Electronic Thesis and Dissertation Repository


Master of Science


Microbiology and Immunology


Dr. Bhagirath Singh


Interleukin-22 (IL-22) is produced by T helper 17 (Th17) cells. Th17 cells have been shown to be pathogenic in autoimmune diseases, however their role in type 1 diabetes (T1D) remains controversial. We have shown that Th17-differentiation of naïve T cells can be driven by IL-23 + IL-6 to produce large amounts of IL-22 and induce T1D. Conversely, polarizing T cells using TGF-β + IL-6 led to nonpathogenic Th17 cells that produced lower IL-22 levels. We have shown that neutralizing IFN-γ during polarization leads to a drastic increase in IL-22. We have also found IL-22-producing cells in the pancreas of diabetic NOD mice. The receptor for IL-22 increases in the pancreas of NOD mice during disease providing a target for IL-22. However, neutralization of IL-22 by antibody in vivo does not significantly alter disease progression. Therefore, IL-22 may not be the sole factor or play a non-redundant role in T1D pathogenesis.