Grant: Doctoral Research Award: Canada Graduate Scholarships

Some viruses can make us very sick, but we then get better because our immune system fights them off. Other viruses can last a lifetime, such as HIV or hepatitis B where our immune system can't get rid of them. There are some viruses that also stay with us forever and come back intermittently, such as herpes simplex viruses that causes cold sores and genital warts. Our immune system works hard throughout our life to try and fight these viruses off. Over time, weakens our immune system, which can mean that we are less able to fight off common infections than we could when we were younger, such as the flu. If our immune system is weak, we are also more likely to get certain cancers caused by some viruses such as lymphomas. People living wit HIV tend to have more of these other viruses and they also get more age-related diseases earlier in life, perhaps because the viruses weakens their immune system, even if their HIV is successfully treated. I hypothesize that persistent virus infections damage our immune system over time, increase the amount of inflammation our bodies experience, change the number and type of immune cells we have, and reduce our immune cells' ability to activate to fight new infections. We also argue that the on and off activation cycles of the immune system due these lifelong viruses ages some immune cells that are critical to control infections. I propose to study a group of 420 people ranging in age from 1 to 80 years, half of them living with HIV, the other half not, half of them male, half female. I will look at the types of immune cells that these people have, and how many tired and old immune cells they have, and how these relate to number of viruses that the individual may be living with. Understanding the effect of these viruses on immune cell aging will inform on the potential benefits of treating or vaccinating against these viruses in the future.