Resistance to diseases like CMV depends, at least partially, on the ability of our body's defense mechanism to recognize and destroy them. "Detecting these pathogens is not always easy," says Dr. Silvia Vidal, a Canada Research Chair in Host Response to Virus Infection based at the MUHC and lead author of the new research. "CMV has developed cunning disguises to avoid detection by our Natural Killer cells--one of several cell types that hunt-down and terminate unwelcome invaders within our body." Our Natural Killer cells and the pathogens they fight have been locked in an evolutionary arms race for millions of years in an attempt to overwhelm each other.
Dr. Vidal and her team have spent the past 10 years studying CMV-resistant mouse strains in an attempt to describe the nature of their genetic resistance. "This research marks our second discovery of genetic resistance to CMV," she says. Most significantly, this new research documents an entirely new mechanism of resistance to CMV, involving the interaction between two genes. One gene flags virus-infected cells for destruction, the other gene allows our Natural Killers cells to recognize and terminate them. "This is a new concept in natural disease resistance," notes Dr. Vidal. "Our research suggests there are many different mechanisms for fighting viruses; in the future we expect to discover additional resistant genotypes."
CMV infects most of the world's organism s, including upwards of 80% of the human population. Although healthy people suffer only mild symptoms, infection can trigger fatal reactions in those with a compromised immune system, such as organ transplant recipients, newborns and persons infected with human immunodeficiency virus (HIV). Dr. Vidal believes her groundbreaking discovery increases the likelihood that therapies will be developed to fight CMV.