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genes – he hopes to be able to suppress the ability of the virus which causes AIDS to replicate in the body. However, just repressing the ability of HIV to replicate is not enough. The virus is prone to mutation and difficult to control even when researchers successfully ‘program’ RNAi to slow down HIV mutation in key areas of our immune system (especially T cells and macrophages). To overcome this, Prof Lee and his team are working with ‘short interfering RNA’ (siRNA--works together with RNAi to interfere with the expression of specific genes) and targeting highly conserved viral sequences that have lower mutation rates thereby increasing the chances of successfully reducing HIV replication. The trick is delivering the siRNA to the infected cells without being ‘spotted’ and destroyed either by the bodies’ own immune defenses or the infected cells. To create his horse of Troy Prof. Lee ‘hid’ the siRNA in surface antigens present on human T cells. These antigens are the first substances which appear after HIV infection and they can be used as a warning ‘flag’. They provoke the production of antibodies in the body which will come and try and neutralise or destroy the ‘invader’. Critically the receptor is rapidly ‘internalised’ after the antibody binding, so like the Trojan horse the siRNA silently enters the cells to do its work. Of course despite the progress there is a somber reality to Prof. Lee’s research. He recalled a recent phone call he received from a man who had just been diagnosed with HIV. He asked when Lee thought his new therapeutic techniques would be available to patients. When Lee admitted that it could be many years before they were commercially available, the man burst into tears. “Researchers sometimes forget” Prof Lee said gravely, “My focus was always on progressing to the next stage of the research…to getting that paper published in a top ranking journal. That phone call changed that, it reminded me that the real focus is not the next publication, but to help those suffering from HIV.”
C. Goldsmith
Developing a Trojan horse to target HIV ‘Deception’ is not a word often associated with the scientific process. However, this is exactly what Professor Lee Sang-Kyung, from the Department of Bioengineering at Hanyang University, spends his time doing. By modifying a naturally occurring process in living cells, Prof. Lee is hoping to develop antiviral therapies to target, for example, the human immunodeficiency virus (HIV) that causes acquired immune deficiency syndrome (AIDS). When targeting disease we often think simply about the ‘drug development’. A major obstacle however is the delivery of drugs to the required cells and tissues in the human body. Prof. Lee's work aims to develop the tools which will actually ensure that the drugs reach their destination. Using RNA interference (RNAi) – a naturally occurring process in cells that moderates the activity of
Scanning electron micrograph of HIV-1 budding (in green) from cultured lymphocyte
For further information contact: Professor Lee Sang-Kyung Dept of Bioengineering Hanyang University, South Korea Email: sangkyunglee@hanyang.ac.kr