IL-10 and its related cytokines for treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis are chronic inflammatory disorders of gastrointestinal tract. Although the etiology is incompletely understood, initiation and aggravation of the inflammatory process seem to be due to a massive local mucosal immune response. Interleukin-10 (IL-10) is a regulatory cytokine which inhibits both antigen presentation and subsequent pro-inflammatory cytokine release, and it is proposed as a potent anti-inflammatory biological therapy in chronic IBD. Many methods of IL-10 as a treatment for IBD have been published. The new strategies of IL-10 treatment, including recombinant IL-10, the use of genetically modified bacteria, gelatine microsphere containing IL-10, adenoviral vectors encoding IL-10 and combining regulatory T cells are discussed in this review. The advantages and disadvantages of these IL-10 therapies are summarized. Although most results of recombinant IL-10 therapies are disappointing in clinical testing because of lacking efficacy or side effects, therapeutic strategies utilizing gene therapy may enhance mucosal delivery and increase therapeutic response. Novel IL-10-related cytokines, including IL-19, IL-20, IL-22, IL-24, IL-26, IL-28 and IL-29, are involved in regulation of inflammatory and immune responses. The use of IL-10 and IL-10-related cytokines will provide new insights into cell-based and gene-based treatment against IBD in near future.