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Understanding the HIV virus
December 24, 2009
Ever since the HIV virus was discovered in 1983, a lot of research has been done around its genome. In the face of emerging and re-emerging viral threats, large-scale genome sequencing efforts are underway to monitor viral evolution in real-time. To fully appreciate the mechanisms of viral adaptation and evolution, and to also develop reagents and resources for a better molecular diagnosis of viral infections, there have been efforts at producing full-length viral genome sequences.
Research has shown that HIV drug resistance can be identified by genome sequencing. Hence it is important to study the influence of the changes in the HIV genome. At the National AIDS Research Institute (NARI) in Pune, scientists are just six months away from completing the sequencing of the HIV genome. And according to Director Dr R.S. Paranjape, initial trends show that the Indian virus is slower in its progression than the South African Sub type B and C. The Indian subtype C strain of HIV is different from the subtype C strain in China and South Africa, he explained.
NARI has been working on this project for two-and-a-half years and has sequenced 60 strains in the country. “What is the genetic make up of the virus? How has it evolved? How can the evolution go further? These are the issues being looked at. A large number of samples from patients, stored away for years, is being analysed and we are looking at evolutionary trends,” says the director.
Dr Jayanta Bhattacharya, who is also working on the project, says genome sequencing basically means to read the genetic makeup of a given virus strain. The genetic sequence of HIV is obtained by amplification (through polymerase chain reaction) of the integrated provirus in peripheral blood mononuclear cells (PBMC) or from the HIV + plasma and subsequently reading the DNA sequences with the help of a genetic analyser.
December 04, 2009
Antiretroviral drugs are medications for the treatment of infection by retroviruses, primarily HIV. When several such drugs, typically three or four, are taken in combination, the approach is known as highly active antiretroviral therapy, or HAART. The American National Institutes of Health and other organizations recommend offering antiretroviral treatment to all patients with AIDS. Because of the complexity of selecting and following a regimen, the severity of the side effects and the importance of compliance to prevent viral resistance, however, such organizations emphasize the importance of involving patients in therapy choices and recommend analyzing the risks and the potential benefits to patients without symptoms.
There are different classes of antiretroviral drugs that act at different stages of the HIV life cycle.