How does HIV cause AIDS?  After 25 years of research by some of the
world's top scientists, almost 22 million deaths and a price tag of
billions, no one knows!

The search continues...

<http://www.in-pharmatechnologist.com/news/ng.asp?n=78706-hiv-aids-immune-activat
ion-tlr-interleukin>:

-----  Begin quote -----

Remarkably, despite being over 25 years into the HIV/AIDS epidemic,
scientists still don't have an answer to the seemingly simple
question: how does HIV cause AIDS?

----- End quote -----

But there is some good news.  A clever, well paid, HIV researcher
believes he has the answer.

-----  Begin quote -----

Istwas this conundrum that Dr Michael Lederman sought to review in his
presentation to delegates at the International Aids Society (IAS)
meeting in Sydney, Australia, last week. Specifically, is viral
replication sufficient to explain the loss in CD4 T cells seen in HIV
patients. And if not, what other factors contribute?

Lederman thinks that through a combination of research within his
group and other scientists' work, he might finally have an answer -
immune activation. Counter-intuitively, this finding could mean drugs
that suppress the immune system will prove to be valuable weapons in
the fight against HIV.

----- End quote -----

Yes, Dr Lederman has come up with the novel idea of treating HIV by
switching off the human immune system.  I suppose that's one way to
get around the nagging question I began with: "How does HIV cause
AIDS?"