Diabetic patients exhibit dysregulated inflammatory and immune responses that predispose them to chronic
wound infections and the threat of limb loss. The molecular underpinnings responsible for this have not been well elucidated, particularly in the setting of
wound biofilms. This study evaluates host responses in biofilm-impaired
wounds using the TallyHo mouse, a clinically relevant polygenic model of
type 2 diabetes. No differences in
cytokine or
Toll-like receptor (TLR) expression were noted in unwounded skin or noninoculated
wounds of diabetic and wild-type mice. However, diabetic biofilm-containing
wounds had significantly less TLR 2, TLR 4, interleukin-1β, and
tumor necrosis factor-α expression than wild-type
wounds with biofilm (all p < 0.001). Both groups had similar bacterial burden and neutrophil infiltration after development of biofilms at 3 days postwounding, but diabetic
wounds had significantly less neutrophil oxidative burst activity. This translated into a log-fold greater bacterial burden and significant delay of
wound epithelization for biofilm-impaired diabetic
wounds at 10 days postwounding. These results suggest that impaired recognition of
bacterial infection via the TLR pathway leading to inadequate
cytokine stimulation of antimicrobial host responses may represent a potential mechanism underlying diabetic susceptibility to
wound infection and ulceration.