Rice seeds could hold key to preventing HIV infections

Sep 20 2018

As incredible as it sounds, a rice paddy field could one day yield an inexpensive way to prevent HIV.

A Cambodian farmer throws rice seeds onto his paddy fields on the outskirts of Phnom Penh. Modified rice seeds could hold the key to fighting HIV. (© Heng Sinith/AP Images)

An international team of scientists has figured out how to put three HIV-blocking proteins into ordinary seeds of rice that could be turned into an ointment to prevent infections.

The seeds could simply be ground and mixed with water to create a cream that women in developing countries could apply daily to protect themselves, says Evangelia Vamvaka, the lead researcher.

“This groundbreaking strategy is realistically the only way that microbicidal cocktails can be manufactured at a cost low enough for the developing world,” the 15 scientists reported in the Proceedings of the National Academy of Sciences.

“This is not a magic bullet,” says Vamvaka, a professor at the University of Lleida’s Agrotecnio Center in Spain who is currently conducting research at the University of California, Berkeley. But it would give women in developing countries “a way to take control and be protected” if male partners balked at using condoms.

Scientists at the U.S. National Cancer Institute, Imperial College London, the IrsiCaixa AIDS Research Institute in Barcelona, Spain, and other institutions carried out the work, which builds on earlier studies on three continents involving tobacco, soybean and maize plants.

Barry O’Keefe, chief of a National Cancer Institute branch that develops potential cancer treatments from natural products, says the most powerful protein in this experiment came from marine red algae from New Zealand, which he first showed in 2005 could work as a microbicide — an agent to kill microbes like viruses or bacteria — against HIV.

To the scientists’ surprise, combining the three HIV-neutralizing proteins in the rice boosted their ability to block the virus.

AIDS has claimed 35 million lives, and nearly 37 million people are living with the infection. Despite advances in treatment and prevention, 1.8 million people were newly infected in 2017, most in low-income countries in Africa, the World Health Organization says.

Many infected by the virus are getting antiretroviral drugs, thanks to the President’s Emergency Plan for AIDS Relief (PEPFAR) and other humanitarian initiatives. But 16 million infected people worldwide go untreated.

Vamvaka said that if sufficient funding is found for further research, an HIV-prevention ointment could become a reality in five to seven years. It first must be shown to work in animal studies and human trials.

But a New York medical center has already begun a clinical trial of a microbicide women could use to protect themselves against sexually transmitted diseases, including HIV, O’Keefe says.