The 2008 Nobel Prize in Medicine
The Discovery of HIV and Research Towards a Treatment of AIDS.
Nov 6, 2008
In 2008 one half of the Prize in Physiology and Medicine was shared by Françoise Barré-Sinoussi, of the Institut Pasteur, and Luc Montagnier, Director of the World Foundation for AIDS Research and Prevention, for the discovery of the human immunodeficiency virus (HIV). The Nobel Assembly stressed that this was not just for the scientific and theoretical importance of the discovery, but also for the great step forward towards an eventual cure to one of the most distressing and widespread of human diseases.
Background to HIV
In 1981 a new serious medical syndrome was described in the USA and given the name Acquired Immune Deficiency Syndrome (AIDS). Within just a year the syndrome was seen to have spread globally. The immunodeficiency was associated with the rapid elimination of T lymphocytes, which are the cells in blood plasma vital for the body's immune defences, and subsequent opportunistic infections from a range of bacteria and viruses. It was established that the disease was being transmitted by sexual contact, through the placenta or by the transfusion of blood plasma. The data pointed towards a retrovirus, but researchers were unclear as to the causative agent.
How HIV was Discovered
Françoise Barré-Sinoussi and Luc Montagnier isolated and cultured lymph node cells from patients that had swollen lymph nodes characteristic of the early stage of acquired immune deficiency. They detected activity of the retroviral enzyme reverse transcriptase (RT), a direct sign of retrovirus replication. Electron microscopy subsequently found retroviral particles about 100 nm in size budding from cell membranes. In contrast to previously characterized human oncogenic retroviruses, the novel retrovirus they had discovered, now known as HIV, did not induce uncontrolled cell growth. Instead, the virus required the T cells to be active for it to replicate but then caused the fusion of the same T lymphocytes, thereby destroying them and impairing the immune system. By 1984, Barré-Sinoussi and Montagnier had obtained several isolated examples of the novel human retrovirus that they identified as a lentivirus.
The Importance of HIV Discovery
Soon after the discovery of the virus, several groups contributed to the definitive demonstration of HIV as the cause of AIDS and rapid cloning of the HIV-1 genome possible. This has allowed identification of important details in its replication cycle and how the virus interacts with its host. Furthermore, it led to development of methods to diagnose infected patients and to screen blood products, which has limited the spread of the pandemic. The unprecedented development of several classes of new antiviral drugs is also a result of knowledge of the details of the viral replication cycle. The combination of prevention and treatment has substantially decreased spread of the disease and dramatically increased life expectancy among treated patients. The cloning of HIV enabled studies of its origin and evolution but it is still unclear why the epidemic spread so dramatically from 1970 and onwards.
The Future of AIDS Research
The ways HIV evades the host’s immune system by impairing lymphocyte function, by constantly changing and by hiding its genome in the host lymphocyte DNA, makes its eradication difficult even after long-term antiviral treatment. As Luc Montaignier says,”[...] after 20 years we are still fighting this virus, very strongly, and [...] my message is that we should continue the research. And myself I'm working on a vaccine – not a preventive vaccine but on a therapeutic vaccine which is aimed at completing the antiretroviral therapy which is now given to many patients even in Africa, but which does not cure. So the idea is to eradicate the virus infection. I think this is the main step now.”
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