Effect of recombinant Lactobacillus casei expressing interleukin-10 in dextran sulfate sodium-induced colitis mice

Objective To study the effect of recombinant Lactobacillus casei (L.casei) expressing interleukin (IL)-10 combined with 5-aminosalicylic acid (5-ASA) in dextran sulfate sodium (DSS)-induced colitis mice. Methods Recombinant L.-casei CECT 5276, which can secrete IL-10, was constructed. The length of colon tissue, disease activity index (DAI) and histological score (HS) of the mice were determined to evaluate the modeling and the effectiveness of L-casei. Real-time polymerase chain reaction (PCR), Western blot and ELISA were used to determine the levels of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B), peroxisome proliferator-activated receptor (PPAR)-gamma, interferon (IFN)-gamma, transforming growth factor (TGF)-beta and IL-10. Results Recombinant L. casei expressing IL-10 combined with 5-ASA was more effective than L. casei with 5-ASA. Among the three different concentrations of the recombinant L. casei, the highest concentration group (2x 109 colony-forming units/mL) had the best effectiveness. Conclusions Recombinant L. casei combined with 5-ASA is effective in the treatment of DSS-induced colitis. The possible mechanism might be the blocking of the excessive activation of NF-kappa B pathway, thus suppressing the release of inflammation-related factors.