Tre Enzyme offers hope for HIV infected

Customised Tre Enzyme can cut HIV-1 from infected cells.

30 June, 2007:

In a significant breakthrough that could probably lead to a cure for human immunodeficiency virus (HIV) infection, scientists have found out a way to remove the virus from infected cells.

HIV is a retrovirus, which means that not only does it infect human cells but also splices its own genetic code into the host cell’s DNA, effectively merging itself with the patient’s own tissues.

During a study conducted recently, scientists engineered an enzyme called Tre that attacks the DNA of the HIV virus and cuts it out of the infected cell.

According to the study published in Science magazine, the Tre enzyme is still far from being ready to be used as a treatment, the authors warned, but it offers a flicker of hope for over 40 million HIV-infected people worldwide.

Alan Engelman, of Harvard University’s Dana-Farber Cancer Institute, wrote in an article accompanying the study that the customized Tre enzyme that effectively excises integrated HIV-1 from infected cells in vitro might one day help eradicate the virus from AIDS patients.

Current treatments focus on suppressing the HIV virus in order to delay the onset of AIDS and dramatically extend the life of infected patients.

What makes HIV so deadly, however, is its ability to insert itself into the body’s cells and force those cells to produce new infection. This mean that the virus becomes inextricably linked to the host, making it virtually impossible to ‘cure’ AIDS patients of their HIV-1 infection.

That situation could change if the enzyme developed by a group of German scientists can be made safe to use on people.

The enzyme was able to eliminate the HIV virus from infected human cells in about three months in the laboratory.

The researchers engineered the Tre enzyme, which removes the virus from the genome of infected cells by recognizing and then recombining the structure of the virus’s DNA.

This capability to recognize the DNA of HIV might one day help overcome one of the biggest obstacles to finding a cure – the ability of the HIV virus to avoid detection by reverting to a resting state within infected cells which then cease to produce the virus for months or even years.

Numerous attempts, Engelman wrote, have been made to activate these cells, hoping that such strategies would sensitise the accompanying viruses to antiviral drugs, leading to virus eradication. However, advances with such approaches in patients have been slow to materialize.

New experiments must be designed to see if the Tre enzyme can be used to recognize these dormant infected cells, wrote Engelman.