ANALYSIS OF BURN AND NON-BURN WOUND INFLAMMATORY RESPONSES IN A MURINE MODEL OF INJURY

Background: Healing of the burn wound is a critical component of the patient's successful recovery from this form of injury. In this regard, inflammation, by supplying growth factors, cytokines, and other mediators is a critical component of the healing process. Nonetheless, it is unknown whether the inflammatory and cellular responses differ between non-burn and burn wounds. Methods: C57BL/6 male mice were subjected to burn injury (3rd degree; 25% TBSA) or sham procedure. Wound cells were collected by implantation of PVA sponges beneath the burn site in injured mice or beneath uninjured skin in sham mice. Three days thereafter wound fluid and infiltrating cells were collected for analysis. Results: Significant levels of TNF-α, MCP-1, and IL-6 were observed in the wound fluid from burn and non-burn injuries (Fig). Burn injury, however, induced 3-fold higher levels of TNF-α and 50-fold higher levels of IL-6 in the wound fluid as compared to non-burn injury. Wound cells from burned mice were larger and more granular as compared to non-burn wound cells. In vitro stimulation with LPS or ConA induced TNF-α, MCP-1, IL-6, and IL-10 production in both cell populations. The levels of TNF-α, IL-6, and IL-10 were markedly suppressed in burn wound cell cultures as compared to non-burn. Conclusions: These findings indicate that the inflammatory response in burn wounds differs markedly from that of non-burn wounds with regard to cellular morphology and cytokine responses. (Supported in part by NIH grant AI49960 awarded to MGS)