MadSci Network: General Biology |
Hi Shawn,
This is a really interesting question. As I’m sure you know,
AIDS (Acquired Immune
Deficiency Syndrome) is a disease caused by the HIV (Human Immunodeficiency
Virus)
virus. Once the virus gains access to the blood
stream, it works by infecting and destroying cells of the immune cells
(notably
CD4+ T-
helper
cells). When the number of
CD4+
cells in the blood drops below a certain level, the body is no longer able
to
properly mount immune responses to pathogens, allowing a variety of
microbes to
infect the body; this is AIDS. It is
these
“opportunistic
”
infections that go on to kill people with AIDS.
HIV is a retrovirus
– that is, it is a virus that has a genome made of RNA that has to convert
its
genome back to DNA when it infects a cell using an enzyme called reverse
transcriptase. Because human cells lack reverse
transcriptase, it was the earliest and one of the most effective targets in
treating HIV…reverse transcriptase inhibitors like Zidovudine
(AZT) were the very first drugs used to fight HIV. HIV also requires special protein cutting
enzymes called proteases to cleave large protein products into smaller ones
for
viral production…inhibitors of these proteases, appropriately called protease
inhibitors,
have also been used successfully therapeutically.
Now, let’s address your question.
I am familiar with the experiments using hydrogen sulfide gas to
place
mice in states of suspended animation.
Importantly, these mice did not become metabolically inactive…
indeed,
they maintained constant blood pressure.
Thus, removing their blood would almost certainly kill the mice…and
would absolutely kill a person.
There is a relatively new technique that people have been
researching that is similar to what you suggest. I mentioned earlier that CD4+
cells
were targeted by the HIV virus. The
HIV
virus actually requires a second protein on the cell surface called CCR5 to infect those cells.
Some people have mutations in this
protein
called the “delta 32” mutation which the HIV virus cannot recognize; these
people are immune to AIDS. When
doctors
in Germany removed the bone
marrow of an HIV+ leukemia patient, effectively removing his
body’s ability to produce blood, and replaced it with the bone marrow of a
donor
who had the delta 32 mutation, the patient was
cured
of HIV. This work is still in its infancy, and the
dangers associated with bone marrow replacement and the shortage of
available
donors makes it technically impossible as of now, but it is certainly the
focus
of much research.
Bone marrow is just one of the myriad targets of intense HIV
research. I’m including some links
to reputable
sites that discuss some other approaches.
I like the way you think – keep asking questions!
Billy.
·
This is a link to the BBC report about the
bone marrow transplant. Very
interesting!
http://news.bbc.co.uk/2/hi/7726118.stm
·
AVERTing HIV
and
AIDS: A cure for AIDS.
This is really interesting. It mentions the bone marrow case I talked
about, as well as using gene therapy.
It
also briefly introduces an idea focused around activating CD4+
cells
that might be “hiding” HIV virus. It
also has links to very detailed descriptions of the topics they mention.
http://www.avert.org/cure-for-aids.htm
·
AMFAR (American Foundation for AIDS
Research)
is an organization that provides funding for laboratories investigating HIV
and
AIDS. Their section “In the Lab” is
a
treasure trove of information regarding the newest techniques in treating
HIV/AIDS…I think this is a particularly interesting site because it
includes
even very early projects on HIV treatment.
·
Finally, in July of 2010 the journal Science published a review of
current
knowledge and potential therapies for HIV/AIDS.
It’s a pretty dense read, but it has some
valuable
information.
“HIV
Persistence and the Prospect of Long-Term Drug-Free Remissions for HIV-
Infected
Individuals.”
Trono D,
Van
Lint C, Rouzioux C, Verdin
E, Barre-Sinoussi F, Chun T, and Chomont
N. Science.
174 – 180.
2010.
http://www.sciencemag.org/content/329/5988/174.full