The platform that created the rice could potentially be used to make other biologics as the researchers used findings from two previous studies to create the antibody, according to Nature Reviews Drug Discovery.
Researchers have genetically engineered rice to produce high yields of a rotavirus-specific antibody fragment, according to a study published in the Journal of Clinical Investigation. The study demonstrated the effectiveness of the antibody in treating and preventing rotavirus-induced gastrointestinal symptoms in mice.
Rotavirus is the leading cause of diarrhea in infants and young children worldwide, causing more than 114 million episodes of diarrhea annually in children under the age of five, 80% of which occur in developing countries.
The researchers used findings from two previous studies to generate the antibody. One of those studies involved the immunization with the G3 strain of rhesus rotavirus and the resulting antibody fragment, known as ARP1, which has been patented by Unilever.
According to Nature, llama antibodies are particularly attractive to use for biologics because their variable domain of the heavy chain has a high binding capacity and is resistant to pepsin and heat. Moreover, the small size and simple structure of the llama antibodies means that they are uncomplicated to produce as recombinant proteins.
Both Shire and Merck Serono have utilized llama antibodies, which they say can offer advantages over inbred, transgenic mice.
A recent clinical trial in Bangladesh also showed that yeast-derived ARP1 was effective in reducing the severity of the disease in RV-infected children with no adverse events considered to be related to ARP1 treatment, according to the study authors.
The authors said there were three distinct advantages to a plant-based antibody system. The first is that large amounts of antibodies can be produced at a low cost. A second is that, in contrast with previous systems, there is no need for purification since MucoRice-ARP1 originates from edible rice seeds and can be “applied orally as a rice powder or rice water by simply dissolving the MucoRice-ARP1 rice powder in water (at room temperature), thus eliminating the costs for purification.”
“A third important aspect is that cold-chain transport and storage are unnecessary, as RV antibodies are primarily needed in developing countries,” while antibody-producing tobacco leaves need storage under –20 degrees, and antibody-producing tomatoes need a temperature of less than four degrees, they said.
“In conclusion, we have developed a high-yield, purification-free, cold-chain–free, and heat stable, rice-based antibody fragment containing product for oral administration that provides protection against RV of different serotypes in vitro and reduction of virus shedding and disease in both immunocompetent and immunodeficient mice,” the authors said.