Virus uses decoy strategy to evade immune system

Date:
August 13, 2020
Source:
University of Otago
Summary:
Researchers have learnt more about how viruses operate and can
evade the immune system and are now using their discovery to help
learn more about COVID-19.



FULL STORY ========================================================================== University of Otago researchers have learnt more about how viruses operate
and can evade the immune system and are now using their discovery to
help learn more about COVID-19.


==========================================================================
The recent research, led by Dr Mihnea Bostina and PhD student Sai Velamoor
from the Department of Microbiology and Immunology and Otago Micro and
Nano Imaging, Electron Microscopy, specifically looked at the Oryctes rhinoceros nudivirus (OrNV) virus, an important biocontrol agent against
the coconut rhinoceros beetle, a devastating pest for coconut and oil
palm trees in Southeast Asia and the Pacific Islands.

The Otago scientists found the virus used a "decoy" strategy to evade
the immune system. Dr Bostina explains the findings are a small step in
the bid to better understand infectious disease.

The research team is now using the same technique to investigate changes
in cells infected with SARS-CoV-2, the coronavirus that causes COVID-19.

"We have used the same technique to investigate changes in cells infected
with SARS-CoV-2 and are continuing work in this area." Dr Bostina
explains that viruses that replicate and assemble inside the nucleus have evolved special approaches to modify the nuclear landscape for their
advantage. The research team used electron microscopy to investigate
cellular changes occurring during nudivirus infection and found a unique mechanism for how the virus works.



==========================================================================
"Our study revealed that the virus acquires a membrane inside the nucleus
of the infected cell and it gets fully equipped to infect new cells at
this precise location. This is in contrast with other enveloped viruses
-- like coronavirus, which is also an enveloped virus -- which derive
their membranes from other cellular compartments.

"After it gets fully assembled, the virus uses a clever tactic of passing through different environments, packed inside various membrane structures
until it gets released at the cellular membrane." Ms Velamoor says
this strategy implies that many of the viruses released by the infected
cells will be enclosed in a cellular membrane while travelling inside
the infected organism.

"This means they will be missed by the immune system and they can use
this membrane decoy to penetrate any other type of cells, without the
need of a virus specific receptor.

"It shows for the very first time a clever strategy available to insect viruses. It will be interesting to find in what measure other types of
viruses -- like the ones infecting humans -- are also capable of carrying
out a similar process." Dr Bostina says the research demonstrates
another manner in which viruses are capable of hijacking infected cells
and alerts scientists to the novel mechanism of viral transmission.

"Viruses will never cease to amaze us with their indefatigable arsenal
of tricks. Only by studying them can we be prepared to adequately respond
when they infect us."

========================================================================== Story Source: Materials provided by University_of_Otago. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Sailakshmi Velamoor, Allan Mitchell, Bruno M. Humbel, WonMo Kim,
Charlotte Pushparajan, Gabriel Visnovsky, Laura N. Burga, Mihnea
Bostina.

Visualizing Nudivirus Assembly and Egress. mBio, 2020; 11 (4)
DOI: 10.1128/mBio.01333-20 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200813100639.htm

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