Interleukin‐22, a Pro‐inflammatory Cytokine, is Increased in the Serum of Canines with Inflammatory Bowel Disorder

Abstract

Inflammatory Bowel Disease (IBD) is characterized by a chronic and/or recurrent inflammatory condition associated with adverse gastrointestinal signs including diarrhea, vomiting, and weight loss. Inflammation plays a key role in the initiation and continual progression of IBD. Interleukin 22 (IL‐22) is a pro‐inflammatory cytokine that is expressed by various cells of the immune system including dendritic cells, natural killer cells, and T cells. IL‐22 is a cytokine that can have either a helpful or a deleterious role in the intestine. The protective role of IL‐22 includes promoting mucosal barrier integrity and epithelial cell regeneration. Its deleterious actions may depend on the presence of other cytokines as well including IL‐23 and IL‐22 binding proteins. Regardless, a continually increased level in IL‐22 can increase associated gastrointestinal inflammatory processes. We tested the circulating levels of IL‐22 in the serum of dogs that were clinically diagnosed as having IBD following an endoscopy conducted by a veterinarian. Blood was collected from dogs with IBD (n=6; 2.2–13.1 yr) and control dogs (n=5; 2.2–11.3 yr) which did not show any signs of IBD. Blood was collected at two different time points (~1 year apart) from the same dogs. Using an ELISA technique, we found that the mean levels of serum IL‐22 from both time points were significantly higher in IBD (286.5 ± 69.32 pg/ml) when compared to controls (104.2 ± 17.8; p<0.05). The levels of IL‐22 in IBD dogs were higher than controls at both individual time points assessed as well. Our results identify IL‐22 as a promising biomarker of inflammatory bowel disorder in dogs and strategies to decrease a continual and elevated level of IL‐22 may be an effective way to reduce the adverse conditions associated with IBD. Further, an optimal anti‐inflammatory nutritional therapy may be a promising option to pursue as a therapeutic measure for IBD in caninesSupport or Funding InformationFunded by Hills PNCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.