Date of Award

January 2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Comparative Pathobiology

First Advisor

Chang H. Kim

Committee Member 1

Ramesh Vemulapalli

Committee Member 2

Arun K. Bhunia

Committee Member 3

Susan Eicher


The gastrointestinal tract contains multiple types of immune cells that induce various immune responses to dietary antigens, commensal bacteria, and pathogens. Maintaining homeostasis at this mucosal barrier requires stringent regulation of the immune responses, including mechanisms to convey information about environmental conditions. Dietary nutrients can be converted into gut metabolites through either host or microbial enzymatic activities. Accumulating evidence demonstrates that these gut metabolites have a significant impact on the regulation of intestinal immune responses; however, the underlying mechanisms by which gut metabolites regulate the intestinal immune system are incompletely understood. Thus, we have studied the role of gut metabolites, specifically short chain fatty acids (SCFAs) and retinoic acid (RA), in regulation of intestinal immune responses. Our research revealed novel pathways that SCFAs and RA use to contribute to anti-bacteria immunity through modulation of epithelial cells and innate lymphoid cells (ILCs), respectively.