Molecular mechanism of cross-species transmission of primate
lentiviruses
Principle of lentiviral cross-species transmission leading to the
emergence of the AIDS virus

Date:
October 7, 2020
Source:
The Institute of Medical Science, The University of Tokyo
Summary:
A research group showed that gorilla APOBEC3G potentially plays a
role in inhibiting SIVcpz replication. Intriguingly, the research
group demonstrated that an amino acid substitution in SIVcpz
Vif, M16E, is sufficient to overcome gorilla APOBEC3G-mediated
restriction.



FULL STORY ========================================================================== Humans are exposed continuously to the menace of viral diseases such
as those caused by the Ebola virus, Zika virus and coronaviruses. Such emerging/re- emerging viral outbreaks can be triggered by cross-species
viral transmission from wild animals to humans.


==========================================================================
To achieve cross-species transmission, new hosts have to be exposed to
the virus from the old host. Next, the viruses acquire certain mutations
that can be beneficial for replicating in the new hosts. Finally, through sustained transmission in the new host, the viruses adapt further evolving
as a new virus in the new host. However, at the outset of this process,
the viruses have to overcome "the species barriers," which hamper viral cross-species transmission.

Mammals including humans have "intrinsic immunity" mechanisms that
have diverged enough in evolution to erect species barriers to viral transmission.

HIV-1 most likely originated from related precursors found in chimpanzees
and gorillas HIV-1, the causative agent of AIDS, most likely originated
from related precursors found in chimpanzees (SIVcpz) and gorillas
(SIVgor), approximately 100 years ago.

Additionally, SIVgor most likely emerged through the cross-species jump
of SIVcpz from chimpanzees to gorillas.

However, it remains unclear how primate lentiviruses successfully
transmitted among different species. To limit cross-species lentiviral transmission, cellular "intrinsic immunity," including APOBEC3 proteins potentially inhibit lentiviral replication. In contrast, primate
lentiviruses in this evolutionary "arms race" have acquired their own
"weapon," viral infectivity factor (Vif), to antagonize the antiviral
effect of restriction factors.

Suggesting that a great ape APOBEC3 protein can potentially restrict the
cross- species transmission of great ape lentiviruses A research group
at The Institute of Medical Science, The University of Tokyo (IMSUT)
showed that gorilla APOBEC3G potentially plays a role in inhibiting SIVcpz replication. Intriguingly, the research group demonstrated that an amino
acid substitution in SIVcpz Vif, M16E, is sufficient to overcome gorilla APOBEC3G-mediated restriction.

"To our knowledge, this is the first report suggesting that a great ape
APOBEC3 protein can potentially restrict the cross-species transmission
of great ape lentiviruses and how lentiviruses overcame this species
barrier. Moreover, this is the first investigation elucidating the
molecular mechanism by which great ape lentiviruses achieve cross-species transmission," said the lead scientist, Kei Sato, Associate Professor (Principal Investigator) in the Division of Systems Virology, Department
of Infectious Disease Control, IMSUT.


========================================================================== Story Source: Materials provided by The_Institute_of_Medical_Science,_The_University_of Tokyo. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Yusuke Nakano, Keisuke Yamamoto, Mahoko Takahashi Ueda, Andrew
Soper,
Yoriyuki Konno, Izumi Kimura, Keiya Uriu, Ryuichi Kumata,
Hirofumi Aso, Naoko Misawa, Shumpei Nagaoka, Soma Shimizu, Keito
Mitsumune, Yusuke Kosugi, Guillermo Juarez-Fernandez, Jumpei Ito,
So Nakagawa, Terumasa Ikeda, Yoshio Koyanagi, Reuben S Harris
and Kei Sato. A role for gorilla APOBEC3G in shaping lentivirus
evolution including transmission to humans. PLOS Pathogens, 2020
DOI: 10.1371/journal._ppat.1008812 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201007093631.htm

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