Phylodynamic analysis of human immunodeficiency
virus type 1 in distinct brain compartments provides a model for the
neuropathogenesis of AIDS
September 2005 - by Marco
Salemi, Susanna L. Lamers, Stephanie Yu, Tulio de Oliveira, Walter M. Fitch,
and Michael S. McGrath.
The spread of AIDS is accelerating
and has reached every corner of the globe. 40 million individuals are estimated
to be infected with the virus that causes AIDS, including five million new
carriers during 2004. Three million people died of AIDS last year. Estimates of HIV infection for the year 2010
have been as high as 200 million.
One of the common problems in
patients infected with the human immunodeficiency virus (HIV) is the
development of meningitis during the early stage of infection, and dementia in
the late stages. In fact, about 20% of
newly HIV-infected individuals show symptoms of meningitis soon after the
primary infection, probably due to the early migration of HIV-infected cells
into the brain.
In a collaborative effort between
major universities, using state-of-the-art computer techniques and phylodynamic
analysis,researchers have now
developed a theory that could explain how and why HIV damages the brain and
could open the way to development of a new therapy.
Scientists were able to trace the
migration of HIV-infected macrophages (one of the immune system cell types
infected by the virus during the disease) in different regions of the brain of
a patient who died with HIV-associated dementia. The research shows that HIV is migrating
mainly to the temporal lobe where the virus accumulates mutations about 100
times faster than in other parts of the body. Such an exceptional increase in the HIV evolutionary rate in the
temporal lobe could cause the continuous accumulation of macrophages in the brain,
causing a persistent inflammation of tissues and leading, eventually, to
dementia.
The study, which was published in
the September issue of Journal of
Virology, is the result of a collaboration among the University
of Florida at Gainesville,
the University of California at San Francisco, the University of California at Irvine,
the Evolutionary Biology Group at Oxford University (UK), and Gene Johnson Inc.
Related news:
Scavenger cells could be key to treating HIV-related dementia
National Science Foundation News
