Jamie Scott's quest for a new way to vaccinate against disease, including AIDS, has won her a $96,000 (Cdn) grant from the Medical Research Council of Canada and, more recently, a $150,000 (U.S.) grant from the National Institutes of Health's AIDS Innovation Grant program for approaches in HIV vaccine research.
Scott, a molecular biology professor at Simon Fraser University, has centered her career's research on the human immune response to disease. Her research into antibodies, the molecules in the bloodstream responsible for our body's 'immune memory,' has revealed a promising new way to create a vaccine that can stimulate the body to produce just the two or three antibodies that are most effective at preventing a virus like HIV-1, the AIDS virus, from attacking the body.
A traditional vaccine against AIDS would use a 'shotgun' approach, stimulating the body to produce all possible antibodies against HIV-1, instead of producing only the most effective antibodies for fighting the virus.
Scott's novel vaccine concept combines her research into peptides (small protein molecules that bind tightly to antibodies) and Austrian and Californian research that has discovered three human antibodies that each kill a broad spectrum of the HIV-1 strains that cause AIDS. Working with two of the antibodies, Scott has obtained for each, a peptide that binds specifically and tightly to it, 'mimicking' the viral site to which its corresponding antibody normally binds.
She plans to use these 'peptide mimics' to prepare a vaccine that will stimulate the body to produce the two HIV-1 killing antibodies. Then, if the AIDS virus enters the body, these antibodies will be there to prevent the infection.
"This vaccine approach should produce an unbelievably focused antibody response compared to that produced by the more traditional whole virus or subunit vaccines," says Scott, who also points out that such vaccines have so far failed to produce protective antibodies against AIDS. "There really aren't many other ways (but ours) by which a vaccine can selectively produce protective antibodies."
Scott's vaccine concept, however, isn't the complete answer to coming up with the ideal vaccine against AIDS. "We're really working on only half the overall immune response that could be used to prevent infection," she says. "Protective antibodies can prevent infection, but we haven't even addressed the other part of what the ideal vaccine would do, which is also to train the body's immune cells to attack the tiny amount of virus that might slip past the protective antibodies and infect cells.
"The ideal vaccine would offer two levels of protection by killing the free virus before it can infect cells, and by killing virally-infected cells in their early stages, before they have a chance to produce more virus that can spread to the rest of the body."
Over the next two years, Scott expects that her research will determine whether a vaccine using peptides can enter human vaccine trials against AIDS infection. "We envision our peptide mimics as one component of a vaccine that elicits both antibody and cell-mediated immunity -- a vaccine giving us the best of both worlds."
Contact:
Jamie Scott, 604-291-5658/5656/5630
Diane Luckow or Marianne Meadahl, media/pr, 604-291-3210