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Hello everyone, my
name is Luca Shytaj.
I'm a virologist and
senior lecturer at the
University of Bristol, UK.
Today, I will be discussing
a fascinating and
complex topic in
the biology of microorganisms,
that is, viral latency.
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Let's begin by introducing
the overall topic with
some definitions.
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Viral latency refers to
a state in which a
virus persists in
the host without producing
infectious particles.
During this phase,
the viral genome remains
within host cells,
but its gene expression is
largely silenced or
highly restricted.
This allows the virus to
evade detection by
the immune system.
However, latent viruses are
not permanently inactive,
and they can reactivate
under specific conditions,
as we will see through
the course of this talk.
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Why is viral latency
so significant?
This ability to persist
in a latent form is
a key survival strategy
for many viruses.
By remaining dormant,
viruses can persist in the
host for extended periods,
often for the host's lifetime,
while avoiding detection
by the immune system.
This makes it difficult to
completely clear the infection.
Reactivation of
latent viruses can
result in a renewed replication,
which may cause disease and
increase the risk of
transmission to others.
Ultimately, understanding
viral latency is
essential for addressing
the challenges posed by
persistent infection and
for developing strategies to
manage reactivation
and its impact.
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Latency is a highly successful
evolutionary strategy as
evidenced by its adoption by
a diverse range of viruses that
infect different
cells and tissues.
This slide highlights some of
the main viruses capable
of establishing latency,
including some well-known
pathogens such as
herpes viruses; retroviruses,
for example, HIV;
hepatitis B virus;
papillomaviruses;
and adenoviruses.
A key feature common
to these viruses is
the latent genome
being composed of DNA.
While viruses exist
in various forms,
including single- and
double-stranded RNA,
DNA is a more stable molecule,
making it more suited for
establishing true
long-term latency.
A striking example of
this is provided by
retroviruses, as
I mentioned, HIV,
which can become latent after
converting their RNA
genomes into DNA.
