Malaria Conference's Second Day Focuses on the Big Picture (web article)

Young researchers entering the battle against malaria must pay attention to historical data tucked away in libraries so they can ask the right questions today.

“When viewed together, the old and new data can give rapid and penetrating insights into what some might now term the 'systems biology' of Plasmodium,” said Robert E. Sinden, PhD, Department of Biological Sciences, Imperial College, London. Sinden delivered his talk, Malaria and the Mosquito in the 21st Century: Back to the Future, during the final day of the Second International Malaria Research Conference at the Johns Hopkins Bloomberg School of Public Health.

Anopheles mosquito

Though he was chided as a young investigator for not studying the malaria parasite in humans, where the damage is done, Sinden still urges young investigators to focus on blocking Plasmodium as it passes through the mosquito vector. “I think if we are ever to achieve control of malaria, we must attack it in the mosquito,” he says. His reasons:

• Usually, the distribution of the parasite is dictated by the distribution of the insect.
• Vector control is known to be very effective in reducing malaria cases.
• Just 5 to 50 cells may infect any one mosquito, whereas 1010 parasites can infect a human being. “Which would you prefer to attack?”
• While Plasmodium is busying itself inside the mosquito, the parasite is accessible to attack by the immune system for hours, rather than seconds, as is the case at other points in the parasite's life cycle.

Nirbhay Kumar, PhD, is already working along the same lines of attack as Sinden by targeting Plasmodium in the mosquito. In his lecture on the conference's first day, Kumar discussed his plan to attack the parasite during its sexual stage in the mosquito. Blocking the infectious, sexual stage will stop the parasite in its tracks.

Kumar, a professor of Molecular Microbiology and Immunology at the School, explained how he and his team have succeeded in selectively disrupting or "knocking out" expression of a gene that governs production of a protein, Pfg27, crucial in moving the parasite from its immature form to its infectious sexual form. Parasites that lack Pfg27 resemble hollowed-out husks, which soon break down and disintegrate.

Besides trying to find out the exact function of Pfg27, Kumar's team is also searching for new candidate proteins in Plasmodium to attack.

More than 275 researchers from 13 countries attended the Malaria Research Conference sponsored by the Johns Hopkins Malaria Research Institute at the School of Public Health. The conference concluded March 26, with a lecture by Nobel laureate Peter Agre. --Rod Graham

Conference images