establishes a latent infection by entering a sensoty nerveaxon ner the infection site.
The virus then moves to the neuron’s nucleus in the trigeminal nerve ganglion
The initial productive infection takes place in epithelial cells of the oral cavity.
HSV is neurotropic and it establishes a latent infection by entering a sensoty nerveaxon ner the infection site.
The virus then moves to the neuron’s nucleus in the trigeminal nerve ganglion