Your attention
is directed to three articles published simultaneously in
the March 4, 2008, issue of the PNAS (Proceedings of the
National Academy of Sciences) with editorial comments
by Jonathan Stoye and Melvyn Yap.
Background: Humans develop AIDS because
we are susceptible to HIV-1 infection. Other primate species
have evolved mechanisms to block HIV-1 infection. In rhesus
monkeys (a species of Old World monkeys), the blockage is
mediated by a restriction factor called TRIM5a protein. In
New World monkeys, such as owl monkeys, this block is accomplished
through TRIMCyp, which is created by inserting a cyclophilin
A gene into the TRIM5a gene. Humans express an inactive form
of TRIM5a protein thus susceptible to HIV infection.
News worthiness: These results represent
an example of "convergent evolution." Primates have
evolved different mechanisms to achieve the same goal, in
this case, to fend off assaults brought about by retrovirus
(e.g. HIV) infections.
Significance: These findings indicate that
primates have been under selective pressure by HIV-1-like
retroviruses for millions of years, much longer than previously
thought.
Implication: Understanding of mechanisms
that primates use to resist retrovirus infection may yield
insights in identifying novel targets for anti-HIV therapy.
It may also help the development of animal models to study
HIV infection and AIDS.
University of Washington, Seattle Researchers:
Professor Shiu-Lok Hu (PI), Brennan (DVM, PhD Candidate),
Kozyrev (Res Scientist) <hus@bart.rprc.washington.edu>
References to the laboratories:
Brennan G, Kozyrev Y, Hu S-L (2008) Proc Natl Acad Sci USA
105:3569-3574. (UW Researchers)
Virgen CA, Kratovac Z, Bieniasz PD, Hatziioannou T (2008)
Proc Natl Acad Sci USA 105:3563-3568.
Wilson SJ, Webb BLJ, Ylinen LMJ, Verschoor E, Heeney JL,
Towers GJ (2008) Proc Natl Acad Sci USA 105:3557-3562.
Newman RM, Hall L, Kirmaier A, Pozzi L-A, Pery E, Farzan
M, O'Neil S, Johnson W (2008) PLoS Pathogens 4(2):e1000003.
Liao C-H, Kuang Y-Q, Liu H-L, Zheng Y-T, Su B (2007) AIDS
21(Suppl 8):S19 -S26.
References to the articles:
http://www.pnas.org/current.shtml#THISWEEKINPNAS
http://www.nature.com/news/2008/080229/full/news.2008.634.html
TRIMCyp expression
in Old World primates Macaca nemestrina and Macaca
fascicularis
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