Project 466819

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 C, where our immune system cant get rid of them. There are viruses that 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 fight these viruses off. Over time, this tires our immune system which then becomes weaker. This can mean that we are less able to fight off common infections than we could when we were young, such as the flu. If our immune system is weak, we are more likely to get cancers caused by some viruses such as lymphomas. People living with HIV tend to have more of these other viruses and they also get more diseases earlier in life, perhaps because the viruses weakens their immune system, even if their HIV is well treated. I hypothesize that persistent viral infections damage our immune system over time, change the type of immune cells we have, and reduce our immune cells ability to activate to fight new infections. I also argue that the on and off activation cycles of the immune system due these lifelong viruses cause the killer cells to become old and tired over time. 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 male and 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 have. 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.