[procaare] HIV Drug Resistance Target Find

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

HIV drug resistance target find
BBC News Online: 30 April 2008
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A specific protein in the body may be the key to overcoming the 
increasing problem of resistance to HIV drugs.
Inactivating the ITK protein which is involved in the immune 
response blocks many steps of HIV replication, studies in the 
laboratory show.

Most current HIV drugs attack the virus itself which is liable to 
mutate and become resistant to treatment.

HIV experts said the results were promising but any drug would take 
a long time to get to the clinic.

ITK is involved in activating a type of immune cell called a T cell 
in the presence of infection.

HIV works by infecting T cells, taking them over so they can 
replicate and create large quantities of the virus, compromising 
the whole immune system.

The team at the US National Institutes of Health realised that many 
of the pathways regulated by ITK were also needed for HIV to take 
hold in the body.

Tests in human cells in the laboratory showed that removing or 
inactivating ITK could, as predicted, block many different steps in 
the ability of HIV to enter a cell, spread and replicate, the study 
in Proceedings of the National Academy of Sciences showed.

Drug development

Dr Pamela Schwartzberg said each of the steps only had a small 
effect but together they were significant.

What remains to be seen is how effective targeting ITK would be 
compared to existing drugs she said.
But due to other research looking at the role of ITK in immune 
responses in asthma, there are already potential drugs in 
development.

"Currently we have multiple options for treating HIV and we use 
multi-drug regimens but most of these therapies are directed 
against viral proteins which are subject to rapid changes allowing 
mutations to develop.

"Our own cellular machinery is less prone to making mistakes.

"ITK had an effect on HIV replication at several stages which if 
you add them up seems to be a profound effect."
Professor David Back, an expert in HIV pharmacology at the 
University of Liverpool said development of drug resistance was the 
main problem with current therapy.

"There is no question that we need new drugs acting on existing 
targets but also new drugs acting on new targets.

"Consequently any glimmer that a target protein may be less 
susceptible to mutational changes is an exciting prospect - this 
study on ITK looks just that."

However, he said there is a long road between proof of concept and 
a drug molecule ready for use in the clinic.

Online: http://news.bbc.co.uk/2/hi/health/7367142.stm