On Campus

Study finds link between ethnicity and immunity

Simon Fraser researchers part of team

A team of North American scientists has cracked a particularly-complex genetic code that reveals ethnicity may determine how well a person is able to fend off diseases such as HIV or the common flu.

Five scientists from Simon Fraser University were among those who found a link between race and antibodies, the culmination of years of research that may have implications in the way doctors treat patients.

The team found certain ethnicities have missing or added DNA links, a factor that could influence immunity to certain diseases, said Corey Watson, one of the team’s 14 researchers.

A “good number” of antibody genes vary from person to person, scientists discovered, which can effect how well the genes operate and which diseases they battle.

Watson said these missing or added links may be attributable to environmental conditions or past exposure to certain pathogens, which is why certain ethnic groups combat diseases differently.

The culmination of about two or three years of work, the study represents the tip of the iceberg when it comes to this kind of genetic research, Watson said in a telephone interview from New York, where he does postdoctoral research at Mount Sinai School of Medicine.

But it’s too early to speculate how the findings will effect drugs, vaccines and treatments that have typically been used to treat whole populations, the researcher said.

“Despite the fact that antibodies are essential to our immunity, they haven’t really been studied that much at the genetic level. So one thing our study has done is sort of … set the stage for this to happen,” Watson said.

Key to unlocking the discovery was the team’s success at determining the sequence of a highly-repetitive DNA chain, one million nucleotides long.

A nucleotide is a minute part of the DNA chain.

“This is the first time that the region’s been sequenced in its entirety,” Watson said.

Scientists have long known that the repetitive DNA chain, called an immunoglobulin-heavy chain locus, produces most of the body’s 50-plus antibodies that cells use to fight off infections and disease.

Watson’s work encompasses the most complete mapping of this genetic sequence, Simon Fraser University researcher Felix Breden says. Prior to this, scientists really only had piece-meal data.

But the evolutionary biologist added there’s so much scientists still don’t know when it comes to genetics, in light of the fact that the entire human genome — which encompasses the entirety of the human body, characteristics and traits — is comprised of three billion nucleotides.

Nucleotides are biological molecules that form the buildings blocks of DNA.

“We really don’t know how much they differ between ethnicities,” Breden said. “We only now can start because of Corey’s work.”

Breden added it’s still early but the findings could boost the push towards “personalized” medicine — treatments that take a person’s genetics, life history, socioeconomic status, ethnicity into account.

The discovery also has implications for scientists who do genetic research in future, because they’ll need to take the ethnicity of DNA samples into account for accurate results.

The study of 425 people of Asian, African and European descent was published last month in The American Journal of Human Genetics.

Jamie Scott, Jeffery Joy, Jeremy Willsey and Robert Holt were among the other Simon Fraser faculty and alumni involved with the study.

—Rebekah Funk

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