Suppression of Human Protein Reduces HIV’s Ability To Enter T Cells, Replicate, Study Finds

Researchers have found that suppressing the human protein ITK in CD4+ T cells reduces HIV's ability to enter the cells and replicate, according to an NIH study published Monday in the Proceedings of the National Academy of Sciences, Reuters reports.

For the study, Pamela Schwartzberg of Boston University and colleagues used human cells in a laboratory to test two methods of inactivating ITK. One method stopped ITK from functioning. In the other method, the researchers used a drug to chemically interfere with the protein (Dunham, Reuters, 4/28). "Suppression of the ITK protein caused many of the pathways that HIV uses to be less active, thereby inhibiting or slowing HIV replication," the researchers said (AFP/Google.com, 4/28). Schwartzberg added that the researchers did not "completely block (infection), but we certainly severely impaired it. It has minor effects at multiple stages of HIV life cycle, and together that all adds up to a more profound effect" (Reuters, 4/28).

The researchers said that they were concerned that ITK suppression "might kill or otherwise impair the normal functions of T cells." However, both suppression methods slowed HIV replication but did not interfere "significantly" with T cell survival, according to the study. In addition, the researchers said that mice with ITK deficiencies were able to fight other viral infections (AFP/Google.com, 4/28).

According to the PA/Google.com, ITK suppression could help address the emergence of drug-resistant strains of HIV because it targets a human protein rather than the virus (PA/Google.com, 4/28). Study researcher Andrew Henderson of Boston University added that treatments based on ITK suppression could complement existing antiretroviral drugs. Schwartzberg said that it likely would be several years before a drug that suppresses ITK could enter human clinical trials. She added that more lab experiments are needed to assess other ways of suppressing the protein.

NIH and the researchers have filed for a patent on suppressing ITK to treat HIV with the U.S. Patent and Trademark Office. The protein also is being examined as a possible target to treat asthma and other illnesses involving the immune system, Reuters reports (Reuters, 4/28).

The study is available online (.pdf).