Virus hunter: Luc Montagnier, pictured here in front of an electron micrograph image of the HIV virus.
Credit: Photolibrary
It was then that we started to hear alarming news reports that AIDS was spreading rapidly in Africa. As early as September 1983, I isolated HIV from a Congolese woman, and tests on stored African samples showed that the virus had been present for at least a decade, but potentially much longer.
In retrospect, the discovery of HIV can be seen as a major step towards the control of the new pandemic: it led to the design of efficient new drugs that inhibit HIV multiplication, thus saving the lives of millions.
But, sadly, many HIV sufferers do not have access to these and the treatments do not completely cure the infection. The epidemic is still spreading wildly throughout Africa and other developing countries, and around 40 million people are now infected globally.
Since the discovery, I have co-founded the UNESCO World Foundation for AIDS Research and Prevention, which has contributed to the creation of centres for research and prevention in Africa. I have also helped create biotech companies to pursue the same objectives. My next goal is to work towards creating a new vaccine that will hopefully eradicate the infection, and prevent the suffering of millions.
FROM RNA TO RETROVIRIDAE
DNA carries the blueprints for the construction and activity of all living cells. It does this by converting those instructions into proteins that have useful functions. But how do we get from the DNA of a gene to the complex sequence of a protein? This is where RNA comes in. It’s another type of nucleic acid (ribonucleic acid, rather than DNA, or deoxyribonucleic acid), which translates the language of genes into the amino acid unit language of proteins.
RNA carries the sequence of the original DNA but also has the ability to attach to corresponding amino acids, which are then strung together into proteins.
Unlike more complex organisms, some viruses employ RNA in place of DNA to encode their genes. Retroviruses – such as HIV – are a type of RNA virus that reproduce themselves by inserting their genes into the DNA of a host cell. They rely on the reverse transcriptase enzyme to convert their RNA into DNA. Following this they are replicated as part of the host cell’s own DNA. At this stage HIV can lay dormant in the immune cells (T-lymphocytes) it infects. The life cycle is completed when the viral DNA makes RNA copies of itself, which are wrapped in a protein coat and ejected from the host cell. As with HIV and T-lymphocytes, this process has the potential to kill the host cell. — John Pickrell
Luc Montagnier is the chairman of the UNESCO World Foundation for AIDS Research and Prevention, based in Paris, France.
