Gianna E. Hammer, Ph.D.

Research

The goal of my research is to understand the cellular and molecular mechanisms by which immune cells are inappropriately activated in inflammatory bowel disease (IBD). The bacterial community that resides in the gut can sometimes trigger an unwarranted activation of the immune system- an overreaction that can lead to IBD. But it is not known how and why these innocent microbes trigger rampant inflammation. As a postdoctoral fellow, I determined that a specific type of immune cell, dendritic cells, play a central role in the process. These cells ingest bacteria and present the digested pieces of the bacteria to other immune cells, called T cells, a signal that ultimately primes them for attack. I will isolate T cells that are activated inappropriately during IBD and determine which microbial fragments are inciting these overzealous cellular sentinels. Defining the means by which T cells are overstimulated could lead to new therapeutic approaches for the treatment of IBD, including the elimination of either the offending microbes or those immune cells that are hypersensitive to otherwise harmless, health-promoting bacteria.