Can latent HIV infections be cured?

Cancer medicine can lure HI viruses out of hiding

07/26/2012

Researchers at the University of North Carolina have investigated why HI can be kept at bay in the body of an infected person, yet it can not be defeated. A possible clue is special cells that contain the genetic material of the AIDS pathogen but do not produce viruses themselves. In several studies, scientists have come closer to the cause. Based on the research findings, researchers now believe that latent HIV infection can be treated with medication. For this purpose, a cancer drug must be administered to latent HI viruses „to lure you from sleep“.

Already previous research had determined that a drug that was actually designed for cancer therapy, animate in a present HI virus infection so-called sleeper cells. The active ingredient contained „Vorinostat“ has, according to available results, the property, cells that contain the pathogen genome, but do not release viruses, still be active. The viruses are put together and released from the cell, as the research team in their study report in the journal „Nature“ to report. Through this determined effect „HIV drugs have again a point of attack to tackle the HIV infection“, as the scientists summarize around David Margolis and colleagues.

Latent HIV infection could be treatable
„The results are the first evidence that latent HIV infection can be treatable“, emphasize in the technical report. In a latent infection, the body's defense cells would indeed contain genetic information of the virus, „but do not produce new viruses with this blueprint“. The problem: Conventional drugs in HIV therapy have no point of attack under these circumstances. The infection would become „successfully hiding from a drug attack of antiretroviral therapy“.

For the investigation, 16 test persons were bled and subsequently examined by laboratory techniques. From the blood of the participants were cells of the type „CD4-positive helper cells“ isolated and mixed in the test tube with the active ingredient Vorinostat. Six hours later, so-called gene expression was in the cells of 11 participants „significantly up-regulated“. In eight of the eleven serums the active ingredient struck. The subjects, in whom the cancer drug in the test tube showed an effect, were given the drug orally afterwards. „In all, the gene expression of the HIV genetic material has increased by a factor of one and a half to ten times“, Margolis and colleagues explained.

Certain proteins attract HI viruses
The study has shown that certain enzymes can attract viruses from sleeping cells. This assumption has been around for some time, according to the researchers, because the histone deacetylase inhibitors could expose genomic regions, so the previous presumption of some researchers. This would activate the gene sequences, with the result that the blueprints can be read out.

The researchers at the University of North Carolina at Chapel Hill have now succeeded in cooperating with other research institutions such as the pharmaceutical company Merck and other universities to confirm the suspected mechanism. „The molecular mechanism works and with the histone deacetylase inhibitor vorinostat“, write the authors. The named active pharmaceutical ingredient is already approved in the US market for the treatment of cancer patients and is named by the pharmaceutical company „Zoliza“ expelled.

First preliminary results of the study results were already at the congress „Conference on Retroviruses and Opportunistic Infections“ Introduced in early March 2012 in Seattle. More details will be presented this week at the World AIDS Conference in Washington D.C. reported.

Valuable study but open questions about dosage
The results also cause a stir among experts in Germany. „The study is very valuable“, commented Georg Behrens from the Department of Immunology and Rheumatology at the Hannover Medical School (MHH). Behrens is researching HIV therapies even with colleagues. „It was worked with very sensitive and also new methods. It is amazing that the effect of the drug in humans was even more pronounced than in cell culture. "However, in the „Nature“-The report does not elaborate on some important aspects, the expert said. For example, it was unclear whether a single dose of the cancer drug was enough to wake up all latently dormant HIV cells. Also, do not kill every cell when it produces and releases HI viruses into the blood. (Sb)

Read also about HIV:
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HIV protection: anti-AIDS pill no miracle cure
Anti-HIV pill just before approval
AIDS: drug to protect against HIV infection

Picture credits: Gerd Altmann