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-κB), peroxisome proliferator-activated receptor (PPAR)-γ, interferon (IFN)-γ, transforming growth factor (TGF)-β 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 (2 × 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-κB pathway, thus suppressing the release of inflammation-related factors.