Burn induces a Th-17 inflammatory response at the injury site

Introduction: The high incidence of morbidity and mortality following major burn can be in part attributed to immune dysfunction and wound healing complications. Inflammation plays a major role in the complex process of wound repair. Recently, a novel class of T-helper cells, termed Th-17 cells, has been found to secrete the pro-inflammatory cytokines IL-17 and IL-22. The Th-17 response also involves other cytokines, such as IL-6 and TGF-β, which have been shown to be associated with burn-induced inflammation. Nonetheless, the relationships between the Th-17 response and post-burn inflammation are unknown. Methods: C57BL/6 male mice (n = 5-6/group) were subjected to a major burn (25% TBSA) or sham procedure. Three hours thereafter, skin samples were collected (uninjured skin and burn skin) and processed for the determination of Th-17 cytokine (IL-6, IL-17, IL-22, IL-23, IL-27, and TGF-β) levels by ELISA. Results: At 3 h after burn a significant (∼3-fold) increase in tissue levels of IL-17 and IL-22 was observed at the burn site as compared to sham skin. The burn-induced Th-17 response was independent of statistically significant changes in other Th-17 cytokines (i.e., IL-6, IL-23, IL-27 and TGF-β). Conclusions: These findings indicate the development of a robust Th-17 response at the burn site that may play an important role in subsequent immune and wound healing derangements.