[procaare] Men's testicles 'HIV hiding spot'

["BBC Online News" <procaare@healthnet.org>]

Men's testicles 'HIV hiding spot'
BBC Online: 4 Feb 2007
http://news.bbc.co.uk/2/hi/health/6323191.stm
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HIV can dodge destruction by powerful antiretroviral drugs by hiding out in 
the testicles, scientists say.

The French work in the American Journal of Pathology suggests the gonads 
provide an ideal environment for the Aids virus to replicate itself. 
Evidence shows even the best antiretrovirals find it difficult to penetrate 
the testes.  This may explain why HIV can still be found in the semen of men 
on drugs that successfully clear their blood of it.

Infected semen

The team say their work could help with the development of new 
antiretrovirals that can target HIV in the gonads. This is particularly 
important given that sexual transmission is one of the main ways HIV is 
spread from person to person.

According to the most recent World Health Organization data, 39.5 million 
people are infected with HIV.

Dr Nathalie Dejucq-Rainsford and colleagues from Rennes University examined 
testicular tissue.  They discovered certain immune cells had the necessary 
machinery to allow HIV safe passage. These cells, called macrophages, had 
all of the required receptors - CD4, CXCR4, CCR5, and DC-SIGN - to bind HIV. 
Closer inspection revealed HIV was making copies of itself within the 
testicular macrophages. When they took some more of the testicular tissue 
and grew it in the lab, they found HIV was able to thrive there and was 
capable of infecting other cells.

The study authors explained: "Although highly active antiretroviral therapy 
(HAART) may achieve undetectable virus levels in the blood, virus 
replication in the testis may permit continued spread of the virus.

"The infected cells appeared to be testicular macrophages located within the 
interstitial tissue."
A spokesman from Avert said: "It has long been known that the testes act as 
a reservoir for HIV, but this is the first piece of research that really 
demonstrates exactly why this is the case.
"If methods developed by these researchers were to result in new products 
that could suppress HIV replication within the testes, then this would 
represent an exciting advance in prevention technology.

"However, it seems unlikely that these would be available any time in the 
foreseeable future, so for the moment, condoms remain the best method of 
preventing HIV during sexual intercourse."