Nicole Chapman does not shy away from complexity. A Ph.D. candidate in the Interdisciplinary Graduate Program in Immunology, she marvels at the variety of cell types that work together to successfully clear pathogens and prevent people from getting sick.

“I like complex things,” says Chapman. “I think that’s what really piqued my interest in immunology.”

Chapman studies the regulation of T cell activation. T cells are a type of white blood cell that play a central role in fighting infection.

“If you get some sort of viral infection like the flu, T cells will go in there and kill those virally infected cells,” says Chapman. “They are potent gatekeepers of the immune system. They sit in this central node and protect against infection at its basic core. They’re sentinel cells.”

To do their job, T cells must be activated. This is essentially a lock-and-key process in which a T cell’s ability to function is switched on through bonding with components of another cell. However, if T cells are not activated properly, big problems can arise. Improper T cell activation is linked to the development of a number of diseases and disorders, such as type 1 diabetes. This is of personal interest to Chapman, since diabetes affects some members of her family.

Proper T cell function also aids antitumor responses in the event of cancer, but improper T cell activation can result in the development of lymphoma. She says allergy and asthma are also linked to aberrant T cell responses. Chapman says some of her motivation to do this work comes from the desire to help her family, but she hopes that the ideas she finds in the literature and the lab will make a positive impact for everyone. “I think all of us know somebody who’s touched by one of these diseases,” she says.

Chapman’s research aims to explain how the proteins Fak and Pyk2 regulate normal T cell activation, findings that may eventually indicate how inappropriate T cell responses are linked to disease since changes in protein signaling can alter T cell activation.  “You get changes in protein expression, or changes in the activation of different proteins,” says Chapman. “This leads to an imbalance in those signaling pathways, and then the T cells start to act abnormal. Why that happens is still unclear.”

Chapman’s research, in conjunction with literature in the field, suggests that changes in Fak and Pyk2 expression may result in improper T cell activation that is involved in diseases such as lupus and cardiovascular disease.

Chapman hopes the work she will publish related to Fak and Pyk2 will push science forward and advance our understanding of how T cells are activated. “These proteins have been studied for decades, but we still really aren’t clear about what they do in terms of how they relate to T cell activation. I hope our work will branch out into these multiple facets of human disease, so we can really understand how they are being initiated and to treat them better in the future.”