WORLD – An international team of researchers from Spain, the United States, and the United Kingdom has successfully created a strain of genetically modified (GM) rice that will produce HIV-neutralizing proteins.
According to Crop Biotech, the scientists have been developing possible treatments for people infected with HIV.
Their efforts to produce a vaccine against the virus have been unsuccessful, but oral medications have been developed that can stave off an infection for a short period of time.
These medications, however, are unavailable in third world countries.
To help people who are at risk, the research team developed a strain of rice with the same HIV-neutralizing proteins as the oral medications.
Once grown, the rice produces seeds that can be processed on-site to make a topical cream containing the proteins.
The cream can then be applied to the skin to allow the proteins to enter the body.
The research update stated that the GM rice produces one type of antibody and two kinds of proteins that bind directly to the HIV virus, preventing them from interacting with human cells.
The researchers also noted that the cost of making the cream is nominal once the rice has been grown, and people living in infection areas can grow as much of the rice as they need, then make the paste and apply it themselves.
“Our paper provides an approach for the durable deployment of anti-HIV agents in the developing world.
We developed a transgenic rice line expressing three microbicidal proteins (the HIV-neutralizing antibody 2G12 and the lectins griffithsin and cyanovirin-N).
Simultaneous expression in the same plant allows the crude seed extract to be used directly as a topical microbicide cocktail, avoiding the costs of multiple downstream processes.
This groundbreaking strategy is realistically the only way that microbicidal cocktails can be manufactured at a cost low enough for the developing world, where HIV prophylaxis is most in demand,” a statement from the research wrote.
The transmission of HIV can be prevented by the application of neutralizing monoclonal antibodies and lectins.
Traditional recombinant protein manufacturing platforms lack sufficient capacity and are too expensive for developing countries, which suffer the greatest disease burden.
Plants offer an inexpensive and scalable alternative manufacturing platform that can produce multiple components in a single plant, which is important because multiple components are required to avoid the rapid emergence of HIV-1 strains resistant to single microbicides.
Additionally, the crude extracts can be used directly for prophylaxis to avoid the massive costs of downstream processing and purification.
“We investigated whether rice could simultaneously produce three functional HIV-neutralizing proteins (the monoclonal antibody 2G12, and the lectins griffithsin and cyanovirin-N).
Preliminary in vitro tests showed that the cocktail of three proteins bound to gp120 and achieved HIV-1 neutralization.
Remarkably, when we mixed the components with crude extracts of wild-type rice endosperm, we observed enhanced binding to gp120 in vitro and synergistic neutralization when all three components were present.
Extracts of transgenic plants expressing all three proteins also showed enhanced in vitro binding to gp120 and synergistic HIV-1 neutralization.
Fractionation of the rice extracts suggested that the enhanced gp120 binding was dependent on rice proteins, primarily the globulin fraction.
Therefore, the production of HIV-1 microbicides in rice may not only reduce costs compared to traditional platforms but may also provide functional benefits in terms of microbicidal potency.”