"Now that we know that some T cells need to see these types of modifications to identify an invader, we can see if incorporating such changes into the proteins is helpful for vaccination," says senior author Emil R. Unanue, M.D., the Edward Mallinckrodt Professor and head of Pathology and Immunology.
The finding may also be relevant to autoimmune conditions where the immune system erroneously attacks healthy tissues. Such disorders include rheumatoid arthritis, multiple sclerosis and type 1 diabetes.
"We show in this study that during some infections, these same types of modifications can be made to our own proteins, potentially leading to T cell attacks on the self," says Unanue.
Unanue and colleagues, who publish their results on May 31 in the Proceedings of the National Academy of the Sciences, conducted their studies in mice and in cultures of mouse cells. Jeremy Herzog, a research associate in Unanue's lab, did many of the experiments and was the lead author of the study.
T cells belong to a class of immune cells known as thymic-lymphocytes, which in turn are a component of the branch of the immune system known as adaptive immunity. This branch responds to pathogens after they interact with the other major branch, the innate immune system. T cells kill pathogens or produce molecules like cytokines that stop their growth.
Scientists have known for some time that a second class of innate immune system cells known as antigen-presenting cells helps T cells determine what to attack. They do this by displaying fragments of proteins they have picked
Contact: Michael C. Purdy
Washington University School of Medicine