Author
ZHANG, Q - Purdue University | |
Eicher, Susan | |
AJUWON, K - Purdue University | |
APPLEGATE, T - Purdue University |
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/1/2017 Publication Date: 6/16/2017 Citation: Zhang, Q., Eicher, S.D., Ajuwon, K.M., Applegate, T.J. 2017. Development of a chicken ileal explant culture model for measurement of gut inflammation induced by lipopolysaccharide. Poultry Science. 0:1-8. doi: 10.3382/ps/pex160. Interpretive Summary: The lining of the gut is made of a single layer of cells (epithelial) that produce mucus and provide a barrier to outside pathogens. It also contains the largest mass of immune tissue in the body. While epithelial cell culture is widely used to assess intestinal barrier functions, it has limitations for studying cellular interactions with other cells, in particular those of the immune system. In this work, a chicken intestinal model was developed for investigating short-term gut inflammation in a laboratory environment. Chicken intestines that were cultured remained viable up to 2 hours after collecting and the appearance of the intestines had normal structure, further confirming that short-term culture for a 2-hour duration is an acceptable model for studying regulation of inflammation in the gut. The study of the functions of the tissues showed that the intestinal tissue released bacterial killing substances and had immunological and mucus production in response to a bacterial component. These results demonstrated the potential usefulness of this intestinal culture model for short-term study of cellular interactions as well as evaluating effects of biological factors in gut inflammation. Technical Abstract: Gut mucosa holds a single layer of epithelial cells and the largest mass of lymphoid tissue in the body. While epithelial cell culture is widely used to assess intestinal barrier functions, it has limitations for studying cellular interactions with other cells, in particular those of the immune system. In this study, a chicken ileal explant culture model was developed for investigating short-term gut inflammation in an ex vivo environment. Initially, ileal explants from broilers at 21 d of age were cultured ex vivo up to 6 h. Explants cultured for a maximum of 2 h remained over 90% viable, based on lactate dehydrogenase (LDH) activity. Morphologically, explants cultured for 2 h displayed normal morphology compared to those cultured longer, further confirming that short-term culture for 2 h duration is an acceptable model for studying ex vivo regulation of inflammation. Subsequently, LPS dose-related responses were determined for explants cultured for 2 h. Results from LDH activity assay showed that the viability of explants was decreased (P < 0.05) at an LPS dose higher than 50 µg/mL. A significant (P < 0.05) nitric oxide release was observed at LPS concentrations of 10 and 20 µg/mL. In addition, the highest inflammatory response was detected at 20 µg/mL LPS based on gene expressions of TLR-4, IL-1ß, IL-8, MUC2, IgA and pIgR. These results demonstrated the potential usefulness of this intestinal explant culture model for short-term study of cellular interactions as well as evaluating effects of biological factors in gut inflammation. |