CAPE TOWN, South Africa – For four days this July, hundreds of scientists, medical experts and policy makers trooped to the Cape Town International Convention Centre in this city to discuss the latest advances in prevention of HIV infection and treatment of full-blown AIDS.  

Lost in the shuffle was an e-poster presentation by a group of Japanese and Filipino scientists who are investigating a novel approach to creating a vaccine against HIV.

Prof. Marni Eusebio Cueno, who finished a BS Biology degree Major in Genetics as well as a Master of Science degree in Molecular Biology and Biotechnology at UP Los Baños, has had eight years to prepare for his research in the fight against the AIDS pandemic.

During his time with UPLB Institute of Plant Breeding, Cueno studied the molecular aspects of coconuts and even helped in developing a genetically modified (GM) coconut with increased lauric acid.

“During those days, there was a growing interest in VCO (virgin coconut oils) and its numerous health benefits. One aspect which did interest me was its ability to fight off pathogens such as HIV. Unfortunately, there was no scientific background that would have supported this claim. Since my background those days were mainly on Plant Sciences, I didn't focus much on the medical aspect,” Cueno said in an e-mail interview.

In 2003, however, an opportunity presented itself that would allow Cueno to delve further into the medical benefits of his research.

Two Japanese scientists, Takashi Okamoto M.D., PH. D., and Antonio C. Laurena, PhD., started research into developing an HIV-edible vaccine using tomatoes. The research project then became a joint effort between the Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences in Japan and UPLB’s Bioechemistry Laboratory Institute of Plant Breeding.

“Since they needed someone knowledgeable enough to pursue this type of research, they were kind enough to involve me in [the project]. That was when I was introduced to HIV research,” Cueno said.

Complications, however, arose during the course of their work, he said. Since most of the equipment needed for the research was in Japan, Cueno applied and got accepted for a Japanese government scholarship to study in Dr. Okamoto's laboratory while working on the development of an edible HIV vaccine with five other scientists.

Humoral, cellular immune responses

To date, the group’s most exciting discovery has been to produce humoral (antibody production) and cellular (cytotoxic T lymphocytes production) immune responses in mice that were injected with the experimental vaccine. The group has also shown that a gene from a human virus such as HIV-1 Tat can also affect a plant when transiently expressed.

According to Cueno, both findings are promising enough to warrant further clinical studies.

“At present, there are two previous researches done in Mexico and Russia that were only able to produce a humoral immune response. Our results, thus, further support the idea of producing potential HIV-1 vaccine in plants,” he said.

Cueno said the group hopes to test the vaccine by feeding it to mice, then monkeys and finally to humans.  

He added that the group is also diversifying into making a plant-based influenza vaccine due to the spread of the Influenza A (H1N1) virus. “Unlike the commercially made Influenza vaccine, we are adding a plant-based twist in our vaccine design,” he said.

Cueno said his Plant Sciences background has helped him offer something unique to the worldwide search for an AIDS vaccine. To date, no HIV vaccine tried in humans has induced the kind of broadly neutralizing antibodies required to prevent HIV from entering cells.

“The main feature of this AIDS vaccine which I am trying to develop is that it would be produced in plants, making it less expensive than commercially available vaccines,” he said.

“I personally believe that this research that I am doing, or would be doing in the future, can actually make a difference. I really hope it does.”