Scientists moving closer to eradicating HIV

Transcript

Hope is on the horizon for the 34 million people living with HIV, thanks to a team of scientists working to eradicate the virus using the properties of a type of Samoan tree.

A professor of chemistry and systems biology at Stanford University in the United States, Paul Wender, says the initial discovery of the prostratin molecule in mamala tree bark was made in the 1970s.

A decade later an ethnobotanist from the United States spending time with Samoan healers noticed that people with what appears to have been hepatitis got better from drinking a tea made from the bark.

Professor Wender says subsequent screening found prostratin to be capable of activating latent HIV virus.

He told Annell Husband the idea is to use synthetic compounds that work in the same way, in conjunction with anti-retroviral therapy.

PAUL WENDER: Because this is a new idea and a new strategy, one has to approach it cautiously. Because, after all, we are activating, if you will, these reservoirs that produce active virus. But in the process of activating the reservoirs we hope that that activation process will kill those reservoir cells. So the cautious approach to this is that you just stimulate them ever so slightly to get... let's say you have a million of these reservoir cells. Well, maybe in the first round of therapy you nudge 100,000 into activation and 100,000 die, which means you have 900,000 left. So maybe a week or two or three later, you go after the other 900,000 and over a period of time you reduce the number of cells that are resupplying the active virus, and presumably you might be able to get it to a point where you reduce that number of cells down to a few dozen, and then maybe our own immune system, even our own inadequate immune system, might be sufficiently effective in getting rid of the final bit of cells, cleaning things up completely.

ANNELL HUSBAND: So when you say 'activate them', in those reduced numbers is the immune system able to overcome them?

PAUL WENDER: It depends on how mature the disease is. So in early-stage infections we would speculate - and again this is theory, not evidence that we have - in early-stage disease the immune system would be less degraded, therefore it would be, itself, better able to deal with the cells. In later-stage disease the immune system is compromised. In later-stage disease our plan would be supplement the activation process with what are referred to as 'immuno-toxins'. And that's a fancy name for compounds that would search the body for cells that have the latent virus, and when they find those cells they would kill them. So if our treatment doesn't kill those cells, we would have Plan B to put in place, and that is to use the immuno-toxins to go in and kill whatever cells our treatment doesn't kill or whatever cells a person's own immune system doesn't kill.