Response to soy: T‐cell‐like reactivity in the intestine of Atlantic salmon, Salmo salar L.

• Published in: Journal of Fish Diseases
• Main Authors: Bakke‐McKellep, A M, Frøystad, M K, Lilleeng, E, Dapra, F, Refstie, S, Krogdahl, Å, Landsverk, T
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2007
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/j.1365-2761.2007.00769.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2761.2007.00769.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2761.2007.00769.x

Abstract T‐cell‐mediated hypersensitivity could be central in soybean meal (SBM)‐induced intestinal changes in salmon. However, tools for immunohistochemical detection of T cells have been lacking in teleosts, including Atlantic salmon. Application of a specific histochemical protocol allowed demonstration of T‐cell‐like reactivities in formalin‐fixed, paraffin‐embedded tissues using an antibody reacting to a conserved region of human CD3 ɛ (Dako A0452). Characteristic staining was observed in cells of the thymus as well as distal intestine, skin, gills and spleen. These cells were negative for immunoglobulin M (IgM). Intestinal intraepithelial leucocytes were CD3 ɛ positive. During the SBM‐induced enteropathy, the mixed inflammatory infiltrate in the lamina propria of the distal intestine included many lymphocytes with a T‐cell‐like reactivity. Real‐time polymerase chain reaction revealed significantly increased expression of a complex polypeptide (CD3pp), CD4 and CD8 β ( P < 0.05) in the distal intestine of SBM‐fed fish compared to fish meal‐fed reference fish. Increased reactivity for extracellular IgM in the lamina propria and a positive material between the epithelial cells at the tips of the folds was observed, possibly due to leakage of IgM through an abrogated epithelial barrier. In conclusion, a T‐cell‐like response appears to be involved in this example of a food‐sensitive enteropathy.