McMaster researchers clone gene, turn corner in race to develop SARS vaccine
 
ANNE-MARIE TOBIN 
Canadian Press


Wednesday, October 01, 2003

TORONTO (CP) - Researchers are a step closer to finding a SARS vaccine after cloning the gene that marks an important nuclear protein of the SARS virus.

A team at McMaster University has inserted the nuclear protein into an engineered common cold virus, and is ready to start testing in laboratory mice. Depending on how it goes, human trials could begin within the year.

"We'll be immunizing mice in the first instance to see that this gene is recognized by the mammalian species, and that an appropriate neutralizing antibody response is generated in the mouse," Dr. Jack Gauldie, chair of the department of pathology and molecular medicine, said Wednesday from Hamilton.

The next step will be to run tests in primates, specifically macaques, to see if they produce antibodies to protect them from organisms that target the lungs, he said.

Severe acute respiratory syndrome made hundreds of people ill in Canada this spring, and was responsible for the deaths of 44 people in southern Ontario. Now, attention is being paid to SARS prevention on several fronts.

This week, Justice Archie Campbell held public hearings in Toronto as part of his review of how Ontario handled SARS.

But in a quieter environment - namely university and research laboratories across the country - scientists are working "vigorously" to find a vaccine that could protect people in the event of another outbreak.

Eight or nine labs across Canada are involved in various stages of developing a vaccine, Gauldie said. His team built upon the findings of the British Columbia Cancer Agency Genome Sciences Centre and DNA sequence data identified in the spring.

"We took the information that the B.C. group had generated about the sequence, and one of the people here, Jim Mahony, made a copy of the one gene," Gauldie said.

"We've taken that copy and inserted it into a vector - the virus vector that we use for immunizations, which is the common cold vector, or the adenovirus vector.

"And that gene is now sitting in a vector that can transmit the information into somebody - a host - that will recognize that gene and mount an immune response against it. This is a true immunization process."

Gauldie said they're doing the same thing with another gene that was provided by a research group in Montreal, which had also built upon the B.C. lab's work.

Dr. Mark Loeb, director of the Canadian SARS Research Network, said the work is an excellent next step in the development of a SARS vaccine.

"SARS is a deadly disease, particularly dangerous to those with compromised health," said Loeb, also an infectious disease specialist at McMaster.

"The development of a vaccine is important in ensuring Canadians are better protected against a reoccurrence of the syndrome."

The race is such that the McMaster group even includes Frank Graham and Ludvic Prevec, both retired professors of biology and pathology who are contributing their expertise.

"These are outstanding molecular virologists," Gauldie said. "You have to know that background before you take it forward."

Gauldie said he doesn't believe anyone else has duplicated the McMaster work.

"We know that in the U.S.A. there are several laboratories trying to generate a similar approach," he said. "In Canada, we're the only people who have done this with using the adenovirus vectors."

But he said it's difficult to predict how long it will be before a vaccine is fully developed and ready for testing in humans.

"The fact is that normally, if there was no real immediate threat, having developed it to this stage we'd probably be looking at a year to two years' worth of pre-clinical work before we get into the stage of preparing and going into the human," he said.

"If there is an immediate threat and there is a need for hurrying up, things could be speeded up and potentially the. . .the animal work could be completed in six months with a great deal of rushing, with a great deal of work and a great deal of money."

Potentially, he added, "you can get into the human within the year."

© Copyright  2003 The Canadian Press