In a setback for a novel approach to curing HIV, researchers involved in a technique that uses enzymes to remove viral genes from the DNA of infected cells have found that HIV rapidly develops resistance to the guide molecules that target the correct part of the DNA sequence. The resistant viruses that develop can in some cases replicate even faster than viruses not exposed to the gene therapy (though they are still susceptible to conventional antiretroviral (ARV) drugs).
Furthermore, the researchers suggest, the way the gene therapy works may actually promote the development of resistance, as it actively creates small mutations at the site where it bisects the cellular DNA. Resistance arises rapidly – within 8-10 days of the therapy first starting to work.
This does not mean the whole gene-splicing approach is doomed to failure, but it does imply that the gene-degrading enzyme would need to be attached to a variety of different gene probes, designed to attach to a number of different points on the viral DNA hidden within the human DNA inside infected cells.