The path of most resistance

The path of most resistance

In his quest to find a vaccine for HIV/AIDS, a University of Manitoba researcher is working to isolate the gene that makes some people naturally immune to the virus
January 31, 2005
In the mid-1980s, Frank Plummer was working at the University of Nairobi in Kenya studying infectious diseases. That's when he first crossed paths with HIV—a virus that would become the focus of his work for years to come.
 

"When I was in Nairobi and HIV came along, it was pretty hard to ignore it as a problem," says Plummer a Professor of Medicine and Medical Microbiology at the University of Manitoba and one of the world's leading experts on HIV. The answer may lie deep inside the common fruit fly buzzing around your kitchen compost.

At the time, HIV/AIDS was regarded as a disease largely confined to homosexual men. Today, Plummer's work with the International Centre for Infectious Diseases brings him face-to-face with the stark tragedy of the HIV/AIDS pandemic. When he travels to Kenya, where he lived from 1984 to 2001, he sees daily evidence of the ravages of HIV/AIDS. "The human tragedy is huge. One can't help but be affected by it. You have to try to deal with it without distracting from your goals," Plummer says.

Plummer also sees the real faces behind the chilling statistics from the World Health Organization (WHO). In sub-Saharan Africa, 25 million people are living with HIV/AIDS—2 million of whom die every year—and 20 million orphaned children. "Trying to treat all the people who have HIV and deal with the societal impact and the orphans is almost fruitless unless you can stop the epidemic," he says.

Fueled by the grim reality of HIV/AIDS, Plummer and his colleagues at the University of Nairobi and around the world are on a quest for a vaccine. That quest has brought him to study female sex workers in Kenya who have built up a natural resistance to HIV—now the focus of his investigations. Finding the genetic clues to that natural immunity may well lead to a vaccine for HIV/AIDS.

Initially, Plummer was studying Kenyan sex workers in 1984 to see if they were resistant to gonorrhea. He discovered that two-thirds of the 600 women he was studying were infected with HIV—at a time the scientific community thought HIV was largely a disease of men. Even more surprisingly, he discovered that the longer a woman worked in prostitution, the less likely she was to be infected.

The researchers eventually proved, by following women over time, that some of them did indeed have a natural immunity. "There definitely is clustering of this resistance to HIV in certain families," Plummer says. "We know that there are some genes we've identified that are involved in this, but we're convinced there are more."

As part of the International Centre for Infectious Diseases' continuing work, the researchers are trying to pin down the genetic and molecular structure of this immunity. An investment from the Canada Foundation for Innovation's International Access Fund is helping them do just that. Most of the research will take place in a newly constructed laboratory at the University of Nairobi that will also enhance the researchers' ability to conduct a viral hemorrhagic fever surveillance program.

"Almost all of our current vaccines have been developed out of some kind of understanding of what natural immunity is. It's very important," Plummer says. "We think that having models of natural immunity may very well provide the key to understanding how to make a vaccine."

Benefits

Given the millions of lives being lost to HIV/AIDS every year, and the economic and societal havoc the virus wreaks, the benefits of developing a vaccine cannot be overstated.

Now, thanks to the research and leadership of University of Manitoba virologist Frank Plummer, and his participation in the International Centre for Infectious Diseases, Canadian researchers are making a large contribution to the effort to develop a vaccine.

"Vaccines are the most cost-effective medical intervention that we have," says Plummer. "For any problem, prevention is much better than trying to treat the problem. That's particularly true of something like HIV."

Plummer's work with colleagues at the University of Nairobi on what he calls the "Nairobi project" has helped to train two generations of Canadian and Kenyan scientists. The research project has also helped to forge Canada's role as a leader in the field of infectious diseases, he says.

Plummer also believes that working to alleviate suffering from HIV/AIDS is one of Canada's responsibilities. "HIV is probably the number-one health issue in the world as far as I'm concerned," he says. "It's part of Canada's obligation to be engaged in the work."

Partners

The International Centre for Infectious Diseases, where Frank Plummer is the Director of Training Programs, is a unique collaboration among government, private-sector, and academic partners. Its members include the University of Manitoba, the National Microbiology Laboratory, Manitoba Health, the Health Sciences Centre Foundation, Cangene Corporation, and the Winnipeg Regional Health Authority.

Researchers involved in the Centre also work closely together in the Canada-Kenya Collaboration on Infectious Diseases Research—a partnership project on HIV/AIDS and other infectious diseases. The group includes researchers from the University of Nairobi, Oxford University, the University of Washington, the University of Montreal (through CANVAC), and the University of Ghent in Flanders, Belgium.

Plummer says this kind of multidisciplinary, collaborative research builds on individual discoveries and is essential to developing a vaccine for HIV/AIDS. It's also the key to working with the private sector—including pharmaceutical companies like Aventis Pasteur Ltd., GlaxoSmithKline, and others involved in CANVAC, the Canadian Network for Vaccines and Immunotherapeutics. The network of organizations and scientists, which is dedicated to accelerating vaccine research and development, has been collaborating with Plummer and his team for the past six years.

"Because he has access to patients who have very unique characteristics of resistance to infectious disease, Dr. Plummer brings a lot to CANVAC" says Rafick-Pierre Sékaly, Scientific Director of CANVAC and a Professor of Microbiology and Immunology at the University of Montreal. "His expertise in immunology, epidemiology, and global surveillance is of utmost importance when you are working to develop vaccines."