Immunosuppressive ability of Trichinella spiralis adults can ameliorate type 2 inflammation in a murine allergy model.

BACKGROUND: There is an increase in the global incidence of allergies. The hygiene hypothesis and the old friend hypothesis reveal that helminths are associated with the prevalence of allergic diseases. The therapeutic potential of Trichinella spiralis (T. spiralis) is recognized; however, the stage at which it exerts its immunomodulatory effect is unclear.

METHODS: We evaluated the differentiation of bone marrow-derived macrophages stimulated with T. spiralis excretory-secretory products. Using an ovalbumin-induced murine model, T. spiralis was introduced during three allergy phases. Cytokine levels and immune cell subsets in the lung, spleen, and peritoneal cavity were assessed.

RESULTS: We found that T. spiralis infection reduced lung inflammation, increased anti-inflammatory cytokines, and decreased Th2 cytokines and alarms. Eosinophil, CD11b+ dendritic cells, and interstitial macrophage recruitment to the lung was significantly suppressed, whereas Treg cells and alternatively activated macrophages increased in T. spiralis infection groups compared with that of the ovalbumin group. Notably, when T. spiralis was infected prior to ovalbumin-challenge, intestinal adults promoted CD103+ dendritic cells and alveolar macrophages proportions.

CONCLUSIONS: T. spiralis strongly suppressed type 2 inflammation, and adults maintained lung immune homeostasis.