Proteins produced in transgenic rice prevent HIV infection in vitro

Easier to grow and process than cell cultures, plants could be an inexpensive platform to manufacture drugs in developing countries. An international team engineered rice plants to produce three proteins that synergistically block entry of HIV into host cells. The researchers showed that extracts of the ground whole-grain rice prevented HIV infection in vitro (Proc. Natl. Acad. Sci. USA 2018, DOI: 10.1073/pnas.1806022115). This combination of proteins could offer long-term anti-HIV benefits that are better than previously developed treatments based on single proteins, the researchers say, as it’s difficult for HIV to become resistant to all three molecules. Coauthor Paul Christou of the University of Lleida says that given enough support—the team is seeking public funding to do animal studies and then human trials—these rice-made proteins could be delivered in the form of vaginal or rectal cream to prevent HIV from spreading via sexual intercourse. “Only plants have the capacity of mass-scale production at a very low cost,” Christou says, which is important for people in developing countries. He estimates that it would take at least 10 years for the current protein combination to enter real-world application. One of the HIV-blocking proteins in the transgenic rice is a lectin called Griffithsin. Population Council, a nonprofit organization, is currently testing Griffithsin in a vaginal gel in Phase I clinical trials.