Attenuation of intestinal inflammation in IL-10 deficient mice by a plasmid carrying Lactococcus lactis strain

Interleukin-10 (IL-10), one of the most important anti-inflammatory cytokines of the immune response, has potential for treatment of inflammatory bowel diseases; however, systemic and oral administrations lead to undesirable side effects and quick degradation. We therefore previously engineered a Lactococcus lactis (L. lactis) strain capable of delivering, directly to host cells, a eukaryotic DNA expression vector coding for IL-10 of Mus musculus. This study aimed to analyze its therapeutic effect in the IL-10-deficient mouse model (IL-10-/-) that spontaneously develops inflammation. Oral administration of L. lactis MG1363 FnBPA+ (pValac:il-10) strain not only led to IL-10 production, but also diminished the development of the disease, with animals showing lower macroscopic scores and histological damages, increased IL-10 levels and tendency to lower pro-inflammatory cytokine levels. These results show that this strategy is capable of creating and maintaining an anti-inflammatory environment in the GIT and thus effectively diminish the onset of inflammation.