Transcriptional imprinting of transmigrating neutrophils on T84 intestinal epithelial cells

Neutrophil accumulation in crypt abscesses is a pathological hallmark of ulcerative colitis. Based on recent evidence that mucosal metabolic changes influence disease outcomes, we hypothesized that transmigrating neutrophils influence the transcriptional profile of intestinal epithelia. Microarray studies revealed a cohort of hypoxia-responsive genes regulated by neutrophil-epithelial crosstalk. Real-time O2 sensing indicated that transmigrating neutrophils rapidly deplete microenvironmental O2 sufficient enough to stabilize intestinal epithelial cell hypoxia-inducible factor (HIF). Utilizing HIF reporter mice in a TNBS colitis model, we investigated the relative contribution of neutrophils and the respiratory burst to “inflammatory hypoxia” in vivo. Gp91phox-null mice, which mirror human chronic granulomatous disease, developed accentuated colitis compared to control with exaggerated neutrophil infiltration and diminished inflammatory hypoxia. In conclusion, transcriptional imprinting of host tissue by infiltrating neutrophils modulates the host response to inflammation. Likewise, the respiratory burst contributes fundamentally to localized O2 depletion, resultant microenvironmental hypoxia and effective inflammatory resolution.