Immuno-therapeutic and prophylactic potential of Trichinella spiralis antigens for inflammatory bowel diseases

Ulcerative colitis (UC), a severe chronic inflammatory disorder of the colon, is one of the inflammatory bowel diseases (IBD) that affects humans and several domestic animal species, including cats and dogs. Helminth infections and autoimmune diseases are inversely correlated, as explained by the hygiene hypothesis, which suggests that IBD is infrequent in countries where helminth infections are common but more prevalent in developed nations. This study investigated the therapeutic and prophylactic potential of Trichinella spiralis (T. spiralis) antigens in an experimental colitis model for IBD. Mice were divided into eight groups: normal model, colitis model, larval antigen prophylaxis, adult antigen prophylaxis, larval antigen therapeutic, adult antigen therapeutic, larval antigen prophylaxis and therapeutic, and adult antigen prophylaxis and therapeutic. Colitis was induced intrarectally by administering a single dose of 0.2 ml of acetic acid, except in the healthy group, which received PBS (0.2 ml). The mice were euthanized 12 days after colitis induction. The therapeutic and prophylactic potential of T. spiralis antigens were assessed through colitis severity and histopathological, immunological, and immunohistochemical examinations. The results showed a significant reduction in Disease Activity Index (DAI), an increase in goblet cells' acidic mucin levels, reduced iNOS and TNF-α expression, and decreased serum levels of IFN-γ and IL-10 cytokines in Groups IV-VIII compared to the colitis model, particularly in the group that received adult worm antigen both prophylactically and therapeutically. This study demonstrated that T. spiralis antigens, especially from adult worms, had protective and therapeutic effects on experimental colitis, with a superior effect when administered both before and after colitis induction by reducing inflammation and modulating the immune response. Thus, T. spiralis antigens may improve disease outcomes and provide a novel treatment approach for ulcerative colitis.